* oe —-_se we «@
“eae
~
a
ae
ee er Te eee ee eee ere
:
,
(mar) 5
eee ete ve
gfe fete tate
oa
*
eo bm
A Botham
.
Ree eens
a“
+n
eee Ae
7
=
*
.
*
e
5
¥
—. + #
.
‘
~
AM SOM,
:
i*
_
\ | MMO AO
sae
DEEP BOREHOLE SURVEYS
AND PROBLEMS
BOOKS BY THE SAME AUTHOR
MINE VENTILATION AND VENTILATORS
(Charles Griffin & Co., Ltd., London)
LOCATION OF MINERAL FIELDS
(Crosby, Lockwood & Sons, London)
DISRUPTED STRATA
(Crosby, Lockwood & Sons, London)
DEEP BOREHOLE SURVEYS
AND PROBLEMS
BN
M. H. HADDOCK, F.G.8., A.M.I.Min.E.
Principal, The Mining and Technical Institute,
Coalville, Leicester, England
First EpiIrion
McGRAW-HILL BOOK COMPANY, Inc.
NEW YORK AND LONDON
1931
CopyricHt, 1931, BY THE
McGraw-Hitt Book Company, Ine.
PRINTED IN THE UNITED STATES OF AMERICA
All rights reserved. This book, or
parts thereof, may not be reproduced
in any form without permission of
the publishers.
THE MAPLE PRESS COMPANY, YORK, PA.
PREFACE
The amount of trouble, litigation and random specula-
tion that could be avoided by a correct knowledge of the
course of deep boreholes is immeasurably great. It is
generally agreed among those most concerned that the
deep borehole which does not deviate from its intended
direction has yet to be bored. Bearing these significant
facts in mind I have attempted in the following pages to
trace the evolution of modern borehole-surveying devices
and add various problems relevant to strata location and
orientation.
Since most of the world’s deep borehole projects are
outside the British Empire I have supplemented my
experience and observations by information from many
and varied sources. In this respect I have been most
generously aided by many workers in America, Germany,
Russia and elsewhere, and I hope these are all sufficiently
acknowledged where the respective transcriptions appear
in the text. In particular I am indebted to the several
acute and vigorous bodies of oil-field investigators centered
about Oklahoma and the Gulf Coast in America and the
Rumanian societies on this side. Some methods of bore-
hole exploration have not been dealt with here either
because they are shrouded in commercial secrecy or because
they do not appear to add very materially to the advance-
ment of the art.
Generally speaking the present geological engineer does
not seem to be enamored of the highly ingenious and exact
Suite of post-war instruments, being in many cases content
to sacrifice precision to rapidity, ease and cheapness. For
these reasons the old and tried acid-bottle and similar fluid
methods still hold the field in point of numbers, though
the gyrocompass and multiple photographic methods
Vv
vi PREFACE
have entered the lists with the weapons of accuracy and
certainty which alone can solve the problem satisfactorily.
The history of our subject has not always escaped the
stigma of charlatanry and perhaps it has often deserved
it. With the growing application of established scientific
principles and the subsequent checking and verification
of these by other boreholes, shafts, etce., we may regard
the day of skepticism as vanished. There is now arising
an insistent and ever increasing desire for frankness,
clarity and truth in borehole investigation which must one
day achieve the universal respect accorded an exact
science. Built on such foundations it is indeed difficult
to imagine this ideal failing.
M. H. Happocx.
LEICESTER, ENGLAND,
September, 1931.
CONTENTS
PAGE
CHAPTER I
DEVIATION AND Ims CAUSES. . . 5... 4.) 5 5a. i
CHAPTER II
AUXILIARY REGISTRATIONS IN BOREHOLE SuRVEYS. ... 22
CHAPTER III
INSERUMENTAL SURVEY OF BOREHOLES ........ . 46
CHAPTER IV
COweMORUNNIDATIONS os . nc. ea bak sn oe ee et” 4
CHAPTER V
FLuip METHODS OF SURVEYING BOREHOLES. ...... 95
CHAPTER VI
CoOMeASSOAND. EnwMB-BoOB MmrHops. ... 4... . 2. 121
CHAPTER VII
LSE OAU NM GE TE OD Sa 20s, (ee 2 eee bea 18
CHAPTER VIII
PHOROGCRAPHIC™ NIWEHODS (5... . = 2 0 2 2 ss « we LTS
CHAPTER IX
Gyroscoric Compass Mrtuops OF SURVEYING BOREHOLES 204
CHAPTER X
GropuysicaAaL Mretuops or INVESTIGATING BOREHOLES . . 225
CHAPTER XI
JP TRO TRIABINIS goog gs ANE NW i Mette tee lige et gat ee tea 1
CHAPTER Xa
1S UB ROGIRATEIER) 3 eh a yg) gs Cae Ia ca ae Pere)
Li sD) x Te UR. Se Lah hy ee DOF
vii
00525
‘DEEP BOREHOLE SURVEYS
AND PROBLEMS
CHAPTER I
DEVIATION AND ITS CAUSES
The primary purpose of a borehole survey is to determine
the extent of the borehole in length and deviation. The
deviation is surveyed in angular deflection in amount and
bearing; the amount relative to the intended initial direc-
tion and the bearing with respect to the local meridian or
any other fixed reference mark.
In many boreholes frequently only the amount of deflec-
tion suffices. Thus in exploratory borings in unknown
measures the direction of deflection is of less value than the
degree of deflection, owing to the remainder of the data
being absent from our conclusions. However, for a correct
decision respecting the strata penetrated, this knowledge
is unconditionally necessary.
Still more important are these determinations when
the hole has to hold a pumping or bailing plant, as in certain
petroleum borings. Here the longevity of the borehole is
in considerable degree influenced by any noteworthy devia-
tion from the plumb. Rods, or the bailing rope, con-
tinually chafe in the same part of the casing; in a short
time it becomes seriously injured. That all deep boreholes
deviate—and by deep boreholes we imply all those over
1,000 ft. in extent—is established beyond any doubt, and
indeed much shallower boreholes deviate in more or less
degree.
Dr. Otto Stiitzer of Kiel has recently cited a case! where
two boreholes in the Moreni oil field of Rumania, com-
1Z, deut. geol. Ges., Bd. 81, Heft 10, p. 5386 1929.
1
2 DEEP BOREHOLE SURVEYS AND PROBLEMS
menced vertically and at a distance of 60 m. apart, actually
met at a depth of 850 m.
About 25 years ago interest in the survey of boreholes
was quickened by a series of very ingenious contrivances
which were invented to cope with borehole deviation.
Borings hitherto considered vertical were now subject to
doubts. In 1908 Joseph Kitchen presented the results
of his surveys of some 22 deep boreholes on the Rand
before the Institution of Mining and Metallurgy! which
stimulated a wide discussion and was supported by many
other instances of deflection. He surveyed the dip of the
holes at intervals of about 500 ft. and averaged his results,
which method, though not precise, sufficed as an indication
of the great deviation in this area. With an average total
borehole depth of 3,370 ft. he found an average horizontal
displacement of 1,165 ft. with an average lowest depth of
survey points of 3,015 ft. He shows in Table I figures of
average angular deviations obtained by instrumental
survey in the holes.
TaBLE I.—AvERAGE ANGULAR DEVIATION IN RAND BOREHOLES!
Nos. Nos. Nos. Nos. Nos.
Depth, feet 1 to 8, 9 to 16, 1 to 16, 17 to 22° 1 to 22;
degrees degrees degrees degrees degrees
500 4.7 2.5 3.6 8.8 5.0
1,000 10.6 9.2 9.9 15.6 11.4
1,500 20.2 NORA 19.9 20.2 20.0
2,000 24.9 27.8 26.4 25.4 26.1
2,500 27.3 30.1 28.7
3,000 32.9 34.4 33.6
3,500 42.5
4,000 47.7
1 After J. Kitchen by permission of the Institution of Mining and Metallurgy.
These tend to oppose the general rule that inclined strata
exaggerate the deviation which, however, may be a local
circumstance. The accompanying displacement is shown
in Table II.
1 The Deviation of Rand Boreholes from the Vertical, by Joseph Kitchen,
Session 1907-1908.
DEVIATION AND ITS CAUSES
3
Tasie I].—Averace Horizontat DispLACEMENT IN RAND BOREHOLES
Depth, feet
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
Nos.
1 to 8,
feet
15
85
210
400
610
860
1,150
1,485
t Nahe
O 200 400 600
Nos.
9 to 16,
feet
10
70
190
390
635
910
+ At 2000Ft. along Borehole
+> » 3000” » ”
> 49000» »
23
Nos. Nos. Nos.
1 to 16, IZ) 1i@) 22, ton22.
feet feet feet
10 35 20
75 145 95
200 290 225
395 485 420
625
885
uy ! !
200 400 600
18
Fig. 1.—Sketch showing curves of boreholes and amount of horizontal displace-
ment at various depths.
(After Joseph Kitchen.)
(a) Vertical projection.
(6) Horizontal projection.
The displacement is thus in these cases proportional to
the square of the borehole length and it usually tends to
describe a right-handed or clockwise curve.
In one case
the displacement was 2,573 ft. away in a borehole depth
of 4,419 ft., z.e., a vertical depth of 3,288 ft.
Mr. Kitchen
4 DEEP BOREHOLE SURVEYS AND PROBLEMS
grouped his results graphically about the same vertical,
giving the remarkable suite of horizontal displacements
shown in Fig. la and the accompanying angular deviations
shown in plan in Fig. 10.
All other influences considered equal, the amount of
deviation depends a great deal on the method of boring.
Many are of the opinion that the greatest deviation is
obtained in the rotary system yielding cores as in the shot,
calyx or diamond processes, and the least in the percussion
systems particularly the free-fall systems. In a recent!
statistical survey of results which appear to support this
contention the data yielded from 21 boreholes was as
follows:
Taste JI].—Summary or SoME RUMANIAN AND Russi1aAN BOREHOLES
Usine DIFFERENT METHODS
Number Most
Method of boring of Deion, favorable Weng Remarks
meters case
boreholes case
urbme borers sees 5 580 Ie ZOLA | Senos
: : ees In the
(Kapeljuschnikov)..... 4 BGS ulate Dy (5) ee:
Rotary system........ 4 840 AP 30" lee eee hai
aye SOD Ie nako rere: inl! GP
Rod percussive........ 1 480 1° 20’
Rope percussive....... 1 606 3 LOM eee In the
American rotary....... 10 580 92220! 4 Ble same
“A HOOK alitenieen cee 25° 0 strata
American-Chield rotary 1 595 5° 10) Gee ee
However, this point is very debatable. The diamond-
drillers claim that diamond-drilled holes can not drift as
much as holes drilled by other methods because the core
barrel nearly fills the hole. In hard rock the core barrel
normally occupies all but 14.6 in. of the diameter of the
hole.
The rotary drill prevents the hole from drifting as much
as would occur by other methods by using at the bottom
a long steel drill collar of a diameter nearly equal to that
1A. L. Schachnazarov, Engineer ‘“Asnef’’ Oil Trust, Baku, in Petroleum,
Not 235 pe (2:
DEVIATION AND ITS CAUSES
LL
92
8¢
g8
88
68
qua0 10d
qd:
T &62
6 STS
LZ LOE
¢ FOL
9° OT
4ooj
‘OSBIOAV
“MOIZIOIIP SUIS 9Y} Ul SAVM|S OIG SUOTZVIAVP OY} SUILENSSE ‘UOTZCIAZP [8309 OG, CG
= “4 OOT 19d 4093 pu’ sooisop Ul 9[sUB UOTZeUI[DUI Oy, YO
‘quiod painsveu 944 YSNOIY) [BOI}ZIOA B pUw YNOUT VJoOYoI0gG 94} UVeM4oq 9DUBISIP [BQUOZTIOFY _
OOT 10d OOT 10d OOT 10d
4F 1 °8E SIR P 438° 06
0 L¢9§ 866% 1GE 066 10€ 0G iST 0of9 F 68S FL
0OT z9d OOT 108d OOT 19d
4I SLE 43.60 43 8°82
0 16 GIST WP oGT i0€ oO 100 069 8 968 66
OOT 10d OOT 10d OOT 10d
43 9° GT 436°0 439° P9
9°22 G8z'T 100 06 10€ 00 1ST OV G96 9
OOT 10d OOT s0ed OOT 10d
43 1°11 436°0 43 PS
0 LF 0¢gs IGF 09 10€ 00 IST 0GE ¢ oI 6
OOT 10d OOT 10d OOT 10d
TL 43€°0 “43 €°9G
GT LSP 190 oF JOT 00 “SL oS G 68 6
OOT 10d 0OT 19d
4S F°S 431°96
00 TEL 190 0& 100 00 JOE oGT 6 OF G
001 sed OOT 10d
WS E 439° F1
0:0 FIT 160 06 100 00 106 o8 L8 0
ee eee esBIoAy | UINUITUIT, | WNUIxey foes peer
WINUITUIYAL |UINUIXB YY | Pay : ‘eseioAy | ‘UINUIIUITy
ad 10) q
(wossapuy laifV)
CPs
GcP
Tél
LE
yooy
“UINUIIXB IA,
SHIOHHNOG VINUOAITVD GGZ WOUd VIVG AATIdNO)— A] AITEV |,
000°9
000°¢
000°F
000°€
000°%
000'T
00g
4023 ‘y3dep
poinsveyy
8&
VOT
S91
616
ES
GGG
GGG
sofoya10q
jo Ioquinn
6 DEEP BOREHOLE SURVEYS AND PROBLEMS
of the hole. On the other hand, percussive borers claim
that curvature is more easily detected and rectified by a
reciprocating action especially by a free-falling tool.?
With regard to rotary boreholes a perusal of Table IV
will well repay the reader. The table is taken from a
compilation® covering 255 California boreholes bored by
the rotary system. The total depth was 1,158,542 ft.
and the total number of measurements 13,150. As addi-
tional proof of this almost universal deviation of deep holes
we may cite the recent researches of D. R. Snow and H. B.
Goodrich‘ carried out upon some 90 wells in the Seminole
oil field of America. These holes have been drilled since
1927 and show the data collected in Table V.
TaBLE V.—SUMMARY OF RESULTS oF 90 Ort WELLS
(After Snow)
Maximum
| Vertical EP exGEHLENS © possible
Number of wells | ee total wells :
correction, feet Wiad ee horizontal
: drift, 4,500 ft.
20 Less than 25 PPA. L3P, 474
9 From 25 to 50 10.00 669
28 From 50 to 100 Bll, Wi 943
24 From 100 to 200 26.67 1,327
4 From 200 to 300 4.44 1,615
5 Over 300 5.56
90
Total surveyed: 377,719 ft.
Total vertical correction: 9,290 ft. (per well, 103 ft.).
Average angle of deflection: 12 deg. 44 min.
In some relatively shallow boreholes, as in the concentric
circumferential suites of boreholes preliminary to sinking
shafts by the freezing process or by cementation, extreme
accuracy of data respecting the course of the holes is of
1 Diamond Drilling, U. S. Dept. Commerce, Bur. Mines, Bull. 248, p. 60.
2 Of. Organ des Verein der Bohrtechniker, No. 23, p. 279, 1910.
3 A. Anderson of Fullerton, California, in Oil Weekly, October, 1929.
4 See also Oil Gas Journ., p. 32, Mar. 14, 1929, and p. 218, Apr. 4, 1929.
DEVIATION AND ITS CAUSES 7
great importance. It is here that we find the greatest
advancement in the technique of borehole-survey apparatus.
This is significant not only because the proximity of other
boreholes greatly increases the possibility of deflection
but ignorance of the actual courses of the holes here would
give rise to great trouble and expense later on; and perhaps
500 500
500
500
00
ox|500
OY LOO 350 450 500
500
450 250 450 we
450
500
500
500
Fic. 2.—Course of a full suite of boreholes for a freezing shaft (depths in meters).
disaster when encountering the unsolidified gaps between
widely isolated frost walls or cementation zones. ‘These
possibilities will be apparent from a perusal of Fig. 2,
which is an actual survey of the course of such holes previous
to sinking operations.
As the shallower seams and veins are won in the world’s
mineral fields it is manifest that deep prospecting holes to
8 DEEP BOREHOLE SURVEYS AND PROBLEMS
fresh deposits will become more common. In these daily
growing cases, especially in those situated near property
boundaries, legal disputes will be settled by the results of
borehole surveys. Again the deep borehole being the most
straightforward and direct verification for any completed
geophysical survey, any doubt which may arise as to (1)
mapped lenses being missed in the borings, (2) the nature
of the body surveyed aboveground (3) its extent, etc., can
only be verified by a thorough instrumental survey of the
boreholes concerned. Since deviation of a string of tools
may take place in the ultimate up to and beyond 60 deg.
from the originally intended direction,' and boreholes are.
now attempting the enormous depth of 10,000 ft. and more,
the great significance of deflection surveys is obvious.
Horizontal and inclined boreholes, particularly upward
inclined holes, deviate sooner and to greater extent than
vertical ones.2 They also give rise to a special set of
deflection apparatus, but, generally speaking, results of
surveys of such holes are not so reliable as those of vertical
ones. Thus most of our remarks will apply to deep vertical
boreholes.
There is no doubt that the best evidence of initial or
subsequent deflection in boreholes is to be obtained from
the precision with which the working of the entire system
of boring is checked. ‘The onus rests almost entirely upon
the boring master and personnel, chiefly because the site
is usually situated far from the headquarters of the boring
company and its direct command. Thus the master borer
should be selected mainly on his experience, skill and
ability, other qualifications notwithstanding. There is
more responsibility upon him than in any other sphere of
technical work. This applies more in foreign and remote
lands. Thus it is important that all hands graduate in
the actual school of practice from the meanest position
upward.
1 Kitchen, op. cit., mentions one deflection of 66 deg.
2 Justice, J. N., CHANNING, Park, Trans. Inst. Min. and Met., Vol. 12,
p. 319; Proc. Lake Superior Min. Inst., Vol. 2, p. 23, 1894.
DEVIATION AND ITS CAUSES 9
The modern tendency to standardized reserve parts
and processes, also the recent step toward normalizing
as many of the movable or removable parts as possible will
tend to unify knowledge of and the results of deflection.
It will tend toward closer correlation of data and more
exact anticipation of deviation and therefore more successful
handling of the problem when it arrives.
This will be aided by duplicating staffs too, such as
smiths and fitters in diamond boring and tool dressers in
chisel boring. They must always have a clear rinsing
circuit with the borehole base, especially in rapid-stroke
boring as by the Raky method. They will need exceptional
skill in rope boring.
Another essential adjunct to the detection and elimina-
tion of curvature lies in the supervision of the water circuit
by the master borer and the leading hand and by maintain-
ing a keen supervision for traces of oil or minerals. This is
closely connected with the amount of water struck in the
borehole, the pressure on the rinsing pumps, etc., so that
they may have to decide upon the cutting off of water
according to the strata pierced or its increase under certain
conditions; or even decide to change the type of borer.
In their responsible positions as borehole casers and core
extractors much will be learned respecting deflection which
can scarcely be described in writing.
The best aid to all of these observations will be found in
a thoroughly checked and entered log of progress, a study
of which will assist very materially in reading any progress
graph which may be attached in the derrick house. These
provide pictorial and descriptive checks on the tendencies
to deviate and often their causes. Strata profiles and
sections should be kept as well as vertical sections. Finally
the care of the actual samples, or cores, is absolutely essen-
tial as the final check on any adduced ideas as to deviation,
etc. It will be seen that the requirements demanded
of a good master borer are so exacting and varied that the
systematic training of such a person is a really essential
10 DEEP BOREHOLE SURVEYS AND PROBLEMS
need. Unfortunately, apart from Rumania, there are no
actual master borers’ schools in Europe.
The Detection of Incipient Curvature in Boreholes.—
Suspected curvature of the rods may be checked by noting
the following surface indications of the deflection. It must
be noted that these indications may be entirely absent,
making the curvature untraceable without instrumental
means. ;
a. The uneven wearing of the chisel or crown bit due to
encountering unequal resistances at the floor of the hole.
The contact surface of the tool tends to become inclined due
to excessive wear on one side. It also tends to snap off.
b. Lateral abrasions of the rods and brushing of the rope
sides in rope boring. ‘This is due to side wear and in the
case of rigid rods will usually show the side on which curva-
ture is occurring, 2.e., the “‘off”’ side.
c. Difficulty in Inserting the Casing.—Frequently the
casing sticks fast as often does the boring tool owing to the
curvature.
d. Scoring of the core and core box in rotary boring. This
will often provide fair information as to the cause of the
deflection.
e. Laboring of the Rig Gear.—The surface engine labors
under the extra load, the bearings run hot and general signs
of lack of uniformity ensue.
f. Study of the Progress Reports.—This often provides
clues which can be reduced to curvature as the cause of
variations in the progress graph.
g. Throttling of the circulating water, the circuit being
accomplished in gusts and frequently hindering or loading
the plant. Lesser deflections may be corrected by second-
ary boring or partial reaming. The borehole will thus be
widened and the casing set without being influenced by
the previous borehole walls. This simple remedy only
applies to deflection which has been detected just after it
has begun.
h. Instrumental Means. The Anschiitz-Kaempfe Acoustic
Device.-—Nearly all of the many and varied devices for
DEVIATION AND ITS CAUSES At
surveying boreholes and many of those applied in core
orientation may be used for detecting initial curvature or
deviation. However, most of these are only suited to
separate application, very few of them being fitted for
employment during actual boring operations especially with
percussive boring systems. The difficulty has been well
solved by the device of Dr. Hermann Anschiitz-Kaempfe
of Kiel which provides an acoustic or audible warning
of the initial stages of deflection. He invented this
apparatus in 1915 and improved on it a few years later.
It applies particularly to percussive boring but may be
modified for rotary boring. It is essentially a means of
detecting deviation, measuring it, and later correcting it.
It has been applied successfully in both Europe and
America. The apparatus as applied in borehole surveys
is Shown in Plate I, Figs. 1 to 5.
Figure 1 (Plate I) is a vertical section of the boring
chisel bar and bit. Figures 2 and 3 are enlarged views of
_ this section at an angle of 90 deg. to each other, while Fig.
A shows the electric drive circuit. The hollow bit holder a
holds the beveled bit a; below and the connection a; above
to the rods, the dotted lines xx being the normal flushing
circuit. A closed outer casing tube a3 mounted in the hollow
bit holder a holds the transmitter and the inner casing tube
ai; which is longitudinally adjustable in this by means of
buffer springs b and 6, and held by lugsc. An accumulator
battery with electric motor d in the transmitter drives a
worm d, with its wheel d, on support d3 and thus the toothed
wheels ds. Four pins e about the worm wheel dz engage
consecutively on rotation with the finger f of hammer /;
controlled by pressure spring g. Thus for each revolution
of wheel dz four blows of the hammer f; are produced at fo.
Toothed wheel d, engages another toothed wheel h on shaft
h, and carries a screw thread barrel h; which can be dis-
connected by spring slides 7, 7; and72._ There is an electric
contact k on slide 2.
The ball and socket end / of the barrel shaft hi allows it
to oscillate under the adjustable spring pressure pin m
DEEP BOREHOLE SURVEYS AND PROBLEMS
12
SS
S
N
N
So
a
PuatEe I.—The Anschiitz-Kaempfe deviation detector.
DEVIATION AND ITS CAUSES 13
and m, held by springs n and n,; and plungers n2 and 7;
in cylinder 0. Rod m, passes up into a hollow space in
plunger 72 so that when the pressure of spring n acts, pres-
sing plunger nm» downward, rod m, passes into the space in
m3. ‘This space has a check-valve controlled upper end p,
which opens when the plunger n. descends and closes when
it ascends, equilibrium of pressure being effected by a fine
bore pi. The brackets q carry an electrical contact r
which is closed when plunger nz is in its upper position
(Fig. 2) and broken when this descends.
The lugs s hold the heavy pendulum ¢ in a frame and the
swing of ¢ into casing a, is arrested by a stop wu and in
the other direction by a stop u;. This pendulum carries
a second part of the contact k of slide 2 so that the positions
of the pendulum ¢ and slide 7 decide whether the contact
k is opened or closed. The two electric contacts k and r
are arranged in the circuit from the source of power d,
which operates worm d,;. These two contacts (Fig. 4)
are arranged in series so that the motor is stopped if only
one is switched out. This occurs as follows: The plunger
mM, continues its descent by momentum after the boring
tool has struck its blow, and this compresses the adjusted
springs n and 7, thus turning the screw spindle h, and disen-
gaging it from the half nut h. so preventing slide 7 from
moving. But contact r is now broken, stopping motor
d and screw spindle h,. Plunger nz can only move back
upward slowly, owing to the design of air valve p and the
hollow space n3, and this is designed so that before the spin-
dle can return to its working position and r close a new
blow—assuming regular working—with a downward move-
ment of the plunger takes place. In interrupted working,
say over 20 sec. between blows which is a maximum time
for springs n and n,, the mass of plunger n» and the valve p
function; n2 returns to its initial position, throws in spindle
h, and closes the r contact. This starts motor d if contact
k is also closed. The closure depends on the position of the
pendulum ¢, for when we have deviation of the bit to the left
throwing ¢ to the right, or engaging it with stop w:, contact
14 DEEP BOREHOLE SURVEYS AND PROBLEMS
k is open and the motor with its connections stops. If,
on the other hand, the bit holder has deviated to the right
(Fig. 5) the working circuit is closed, the motor actuating
worm d;. Now worm wheel d, with pins e engages hammer
f, to strike the wall of casing a, as each pin passes lug f.
These blows on the casing are clearly perceived at the sur-
face and counted by means of a listening earpiece on the
rods or any simpler device.
At the same time as worm wheel d, starts, the screw spin-
dle h; moves slide 7 to the left in opposition to the action of
spring 72. The pendulum contacting on the slide follows
this motion until it hangs free, breaking contact k and
stopping motor d. Until this happens we get four hammer
blows per revolution of worm wheel d:, so the observed
total number of blows indicates to what extent slide 7
has moved to the left in order that pendulum ¢ hangs free
and vertical; that is to say, it is a measure of the deviation
of the bit holder and bit.
The surface observer has now only to stop the boring
blows from time to time and listen to the blows of hammer f;
against the boring rods in order to ascertain the extent of
the deviation.
Turning the chisel 90 deg. gives the inclination compo-
nent in the plane of the reader’s vision as against that of the
drawing and where the component is greatest is the direc-
tion of maximum inclination. Otherwise two independent
pendulums in planes at 90 deg. to one another can be used.
Having got this line of major inclination the deep edge of
the beveled chisel is turned to deal with it and correct the
deviation.
Though the device gives only the inclination component
relative to the chisel and not to the geographical position
of the borehole, twisting of the rods need not be heeded so
long as the transmitter does not twist relative to the
chisel. |
In this way incipient or initial deviations can be quickly
detected and corrected. The device can, with suitable
modification, be applied to rotary boring and it can also
DEVIATION AND ITS CAUSES 15
be employed apart from the bit holder as a plumbing
apparatus, the principle of acoustic signals being preserved.
However, in spite of all precautions we cannot always
note at once a big and gradual curvature at its commence-
ment from the above observations alone. The detection
of a suspected curvature being essentially a surface task
in the initial stages of deflection, the next procedure is to
investigate the causes previous to checking the amount
and direction of the deflection. ‘The causes are numerous
and often local, and in many cases are due to faulty surface
conditions.
The Causes of Borehole Deviation.—a. Incorrect Center-
ing at Surface-—This, though sometimes tending to right
itself in such methods as the free-fall system, of course soon
leads to heavy deflections.
b. Alternating hardnesses of successive layers of hard and
soft rock. Inexpert handling of the drill feed whether
by the multiple gear or hydraulic feed here tends to cause
racing in the shaly and soft beds and laboring in the harder
strata. The tool tends to supplement this by following
the softer stratum unless fed or geared to meet the circum-
stances.! In such cases boring has to be undertaken very
carefully and frequent patroning, or damming and reguid-
ing, has to be resorted to, thus removing immediately the
slightest deviation from the plumb.
Taste VI.—Mon’s ScaLe or HARDNESS
No. Mineral Relative hardness
TL. ONE hey aes es eee eras i ee Hasily scratched with the finger nail
2 | Rock salt................| Not easily scratched with the finger nail
3 | Cale-spar................| Easily scratched with a knife
4 | Fluor spar | _ : : ree
3 | Anette .| Not easily scratched with a knife
Gia Pes pareiacnes sen cae es Difficult to scratch with a knife
7 | Quartz |
2 eae Pee et tL Cannot be scratched with a knife
9 | Sapphire
10 | Diamond
1 See also Hugh F. Marriott, discussion to Deviation of Rand Boreholes,
etc., p. 115.
16 DEEP BOREHOLE SURVEYS AND PROBLEMS
Thus if any mineral above be used in the form of a sharp
point it will scratch the preceding members of the series,
e.g., Should we find a piece of mineral which will scratch
calcite but not fluorite its hardness is between 3 and 4,
say about 3149.
TaBLE VII.—HARDNESS OF SOME ComMMon MINERALS
Mineral Hardness Remarks on cores
Asphaltie seo 0) cr amoeer eS Melts at about 100°C.
NUM. goo 55e 5.5
BATIEESA Aen ay et ee oe 2.5
Bommmnoniieae eee 2.25 Brittle
Brown haematite....... 4.25 Lenticular fracture
Calaminesee epee 5
Cassiteritesom ante con ee GES
CenUSsiteme aes veces 3.25
Chromitesyare eee on at) Sometimes magnetic
Coppenclancese anes DAS
Conindume ena ee 9
Hels ens aaren cucyan irre ye 6.5
Graphitese. 7 soy see ie Splits easily
GuyPSUIN ae eyes Alea, Oe 1.25 Cleaves readily
aematiicus as ee ee 5.5
iHorblendesssse sense: 5).
liimientiewe ree anaes 5.5 Sometimes magnetic
Maonetite cy sea en 5.5 Very magnetic
Mealaichitenaeae eee 3.25
IMCS rai erage ears ns 25 Cleaves easily
IMOKRPONCIREL, Ss0 cose oso s6 5.5
Native copper.......... j 2.25
Ozokeritesyos meee se OM5 Melts at about 60°C.
Pyrolusite..... Ph)
Quartz U Cleaveless
Sal lGaee eee tenant 2.5 Dissolves in water
Silver/clanceauer ean see BD DN5s Breaks in slices
Sodasnitens. eases 125 Dissolves in water
Spathicvoress. seo oe eee 350 Nodular
Stibniteyecr ete ee D, Sometimes flaky
Sul phurs. seceyicae cane 1.55 Brittle
Roum Aline sea een Me25 Fractures easily
\WWOlBEMIS pasado aap dos 5.25 ;
ZAIN GAO ENCE we arene 3.25
Coals:
ANTHIMNCNKS 0.606000 0 2.25 Brittle, shelly fracture
Bit UIMINOUSsEe eee 25) Brittle, cubic fracture
Gites cv Soeur cites 5 Friable and platy
DEVIATION AND ITS CAUSES 17
The hardness of minerals is fairly constant but of rocks
this is not the case. This is due to the fact that minerals
have a more definite and rigid chemical constitution than
rocks, since the latter are aggregations of minerals. The
minerals in rocks being in any proportions between certain
arbitrary limits the hardness of a particular rock varies with
its type, 7z.e., the percentage of its dominant mineral.
c. Inclined strata especially rapid changes in the inclina-
tion as in boring through sharp unconformities, domes,
folds and thrusts. The tool tends to follow the dip at
the contact. (However, this is not a rigid statement.)!
If we are dealing with the percussive system we must bore
with short strokes so that the cutting tool meets a cleaner
face since the rinsing water can better deal with the débris.
With no rinsing system the hole must be sludge pumped
often so that the direction of impact is in the prolonged
line of the rods. If this is not done the chisel will nurse
the dip. In the rotary system of boring these difficulties
are often almost insurmountable.
Other geological causes of deviation of a drill hole may
be:
1. Bowlders, concretions and dykes.
2. Faults, thrusts and unconformities.
3. Caving and movement of strata in the uncased part
of the hole.
4. General earth movement.
d. Lack of Rigidity in the Rods.—Even in the tightest
joints the slightest joint play will initiate curvature with
straight rods, just as railway curves can be made entirely
of straight rails.
e. The Proximity of Other Boreholes—In boring by
percussive methods, for instance in the freezing process
for shafts, the ground is disturbed by the continual shock
of the tool so that new holes put down near by tend to
deviate into the zone of least resistance. Again any iron
such as parts of old tools or casing in the old hole will
accentuate the deflection. This of course applies also
1 KITCHEN, op. cit., p. 100.
18 DEEP BOREHOLE SURVEYS AND PROBLEMS
to new holes near those old holes which have been shattered
at their base by time charges to increase the yields as was
first done in the Pennsylvania oil field.
f. Fissured Strata.~—These may direct a borehole in any
direction.
g. Pressure on the Rods.—In many boreholes, particularly
in diamond drilling, the tool tends to turn against the dip
of the strata and this is greatly affected in the case of a
hole nearly meeting the strata plane, 7.e., nearly flat strata
in vertical holes; that is to say, ‘‘face on”’ in inclined holes.
Hydraulically fed drills in these cases are best, like the
Sullivan, which control the rod pressure and adapt it to
keep the crown pressure constant. Thus in soft strata
the water escape in the hydraulic cylinder being more
rapid the drill descends more quickly and vice versa in hard
strata. On the other hand, screw feed drill speeds are set
between fixed limits regardless of petrologic changes in the
hole. In harder strata greater pressure on the rods tends
to produce a screwlike action.
h. Reduction of Borehole Diameter—The necessary peri-
odical changes in diameter to lessen the weight on the engine
and crown no doubt affect the plumbness of the hole.
The upper parts of the hole being wider allow the rods
more latitude, and the rods tend to curve by displacing
the center of the crown bit from the hole center. Alterna-
tions in hardness supplement this eccentricity. Longer
core barrels up to 50 ft. have in places been adopted to
ameliorate this tendency.
1. Oversetting the Diamonds in the Crown.—It is considered
good practice to set the diamonds so that the hole is about
14, in. more in diameter than the core barrel; 72.e., 442-in.
projection for the diamonds over the crown.
Any greater overset makes too much play between the
core barrel and hole or between drill rods and hole so tending
to set up lateral movement.
qj. Weak Core Barrels and Small Holes—Weakness of the
barrel especially at the crown screw tends to twist the tool
1 Dickinson, Josepy, F. G.8., Trans. Inst. Min. Eng., Vol. 35, p. 397.
DEVIATION AND ITS CAUSES 19
and in turn the hole. Thus long barrels are often faulty
for want of strength and undue pressure on the crown.
There appears to be much in favor of bigger holes and
reduction not proceeding beyond 114 in. at 2,000 ft. Weak
barrels may cause screw deflection. The crown often
returns to its original direction after deflection has occurred
in some West Australian borings. With big rod reductions
the play cannot be entirely eliminated at the step joint.
k. Static Electricity and Magnetism of Rods.—This effect
due to frictional abrasion is often very pronounced and
ean be demonstrated by means of a poker of soft iron, a
hammer and compass. It must, if of definite persistent
polarity, tend to deviate the rods toward the pole sought.!
Magnetism will tend to arise also from brushing with casing
and the strata if heavily iron borne as in the basic igneous
rocks. Some further notion of the causes of borehole
deviation may be obtained by considering the eventualities
inherent in all boreholes, as yet beyond human control,
as are evidenced in any attempt to fix the dip of strata abso-
lutely from observation on a given core.
Only approximately can we obtain the dip angle of strata
bored through by considering the core features alone.
This is very simple but the estimating of the direction of the
dip and thence the strike of the beds in such a case cannot
be done without some form of stratameter which gives
the dip and strike accurately from the data presented.
The objection here is that the observation is too local and
the data too scanty. We have to assume that the core
yielding the data has been accurately gripped by the core
catcher. ‘Thus in the surface check on the core no account
has been taken of the turn of the rods on tearing off the core
previous to extraction. An American method of partially
avoiding this is to score a continuous line down the rods
after tightening with special joints and then check the dip
shown against this line of known azimuth. Now the
longer the line of rods and tools the less can they be regarded
1 JENNINGS, J., Jour. S. African Assoc. Eng., Vol. 12, p. 7, 1906; CooKE,
L. H., Trans. Inst. Min. and Met., Seventeenth Session, p. 126, 1907.
20 DEEP BOREHOLE SURVEYS AND PROBLEMS
as a rigid rod because under the influence of their growing
proper weight, rending, shear and turning forces arise which
cannot be checked aboveground. Unfortunately, regard-
less of any errors of observation or measurement at the sur-
face, the circumstances attending the wrenching off
of the core and the working of the rods influence the deduc-
tions very greatly. In solid strata the core is wrenched off
by a sharp jolt, otherwise we cannot tell whether the core
and strata are in their proper natural relation as before
rupture. In friable strata the core is frequently released
during boring operations due to the successive boring
shocks, and this also occurs frequently in rigid strata where
we have intercalated beds of clayey and shaly rocks.
Furthermore, the instant of jar for tearing off the core
often witnesses a slight rotation of the rods. The lower
surface of each core section should exhibit no traces of
shear horizontally; the fracture should be clean, for then
we can feel more secure that the small wrench twist is
absent. In order to ensure that the twist is eliminated or
minimized, the rod should be raised a little off the hole
base before the fangs of the core catcher come into action.
This gives the grip a better chance of making an accurate
engagement, because the spin of the string of tools has
abated. This spin definitely affects the direction of bore-
holes. The catcher now brought into action, a sharp
upward thrust will stand a better chance of yielding a core
with the conditions between core and strata preserved as
before rupture. No change from this position must occur
during extraction of the rods. The rod marks must be
carefully watched and bumping of the string of tools
on the borehole walls prevented. There should be no traces
of turning at the core grips.
These conditions are so rigorous and so difficult of
application and the circumstances attending the wrenching
off of the core are so utterly beyond entire control that
absolutely exact results can not be hoped for from one core
alone. With cores of small diameter the small wrench twist
gives an error of several degrees and the smaller the diam-
DEVIATION AND ITS CAUSES 21
eter the greater the error; furthermore the smaller the diam-
eter the greater the lack of control in extraction or boring,
hence the greater tendency to deviate. The best dip
and strike data are to be obtained from computations
on depths yielded by three or more boreholes not in the same
straight line.
CHAPTER II
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS
Previous to discussing the various instrumental methods
of surveying deep boreholes some of the more important
ancillary records kept on modern plants will be described.
These additional memoranda aid very materially in check-
ing the accumulated borehole data in that they frequently
save much time and guesswork as to causes of various
curious features incident to deep boring.
PROGRESS RECORDS
These are continuous automatic checks or descriptive
graphs of the progress of the borehole in respect to length
and time. They provide a check on the difficult and
often unreliable observations of the boring personnel.
They yield conclusions as to the successive hardnesses
of the strata pierced and assist in their determination,
since each stratum corresponds to a definite boring pace.
The simplest device is a scale fixed on the rods and read
every 5 min. and booked, but it is more exact to have a
record depending on the length of hole and revolutions per
minute, since the rapidity of boring through strata depends
on the r.p.m. of the rods in the rotary or the number
of strokes per minute in the percussive system. They are
known as stratigraphs or strata-progress recorders.
Jahr’s stratigraph! (Fig. 3) consists of a pen recording
on a graph drum the latter revolving at the same rate as
the rods and its motion round being at right angles to that
of the pen. Thus the increase of depth of the crown bit
will appear as abscissae and the corresponding revolutions
as ordinates. The recorded line is thus the steeper the
1, Jahr, Chief Mine Surveyor, Breslau.
22
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 23
faster the boring progresses and the flatter the slower the
crown penetrates the measures; therefore a horizontal
portion of the line shows that the tool is not piercing the
rocks even though the rods are rotating; that is to say,
that the rod feed is not paying out. When the plant is
D
| ee i
WA LAE
Fig. 3.—Jahr’s stratigraph—the derrick drive.
idle, and therefore the driving shaft of the recorder, the
registration ceases. The most important inferences from
the record are provided by changes of direction in the pen
line because they show that different strata have been
struck and thus provide valuable clues as tothe conditions
arising in this new ground. Such a change in the line only
occurs in the flatter measures; in inclined deposits the change
is more gradual because the crown only then penetrates
the new stratum gradually. In Fig. 3 note that the motion
24 DEEP BOREHOLE SURVEYS AND PROBLEMS
of the graph paper n is caused by the sinking of the rods a.
A hook e on aring on the boring spindle catches in the chain.
This chain runs over the rollers g, gi and g2 and is kept
taut by the weight h. The motion of the roller g is trans-
mitted by means of a bevel wheel on the shaft / so that the
paper moves corresponding to the deepening of the borehole.
The speed of the paper depends on the transmission between
the bevel wheels 7 and k. The pen moves on an endless
chain p (Fig. 4) at right angles to the direction of the drum
graph, and it is driven by the toothed wheels qg and q!.
Yj
Z
=
N
N
ale
pd |
We at
Van ela
—— —— °
Revolutions
of the Crown
> |
XJ
Borehole SXSSSSS885
depth |SClay Shales
WANN ANNAN
ne, 4b, Fia. 4a.
Fic. 4.—Jahr’s stratigraph—the recorder.
Fig. 4a.—Showing relation of record to measures for estimating depth and
thickness of beds.
The chain is driven by belting r from the driving shaft
of the engine S. The recorder has several pens m1, m?,
etc., spaced on the chain p at vertical distances equal
to the depth of the record paper. Whenever a pen reaches
the top edge of the paper it leaves it just as the next lower
pen comes into action to continue the record, since their
distances apart equal the depth of the graph paper. ‘Thus
the record is got as a continuous series of broken lines
which can be cut and arranged later if desired.
It will be seen that the quicker the boring rods sink the
more the curve will approach the abscissa direction and
there will be a change in the curve for every different speed
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 25
of sinking. On the upper edge of the paper (Fig. 4), a
curve scale can be fixed for the continuous series of borehole
depths, which can be diminished to a definite scale by means
of suitable transmission bevels 7 and k. Thus, given
favorable conditions, we may obtain the approximate
dip of the strata by noting the length of the transition
in the curve between two changes in it. Note in Fig.
4a, which shows the progress of a diamond-drill borehole,
that the curve is uniform to a as the crown is cutting in
clay shales; from a onward, where the crown encounters
the milder strata (coal) the curve flattens, and from b to
c where it is entirely in coal it flattens more, steepening
again at c on passing through the softer coal into more hard
shale. An enlarged view of the borehole is shown in Fig.
4a to assist in elucidating the problems arising. Thus
bd is the borehole diameter and ab the depth difference
read on the curve scale, hence the strata dip
ab
tan a = bd (1)
from which the actual thickness cg is easily obtained, since
thickness of strata = ac COS a.
To facilitate reading, the depth of each change of strata
may be marked on the record. If necessary the recorder
can be driven independent of the plant. This method
has been well tried with good results at one of the deepest
boreholes in Germany, at Czuchow in Upper Silesia. Still
it is only an aid to recording strata and is not infallible
especially in very varied thin alternations of highly inclined
beds. Better results would arise if the paper were made to
move corresponding to the strata dips. Jahr’s method
may, however, be regarded as a valuable adjunct to boring.
Lapp’s Stratigraph.—Here the pen moves by clockwork
at a definite rate over the paper which moves corresponding
to the deepening of the borehole. The recorder is connected
to the rope drum shaft on the pay-out feed from which
the rods hang. In Fig. 5 we have a view of Lapp’s device
in which the worm wheel s transmits its motion through a
26 DEEP BOREHOLE SURVEYS AND PROBLEMS
chain on to the scroll paper winding on a shaft. As
soon as the feed apparatus turns backward, e.g., on dropping
into the borehole, the paper roll is automatically cut out;
the pen then indicates a straight line across, as when the
plant is at rest. The pen works by clockwork and in one
hour moves over the breadth of the paper and after auto-
matic reversal works back in the next hour. Thus the
record is a continuous zigzag line. The apparatus is
enclosed in a glass-topped case which permits of a constant
Fig. 5.—Lapp’s stratigraph.
observation of the progress of the borehole respecting the
corresponding time. It does not cut out when the plant
is idle as in the case of Jahr’s device, and, since this latter
is a check on the actual working time, it can be considered
that Jahr’s method is superior. But it can be applied
to percussive boring since it works off the tool feed; however
this may be a source of uncertainty since the feed is here
hand operated. Thus the record depends on the careful
manipulation of the feed which if correct, 7.e., if the record
corresponds exactly to the progress of the hole, will give
uniform results with Jahr’s method. Both methods lack
in that uniform rotation of the rods is not always obtained
in practice.
The Foraky Recorder.—This stratigraph is a clockwork
device with paper roll and recording apparatus. The
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 27
principle of recording the progress of the borehole is here
again dependent on the sinking of the rods and time.
The paper is turned by clockwork and the recording pen is
driven by the feed device. The paper roll is chosen of
such diameter that the clockwork rotates it on its axis once
in 12 hr. and 1 mm. of paper corresponds to 1 min. of time.
Therefore millimeter paper is chosen for the graph. The
CL MMT
C6]
Fic. 6.—Foraky stratigraph.
recording contrivance is driven from a screw spindle on
the rod feed in such a way that a sinking of the rods of 10
em. corresponds to a progressive motion of the pen of 1
em.
The inked pen C (Fig. 6) moves! proportionally with the
descent of the rods. It is connected to the rods by the screw
spindle d from the feed device and by a cone-wheel trans-
mission gear e actuating the screw spindle f. This carries a
positive nut g holding the penc. The axis of the clockwork
b gives the true reading and the whole is encased in the
casing h for protection. The apparatus is placed on a frame
in the boring tower but not in contact with it. It has been
successfully applied to depths of over 4,000 ft.
1 Gliickauf, p. 417, Mar. 18, 1911.
28 DEEP BOREHOLE SURVEYS AND PROBLEMS
The results obtained are very satisfactory but the
apparatus exhibits the same deficiencies as Lapp’s appa-
ratus because the basis of the record is time and not the
revolutions of the rods, and here even in a higher degree.
Since the motion of the recording surface is always uniform
it turns too quickly in solid strata and too slowly in broken
strata. In this way the variations in the recorded line,
upon which the stratigraph depends as stated previously,
are weakened, while in Lapp’s method where the pen
works by clockwork they are increased. The irregularities
in the velocity of rotation of the rods in working are of no
great importance since the expenditure of power for the
proper action of the crown is small as compared with the
movement of the rods.
Depth Measurers.—There are many types of these, the
. Measuring
Kc Whee!
\ SN
Fig. 7.—Depth measurer.
direct depth measurer of the Lucey Products Corporation
of Tulsa, Oklahoma, known as the Thatcher Depth-
ometer. It is easily assembled on a rod frame and is very
portable, being only 15 to 16 lb. in weight and can be used
on ropes up to 114 in. diameter. The measuring wheel
transmits its revolutions by toothed gearing for direct
reading, and it can be used on bailing and apparatus lower-
ing ropes as well; also it can be used when letting the rope
into the hole or when pulling it out.
Borehole Diameter Measurers.—Decisions as to the
variations in the diameter of a borehole are often necessary
to settle difficulties arising during boring.
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 29
These difficulties may occur when
. Casing operations are obstructed.
. Cutting bits jam on extraction.
. Abrasion develops at localized places.
. Cushioning occurs on the percussion stroke.
. Water circulation is affected.
6. Sludging, pumping, bailing and such operations are
hindered.
The action of these gages need not be intermittent, 7.e.,
a continuous reading can be made for only one insertion
of the apparatus. Former methods of laborious multiple
readings are thus avoided. A borehole becomes restricted
chiefly owing to the following causes:
1. Inexpert tiller work on hand-turned drilling with a
straight bit; cruciform or horseshoe bits are less likely to
cause diameter restriction.
2. Buckled casing due to joint or sheet rupture under
internal pressure or external strata movement on weak
casings.
3. Earthquakes.
4. Time charges at hole base.
5. Curvature of the borehole and its causes.
6. Uneven wear on the cutting tool not attended to in
time.!
Rumpf and Kleinhenn’s Apparatus.—This apparatus
can also. be used for tubes and flues. The chief part
SD OP ON
of the device (Fig. 8) consists of a system of calipers
arranged to follow the inner walls of the borehole or casing,
its movement being obtained as a magnified image either
optically or mechanically inside the borehole.
1Wotzasek, F., Z. J.V.B., p. 178, June 20, 1928.
30 DEEP BOREHOLE SURVEYS AND PROBLEMS
Figure 8 shows a longitudinal section of the device
placed in casing 6 being examined. It will be seen that the
central body 1 of the apparatus closes the tubular wall 2
into a chamber. About the central body 1 are the levers
4 which turn on axes 3 and carry rolling calipers 5 following
the borehole or casing walls. These levers 4 may have
any suitable form in cross section, preferably a definite
form at their ends 8, e.g., triangular, in order to get a sharp
projection image which is thrown on the frosted glass
10 by a dry-battery lamp 9. The levers press on the casing
walls by the action of springs 7, pressing them against the
central boss on the other side of the fulcrum axes.
Figure 9 shows another form of construction wherein the
caliper system 5 and spring 7 are arranged in another order
of leverage. In each case springs 11 also assist springs 7
in centering the apparatus in the borehole or casing. A sim-
ple removal device is a set of hooks 12 and draw cables 13
uniting into a central cable.
ee ee ae
== Tous Ell
=
\
Ere. 110.
Figure 10 shows the most recent form of the device
produced in the laboratories of the Batavian Petroleum
Company (Astra Romana). Here the displacement of
the caliper system due to diameter variation is indicated
optically in a magnified image. The caliper system 5 is
here a piston system working in a cylindrical case and
pressed on to the borehole or casing walls by springs 7.
A source of light produces a magnified image on dise 10
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 31
through a system of lenses 14. It is found advantageous
for registering results to have a series of concentric circles
on the frosted glass plate 10, each circle corresponding to a
definite variation in the diameter of the borehole. A
kinematographic registration also suits the apparatus well,
in which case the hood 10 is completely replaced by a kine-
matographic recording device. When employing the latter
the motion of the apparatus down the hole must be uniform,
so the survey film obtained will yield an exact image of the
condition of the borehole or casing diameter.
We will not deal with any of the old time-wasting and
tedious methods of single observations and records.
PRESSURE RECORDS
It is well known that in horizontal and inclined boreholes
the tendency to deviation is greater than in vertical ones!
Although this tendency is mostly downward with horizontal
and upward with inclined holes, many holes, particu-
larly in inclined measures, tend to deflect upward.? Alter-
nating hardness, etc., also affects this. These deviations
are accentuated by the action of gravity and lower side
abrasion on the rods due to the weight of the crown. In
the case of horizontal and well-inclined boreholes (from
the vertical) maximum manometers are employed to
register the water pressure in the hole.
The ‘‘Burbach’’ Pressure Recorder.—Where the deflec-
tion is downward, as in the usual cases, this method employs
the principle of gaging the pressure of the rinsing water
at various points in the borehole and contrasting these
records with the conditions at the borehole mouth. Where
the deflection is upward the pressure on the rinsing pump
may be gaged.
a. When the borehole deviates downward, a tube piece is
screwed on to the boring rods. The apparatus of the
1 Justice, J. N., Trans. Inst. Min. and Met., Vol. 12, p. 319; KircumEn, J.,
ibid., Seventeenth Session, 1907-1908.
+ JANSON, Proc., Vol. 11, p. 48; Lake Superior Min. Inst., Vol. 2, pp. 26-30,
1894,
32 DEEP BOREHOLE SURVEYS AND PROBLEMS
Burbach Works, Beendorf, Germany, contains a manom-
eter c with a bent measuring tube d (Fig. 11). The fluid
enters through holes a from the borehole and holes 6b to
the measuring chamber and gaging tube. The manometer
is provided with an indicator which fixes the highest pres-
sure. The measurements are very simple; the rods and
BERN BESS
Uf
Y
po en,
LLLLEXZPIPIS 1 — BSS ESS
Fig. 11.—Horizontal borehole pressure recorder. (Burbach.)
gage are pushed into the hole to the spot to be measured,
the hole being full of rinsing water. Then on pulling
the gage out and reading the highest pressure thereon the
deviation from the horizontal can be calculated by consider-
ing the specific gravity of the rinsing fluid. This latter,
of course, is essential since water is not the only fluid; in
potash mines magnesium chloride liquor is used.
Borehole set horizontal
Atmospheres
of Pressure
Fic. 1la.—Horizontal borehole profile.
Figure lila illustrates this simple principle, being an
actual example from a German potash mine where a fluid
of 1.275 sp. gr. is being employed. To get the ordinate
at the length 340 m., where the gage has registered 2.5
atm. of pressure fall, proceed thus:
1975.7 19.60 m
and similarly for the length 500 m. registering 4 atm. fall:
10D 4
b. When the borehole deviates upward, the pressure 1s
read at each desired spot by sending in the gage on the rods
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 33
to the place noted and then extracting and reading. Or,
as said before, a continuous pump pressure record is
kept.
The borehole depths read from the rod are entered as
abscissae and the computed deviations from the horizontal
as ordinates, as shown in Fig. lla above. We thus get a
line showing the course of the borehole. When the
actual borehole is not intended to be horizontal the depths
are projected, otherwise we get foreshortening errors. To
lessen errors we may plot true borehole lengths against
measured pressures direct. These methods are not affected
by the smallness of the hole.*
Brigg’s ‘‘Clinoscope.””—This is another and more recent
method of measuring the deviation of horizontal boreholes.
It consists of a mercurial transmitter and Wheatstone
! 5 az
\N a Se
YAN
s
Fig. 12.—Brigg’s clinoscope, vertical section of transmitter.
bridge recorder, the tilting of the mercury into the horizon-
tal position varying resistances which are measured by the
bridge.
Fie. 13.—Brigg’s horizontal clinoscope. Plan of transmitter.
In Figs. 12 and 13 is shown the transmitter which is a
fiber box half filled with mercury g in the container d.
Two circular pits at i, 7 (Fig. 13) are connected by a slot
s, the surface of the mercury, when the transmitter is level,
1 THIELE, P., Verfahren zur Ermittlung der Abweichung von Horizontal-
bohrungen in der Vertikalebene, Kali, p. 32, Jan. 15, 1913.
34 DEEP BOREHOLE SURVEYS AND PROBLEMS
being at g. Two parallel resistance conductors a‘ and a’
and a steel needle c pass through the fiber lid 1. The
needle connects the mercury to earth by way of the trun-
nion n, the case e and the borehole lining. By dipping
into the mercury the conductors are connected in parallel.
Any change of inclination alters the length of conductors
immersed, and thus the relation between the resistance of
the conductors is a direct function of the tilt. This rela-
tion is determined by means of a Wheatstone bridge which
will be detailed later when discussing Professor Brigg’s
‘‘clinophone”’ for vertical boreholes. The most disagree-
able feature of the apparatus is the employment of mercury,
which is an unsatisfactory medium to employ in mining
owing to its so easily becoming dirtied and thence unreliable.
THERMAL SURVEYS
These are usually resorted to in cases where we need
1. The geothermal gradient of the strata of a given area.
2. To investigate the frost columns in a freezing shaft.
3. To employ geophysical data in oil zones, etc.
4, Purely scientific researches.
They are purely thermometer surveys undertaken with
some special form of maximum or minimum thermometer
using various fluids and systems of calibration. Numerous
devices! have been invented to meet these needs, and in
all cases it is necessary for the apparatus to remain in the
hole some hours in order to acquire the temperature of its
surroundings.
a. Measuring Decrease of Temperature-—The Mom-
mertz apparatus (Fig. 14) is one of the best known low-
temperature contrivances used in borehole temperature
surveys, 1.¢., in freezing shafts. A sheet-iron flask a
contains a liquor which can withstand great cold, and this
vessel is closed by means of a wooden plug. It hangs inside
another flask c and between them is an insulating space
on the vacuum-flask principle of exhausted air. The outer
1 See the final chapter of Ambronn and Cobb’s “‘ Elements of Geophysics ”
McGraw-Hill Book Company, Inc., New York.
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 35
flask has a screw top and suspending device. Its base is a
pointed lead end.
After the flask has hung a long time at the spot being
measured, it is rapidly taken out and the temperature of
Shaft .aq Freezing Pipe
SS
p <5
Lead d; “Vacuu
iy ==
hkK— @=—— Liquor Pa nor —— ess
.
ELLE PAE L LS
SSS
Fig. 14.—The Mommertz low temperature borehole thermometer.
the solution read. This gives the temperature at the said
spot after due allowance for the fluid being used. The
time needed for the apparatus to assume the temperature
of its surroundings is decided by trial for each case.
The results are more or less approximate
but useful.
b. Measuring Increase of Temper-
atures.—There are many kinds of maxi-
mum and minimum thermometers in
use. A favorite type of maximum ther-
mometer is that in which the capillary
is left open and ground off into a fine
point with a reservoir surrounding it for
the overflow. This overflow can be
measured in various ways against known
bath temperatures. The Hallock! type
has a secondary capillary for measuring
the separated mercury.
A well-known type of maximum and
minimum thermometer is that of Six
(Fig. 15) in which the liquid is alcohol
Fig. 15.—The Six
maximum and mini-
mum thermometer.
in the tube A at the end B of which is a thread of mercury
BC, the remaining part of the thread and part of the bulb D
being again alcohol. The former end of the thread is for
minimum and the latter for maximum readings. There are
two indexes, one of glass the other of iron or both of glass
1 Jonnson and Apams, Econ. Geol., Vol. 11, pp. 741-762, 1916.
36 DEEP BOREHOLE SURVEYS AND PROBLEMS
with side springs of steel as at G. For the bottom index
glass is used. Glass being wet by alcohol the index
retreats with it owing to capillarity and on rise of tempera-
ture the alcohol flows past it without moving it, the spring
also holding it; thus we get the minimum reading £.
The upper index may be of iron, since alcohol does not
wet iron, so that on rise of temperature the iron is pushed
up and remains there when the column falls, showing the
maximum temperature F. Otherwise the spring glass
index is used. These can afterward be reset by a small
magnet acting on the springs. Full accounts of up-to-date
thermal survey methods can be obtained elsewhere.
Length Recorder for Use When Inspecting Ropes.—
This device? is now employed for hoist ropes, and lowering
Fig. 16.—Elevation. Fic. 16a.—Plan.
ropes for valuable apparatuses and is used to enable a rope
inspector to find the position of broken wires or worn or
distorted places accurately to within a few inches. In
Figs. 16 and 16a a measuring wheel a, grooved to suit the
diameter of the rope d, is kept in driving contact with the
1 VAN ORSTRAND, C. E., Apparatus for the Measurement of Temperatures
in Deep Wells by Means of Maximum Thermometers, Hcon. Geol., Vol. 19,
pp. 229-248, 1924.
McCourcuin, J. A., Bull. Amer. Assoc. Petroleum Geol., Vol. 14, No. 5,
p. 5386, May, 1930.
SEIFERT, C., Fortschritte Mineral., Bd. 14, Part 2, pp. 167—291, 1930, for
notes on geological thermometers and bibliography.
2The firm of Reinhard Wagner, Bergwerksdarf Oberhausen (Rhld),
Germany; see also Gliickauf, Dec. 10, 1929.
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 37
latter by two rollers b, c, carried byaframee. The bearing
pressure on a is regulated by the screw h adjusting the com-
pression of the spring g. The base plate p is notched at
r, and the end piece 7 of the frame f is detachable, so that
the apparatus can be put into position round the rope.
The frame f is mounted on a beam / carried by the springs
oand bars m,n. The castors g, mounted on vertical pivots,
ride on the platform on which the inspector stands. The
spindle of the wheel a is coupled directly to the recording
train k, which indicates directly the length of rope that has
passed a at any particular moment. The complete
apparatus, which has proved quite satisfactory in practice,
weighs about 57 lb.
Construction of Borehole Sections or Profiles.—Obvi-
ously it is only possible to portray the course of a borehole
with any degree of accuracy by referring the observed
data all to one plane. Having the depth and inclination
data at hand, there are three methods of plotting these in
any arbitrary vertical plane! viz.:
1. Plotting the angle from the point where recorded
down to the next recorded point.
2. Reversing 1 by plotting upward to the preceding
recorded point on the chart.
3. Averaging 1 and 2 by plotting at the point on the
chart either way, downward and upward, halfway to meet
subjacent and superjacent plotted points obtained in the
same way.
Since methods 1 (A Fig. 17) and 2 (B Fig. 17) assume no
gradual change of dip as usually obtaining in practice,
but imply sudden regular dip changes, they are not now
employed or recommended. Method 3 (C Fig. 17) will
enable us to average subjacent data and plot this mean.
The three lines A, B and C (Fig. 17) are plotted on the
assumption that the hole deviates in one plane, say the WE
plane of the paper. If a hole has been assumed to bear in
1 These methods are also discussed by Prof. F. H. Lahee, Bull. Amer.
Assoc. Petroleum Geol., Vol. 13, No. 9, p. 198, to which we are indebted for
Fig. 17.
38 DEEP BOREHOLE SURVEYS AND PROBLEMS
only one plane (a common error of borehole chart makers)
and it is later decided to allow for lateral directional devia-
tions, or for depicting any borehole data in one plane,
proceed thus:
In Fig. 17a the profile of C (Fig. 17) is reproduced dotted
and the hole is assumed to have the C hole dips and depths
A_B C __ Surface
ne, 7. Pia. 17a.
Fic. 17.—Section showing methods of plotting deviation of boreholes where
readings are made at intervals and angular deviation is assumed to be all in same
vertical plane.
Fic. 17a.—Section showing a hole wandering in three dimensions revolved into
the WE plane.
Fie. 17b.—Plan of Fig. 17a.
throughout but alters in azimuthal directions from point a
as shown on the left of the figure. Our problem is to
visualize the borehole in the WE plane as in the previous
Fig. 17. As ab is now bearing N.55°E. rebat it 35 deg.
to ab’; project this line to ab? and drop perpendicular
to the depth line of 6 at b?. (Imagine a to be the apex
of a cone of side and dip ab with the new ab 35 deg. out of
the old ab plane; the actual depth and length of the new ab
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 39
are unaltered except for the distortion due to projection. )
Join ab? and draw 6°c, parallel to bc. The hole is now 65
deg. out of the WH plane; slew 6%c; this amount to b'c’
and project to b%c? getting c® on the c depth line as previ-
ously. Join b’c?. In the same way get the due north part
of the hole cd to show a vertical c*d* only, since it can have
no lateral trend in the WE plane of the paper; and so on
to e?, the last length being an extraneous addition to C
(Fig. 17). It would be well to smooth a curve through
these constructed points, and the same applies to the plan
view of Fig. 170.
Borehole Models.—These are very useful and instruc-
tive adjuncts to any scheme of deep boring or precision
boring, as in freezing shafts. 'Thurmann of Halle, Saxony,
constructed the interesting and helpful model shown in
Fig. 18 in 1909 to assist in visualizing the relative trends
and positions of boreholes in a freezing shaft frost wall.
It will be seen that he merely erected discs of sheeting or
millboard at depths on the central rod scaled from the prog-
ress chart, the said rod representing the shaft center.
Thus, in the figure, the dots on the discs represent the posi-
tions of the boreholes at the various levels or depths. The
dotted line shows the position of a supplementary borehole
to deal with the wide space in the frost wall between bore-
holes 2 and 3.
Figure 19 shows a glass model of the Chanslor-Canfield
Midway Oil Co.’s No. 96 Olinda oil well in California, one of
the deepest wellsin the world. Itis thought that some facts
relating to the true shape of the course taken by the lower
part of the well, obtained from a study of the model,
would have remained unknown without its aid.
The model is seen to be easily constructed from depth
planes scaled from the boring logs and the positions of
the instruments on each plane surveyed as shown. The
bottom plane surveyed is 6,948 ft. deep. It is conceiva-
ble that valuable results may be had from models outlining
the course of well or boreholes and these would be more
exact than sketched-in hypothetical underground contours.
40 DEEP BOREHOLE SURVEYS AND PROBLEMS
In this particular model the vertical line represents
the plumb line from the derrick floor. The curved line
is an accurate representation
of the course of the drill
hole through the formations.
The model was made by
drilling holes through sheets
of glass in the surveyed posi-
tions of the hole at differ-
ent depths. A black cord
threaded through these holes
represents the well.
The Sperry-Sun Well Sur-
veying Company of Philadel-
phia also employs an attrac-
tive and useful method of
depicting deviation. They
west
\
eal
mn
YEN 7
ARES SE|7
(oe
lL
|
Q
Pre. 18. Fie. 19.
Fira. 18.—Thurmann’s borehole model.
Fra. 19.—Glass model of the Chanslor-Canfield, Midway Oil Co.’s No. 96
Olinda oil well in the Fullerton, Calif., Field, showing the course of a very deep
borehole. (After Anderson.)
project the surface position of the borehole on to the
lowest depth model plane as the center of deviation
coordinates. From this axis the relative displacements
are plotted at their respective depths (Fig. 19a). The
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 41
finished model is then pasted up at the sides giving the
borehole as one edge of a distorted prism (Fig. 190).
Lesser Deflection Records for Short Holes and Small
Deviations : The Plumbing Basket.—This method employed
in plumbing holes which have not deflected more than
[ms
LSS
|
[ll
ce
ae
(a)
Fie. 19a AND b.—The Sperry-Sun Well Surveying Co.’s model.
the borehole width, is often resorted to, since it is rapid
and cheap. It was evolved by the Parisian firm Entreprise
générale de fongage de puits études et traveaux de mines.
It is much appreciated in surveying freezing shaft holes and
prospect holes. It? consists of a receptacle or basket filled
with lead and let down into the hole on a hawser. The
basket A (Fig. 20) is slightly less in diameter than the hole.
1CaVALLIER and Dauvsine, Annales des mines, Paris, 1900. Series 9,
Vol. 18, p. 392; KoutEeR, Bergbaukunde, Vol. 6, p. 634; Berg und Hiitt.
Zitg., p. 276, 1901.
2Scumipt, Trans. Inst. Mining Eng., Vol. 52, No. 2, p. 178, 1917;
ERLINGHAGEN, Glickauf, p. 705, June 8, 1907.
42 DEEP BOREHOLE SURVEYS AND PROBLEMS
It is preferably, but not necessarily, suspended from the
pulley S over the hole center C at the surface. The dis-
tance CB varies in amount and bearing according to the
deflection. If this suspension point S is at a height h
above, and the basket A at a depth D below, the surface
and the measurable distance CB be called
m, then the deviation X of the hole is
obviously
ID) =e Ip
X=mit2=m i (2)
Erlinghagen! simplified the process in
a survey of freezing shaft boreholes for
the shaft sinking firm of Gebhardt-
Nordhausen. He employed a drum of
0.314 m. diameter, 7.e., 1 m. circumfer-
ence, which carried a wound copper wire
exactly 10 m. above the center of the
Eres Ue mouth of the hole. It carried a heavy
weight or plumb bob which moved freely,
allowing the wire to take up an exact perpendicular posi-
tion. A crosspiece with two measuring lines at right angles
is fixed on the hole mouth to facilitate reading. The depth
is taken from the number of unwound coils from the drum,
each being 1m. The computation (2) above now becomes
i mn Sone 5
10
The method is not bound to fail when the wire fouls the
sides of the hole, for in case of the hole deviating back to its
original position at greater depths the wire will hang free
of the sides. The method can be applied for depths down
to about 300 ft., and instances of its successful application
at over 600 ft. are on record. Certainly with big deflec-
tions it is useless, but for surface and near-by subsurface
conditions in most holes down to 100 yd. it is a useful
auxiliary record.
The all important dimension m is checked as follows
(Fig. 1, Plate II). The coordinates (x1y1) of C, the center
1 Ghiickauf, No. 23, 1907.
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 43
of the hole at the surface, are known with respect to the X
and Y axes, and the depth of any point A on the wire can
be found, since we can get the length L of the wire direct.
f m(L+l)td
X=——— c
L 9192 ayay an
Fic.4
Puate IJ.—Illustrating the basket method.
From the similar triangles SCB and BaA (Fig 1) right
angled at C and a, we get
CB SB CB SB
En a oe = A
and
CB: SA
CO =) ae 8 = ee
Then, by coordinate geometry for the small length CB = m,
CB =m = V (22 — 41)? + (y2 — yi)” (4)
It will be seen that m is a function of the length L of the
44 DEEP BOREHOLE SURVEYS AND PROBLEMS
hole and L + 1 of the wire. The azimuth of CB is easily
taken from
Ly — 1
ee (5)
We first detect contact of the wire in the hole by m becom-
ing constant, but, as already stated, it may vary again if
the hole diverges back to its former direction later on.
If this latter contingency arises it can be demonstrated
as follows: Each deviation of the hole gives a new value
in amount and azimuth for m, thus giving in a crooked hole
a series of values, a1, G2, a3... a, at different points
1,2, 3...mn. At each of these points trace the bore-
hole cross sections as shown in Fig. 4. Here the circles
representing the circumference at the said points 1...
are projected downward on to a line aq . . . » which is
the continuous horizontal traverse of the deflections a;
. Gd, in bearing. The centers of the circles are corre-
spondingly subscript figured 1...n. If the line SA
do not touch the borehole sides, 7.e., it is straight, we
find it on the projected plan as the line ca,. That is to
say, that if we make a vertical section of the borehole
through ca, and draw in SA, it must not touch the sides.
The points must be inside the borehole section circumfer-
ence circles at the corresponding levels. If one or more
do not obey this requirement, point S may be shifted
for a new suspension and therefore new plan point C’.
Failing any agreement with the above demands, on moving
S to the limiting lateral positions, the method ceases to be
of utility any further.
When point C has been retreated a distance d to C’
(Figs. 1 and 5) and the projection completed, the new
deviation w is got from the new suspension and hole lengths
aandb. Thus
w= (a+b) +d (6)
Other but perhaps more troublesome methods have been
adopted as modifications of the above method.!
1K, Scumipt, op. cit., p. 180.
AUXILIARY REGISTRATIONS IN BOREHOLE SURVEYS 45
Errors of measurement arise from the following sources.
a. Incorrect Adjustment of the Plumb in the Hole.—This
arises often in unlined boreholes which frequently prevent
the plumb fitting the hole like a piston. This mostly arises
in chisel-bored holes which tend to ovality in cross section.
Ten millimeters inexactitude renders the method unadopta-
ble. The application of spring-centering mechanism to
remedy this is not to be recommended.
b. Sag of the Rope.—This occurs with long ropes holding
small weights and it renders false readings of m. These
errors increase, with the slope of the hole and its depth,
according to the catenary law. The rope should be very
light compared with the weight; or it may be ridded by
centrally fixing the plumb at the measuring place and
tensioning the rope.!
c. Incorrect Readings.—Inexactitude in reading m in-
creases as m diminishes, greatly influencing the coordinates.
Repeated micrometer readings should be made and the
mean taken.
1See Wache’s device, German Patent No. 3859, or Gltickauf, No. 46, 1904.
CHAPTER III
INSTRUMENTAL SURVEY OF BOREHOLES
The determination of the course of boreholes by instru-
mental means has occupied the minds of investigators
since before the middle of last century. It received great
impetus during the early eighties and the opening years of
this century. Since the World War much work has been
done, principally in the Mid-continent oil fields of America,
South Africa and Germany in devising new means to the
above end. From simple tests with plumbing baskets
and by simple fluid apparatuses the progressive trend
through various mechanical, optical, and photographic
contrivances to the highly skilled gyroscopic methods has
proceeded, until today the last two named means are being
exploited vigorously. Probably the most widely adopted
method in employment today is a modified form of fluid
method, and it is now customary for contracts in drilling
to specify a limiting permissible error in verticality of 1
part in 100. Thus we are faced with a universally applica-
ble standard of attainment expected of any method offered
in the profession. The paramount requirements which
have to be fulfilled by a successful device are as follows:
a. It should record continuously on going down the
hole and similarly make a check record upward on extrac-
tion. Very few inventions meet this need.
b. It should measure both the inclination and bearing
of the borehole. This could be done by simultaneous
registrations from one source or two initial sources register-
ing at the same time. It is the great time-saving
injunction.
c. It should be under direct surface control with respect
to registration as well as depth.
46
INSTRUMENTAL SURVEY OF BOREHOLES 47
d. It should be immune from injuries due to water or
mud pressures, chemical actions in the hole or strata,
etc.
e. It should be uninfluenced by local attractions such as
are set up by magnetic strata, metallic linings and rod
magnetism.
f. It should be simple and free from many technicalities
and therefore less liable to derangement and needing less
supervision.
g. It should be easily understood and, if possible, capable
of being read direct with few adjustments.
h. It should be capable of registering at great depths, 7.e.,
it should be of small diameter. This claim is a failing of
most instruments.
1. Its data should always be subject to check up and down
the hole and also by different means.
The several methods invented to investigate the course
of boreholes may be broadly classified under the following
general heads, though certain instruments may be included
under two or more of these:
1. Fluid methods utilizing the shape of the fluid outline
in a cylindrical retainer. Such a fluid may be hydrofluoric
acid, cement, gelatine, mercury, copper sulphate, wax or
paraffin.
2. Plummet and magnetic needle methods in which the
dip and deflection are read on special arcs in the instrument
or by core measurers aboveground.
3. Electrical methods, wherein plummets are actuated or
pricking cones are set in motion, also electrolytic deposition
devices, wax-warming ares, and other registration con-
trivances.
4. Pendulum methods either simple or compound.
5. Photographic methods wherein the position of plum-
mets and compasses is recorded, or where kinemato-
graphic records of successive positions of these, or direct
photographic views of the unlined sides of the hole, are
provided. Multiple photographic devices and multiple
views of shaped notches, etc., are included here.
48 DEEP BOREHOLE SURVEYS AND PROBLEMS
6. Gyrostatic methods where the principle of the gyro-
scopic compass is employed.
7. Plastic cast methods in which set models of the hole
and its core stump are provided.
8. Pricker methods operated by electromagnet plungers,
levers, plumb bobs or in any other way, on paper strips,
soft discs or plates.
9. Inertia methods wherein the inertia of a heavy rotating
body is employed.
10. Seismographic or geophonic methods in which
vibrations caused on the surface by explosions or the vibra-
tions caused by drilling, particularly cable-tool drilling, are
recorded.
The general subject of borehole investigation can thus, by
the above methods, be broadly divided into two main issues:
a. The actual survey of the course of the borehole in
azimuthal deviation and inclination from the line of its
intended course.
b. Core orientation in which the original underground
position of the core is established. It is, of course, limited
in its field of application by being only applicable to holes
yielding cores.
The two main branches a and 6 of our subject necessarily
merge one into the other by reason of their close relation
and the instruments employed being often of dual utility.
Core orientation provides useful information as to the
direction and amount of stratigraphic dip; information
very difficult to obtain when boreholes incline through
inclined beds. This will be seen by Fig. 21, where we will
often meet the difficulty of having unreliable data as to
whether a or a is the truthful vertical thickness of the seam.
The great value of core orientation surveys in fields insuffi-
ciently mapped geologically, as in wild-cat ventures, is
obvious; also where evidence is misleading or misinter-
preted, as often in unconformities, asymmetric conditions,
hidden dislocations, alluvial deposits and where we get
change of facies.1 The retention or rejection of accumu-
1 Macreapy, G. A., Bull. Amer. Assoc. Petroleum Geol., May, 1930.
INSTRUMENTAL SURVEY OF BOREHOLES 49
lated data bearing on the problem will be decided by this
core knowledge. Also the probable line of development
in the field concerned. It is singularly useful in seeking
index beds or marker or key beds and therefore decides
the spacing of holes and life of a lease.
It is considered that shale with a dip over 5 deg. is the
most favorable stratum for core orientation, since dips are
rarer in massive formations. Hard sands are more objec-
tionable owing to their wearing out the cutters, and soft
sands tend to crumble and plug the barrel; also false bedding
occurs more frequently in sands. The chief difficulty is
the transporting of the cores to the surface in a satisfactory
condition.
At all events sufficient has been said to show that the
practice of borehole surveying and core orientation has
progressed far since the day of Dr. Newell Arber! who was
rather emphatic in disclaiming the reliability of any
methods purporting to show the direction of dip of beds in a
borehole.
In all methods of borehole surveying and core orienta-
tion, one of the prime factors influencing the choice is the
cost, since the cost consists not only in the actual expense
1 Geology of the Kent Coalfield, Trans. Inst. Min. Eng., Vol. 47, p. 694.
50 DEEP BOREHOLE SURVEYS AND PROBLEMS
of the survey but also the time loss which could otherwise be
taken up in drilling.
According to recent findings! the direct and indirect
costs of making separate directional surveys with every
500 ft. of additional hole amount approximately to 2 to 3
per cent of the total cost of a producing well. The increased
cost due to the changes in drilling practice in order to
keep a hole straight and the cost of straightening a crooked
hole ordinarily range from 5 to 10 per cent of the total
cost of the hole, depending upon the work required to
correct possible crooks in the hole. Thus apart from
any considerations (in oil-well drilling) of improved
spacing, better drainage and higher recovery per well
and per acre which arise from correct surveying of boreholes,
it will be seen that good surveying will tend to lighten the
burden of straightening costs. This because it also yields
enlightening data on dry wells and causes of dryness.
Accuracy of Borehole Surveys.—Respecting the accuracy
to be expected in a contract for borehole survey work it
may be mentioned that demands here vary in stringency
with the importance of the survey. Freezing shaft con-
tracts frequently require a minimum limit of reliability
in readings of 1 in 150, 7.e., 1 off the vertical for every 150
deep. Or again they may desire a deflection record not
exceeding 214 deg. off the vertical, since beyond this no
frost wall is safe at depths of over 100 yd. Hence the
desired accuracy decides the type of apparatus being
employed, whether crude methods with unreliable direction
records, like pricking bobs without orientated rod couplings,
or the more precise pendulum and gyroscopic methods which
often yield accurate results up to 1 in 3,000. ‘The purpose
of the boring will therefore, in the end, decide the nature
of the survey apparatus. The purposes for which boreholes
are put down are as follows:
1. To locate a seam, stratum, oil zone, salt or any other
mineral.
1 Mourpny P. C., and Jupson, 8S. A., Bull. Amer. Assoc. Petroleum Geol.
Vol. 14, p. 603, May, 1930.
INSTRUMENTAL SURVEY OF BOREHOLES 51
2. To obtain the thickness, depth and constitution of
such deposits.
3. For shaft sites.
4. For conducting electric cables (Fig. 22), steam and
compressed air pipes, also haulage ropes to the mine.
Connection Wooden Reel
to Pole Line 7-07 which Cable
y was shipped
: hell ?
Several turns of
Wire around Reel,
Timbers
supporting
REQRSES
Casing of .
Borehole 4. ile
(a) Wooden Clamp holding
two strands of Cable
Cb)
Fig. 22.
5. For hydraulic stowing.
6. For utilizing any hydraulic head which peculiar geo-
logical conditions may provide in old workings (Fig. 23).
E/.+800'
Fig. 23.—Ideal cross section of a synclinal basin.
7. To aid ventilation by draining off gases.
8. For circulating tubes when sinking by the freezing
process.
9. For cementation.
10. For checking any other boreholes.
52 DEEP BOREHOLE SURVEYS AND PROBLEMS
This last item of check is probably the most important
aspect of accuracy. If possible the method being adopted
should be checked later by methods dependent on a
totally different operating principle. Then the results
-—
i
!
Derrick Floor
Plan View of an O11 Well
Comparing Results of Several Surveys
Dernickinas
Floor \y!
Derrick--5
Simultaneously"
on One String
of Drill hipe
Fie. 24.—Plan of an oil well comparing Fig. 25.
results of several surveys made under
varied conditions. (After Macready.)
could be compared graphically as in Fig. 24 (after R. P.
McLaughlin)'. Failing this a check survey should be made
in and out of the borehole as in Fig. 25.2 The manner of
compiling a check will be seen from Table VIII, wherein
1 By the courtesy of Bull. Amer. Assoc. Petroleum Geol. (Vol. 14, No. 5,
p. 586, 1930).
2 Ibid., p. 588.
INSTRUMENTAL SURVEY OF BOREHOLES 53
the old and tried method of acid etching is compared with
a recent plunger-pricker method for amount of dip only.!
TasBLteE VIII.— Comparative SURVEYS OF AN O1L BOREHOLE IN THE
SEMINOLE District, OKLAHOMA
Depth, | Driftmeter reading, | Acid-bottle reading,
feet degrees degrees, corrected
252 0 0
499 2 0
748 1 4
1,005 4 1%
1,257 10 124
1,360 10
Te 5l2 17% 19146
1,758 Ie 19144
2,002 24 28
2,094 28
2,268 28 3216
2,502 3416 3814
2,745 38 3916
3,009 4016 4116
3,255 39 4016
However, these checks are relative and cannot be claimed
as absolute; the only absolute checks are actual observa-
tional ones as
1. Where a hole is followed by a shaft or drift.
2. Where a hole has been bored between known and
occupied places, as between stopes, working seams, etc.
3. Where boreholes deviate and meet; all methods thus
registering the same meeting spot in both holes.
1 Petroleum Engineer, December, 1929.
CHAPTER IV
CORE ORIENTATION
Introductory Note.—This branch of instrumental survey
in boreholes being the older of the two main divisions
previously noted, we will deal with it first. It has not been
so extensively employed as the other department of bore-
hole surveying dealing with the course of the borehole
proper. Among the chief factors not already discussed
which either influence the relative positions of boring tool
and strata pierced or provide useful evidence of the same,
we may mention the following, of which a running record
should be kept.?
1. The type, size, and dimensions of bit used.
2. The size of drill stem.
3. The size and depth of the hole.
4, Weight of mud used.
5. Pressure employed on the bit.
6. Speed of rotation or number of strokes per minute.
7. The stroke or fall in percussive boring.
8. The weight on the tool in percussive boring.
9. Rate of water circulation.
10. Ease of running in and coming out with drill stem.
11. Ease of setting the casing.
The various orientation methods can be nearly all
grouped into the four following classes:
a. Orientating the core barrel by measuring or aligning
the drill pipe out of the hole.
b. Attaching an instrument to the core or core box in
the hole during operation previous to extraction.
1 See also a useful questionnaire by F. H. Lahee for the Research Com-
mittee of the American Association of Petroleum Geologists, Bull. Amer.
Assoc. Petroleum Geol., July, 1929, for notes on checking observations, etc.
54
CORE ORIENTATION 59
c. Lowering an instrument on to a freshly cut core and
then extracting it with or without the core.
d. Photographic devices for the walls of the hole.
Kind’s Method.—Kind’s core drill is the earliest form
known, having been employed in coal strata near Forbach
in Lorraine in 1844! using a free-fall percussion drill
(Rotary core drilling was first adopted in 1861 by the French
engineer Leschot).
Kind also made the first core orientation. The method
has long been superseded and information thereon is
Fie. 26.—Kind’s borer. Fie. 27.—Kind’s core breaker.
scarce. It was employed in 1854 in Forbach yielding a
half-meter core which was brought to bank in as unaltered
a condition and position as possible.
Figure 26 shows Kind’s fork-shaped borer which provided
the thin core 12 to 20 in. long and was then extracted. A
core breaker a (Fig. 27) was lowered to tear off and lift
out the core b; this breaker had a toothed inner cylinder c
keeping the teeth d forced out during insertion and sus-
pended by a cord from the surface. To prevent turning
he employed two index arms held against the rods, one by
a man in the derrick near the top of the drill rod and the
other at the derrick floor. These arms aligned the pipe
against twist. The method yielded cores of only about half
1RepMayngE, R. A. S., ‘‘Modern Practice in Mining,’”’ Vol. 1, p. 91.
Macreapy, G. A., Bull. Amer. Assoc. Petroleum Geol., Vol. 14, 1930.
Korsricu, A., Pr. Zeitschrift, Vol. 36, p. 256, 1888.
56 DEEP BOREHOLE SURVEYS AND PROBLEMS
the width of the hole, and diamond drilling with its small
holes later on made it obsolete. A similar method was also
applied by the engineer Zobel in Schénebeck in 1855.1
Lubisch’s Method.—The boring master Lubisch improv-
ed on Kind’s method in the Upper Silesian mineral fields
in 1887. He diamond drilled a core first without a core
catcher, leaving the stub standing in the hole. Then he
lowered a second tube (Fig. 28) over the stub and marked
it in a definite manner respecting the meridian and later
extracted it, orientating it as in Kind’s method. It
suited small holes better. In Fig. 29 the steel tooth of the
orientating tube closes about the core and makes a definite
i
SS
|
ii
SS
SRAAANE
SSS
=
Fies. 28 anp 29.—Lubisch’s core Fic. 30.—Vivian’s pilot-hole core
marker. compass.
mark which was expected to have a definite known surface
orientation. After lifting out this marker device a core
extractor was let down to bring out the scribed core. Now
the scribed longitudinal mark is adjusted to the vertical
plane by means of a spring pen hanging on the rods and the
dip and strike read. Lubisch improved his apparatus
later by adding a cap carrying a steel scriber which gave a
mark at right angles to the side mark, and he also improved
the joints to prevent twisting on insertion and extraction.
Lubisch’s advantage over Kind was in the more rigid
hollow rods and the possibility of working in smaller bore-
holes. For success the following demands, difficult and
nearly impossible to attain altogether in practice, are to be
fulfilled:
1 Mitt. Markscheiderwesen, Heft 4, p. 37, 1902.
CORE ORIENTATION 57
1. There must be no mud or cavings between the core
and borehole walls.
2. The core must be sufficiently rigid so as not to fracture
on extraction and to preserve the markings.
The changing of the rods, etc., make condition 1 very
difficult, since we then interfere with the rinsing. In
very hard rocks condition 2 might be impossible, owing
to lack of clarity in the marking. In soft rocks this latter
condition is impossible. These methods, it will be seen,
take up much time and are not now in operation.
Vivian’s Method.—The method of the American diamond
driller, Vivian,! marked a new departure and significant
advance in core orientation. He drilled a small pilot hole
of a few inches diameter and lowered a small instrument
case into it, so that a part of it was fixed in the pilot hole.
This case held a compass needle clamped by a weight used
in setting the case. When the core was recovered the case
was also recovered attached to its upper end. Figure 30
shows the compass c and its arresting apparatus a and the
tap neck 6 in the pilot hole d. The needle, free at first,
is fixed by letting down the weight. This was all retrieved
later in the normal method of core catching. Above-
ground the needle is freed and the core turned to give the
position before arrest. The core now is in the same posi-
tion as in the hole, and so its dip and strike can be obtained.
The demerits are
1. The apparatus is almost, if not quite, impossible of
use under a big head of water pressure.
2. Cavings filling the pilot hole as when concussion occurs
during coring, rupture of the core and mud.
3. In small holes the pilot hole thins the core itself to a
too fragile degree, the wall thickness in diamond boring
needing to be at least 12 to 18 mm. and in addition we must
consider the play on both sides.
4. A compass can not be set vertically true in a small
core.
1Trans. N. E. Inst. Min. Eng., p. 45, 1881-1882.
58 DEEP BOREHOLE SURVEYS AND PROBLEMS
5. Great loss of time in boring pilot hole, exchanging rods
and extracting cores.
Vivian’s method has had very little usage owing to the
small probability of success.
Kendall’s Apparatus.—This apparatus was invented by
P. F. Kendall at Owen’s College, Manchester, in 1887,
and it was arranged to be set in a pilot hole like the Vivian
method, but the compass in the case was clamped by
lifting off the weight of the setting tool. A core was then
taken out with the compass attached to the top of it. The
magnetic compass is attached by means of a peg or cement
to the top of the core and left standing by the boring tool,
Cc b
———"
Fic. 31.—Kendall’s apparatus.
and the needle is automatically locked by the release of a
spring when the lowering tool is withdrawn. In Fig. 31
is Shown the compass box a with its strong screwed-on lid
b, and inner glass lid c held by a screw collar. The pillar
d bears the compass card e while f is a tube sliding on d
flanged and serrated at the top. About this is a spiral
spring 7 pressing the flange upward for its toothed edge to
grip the compass card e against the glass lid c. A slot and
pin on d prevent rotation of the tube. The catch lever g
holds down f by the flange when the apparatus is set; it
turns on pin g’ on the box floor. The floor trigger h
hinged to g has a flange and spiral spring h’ for operating the
catch lever and permitting f to grip the card bearing the
needle. An India-rubber ring under the card aids the teeth
CORE ORIENTATION 59
grip, preventing sliding. In action the lowering tool holds
trigger h out. At the core and after sufficient time has
elapsed and the needle has come to rest, the lowering tool on
being withdrawn releases the trigger h, throwing the catch g,
allowing f to ascend and lift the card off its bearing, pressing
it against the glass lid c.
_ The core is now wrenched off and lifted to bank and on
unscrewing lid 6 the orientation of the core is read. The
weaknesses of the apparatus are the
same as those of Vivian’s apparatus;
chiefly insufficient protection against
water pressures which is more necessary
here, since there are more moving parts.
\
\
NY
SSNS
SSANS
ANS
“
WSS
YN
WANN
y
SS
~
NSA SSS
NAAN
SS
NSS AASS
AAS
\
NANNY
~‘
SS
SANA
SA
Zl
The drawbacks of space demands in the Gy
core and trouble in the measuring Ve,
method have not been removed any 77277]
more than in Vivian’s method. Again G4
ANNANNANNAANN NANSANNS ANS SNS SS SSS SN
there is the liability of premature dis-
turbance of the needle due to shocks as
in wrenching off the core. ‘There appear
to be as little data in professional
literature respecting its actual employ- GNIS
ment as in the case of Vivian’s apparatus. S327.
Wolff’s Apparatus.—This device was
invented. in 1889,1 and marked the
introduction of a new feature. In this
method the apparatus was lowered
over a stub of core in the hole and
a mold taken. Clockwork was used to clamp a
magnetic needle after a predetermined time. The core
was then removed and orientated from the clamped
needle attached to it. Figure 32 shows Dr. Wolff’s method
for fixing the compass in a mold or cast, the latter being a
plastic material. The apparatus consists of a two-part
tube A,A., with a lead filling B, which serves to guide and
hold tight the lower plastic mass giving the imprint of the
1 See German Patent, 47, 221, Oct. 27, 1888; also Osterr. Z. Berg-Huittenw.,
Nos. 41-43, 1906.
wea
oe
rrr
ZZ
7,
ANAN
ww
N
NSS 4 44447
NSS
meee 49 OTT
ee
NAS ANS (77
Fig. 32.—Wolf’s core-
cast device.
60 DEEP BOREHOLE SURVEYS AND PROBLEMS
core below. Between A; and A» is a compass box C of
non-magnetic material with a compass D and a clockwork
mechanism FE screwed on tight, which has been set to
operate at a predetermined time. The plastic mass having
been lowered over the core stub and allowed to harden,
and the needle arrested, the apparatus is raised and the
position noted. The core is now lengthened by the usual
coring process, wrenched off and raised to bank. Here it is
fitted to the impression in the cast and turned with the com-
pass until the needle plays in the position previously noted.
The dip and strike can now be read.
The method appears theoretically to be well suited to its
purpose and it has the advantage of increased protection
for the compass and clockwork mechanism, and also the
time taken in insertion and employment is shorter than in
previous methods. However, its success depends on many
factors which preclude its adoption in general practice.
Thus we have the following disadvantages:
1. Mud and cavings prevent good impressions.
2. A flat upper fracture on the core surface is more suited
to the process than inclined ones, because very inclined
wrench faces prevent good impressions.
3. On inclined core faces tube A, is likely to slip and ren-
der results faulty.
4. The core must be solid and fast; this is not possible
in shales, schists, ete.
5. On fitting the mold aboveground the core must have
been raised in exactly the same position as it had when the
mold was taken, and this is almost impossible.
6. The minimum size of core is 5 to 6 cm., otherwise the
impression is not clearly recognizable.
7. Even with all the above conditions fulfilled, taking
the mold, lengthening the stub, wrenching it off and raising
it occupies too much time.
Koebrich’s Apparatus.—In this method the position
of the compass with respect to the core is ascertained
by means of a clearly cut mark on the top face of the core
with the aid of the apparatus shown in Figs. 1 to 6 (Plate
CORE ORIENTATION 61
III). In Fig. 1 (Plate III) note that the cross-guided heavy
rod a is connected to the straight bit chisel a; by means of a
conical joint. The bit has a small recess X on one side.
Over the heavy rod the gun-metal body K is fixed by a
conical Oynhausen joint bb’ (Fig. 2). The bored-out non-
magnetic box K encloses a watertight ground-in stopper
fant
|
1
SSSSNSy
SSUS SSS
H
aE oe!
4 el
H ULE_4
Aho
4
i
14
=
UZZZLLLLLLLL LLL
nq Un
pein Ny
(Be q
SS a DDT DEE,
i LOLLY Ly GHEE NS ae aca Str laa T NN ||
Cie
oe a S210) ow a
NO MUCLARTTMULLELILLILLITLILTTLLUY YS ff ff I PPTMSSUTLLLLLLELLTOLELDLESSSTTSSELEET ED
ASSASSA ASSESSES SENS STS TEESE SSS SHES STH TTS SSS TTT GSAS SSE SST SSSR SSSA DSTO NMI.
The internal construction of the
apparatus is much simpler and the arrest of the needle
i +
oO. S 5) a
———— Sy Wy
SS STILE KES
G2 Gen a Ls VL ED
eS
nS ise 1 58 6 5
sy Se Eider
RN ITI
AAANUARRRRRAAANY — ED, TL, yoo YLALUY SS OOH
LS
SSSR SMA SEG LLLLLL LD
oO Zz
for in Meine’s apparatus.
Fig. 37.—The North German Deep
Fic. 36.—Thurmann’s stratameter.
Boring Co.’s stratameter.
occurs much sharper than in Meine’s device, because the
transmission of the arresting action takes place by means of
only two pieces of mechanism and not by means of a series
of intermediate members.
The North German Deep Boring Company’s Strata-
meter.—The North German Deep Boring Company of
Nordhausen have produced a device of the stratameter
72 DEEP BOREHOLE SURVEYS AND PROBLEMS
type but somewhat different in construction.' In Fig. 37
the tube R, lies inside a wide tube R2 (moved by the rods
with nuts and spring) and carries in its upper part the closed
compass box B filled with oil. The rinsing current escapes
by way of the holes O, O, in the head of the core tube A:.
When a determination is being made the external tube is’
lifted up so far that these openings are covered by the
internal projections V of the external tube. In this way
an excess pressure of water is set up which actuates a spring-
loaded piston k a little further up through the bores n,n.
This causes the rod S to free the needle which was hitherto
fixed. After the needle has settled down, the external
tube is lifted higher and when the water holes O, O are
passed by V, they are again free and the piston k is unloaded.
Then the spring F again comes into operation and the needle
is fixed orientated. It can now be drawn further so that
the core, broken off by the core breaker on the external
tube, can be raised to bank.
The apparatus is in many ways similar to that of Meine
or Gothan in principle and construction, but the needle
is freed by the rinsing water pressure by moving the tubes
relative to one another. The needle is also brought to rest
inasimilar way. There are two advantages in these varia-
tions over the other methods. First, there is a slight saving
of time in that the needle does not follow the turning
movement of the rods but after adjustment can rotate with
them and swing back before coming to rest. Second,
there is the by no means small advantage that the needle
is always ready for measurement and cannot be thrown off
through unavoidable thrusts on the pin. Unintentional
freeing of the needle is absolutely impossible, since the
rinsing current is suited as long as the wider openings O, O
are free and should a throttling of the passage through
O, O occur the piston & will soon be influenced. Such a
throttling, however, cannot occur if the outer tube is
raised.
1German Patent No. 168,596; also Osterr. Z. Berg-Hiittenw., No. 48, p.
561, 1906.
CORE ORIENTATION 73
The instrument can also be so constructed that the needle
is not freed by the relative displacement of the two tubes
R, and R, but by an improved water lead in which a valve
is closed under the pressure of a spring. The valve spring
is so adjusted that the valve stays open with the normal
rinsing current and will only shut on an increase in the speed
of the rinsing pump.
The same objections apply in the main here as to the
apparatus of Gothan with respect to core fractures, etc.
Lapp’s Device.—This simple apparatus was invented in
1906 by Heinrich Lapp of the well-known firm of deep
borers in Ascherleben, Germany. The simple principle
shown in Figs. 38, and 39 has been adopted since in numer-
ous devices. Figure 38 shows a longitudinal section’ of
this core orientator with two horizontal sections below.
It consists of a cylinder a of suitable dimensions made in
two halves, the lower one fitting over the core in the hole.
Under the magnetic needle b, which is borne on a spring
spindle bearing c, is a plate d of soft material. The needle
has a lower side pricker e. Above the needle on a rod 2
is a plunger f carried through a shear pin h and having a
ring buffer g at its bottom end.
On the rods being lowered and the bottom of the cylinder
fitting over the core stub, the plunger f descends by its own
weight, or by the rod action, and buffer g presses the needle
down, making an imprint of e in the soft plate d and holding
the needle in its position of rest. The shearing pin h
prevents any turning and the lug & with the peg k’ in the
housing a serves for correctly adjusting the housing in the
core tube.
The device suffers from the usual defects of this type
of apparatus, 2.¢., cavings, poor cores in friable strata,
turning shocks, etc. Compare Hillmer’s deviation and
dip measuring apparatus made by the same firm and dealt
with later on.
Koerner’s Core Orientation Apparatus.—This apparatus
was invented in 1907 by a German engineer, G. Koerner,
1 German Patent No. 171,849, May 25, 1906.
74 DEEP BOREHOLE SURVEYS AND PROBLEMS
of Nordhausen. It is essentially a double-gimbaled pendu-
lum apparatus. It is screwed to the upper part of the core
box and carries indicating needles which are fixed in posi-
O
Q
6,
—
4
4
4g
Hy:
/
Y
j
Yy-
Ne
jee
x
SENN
SSSSSS
ZZZZZE
N
N |
\I
N |
N fd §
\ ee S
Fies. 38 and 39.—Lapp’s core Fie. 40.—Koerner’s core orientating
orientator. apparatus.
tion by dropping in a weight and releasing a fixing device
which forces pointers into a cork disc. Like his deviation
device, it shows the dip in amount better than direction,
the latter being obtained by computation. The pipe drill
and core barrel are orientated out of the well by measuring
each stand. Figure 40 shows the apparatus for aligning
CORE ORIENTATION 75
the cores on the surface. To the upper portion of the core
box a screwed to the boring rods 6 is secured a plate holding
a pipe c, which leaves a space between it and the walls of
the core box for rinsing water. In the center of ¢ are oscil-
lating needles d and e supported on their respective gimbals
or universal suspensions f and g. Gimbals g are weighted
on one side by weight h, causing e to incline. Above d
and below e are cork pistons 7 moved by springs 7 toward
the needle points of d and e. The cork disc 7 is held by rod
k allowing d to oscillate freely and carries an arm lever |
rotatable about the long axis of the apparatus, the lower
end of this lever holding another arm m by means of rod c
to actuate the lower cork plunger 7.
Under the top plunger 7 is a gunlock trigger-releasing
device actuated by rod n operating springs j7 which press
the cork pistons 7 against the points of pendulum needles d
and e. Needle d is used for indicating the dip of the bore-
hole and e for the lateral deviation due to the action of
weight h. ‘To facilitate this the cork discs 7 are faced with
paper scales on which the needle points prick holes. As
electric cables can not be introduced into
the hole during boring, the positions of
the indicating needles are fixed by a
messenger weight dropped in releasing the
above device from n. The movement
relative to the meridian is taken with
respect to a mark made on the core
box.
In core boring the needles are fixed before wrenching
off the core; then the core is extracted and the core box
arranged on the surface in such a manner that it is slightly
inclined and a definite mark arranged on the meridian.
The cork pistons 7 are withdrawn and the needles released,
taking up a position in accordance with the inclination
of the core box. After the needles come to rest pistons 2
are again released, and the new position of the needles, in
which the scale of the apparatus coincides with the merid-
ian, is recorded. Thus, as shown in 40a, we get the points
Fic. 40a.
76 DEEP BOREHOLE SURVEYS AND PROBLEMS
a and b obtained underground to take up the new positions
a’ and 6’ on the surface. In both cases the parallelogram
of displacement gives the direction in which weights h have
dipped plumb needle e; which directions are shown by lines
oc and oc’, and, since the line is in the meridian, angle coc’
will be the rotation of the apparatus on extracting the core
box. If the core is turned with its mark from points c to c’
it will have its proper geographical position aboveground as
below. A pendulum may be used instead of the plumb line.
The chief objections to the appliance are:
1. Dropped messenger weights are unreliable.
2. In the mud rotary system the apparatus may fail to
function.
3. Much time is taken up in surface orientation.
4. Many unaccountable turning movements are not
provided for.
The apparatus, particularly in respect to the methods of
aligning the geographical positions above and below ground,
has been subjected to severe criticism by Dr. Freise' and
the engineer, Erlinghagen.?
Rapoport’s Method.—The idea of this device* is one
embodying the former notion of a mold, as in Wolff’s
apparatus. It is very ingenious and though apparently
unsuited to the conditions of actual practice, in its present
form, contains the germ of an idea which may be useful to
investigators and inventors. We have failed to trace any
literature dealing with its application in the field, but
believe it should not be disregarded.
Figure 41 shows the apparatus which consists of a
cylinder a, let down into the borehole and having an axial
channel 6 to which an upper conductor c can be joined for
compressed air or pressure water. Underneath, channel 6
is closed by a valve d which opens an exit channel e on excess
of internal pressure. The hollow body a possesses four
borings f at 90 deg. to one another radially in superposi-
1 Organ des Verein der Bohrtechniker, 1907.
* Gliickauf, p. 737, June 15, 1907.
3’ German Patent No. 172,179.
CORE ORIENTATION 77
tional planes. In each of these, under the pressure of a
spring, is a movable piston g on rods h carrying on their
exterior ends hinged movable porcelain heads k. If the
rod is moved outward by internal pressure these heads
take a mold of the borehole walls. A compass n whose
needle m is arrestable by the lever o actuated by the spring
p is used for taking the strata strike. There is a piston con-
nected to o which, as a result of the pressure of spring p, can
Fig. 41.—Rapoport’s device.
close a duct leading to the channel 6. The piston is pressed
up when a means of pressure appears in 6 and the needle is
freed to take up its position. If before raising the appa-
ratus out of the hole the pressure channel is closed, the
piston g goes in first and then q is brought by the spring
p to the original position, thus again locking the needle.
Obviously very hard strata, and very friable strata too,
make the application of the device, in its present form,
useless; but, as said, we present the apparatus for its possi-
ble use under suitable modifications.
Florin’s Method.—This ingenious apparatus was in-
vented by a chemist, Jean Florin, of Brussels in 19081 and
1Fiorin, J., Enregistrer l’orientation des strates au fond des trous de
sondage, Annales des mines de Belgique, Tome 13, p. 781, 1908.
78 DEEP BOREHOLE SURVEYS AND PROBLEMS
consists of a photographic device with a lead block base.
The apparatus was lowered over the core which had been
previously marked by the trepan and the lead block took
an impression of the core head while the needle inside was
photographically checked by special appliances.
In Fig. 42 it will be seen that no clockwork or other
complicated mechanism is required, the strong, pressure-
proof box holding very little movable apparatus. This box
Fig. 42.—Florin’s camera device.
is filled with water and inside suspended by rubber rings
is a simple photographic apparatus a. Below this is a
magnetic needle b, a phosphorescent disc ¢ and an inter-
changeable lead base d.
Staggered holes with gratings allow water to penetrate
to the interior in such a way as to counteract pressure
effects while preventing foreign bodies from entering.
Starting at the top we have the photographic apparatus
in the non-metallic box in which is a small round and rigid
celluloid film covered with an emulsion of silver bromide
in gelatine, very sensitive to light and obtainable at any
CORE ORIENTATION 79
chemist’s. This film is placed exactly so as to receive the
image of the needle b and guide marks on the phosphorescent
disc c below it. The very luminous objective has an
aperture of f.3 and focal length of about 40 mm. and is
specially corrected for the refractive index of water; the
distance from the film is constant. In front of the objec-
tive is a small shutter plate h which opens only on pressure
being applied, on a rod projecting externally, when the
apparatus meets the core. The magnetic needle 6 is freely
suspended uncontrolled by any mechanism and is swung so
as to function even when the apparatus is tilted. Behind
it is the thin copper disc c covered with a substance insoluble
in water and containing calcium sulphide. (This is very
phosphorescent when properly made in the way employed
for this device.) It has the property of great luminous
emission. Black guide lines have been traced on the disc.
A small distance from the above parts is a plate of phos-
phor bronze sufficiently thick and strong in which are four
holes of different diameters. These holes serve as guiding
points and enable one to ascertain whether the lead plate
has been displaced during the manipulation of the appara-
tus. Other guiding points enable the bronze plate to be
set; also all the rest of the movable parts of the device.
Against the plate is a lead plate for taking the core impres-
sion on its outside and the impression of the holes on its
upper face.
For action the disc is taken out and made very phos-
phorescent by burning before the surface of the sulphide a few
centimeters of magnesium ribbon; this strongly excites the
phosphorescence so that the disc remains luminous enough
to enable one to read a watch in the dark for 4 or 5 hr.
This is then screwed back in and the lead plate put on and
the shutter closed. Now in a dark chamber the sensitive
film is fixed and the apparatus filled with water and closed
up, the water being as near as possible in temperature
to that in the borehole, avoiding air bubbles. This does
not affect the action of the apparatus at all. The instru-
ment is now ready to lower into the hole.
80 DEEP BOREHOLE SURVEYS AND PROBLEMS
First a trepan is sent down to mark the core head with a
blow and then raised to allow the apparatus to enter.
The lead plate d on the base outside takes an impress
of the core face with its mark. At the same time the lever
coming into contact with the core uncovers the objective.
After a few seconds the needle is at rest and overexposure
of 20 to 30 min. allowed. The image of the needle and the
guide points is thus fixed on the sensitive plate. The device
is now raised, an interior spring closing the shutter. At
the surface the lead plate shows the core-face impress with
trepan mark on the lower side and the impression of the four
holes on the other. The film, when developed, shows the
position of the needle and the guiding marks on the phos-
phorescent disc. Thus the core is orientated and later
coring is completed and the core compared.
The instrument is robust, the lenses of the objective being
completely isolated in the middle of it and being of great
thickness are strong enough for the job. It is only nec-
essary to clean the device carefully after use, the whole
of the parts, except the needle, being of copper alloy.
If the borehole water is too hot for normal gelatine the
film should be plunged into a bath of 5 per cent formalde-
hyde solution; this makes the gelatine insoluble and capable
of resisting decay without impairing the sensitiveness
of the film or the development of the image, which is done
by a slow process. The phosphorescent plate is designed
to do away with electric lamps with accumulators which ~
are not suitable for shocks.
The factors operating against the device are the great
consumption of time in letting in the trepan to mark the core
and its extraction, etc. Cavings also affect the marking
and friable strata prevent its employment. If there is no
orientating coupling it suffers all the defects of any other
apparatus, giving directions aligned on its own markings.
Goodman’s Core Orientation and Borehole Deflection
Apparatus.—This device was invented by Professor Good-
man of Leeds University in 1908 and can be employed
both for orientating cores and surveying borehole devia-
CORE ORIENTATION 81
tions. It consists essentially of a tube which can be
fitted over the core stub, the tube containing a hemispheri-
cal pendulum and clockwork arresting device adjustable to
a predetermined instant.'
In Fig. 43 the hollow cylinder 6 is shown in the borehole
a, its prolonged lower part being capable of fitting over the
core stub with a scratching tooth of steel or diamond for
Fic. 43.—Goodman’s apparatus.
scribing the same. The hollow pendulum c bearing on
pivot d on the circular base e is graduated externally on its
rim c, and has an agate bearing 7 for the pivot. The cone
ends in a short screwed stem g, and a magnet h rests on it.
The hemispherical screwed cap nut k holds stem g, securing
the needle h to the top of the cone c. The base plate e is
borne on a flange of cylinder b and is framed to the upper
clockwork base plate / by pillars m. On top of nut k a small
plunger n is provided axially central passing through the
1See also British Patent No. 23,003, Apr. 29, 1909.
82 DEEP BOREHOLE SURVEYS AND PROBLEMS
upper base plate 1. Its lower end mn; is enlarged and
hollowed round to make an all-round contact on the
hemispherical cap k. A helical spring o about n presses
under 7 and against n. The upper end of n passes up
through lever p which is hinged at g and has a cross pin at
r to facilitate disengagement of n from k. On releasing p
the spring o pushes plunger n down on to cap nut f, fixing
the cone and needle in position. This release is provided
by the clockwork in frame s by means of flexible wire or
cord t, from the alarm spindle uw. After winding up, the
alarm is set at any chosen instant for release and in this
state is lowered into the borehole. When release occurs
tis unwound from u, freeing spring o and pushing n down,
thus fixing the cone and magnet in the position in which
they have come to rest. The hermetical seal is completed
by means of the cap piece w. Other mechanical or electrical
means for release may be adopted.
The magnet is secured so that its center line les in the
central plane of the cone passing through the 0 to 180-deg.
mark. i. - “Depth of Reefalon q ;
hae: Oe Cause of Borehole | '
Bottom of Hole ~ ~
’ \ 1 ' 4765 Estimated
0) 500 1000 1500 [emtriar noce
—_——SS SSS |ve tically below
Mouth of Borehole
Fic. 80.
Mollmann’s Apparatus.—This device,! invented in Dort-
mund in 1904, is an improvement on previous pendulum
or plumb-bob apparatuses in that the vertical position
1 German Patent No. 155,849, Oct. 22, 1904.
132 DEEP BOREHOLE SURVEYS AND PROBLEMS
of the plumb is taken from a pendulum swinging in a definite
rotatable plane with the aid of a vernier and scale on a
graduated circular segment. In this way errors in obtain-
ing the position of the apparatus are either eliminated
entirely or essentially lessened. Figures 1 to 4 (Plate VII)
show the interior of Méllmann’s apparatus. Through the
center of the covers 6 and 0b; of housing a (Fig. 1) go two
screws c and c; bearing a rotatable fork d. Below cover b
is a plate f with an attachment e against the one side of
which presses a spring g in a groove (Fig. 4), and this
presses the portion e against a rod h. This rod h can be
worked up and down by clockwork from the wheel 2’
on its prolonged screwed axis k. According to the lft
of the rod h a lug n under disc f engages, through the bore
m of disc f, a disc p held by spring pressure. Between the
dises f and p there is a plate g which is bridged to the fork
d and can move it up and down in a slit. The plate q
and its bridge is borne on the upper part of the fork under
a constant spring pressure by rod r which at its lower end
lies on the nose y which is likewise spring-pressed against
lever h;. The latter is connected by lever s; to the disc ¢
(seen in end view in Fig. 2) which is displaceable laterally
in the fork d and coated with felt H on one side. On
the same axis as disc ¢ is the upper end wu of the indicator
z which is widened here and toothed. The lower end of z
carries a millimeter or circular graduated vernier while the
primary scale v for this is on the fork d.
A side weight consisting of little tubes of mercury w is
attached under fork d, the purpose of which is to turn the
fork and indicator z at every inclined position of the
borehole.
Above the apparatus a clockwork is placed which fixes
a magnetic needle k’ on one side and can turn toothed wheel
z’ with spindle & on the other side. This turning screws
up rod h turning spring g so far that it brings the bore m
over the lug n above the spring pressed plate p. The attach-
ment n can now enter bore m of disc f, raising plate q and
fixing it between f and p. This fixes the fork on the one
COMPASS AND PLUMB-BOB METHODS 133
|
EY,
==)
Lt
NGNNANN
PN
SN al |= |I
Yfy IISSS
S&S
vA
OW Miiiz EE
——————
PAY | AR
NSW ENR
Ny
KS
FiG.3
Puate VII.—Méllmann’s deviation apparatus.
134 DEEP BOREHOLE SURVEYS AND PROBLEMS
hand, and on the other hand, by the simultaneous raising
of the bar r attached to q, the nose y of lever h; is liberated.
This is drawn away by the pressure of a spring action on
the head of lever s’ and the felt-faced disc ¢ is thus pressed
against the widened part u of the indicator z. In this way
it is brought to rest and permits of a direct reading when
the whole is brought to the surface.
Though the device of Méllmann constitutes a progressive
step in the science of borehole surveying it is intermittent
in action. Owing to the pendulum being only allowed to
swing in the plane normal to the fork beams it rapidly
comes to rest, hardly 8 to 10 sec. being needed. It is also
very easily read by the ordinary boring personnel. The
accuracy of the scale readings is read in 20-min. ares for
10 deg. being thus far superior to previous devices; but even
this accuracy is unnecessarily high owing to its being
greater than that of the compass. This apparatus is
accurate, rapid, reliable and sure in action but unfortunately
it is unreliable in respect to orientation of the deviation.
Bawden’s Apparatus.—This device, invented in Kalgoor-
lie, West Australia, in 1905 by Wm. R. Bawden, contains
many features which are to be seen in Gallacher’s apparatus
of 13 years later.
The inner tube A (Fig. 81) has head joint covers k and k,;
with counterweight sectors g, g: on the loaded axial pivots
which support the tube A. Tube A is attached by further
attachments to the counterbalance sectors g, gi. The mag-
netic needle n is likewise enclosed by a loaded spherical
housing d and by means of Cardan suspensions all round
is thus so mobile that its pin always stands vertical. The
spherical housing d has an opening for filling with fluid
gelatine and is closed from above by a screw cover and
hardwood plate.
For obtaining the dip of the hole two pendulums p, and
2 are provided and are rotatable with graduated ares e and
f on metal plates. On both sides of the plates are reading
glasses. The tube A is connected to the plate by a bow.
Before using the apparatus the pendulum housing and
COMPASS AND PLUMB-BOB METHODS 135
compass housing are completely filled with warmed gela-
tine and then adjusted into tube A which is filled with hot
water to keep the gelatine fluid. Before reading, the latter
is again taken out. The protection tube A’ is screwed over
tube A and the apparatus sent into the hole. The counter-
balance sectors always permit a rotation of the internal
Fies. 81 and 82.—Bawden’s apparatus.
tube in such a manner that the pendulum can always play
free. On the gelatine solidifying the pendulum and the
needle are fixed in their positions of rest and these are read
aboveground.
The apparatus of Bawden utilizes the principle of Mac-
George’s device as also does that of Cross,! which latter
therefore need not be mentioned here. The Bawden
1 Denny, C., ‘‘Diamond Drilling,” pp. 76 et seg., Crosby Lockwood.
136 DEEP BOREHOLE SURVEYS AND PROBLEMS
apparatus does not escape all the defects of MacGeorge’s
apparatus but it is more convenient to handle and more
robust. Its great disadvantage is that its action is not
continuous up and down the hole, it having to be extracted
for every reading.
Hillmer’s Apparatus.'—Hillmer also adopted the prin-
ciple of a plumb-bob point let down on to a prepared base,
as shown in Fig. 88. The cylindrical housing a (Fig. 83) is
filled with a fluid and is let down on hollow
rods into the borehole. It consists of a fluid-
filled cylinder a with a pendulum P sup-
ported on ball bearings in such a way that it
will also maintain its upright position when the
housing is inclined. Above the point S of
the pendulum is a soft plate G which can-
not turn and bears a spring F in such a way
that it keeps off the pendulum point. On
the upper surface of the plate, freely swing-
ing on a point, is a magnetic needle N which
has an attachment A pointing downward.
A piston K is provided over the needle in the
housing the rod of which is carried through a
central opening in the housing top and carries
on its top enda piston K;. There is a spring
F, between the latter and the top of the hous-
ing which by its pressure keeps piston K
in the highest position. In using the device proceed as
follows: After having lowered the apparatus to the spot to
be measured, and both pendulum and needle have come
to rest, a means of pressure (water, compressed air, or the
like) is conducted through the hollow rods on to piston Ki.
This presses down K and plate G. The attachment A
on the magnetic needle and the point S of the pendulum
now bore into the soft plate and both are thus fixed. After
raising the apparatus to bank, the position of the two marks
can be used to get the inclination of the borehole.
Idiel, fq
1F REISE, F., ‘‘Stratameters and Borehole Dip Measurers,” p. 53, Aix-la-
Chapelle, 1906.
COMPASS AND PLUMB-BOB METHODS 137
The device is certainly simple and ready for use at any
time without delay or special preparation, and it is suited
to manipulation by the ordinary boring personnel. Of its
drawbacks we may mention:
1. The pressing down of the plate; the needle and pendu-
lum point might be injured by this but it might be regulated
by controlling the piston pressure.
2. The waste of time brought about by letting hollow
rods into the hole.
3. It has no special centering device and it must be
exactly centered. At great depths unbalanced rod loads
upset instruments not specially centered.
Dr. Freise of Aachen speaks of the apparatus being
shrouded in trade secrecy, a feature that unfortunately does
not apply to this apparatus alone.
Gallacher’s Apparatus.—This apparatus was invented in
Johannesburg in 1918 and possesses features of remarkable
ingenuity and mechanical skill. It is designed to survey
both the deviation from the vertical and from the azimuth,
these to be read direct from the instrument on withdrawal,
without surface calculations. We enter into some detail
respecting it here because it appears to have lacked the
necessary publicity such a device merits.
It consists of an outer casing a (Fig. 3, Plate VIII) with
an inner casing b longitudinally pivoted in it by means of an
adjustable footstep bearing in the bottom end c.
The inner casing (Figs. 1 to 2a, Plate VIII) carries the
controlling and recording elements in the form of clock-
work, plumb bob (in the shape of a weighted cylinder) and
compass, and spring device for controlling the clockwork
and fixing the plumb bob and compass at any desired spot.
This inner casing is suitably cut away and windowed oppo-
site its weighted side.
Figure 1 shows the inner casing at the clockwork d end;
Fig. 1a shows the other end of the inner casing carrying the
cylindrical plumb bob e, compass f and the clamping device
g for both.
138 DEEP BOREHOLE SURVEYS AND PROBLEMS
Figure 2 is a view of Fig. 1 turned on its long axis 90 deg.
with cover on.
Figure 2a is a view of Fig. la turned on its long axis 90
deg. partly in section and partly in elevation with cover on.
Figure 4 is an enlarged view of the plumb bob controlling
and clamping device g in the inner casing and the compass
set free with it, Fig. 5 being a sectional view of Fig. 4 on
line vz. It is possible to have three operative positions
of the fixing and clamping arrangements for the plumb bob
and compass, 2.€.,
a. Compass needle fixed from independent movement
with its compass case and plumb bob free to move about
their pivots.
b. Compass needle and plumb bob both free with com-
pass case held against movement on its pivot.
c. Compass needle and plumb bob both fixed with com-
pass case free to move on its pivot.
Figure 6 shows Fig. 4 when condition c above is obeyed.
Figure 7 shows an enlarged view of the inner casing with
compass f and that part of the clamping device which
directly operates it. Figure 8 shows a cross section of the
inner casing with compass and compass-clamping device.
In the assembled view (Fig. 3) the upper pivot h and
bearing are of non-magnetic material, like phosphor bronze,
as also are the nearest rod connections. In small holes the
apparatus is placed on the end of the drill rods; in large
ones it is let down by a flexible wire. Both inner case b
and outer case a are cast in brass or other non-magnetic
metal. The inner case is suitably weighted to cause it to
turn on the end pivots, bringing the registration device
under the inspection cover windows. The weighting means
are the lower and heavier portions of the controlling and
recording elements and the base plates, their centers of
gravity lying below the center line of the end pivots and
opposite the inspection covers. The clockwork control
2 (Fig. 1), near the pivot end, consists of a lever escape-
ment, a train of wheels j, and their cooperating pinions k
and main spring barrell. The clock itself dis provided with
139
COMPASS AND PLUMB-BOB METHODS
‘snqeiedde s 1oyoey[eg— IIIA ALVIg
>
Ulla UND,
f Ae’
WELZ LLL.
ify
Yy
vem:
iEewane
140 DEEP BOREHOLE SURVEYS AND PROBLEMS
independent setting and adjusting mechanism shown at
m (Fig. 2); its dial n can be graduated to represent any
number of hours, preferably a number not much exceeding
the maximum time of its employment. The clock is, as
said, controlled automatically and capable of wide and
varied adjustment.
The plumb bob e (Figs. 1a, 2a) is a loaded pivoted cylinder
with peripheral graduations for about 110 deg. and it
oscillates in consonance with any variations in the inclina-
tion of the inner and outer casingsa and b. Its graduations
can be read through a casing cover glass o (Fig. 2a), which
carries a zero mark. The spring-operated means for
clamping this plumb bob are the clamping levers p,p, which,
when in action, bear on the plumb bob, retaining it in the
position it assumes at the point to be surveyed. This
clamping of the bob takes place through the cam plate q
(Figs. la, 2a,4,6). This clamping device permits of adjust-
ment of the plumb bob and compass at any of the three
positions a to c above.
Between the plumb bob e and the bottom pivot in the
inner casing 6 is the other recording element, the compass
f (Figs. la, 2a, 8). Its box is pivoted at right angles to the
casing end pivots. Its clamping device is the bell-crank
lever s engaging cam plate g. This lever projects to hold a
spring ¢ actuating the releasing and retaining lever u
keeping lever s engaged in cam plate q and thus, by further
leverage, engaging the compass box e about and below.
The compass box is suitably borne and loose bushed for
leverage clamping by means of springs working in grooves
from the levers, as seen in Figs. 7 and 8. Cam plate gq is
fixed in its position by a pin v before insertion into the
borehole and on its removal allows the necessary initial
engagements to be made. In the position shown in Figs.
la, 2a, and 4, cam q and its cooperating parts are set by pin
v. The clock is now set so that after a predetermined time
the end of releasing lever u will be engaged. ‘This releases
lever u, the plumb bob and compass being both free (Fig. 8)
with the compass needle clamped by a spring x. In this
COMPASS AND PLUMB-BOB METHODS 141
position the whole of the recording elements (plumb bob
and compass) remain until the point to be surveyed in the
hole is reached. In due course a pin y engages with the
end of lever u (Fig. 1) until finally cam gq engages pin z in
the position shown in Fig. 4. This is the position of the
clamping device after the apparatus has arrived at the
survey point in the hole and sufficient time has elapsed for
the compass box to come to rest. Here the compass box is
clamped with needle and plumb bob free on their pivots.
Further movement of lever u disengages a projection or
tooth giving the position shown in Fig. 6. The ensuing
movement of cam qg actuates levers clamping the plumb bob
e and, simultaneously by levers and connecting rods, releas-
ing the compass box and clamping the needle by spring x
as already said. It is clamped in the magnetic north so
that the free compass box gives us the direction of deviation
of the borehole directly; and the graduations on the plumb
bob relative to the zero indicator on the cover plate give the
amount of dip, also directly.
It will thus be seen that this instrument enables the data
to be clamped or released after insertion and also gives
control over the recording elements. The clock can be set
at will independent of its mainspring and both compass
and plumb bob can also be reset at will. All readings are
direct with no additional surface computations and each
element is fully controlled.
Objections which can be raised against this apparatus are
a. The mechanism is too complicated and refined for
small holes.
b. Readings are not continuous down the hole, each
point requiring extraction and reading at surface.
c. Liability to mechanical complications.
d. Compass unreliable in magnetic strata and lined holes.
The Briggs Clinophone.—This is a plumb bob or pendu-
lum device with aural electrical registration applying the
Wheatstone bridge principle and is employed in precision
surveys of boreholes. That is to say, it is used where
deviations of more than 1 in 150 are not permissible, as in
142 DEEP BOREHOLE SURVEYS AND PROBLEMS
some deep freezing shafts. Here contracts frequently
stipulate a survey capable of registering a deviation of 1
in 200 or 1 off the vertical in every 200 deep. The normal
range of this device is about 2 deg. from the vertical.
It makes and maintains claims to simplicity, cheapness,
lightness, rapidity and ability to survey narrow deep holes,
giving a continuous record of amount and direction of dip.
It was successfully employed at Seaham Colliery Sinkings.
We are indebted to Professor Briggs for the following details
and personal notes.
The Transmitter and Receiver.—The transmitter is hung
in the hole on the rods and the receiver is situated near the
mouth of the hole, the two electrically connected with a
flexible five-strand cable.
T\77
SN
L?
SZ
Fie. 84.—Clinophone receiver.
The transmitter! has a plumb B (Plate IX) hung on a
‘‘G”’ violin string A connected to needle H through the
wire wrapping of the string. The needle dips into a solu-
tion (NaSO,) F in the vulcanite cup H# which has four
platinum foil electrodes eyez, es and ew, 90 deg. apart (Fig.
8, Plate IX) each reaching to the cup base. These connect
respectively to the rods Dy,Dz,Ds; and Dy insulated from
1 See also Brypon, A. D., Trans. Inst. Min. Engr., Vol. 71, p. 431; Brices,
H., Proc. Roy. Soc., Vol. 46, p. 223, Edinburgh, 1926.
143
COMPASS AND PLUMB-BOB METHODS
Leather Washer
| Sweated Joints
Rings V andZ
D
o
res
Clamping Plug
f Sectional Elevation
Hal
Klingerite
flasher
“We
Ring R
Rings K andL
te)
2
[res
Square.
Vertical Section on b
b
Fic. 1
Pirate [X.—Briggs’ clinophone transmitter.
144 DEEP BOREHOLE SURVEYS AND PROBLEMS
the outer case and having terminals ty,tz,t; and tw (Figs. 1,
2). A fifth terminal ¢ is connected to line A and therefore
H. The strands c are led to the five terminals. The
cable C goes out to the surface outside the rods. Cup E
can be inserted in only one position and is replaced by a
wooden clamping plug when not in use. A tail piece is
hung 30 ft. below the transmitter to aid centering. Figure
84 shows the receiver connections which are in a wooden
box 11 by10by7in. The cell bis an ordinary pocket torch,
4-volt refill, hence the claim to cheapness, and J is a small
induction coil, its secondary connected to condenser C, for
clearing the telephone note. The five strands of the cable
are attached to terminals 7y,7x,7's,T7w and T (the last is
the plummet strand, the others the above mentioned ty,
ty,ts and tw of Figs. 1 and 2, Plate IX) and from there to the
respective electrodes of the transmitter cup. Needle a
is held by the operator and loose flexed to the dish EH,
which holds salt solution (say, NaSO,) and has four plati-
num electrodes e’x, e’n, e's, e’w. It has a glass floor with a
dial scale the concentric circles of which are minutes of are
and the radial lines 5-deg. bearing each. The operator
wears a low-resistance headphone R, one receiver of which
is coupled to the terminals 1 and 2, giving NS deflections,
the other to 3 and 4, giving EW deflections. The rods have
a special orientating coupling by external scribing in relation
to the vulcanite cup L.!
It will be seen from the wiring diagram (Fig. 85) that the
wiring system involves two applications of the Wheatstone
bridge connections to the liquid resistances of the earphone
indicators. Needle a is moved about the receiving dish
base until the noise in both earphones is a minimum, when
a occupies the same position in the dish as plummet needle
H (Plate IX) in the transmitting cup, and this is read on
the cup base dial. The receiver connections are reversed,
as in Fig. 85, because H will occupy a position diametrically
opposite to the hole dip. The bob must be at rest in the
hole to get a clear minimum sound and it takes about 10
1 Brypon, A. D., op. cit., p. 437.
COMPASS AND PLUMB-BOB METHODS 145
min. to come to rest. The needle position is illustrated in
Fig. 86 and is seen to be at the intersection of two equipo-
tential lines the dotted circle being the actual range of the
plummet needle which is thus the reading needle range.
Differing connections, of course, vary the mesh of equi-
potentials, and a connection suited to a person with uneven
zh SCENE
Ww Dish “Ez
Fic. 86.—Equipotential lines in receiv-
ing-dish. First arrangement.
SS
Transmitting ¥
Dish Tee
‘es
Fig. 85.—Clinophone wiring diagram. Fic. 87.—Equipotential lines in receiv-
ing-dish. Third arrangement.
hearing is found by short-circuiting the electrodes in adja-
cent pairs and coupling an earphone between the pair using
the good ear only. Such an arrangement (Fig. 87) will
give a locus of minimum noise points as a straight line.
Short-circuiting on another cardinal point electrode we get
another minimum noise line. The intersection of these two
loci can be easily and exactly fixed and is the point sought;
now read off its dip and bearing in the dish scale. The
average reading error of an observation is about 5 min. of
arc with an 1814-in. plumb bob, and this may be reduced by
carrying a longer plumb line or by having a check reader
and alternative connections.
146 DEEP BOREHOLE SURVEYS AND PROBLEMS
The instrument we have had the advantage of examining
was suited to a 4-in. borehole and was about 35 lb. in weight,
40 in. long and had 5¢-in. walls. It is efficient and
certainly cheap and convenient and has been tested for an
external pressure of 600 Ib. per square inch.
Kegel’s Apparatus.—This is an ingenious floating
plunger plumb-bob device invented by the mining engineer
Karl Kegel of Freiberg in Saxony in 1919! and capable
of many alternate constructional rearrangements and
modifications.
It gives the apparatus at the place being surveyed a
definite direction from which it cannot deviate. In Fig.
1 (Plate X) the heavy rod 6b or chisel c or both are attached
to the main rods a as also are guide devices d and plumbing
medium e. The action of the last named will be seen
from sections EF and CD, it being premised that other
constructions of plumb and connecting tubes will attain
the same end. The plumb g here floats in the plumbing
fluid h and has a bottom plunger carried through the guide
iso that as a result of the buoyancy it always floats upright
over the guide hole. The upper plunger of plumb g pro-
jects through three contacts j, k and | and lies against a
particular contact should there be any borehole dip. The
guide casing recess belonging to the particular contact
concerned has its own electric motor and current supply.
There are thus three of these, one for each of 7, k and l.
The motion of any one motor is transmitted by a worm and
worm wheel m on spindle n. The wheel and spindle are
connected by spring and groove in such a way that the
spindle may move axially through the wheel. The spindle
passes through the fixed nut o on the housing or casing d
and is displaced according to how it is rotated. With
similar rotation any two given motors will turn back
accordingly and so displace their spindles backwards.
Thus the spindles act as centering screws. On being let
into the hole the three motors with special supply current
may be so switched in as to draw in their spindles and
1 German Patent No. 317,663.
COMPASS AND PLUMB-BOB METHODS 147
reverse again when the survey spot in the hole has been
reached, thus pressing them out against the borehole walls.
The worm wheels thus move back on the spindles and press
back the contact springs p interrupting the direct-current
supply so that only the current to the plumb g and contacts
j, k andl remains. The motors can be set in action at any
PLATE X.—Kegel’s apparatus.
time by means of another current supply from outside;
thus the centering may be actuated at will. Instead of
the plumb g and its connections, a gyroscope or direction
indicator (magnetic needle) may be employed which will
maintain a definite horizontal direction by the action
of an electric motor or plummet, giving thus not only the
amount of dip but its direction also. For example,
the plumb g can be held to a definite orientation by a
gyroscope and the upper plunger rod of the plumb can
give a definite dip. By varying the dip and bearing of
this plunger the direction of the attached boring tool can
148 DEEP BOREHOLE SURVEYS AND PROBLEMS
be altered to give any desired curvature of borehole. We
may get the centering motion without the worm wheel
gearing in other ways, ¢.g., by wedges displaced forward or
backward. Likewise in place of the electric motor other
power can be employed, such as valves operated by the
plumb or a gyroscope. The direction apparatus can be
fixed solid or detachable on the rods.
The greatest demerits of the device are that it is inter-
mittent in action and there is no device to prevent turning
on insertion or extraction.
Maillard’s Apparatus.—This simple and cheap device!
consists chiefly of a simple plumb-bob electrical contact
apparatus. Figures 88 and 89 show a longitudinal section
of the apparatus which is a series of hermetically sealed
hollow rods a connected to a body 6, which has a play
of about 4 mm. in the hole lining A. The body 6 has
external guide springs c for centering. In the upper
part of b is a circular ebony membrane d with an opening
f. Below the membrane d is a conical recess. A cable g
passes through f and holds a brass plumb bob h of cylindrical
shape with a spherical end. This latter rounded part of
the bob is the only part allowed to make contact with the
slanting sides of the recess; it is rounded to lessen friction
on being moved up or down. Cable g is an insulated
electric wire passing through the hollow rods a.
It will be seen from Fig. 89 that the complete electric
circuit is by way of the source j at the surface, through the
cable g, the plumb h, the borehole casing A, the galva-
nometer & and back to the source j.
When taking a measurement the apparatus is let down
into the hole, which is already provided with casing A,
by means of the hollow rods a, successively screwed up
at the surface in the normal way, to the desired spot to be
surveyed. The partial turns of the tube a which may be
called a1, a2 . . . a, are related to a fixed starting direction
1Pechelbronn Société anonyme d’exploitations miniéres et Georges
Maillard. French Patent July 27, 1925. German Patent No. 492,573,
Mar. 4, 19380.
COMPASS AND PLUMB-BOB METHODS 149
such as the true north. The angular displacements of the
apparatus in the hole are found thus: When plumb / is in
last contact (7.e., the last touching position before disen-
gagement) with the sloping side of b, we are at the limiting
position at which the circuit is closed and the galvanometer
Fig. 89.
deflects. By slowly hauling up the plumb bob we can find
this spot, for, after it, the contact is interrupted and the
needle of the galvanometer adjusts itself back to zero.
We thus know the length of the plumb line hanging in 6
from f, because we know the amount hauled out to make
last contact. Thus it will be seen that any angular posi-
tions a1, a2... a, given by the apparatus correspond to
certain critical lengths l,, 1, . . . 1, of the cable g. These
150 DEEP BOREHOLE SURVEYS AND PROBLEMS
can be plotted for maximum, ax, ly and minimum an,
l, values of angular devia-
tions and lengths.
In Fig. 90 we have an
easy way of getting the
borehole inclination 7 at the
depth concerned. Con-
struct the triangle xyz in
which the angle xyz and
the side xy are known from
construction and the side xz
is also known, being equal to
the maximum length ly,
above (previously obtained
by raising and lowering h
and plotting; to this add the
length of the plumb bob).
The angle sought is zzy = 90
deg. — i. Repeat this pro-
cedure from place to place to
get the amount and direction
of dip, the latter being more
satisfactorily obtained by
taking three such readings at
120 deg. apart in azimuth at
Fic. 90.
SSS
I,-V. Batter
Z(10 Used)”
Flexible
Battery Wire
SLT TSS SCS SSCS SSCS CSCC OCSC SSO OCS
ree
4
-Retracting
Spring
SSS SS
PPP LLL LLL Le
5
Universal
/ Bearing
a aa eo
BS)
S555
ra
N
SS
-Electromagnet
SSS
Plumb Bob
SSS
SSS aa
SSSSSS55
Plunger
Controlled
by Magnet
3 5
9. 0 DILL TTT TALLER
2 LILI ILLIA RII SS
oF er a
ASS
==!
i
i
i
“il Paper Disk
Cork Disk
Tapered
Steel Nose
Fig. 91.—The driftmeter.
each given spot and making a graphic or tabular check.
COMPASS AND PLUMB-BOB METHODS 151
It would be difficult to imagine a simpler device and it has
recently been protected in Germany. We may visualize
the following possible defects:
1. The angular positions aj, a2, etc., being dependent on
the inner rods are not free from objections.
2. Friction of the cable at the membrane and hindrance
to the same should pressure water and mud penetrate the
many joints.
3. The device may become cumbersome in deep holes.
4. The borehole must be lined all the way.
The Driftmeter.—This is a recently developed American
apparatus! being a pricking plumb-bob device. The instru-
ment (Fig. 91) is about 31¢ ft. long and weighs about 30
Ib. and is suited for rope lowering with a depth-measuring
appliance or it may be fitted to the rods. The principal
parts are the clock, the ten 114-volt batteries, the leaden
plumb bob fixed on a solenoid or electromagnet and the
magnet-controlled pricker plunger passing
through a universal bearing which has a
mobile suspension. Under the pricker is
a 23¢-in. registering paper (Fig. 92) divided
into 15 circles of 1 deg. each and is thus
suitable for filing. Space is provided on the
back of this paper disc to record depth, well F's. 92-—Drift-
number and other data. In this way deflec- Se ee
tion angles are found direct to about 15 min., no preliminary
work being necessary, the instrument being ready for use
as soon as a new paper disc is fitted and the clockwork set.
The clock can be adjusted to a definite time; then by the
contact brush making connection with the battery and
magnet the plunger is set into action perforating the paper
disc. A retracting spring keeps the plunger off the paper
when the current is shut off. The resulting reading is
direct and needs no computation. The same sheet can be
repeatedly used by marking each perforation as made, so
getting a series of indications of the deviation. Since it
requires no special skill the ordinary boring personnel can
1 The Driftmeter Co., Inc., Tulsa, Oklahoma.
152 DEEP BOREHOLE SURVEYS AND PROBLEMS
use it, thus giving a constant cheap control on the progress.
The plunger being made of a non-magnetic alloy or lead
eliminates any chance disturbing magnetic influences. It
can be made in sizes as low as 1.9 in. for running inside 4-
in. drill pipe. Its greatest disadvantage is that it is inter-
mittent in its action, having to be hauled out after each
record, the clock being reset and, if necessary, the paper
dise changed.
CHAPTER VII
PENDULUM METHODS
Introductory Note.—The physical features of the pendu-
lum which are essentially those of the plummet have been
among the great attractions of physicists for the last 300
years. The outstanding features marking the discoveries
of Newton, Foucault and Kater are all incorporatedin
modern borehole survey instruments of this class.
Our reason for distinguishing this suite of apparatuses
from the compass and plumb bob section is that generally
the plumb bob is used as a dropping pricker, a plunger
pricker, a balanced vertical bar, or in some other way not
fully utilizing its oscillatory properties. This is not a rigid
statement, since many compass devices also apply the
swinging bob.
The pendulum proper is being understood when we con-
sider the elliptic or circular paths of a hanging bob or rigid-
limbed pendulum. It has the outstanding advantage of
independence of the magnetic north or the constitution of
its surroundings, working and obeying its astronomical
north-seeking faculty as well in magnetically disturbed
regions as without them. Its possibilities are evidenced by
the success of submarine and aerial navigation, since
gyrocompass action is an adaptation of the pendulum
principle.
Koerner’s Apparatus for Measuring Deviation.—This
device, which is essentially a spring pendulum apparatus,
was invented in 1906 by G. Koerner, an engineer of Nord-
hausen, Prussia, the suspension of the plumb line or pendu-
lum being altered by mechanical means and the oblique
positions of the same recorded photographically.
In Fig. 93 the tube a is kept to the hole center by the
feeler spring wheels b pressing on the sides of the borehole.
153
154 DEEP BOREHOLE SURVEYS AND PROBLEMS
The central plate c holds a frame d carrying a graduated
glass plate e. A rotatable spindle f in the center of these
\=
1
hy
5355555 AAS
ZA
SSS SSS
SSS
r
SS55559 5) a
WA,
SS
SSS SSS
os Se ee
1
es
Vi
Sassy
LZZLZLLZZZZ
SSS ty eo
WLLL,
Fig. 93.
plates c and e carries a plumb line g on an arm A, and also
a graduated index 7 slotted to take the plumb line. In
the bottom of the tube are four electric incandescent
PENDULUM METHODS 155
lamps 7 for illuminating the glass plate e, the index 7 and the
plumb line g. There is also here a camera k and a rolling
film n driven by clockwork / and electrically controlled
by the cable line m. The frame d and glass plate e and
the plumb line g can be placed at an angle in the tube a
by means of the spring o on rod p and spring q bearing on
plate c.
The staple r is arranged to carry a lowering rope. If the
apparatus is suspended by rod p the frame and springs will
occupy the positions shown bold in Fig. 93, the springs
being compressed and the rod f being parallel to the walls.
If, however, the apparatus is suspended from the staple r
the springs are released to the dotted position of Fig. 93,
forcing the frame to the inclined position.
To make a reading the appliance is suspended by rod p
with two external points on its casing in the meridian.
Then plumb line g takes the position of the dip, and so the
position of the dip of the borehole orifice is found. This
position is photographed from below. Suspend the appli-
ance on the staple r without turning and bring the plumb
line spindle f into the inclined position. The plumb line
g now assumes a position which is determined by the dip
of the borehole and the inclined position of
the axis f in accordance with the parallelo-
gram of displacements. The film n is
advanced by electrically releasing the
clockwork 1; the lamps 7 are again switched _
in and the new position of the plumb line or
recorded photographically. By compar-
ing the two readings a diagram of the type
shown in Fig. 94 is obtained, from which the deviation
is found. The extent of the dip is calculated from the
amount of deflection of the plumb line from the center of
the scale on e and 7 and from the length of the plumb line
itself. The distance of the bottom of the plumb line is
read on a special scale on 1.
The objections to the apparatus are as follows:
1. Double suspension is liable to introduce turning errors.
Fie. 94.
156 DEEP BOREHOLE SURVEYS AND PROBLEMS
2. There is no guarantee of continued alignment of the
meridian indexes.
3. The feeler centering springs are liable to error and they
also preclude the adoption of this method
in very narrow boreholes.
4, Springs are objectionable in boreholes
holding water under high pressure.
5. The apparatus becomes too involved
if attempts are made to obtain continuous
readings.
Erlinghagen’s Apparatus.—This appa-
ratus introduced a significant change in
the construction of deviation instruments.
It is a pendulum apparatus with electrically
operated registration mechanism. It con-
sists essentially of an electromagnet
operated pendulum and a clockwork-driven
recording paper strip in which the pendulum
pointpricks a set of definitely arranged
marks. The clockwork is also released
simultaneously with the pendulum by
means of drawbars.
Provided the apparatus keeps from turn-
ing on being let down the hole, it is a very
suitable apparatus and Chief Engineer
Erlinghagen of Nordhausen, the inventor,
tried various devices to attain this end.
He first employed a longitudinal slit g down
Fic. 95.—Erling- the apparatus c (Fig. 95) with the rope a
EC eae held in the slit. This was not entirely
satisfactory. Later he employed telescopic
lenses held by counterspring nuts in the apparatus, as in
Figs. 96 and 97, which solved the difficulty.
Figure 96, left, shows the entire apparatus assembled
ready for insertion in the hole with the lenses collapsed.
Figure 96, right, shows the device in the extended condi-
tion. Only electric current is used for the determination
apparatus. The tubes can be let out by loosening a brake
i
A
,
t
t
Y
)
i
157
PENDULUM METHODS
an)
i]
O
Cc
2
G
CY)
WY
ae
<
S
32
oS
(S)
tb)
(Up)
Figs. 96 and 97.—Erlinghagen’s new apparatus.
158 DEEP BOREHOLE SURVEYS AND PROBLEMS
f which actuates two drums on which a thin wire rope h
to the head of the lower tube is wound. For closing the
lenses up again spiral springs on the drums coil up the wire
automatically. On the top end of each tube is a headpiece
Side View Section C-D
Ty yd
th
>
(hs
SSS
SSS 7
OLLI
RAL,
CLIO
OTT.
Ga:
YG)
Suction Ele Al Sechoniaee
Fie. 98.—Centering device. Fie. 99.—Erlinghagen’s electromagnet.
X in which the measuring apparatus (Fig. 97) is guided by
the thin ropes h exactly on the center line of the tubes or
lenses. ‘The lower spiral spring 7 and the levers k& serve to
hold the lowest lens of the telescope exactly in the middle
of the borehole when in the extended condition. It will
be seen that in small diameter boreholes the brake loosening
device and telescope lenses would be inadvisable owing to
PENDULUM METHODS 159
the thickness of the lenses themselves (which is at least
60 mm. inside width for high water pressures and 130 mm.
outside). Therefore a new form of fixing device for
simultaneous centering was adopted by Erlinghagen in 1906
in cooperation with Professor Klingenberg of the General
Electric Company in Berlin, as shown in Figs. 98 and 100.
The borehole magnet was made by having an I-shaped
bronze frame, between the webs of which on each end a n-
shaped iron was placed enveloped by a magnetic coil.
The legs of the iron were beveled (Fig. 99) corresponding to
the internal diameter of the borehole. The coils have to be
absolutely watertight. The coil was wound with enameled
wire and the bearing spots repeatedly insulated from one
another and the whole placed in a zinc case and waxed up.
The neck has a soldered bridge through which the winding
wire is carried well insulated. The construction has been
tested for hours under a pressure of 9 atm.
Figure 98 shows the centering device where we have three
link-arm borne steel rolls pressed outward together by a
strong central steel spring, from which it swings down to
the bottom of the apparatus in fixed links. Above, it is
movable up and down by a linked ring and a movable
center bolt. There are three of these centering devices,
one to center the upper magnet, another the lower magnet
and the other to hold the measuring apparatus properly in
the middle. The measuring apparatus (Fig. 100) has a
powerful frame of three steel rings connected by two longi-
tudinal ribs having, in the upper part, a glass encased clock-
work. Under this a roll paper 50 mm. wide winds from roll
r, over the cork-lined plate p on to roll rz with uniform veloc-
ity, only roll r. being clockwork driven. As the angular
velocity of the clock is always the same, that of the paper
increases the more paper is wound on to rz giving a uni-
formly accelerating motion. To control the time points
of the measurements the paper must move uniformly and
this is done by means of the string drive s on roll rz which
has a slipping arrangement. Under the paper strip moves
the point of the universally suspended spring pendulum.
160 DEEP BOREHOLE SURVEYS AND PROBLEMS
moe
Wee eeope wanes ||| __E ars
aos 7 r ji
|
Zale TN
1
n
iS
Fig. 100.—Erlinghagen’s measuring apparatus.
PENDULUM METHODS 161
The pendulum, being very sensitive to shocks and taking
about 20 min. to subside, has a hair brush damping device
h which brings it to its position of rest in about 45 sec.
For working the measuring apparatus a horseshoe magnet
m on the floor of the apparatus is switched in so that con-
nection is made by way of the bearing plate e which is
attracted downward. Plate e is connected by drawbars to
the clockwork. The weight of the clockwork is taken by
springs f so that the magnet has very little force to over-
come. The point of the pendulum sticks up into the paper
strip when measuring, and at the same time four points ¢,
arranged in the center ring and which lie on concentric
circles on the periphery of the guard tube, mark four points
on the paper strip, by which we are able to recognize the
center point of the measuring figure at that instant.
The conductor wire for the magnet coils goes along one
of the long drawbars to a clamp for current rod u. The
head here is specially sealed against entry of water under
high pressure, thus preserving the clockwork and magnet.
This is done by means of opposed nuts c and copper
rods *& on floor 6 bushed to the insulating plate J and slip
rings d,d. ;
The direction line of the paper may be noted on the out-
side of the tube with the whole apparatus above it, so that
on letting it into the hole one knows how it stands. The
conductor and lowering rope are all in one, the conductor
being insulated with cement, bitumen and tape.
The inventor gives details! of surveys carried out with
the apparatus, which did not turn on extraction or insertion,
and these facts were checked by an investigation in a blind
shaft between two levels belonging to the German Solvey
Works in Bernburg. The results of two surveys at Solvey-
hall with the apparatus and a later normal instrumental
survey check are to be seen in Fig. 101. A series of 160-
mm. tubes were arranged for the apparatus test; the normal
survey shows a constant survey traverse distance from the
apparatus survey. Erlinghagen’s apparatus marked a new
1 Gliickauf, p. 748, June 15, 1907.
162 DEEP BOREHOLE SURVEYS AND PROBLEMS
epoch in the evolution of borehole deflection apparatus;
it was the impetus to many later designs and constructions.
It conquered the continuous record problem, if however
crudely, successfully. We may mark from its inception
the rapid evolution of new methods which began in the
first decade of this century. Its chief drawbacks are:
1. It is costly and complicated to make.
2. It is heavy though easy to manipulate.
3. Its mechanism and tubes limit the diameters for which
it can be adopted.
Normal Tre rrumental Garvey
Fig. 101.—Checked survey by Erlinghagen’s method.
4. Pin-pricking devices are crude and likely to cause
confusion in reading.
5. Moisture is likely to injure the apparatus and cable.
Thurmann’s Apparatus.—This apparatus is built on the
proportionality principle, the basis of the lead-basket
plumbing method, but it greatly extends the limits of
applicability of that principle.
H. Thurmann, Sr., of Halle obtained reliable results
with his apparatus, which is a double plumb bob and linked-
tube device, at fair depths. The invention! (Figs. 1 to 9,
Plate XI) consists of straight tubes joined by special cruci-
form joints movable in all side directions but not rotatable.
1 Organ des Verein der Bohrtechniker, No. 17, p. 190, 1909.
163
PENDULUM METHODS
Hrs 0 mca OAT i
1G.
Mo
OT
_——————
——<—=VS
164 DEEP BOREHOLE SURVEYS AND PROBLEMS
An apparatus ¢ is arranged in each link tube 71,72, ete., and
called a ‘‘pot head,’ owing to its first being made pot
shaped. On the floor of this head rests a cork-lined base
m, (Fig. 5) covered with tin foil and having impressed coor-
dinate axes. A tong-shaped device s above the head has
one fixed z and one spring-moved limb s (Fig. 2) which
carries the plumb weights 1. From the latter in each head
or top there is a pair of common threads or wires; this
common wire is laid over the transom d carried by the
tongs. In the base of the little trestle of the tongs is an
adjusting piece n between set screws 0 with two fine holes
for guiding the plummet fibers. This permits of a hair
adjustment of the plummet points exactly perpendicular
over the zero of the coordinate axes arranged under the
head on a perfectly horizontal plate.
The gudgeons of the cross joints f of the link tubes lie at
right angles to one another in their crossing vertical planes.
The coordinate axes of the marked plate and of the tin-foil
plate have definitely arranged and assured symmetrical
positions on the whole of the plumbing heads. Thus in
each tube of the linked series we have a separate measuring
operation assured independent of its neighbor. It does not
matter if the break points between two tubes do not lie on
the axis of the borehole, because the preceding and succeed-
ing errors compensate for each other. In horizontal pro-
jection we then have a simple figure of the deviation of
each tube. The metal plumb bobs are not affected by
water, chemicals, pressures or mud, thus combating some
of the objections to Erlinghagen’s and Haussmann’s appa-
ratuses. The fundamental idea of the apparatus will be
clearly seen by considering two equally swinging pendulums
side by side, especially when they have a small difference in
length. In each apparatus are two plumb bobs on a com-
mon string. The string is led over the transom, and when
let down in a dipping tube the plummets mark parallel
lines on the cross axes at a corresponding distance from the
position of rest. Should the line be at any instant at greater
or less distance than the normal case provides, an oblique
PENDULUM METHODS 165
line will be shown. A graduated sight on the uppermost
link is used for orientating in the vertical against the coor-
dinate axes. Thus the plumb line can be viewed at any time
and a new marking plate can also be put in at any time.
In this way any doubtful measurements can be recognized
at once and remedied at any time, an advantage which did
not hold for the predecessors of this apparatus. In previous
instruments a series of measurements below each other
necessitated separate readings and extractions for each, or
separate depth readings at each place with all the attendant
trouble and waste of time. Again errors increase with the
depth.
This apparatus can be arranged in lengths to suit the hole.
For a 240-m. hole, say, Thurmann would not employ sixty
4-m. tubes but ten or at most twenty tubes respectively
24 or 12m.long. There is a special plumb for each section
of hole surveyed so that any errors cannot be cumulative.
Moreover, each error can be corrected, as said above.
Therefore it is only necessary to correctly orientate the
whole apparatus from the surface down, and to aid this
direction rods (Fig. 9) are used. These are a series of tubes
equal in length to the link tubes and having tooth and
notched ends connected by overscrewed thimble joints
to prevent them rotating. The above noted diopter is
adjusted to the direction rods on exactly the same line
as is chosen for the uppermost plumbing section of the link
tube. In this way the coordinate axes of the marking
planes lie sectionally in exactly uniform orientation for
plumbing.
Freezing shafts are best plumbed from the center by this
device, the center being the coordinate axes center.
The inventor claimed that the method was cheaper than
its predecessors for freezing shafts and also surer; that it
was unaffected by water, mud, chemicals or pressures and
that it was direct and easily controlled. Among its
demerits we may mention:
1. There is insufficient provision against relative turning
of the tubes; this spoils the deduced results.
166 DEEP BOREHOLE SURVEYS AND PROBLEMS
2. It is heavy and cumbersome and thus not suited for
great depths.
3. It is not easy to manufacture and in some cases, 7.e.,
big deviations, will be difficult to manipulate.
4. It uses up more time than a lighter and simpler
device.
5. It has too many movable parts.
The Denis-Foraky Teleclinograph.—This is a pendulum
apparatus and one of the best known of the modern
precision devices employed in freezing shaft boreholes.?
It is remarkably accurate, being in many cases somewhat
of the order 1 in 3,000.2. The principle is best understood
as follows:
Imagine a cylindrical tube (Fig. 102) of length AO with
a system of rigidly orientated coordinates X Y on one end
when in situ in the hole. Knowing the
coordinates of o’ and the projection of A
on the coordinate plane, we also get the
position of the axis zz’ of the tube which
on a centered plumb is the hole axis also.
Then by making a series of 10-m. interval
observations we can get the borehole trace
in 10-m. stretches projected on the horizon-
y talplane. The freely oscillating pendulum
Px], A will, if given an initial impulse, describe
a surface the trace of which on plane X Y
will be an ellipse with center o’, which is the
vertical projection of A. More correctly,
but differing not sufficiently to affect the results with such
small angles involved, it is the sphere to which the above
plane is a tangent upon which the trace is generated. On
the sphere parallels are traced to the axes XX’ and YY’ at
a distance k and actually occupied by the conducting bars
(reglets) on which the pendulum point contacts every time
it crosses one, closing a circuit with a registering apparatus.
rz
CK ¢A>
Fic. 102.
1 See a full description in Prospectus of Foraky, Société anonyme d’entre-
prise de forage et de foncage, Brussels.
2 ApamM, D., Colliery Engineering, p. 414, Nov. 24, 1924.
PENDULUM METHODS 167
The movement of the point on its elliptical trajectory can be
represented by that of a point moving uniformly on a circle
of the same amplitude (sinusoidal law of the pendulum).
In particular the passages over the bars at a, b, c and d
will synchronize with the points of the same order a’, 0b’,
c’ and d’ on the circle (Fig. 103) and o’p measures on this
figure, y, one of the desired coordinates for finding 22’.
Fig. 103.
This uniform circular synchronous motion is indicated
aboveground by a registering pen in the receiving appara-
tus; an electromagnet records the passages over the bars
by controlling the penholder in the circuit.
Thus we may get the figure 0”, a’’, b’’, c’’, d’”’ (Fig. 103a),
the last four points being the passage points of the pendulum
over the bars. The value of y deduced from the diagram
will then be
o''mk
ne
The same reasoning with another projection following
the other system of bars (reglets) would give from the same
diagram completed by the other four points of contact:'
(11)
gL = = (11a)
The ratio of the recording pen and the transmitting
pendulum is k’’/k. k’’ and k’”’ depend on the values of the
lengths OX and OY, usually different.
1 ForAKy, loc. cit., p. 71.
168 DEEP BOREHOLE SURVEYS AND PROBLEMS
The apparatus itself is in three distinct elements; the
transmitter for the base of the borehole, the surface
receiver connected electrically to the transmitter, and the
lowering rods with orientation couplings.
The transmitter is a strong, pressure-proof, steel tube
with a pendulum, the trajectory grid plate and the electrical
connections inside. The pendulum! (Figs. 104, 104a)
Fie. 104.—The Denis-Foraky tele- Fig. 104a.—The Denis-
clinograph pendulum. Foraky teleclinograph
pendulum.
has a Cardan suspension at A the functions of which are
resolved in an elastic system made up of two crossed springs
(Fig. 105). The system has the property of acting in
such a way that the instantaneous centers of rotation of the
pendulum may be taken as coincident with A. The pendu-
lum is not allowed to swing freely under the force of gravity.
No two similar double systems constitute a suspension
without play or friction, and this method of construction
1Happocx, M. H., ‘‘Location of Mineral Fields,” p. 92, Crosby,
Lockwood & Sons, London.
PENDULUM METHODS 169
equalizes the elasticity constant proper to each of the two
perpendicular axes, making it the same in all directions.
An ingenious mechanism gives the necessary impulse
to the pendulum at each station. For
convenience in reading, the ellipse caused
by the pendulum under this impulse
should be as nearly a circle as possible.
This mechanism consists of a crank on
point P (Fig. 106) capable of being dis-
placed along its vertical axis. It is
brought to its initial angular position by ——S—>
a coiled spring and to its vertical position
by a plate spring. By the action of a
surface-operated electric motor placed above the pendulum
top, a half turn is given to the coil spring and simultane-
ously, by means of a ramp, the crank is
displaced on its vertical axis. P strikes
against a copper dome on the pendulum
and the crank is liberated from the action
of the motor, and under the influence of
the spring it describes an arc aM and rises
back to its former position. Point a, struck
by P, describes a tangential trajectory to
the arc. At the moment of release a is
going along the tangent M and the pendu-
lum has to describe the ellipse of major
axis NN’. If the impulse is suited the
path NWN’ will equal a circle MM’.
Actually in the grating or grid the thin
bars (reglets) or coordinate lines are fine V
grooves cut in the spherical silver grating
rae. OG: plate (Fig. 107). The pendulum point
(Figs. 104 and 108) breaks circuit with
the grating surface at these coordinate lines, the break
being recorded by the electromagnet controlled pen in
the surface receiver. This receiver (Fig. 109) is a
1Loc. cit., pp. 72 et seq. The counterforce of the cross springs in the
suspension is analyzed here with the aid of Fig. 104.
Fie. 105.
170 DEEP BOREHOLE SURVEYS AND PROBLEMS
rotating plate with a paper sheet on which the pen
traces a low-pitch spiral each circuit synchronizing with
the pendulum swing. The pen (Fig. 109) is on the
jointed system consisting of an isochronous regulator
ensuring that the periodicity of the pen circuit is constant
for all positions. The trace of the grating pen is an
enlarged reproduction of the pendulum swinging contact
figure owing to the action of the electromagnet on the pen.
This enables the coordinate axes X X and YY to be drawn.
My
w7
NaN
NEN
NIA
35 Ni iN
MIA
MAS
GZ, KY)
40 40 apis
39 39 | 1b Y
Se eee Ss AIRY
0) Lo ICIS) AY
7h SI \| N
SS
33
Fic. 107. Fig. 108. Fie. 109.
The grooves of Fig. 107 form these axes by causing the
breaks in the circle. The coordinates of the grating center,
with respect to the vertical, are obtained from the diagram ;
thus
= CH
and
GE! = ae ilk
Using a coordinate length of 10 m.
XG/) = ae //l
and since
XC = ie BE! 5. ORC /E (116)
we get for a 10-m. length
XC SHO MORE (11c)
PENDULUM METHODS Niza
x is scaled direct from the diagram using the center as zero
: Me ote 10k
and having the indexes at the divisions + - e and placing
it so that these indexes coincide with the lines y’y’, y’’y’”’
(ig. 110).
Fie. 110.—Actual diagram made by teleclinograph showing method of measuring
deviation by coordinates.
There is a special orientating coupling which allows the
rods to follow the hole curvature but maintain their surface
orientation.2 Figure 111 is a survey by the teleclinograph
checked from shaft records later. It was taken in the No.
8 borehole of the Steaua Romana No. 17 suite of shaft holes
and well illustrates the plan wanderings of a hole. It was
surveyed in 1925 and is discussed by Friedenreich.?
Kinley’s Inclinometer.—This instrument, invented by
M. M. Kinley, the oil-field fire fighter of Tulsa, Oklahoma,
1 After ApAM, D., loc. cit., p. 412. See also Scumipt, F., Trans. Inst. Min.
Eng., Vol. 52; p. 178.
FRIEDENREICH, O. L., Analele Minelor din Romdnia, p. 693, November
1926.
2 FORAKY, op. cit., p. 82.
3 INiGl.> Os WOLs
172 DEEP BOREHOLE SURVEYS AND PROBLEMS
does not render the direction of deviation but the amount
only. It is well suited to rapid, simple and fairly accurate
records for working or completed wells. It is essentially
a pendulum or plumb-bob recording device in a cylindrical
watertight housing. The lower end of this housing is
externally threaded and it is attached to the bit or core
catcher. The original Kinley instrument! was lost in a
Texas company well. Here the recording unit (Fig. 112)
includes a support frame B with an upturned arm on a
20.0 20 40 60 80 100cm.
250
er
TSE
PE IRS
PWS QS
Chplemel?
PLISECLITDNSISLTELLS TD GITI RTOS ED
ae ni
NY
eos
ZT one
184 DEEP BOREHOLE SURVEYS AND PROBLEMS
This method was used to survey a hole in the Heidelberg
district of the Transvaal which ultimately deviated 58
deg. off the vertical, the hole being 6,656 ft. deep. A
special pilot wedge device (Fig. 122) 2 in. in diameter
and 18 in. long with oblique face 6 in. long was first lowered
(wedge face upward) and its being solid on the floor
assured by letting down the rods. Another rod 3 ft. long
screwed at both ends was used to get the wedge position.
This last rod (Fig. 123) had a spiral spring on one end
and a 2-in. cup with a 14-in. diameter brass pin through it
at the other end. This cup was filled with lead which
projected about 1 in. beyond its edge and turned to its
diameter. The end of the rod with the spiral spring was
No
Woes
Noi
yn
Pin | Pin
Prick \ \ Prick !
Bie: 121"
screwed into the instrument base instead of the lower plug.
The top end of the instrument was screwed into a brass
tube 10 ft. long and then again screwed to the ends of the
drill rods. It was then lowered in on to the wedge.
A chisel cuts an impression in the lead, a photograph
being taken of the magnetic needle at the same time.
A disc of lead is sawed off on gaining the surface and the
direction of the wedge calculated. The guide wedge
(Fig. 124) is an exact counterpart of the pilot wedge and
is screwed into the said main deflecting wedge, which is
solid, 2 in. in diameter and 7 ft. long. These wedge
devices are not an essential part of the equipment but are
added because they enable other sections of the reef to be
taken in the same borehole, saving the expense of extra
holes.
PHOTOGRAPHIC METHODS 185
Many successful borehole surveys have been made with
this apparatus and W. Gallacher, the inventor of the
instrument illustrated in Plate VIII, added to the above
ancillary devices various means for obtaining successive
22
NSS Z)
\ SYF
m2
Za LLL
H-eper ©
Up
ne, 12s Fig. 124.
Fic. 122.—Pilot wedge.
Fig. 123.—Payne-Gallwey’s wedge surveying attachment.
Fie. 124.—Guide wedge.
deflections in the same hole. It was also a wedge device.
Mr. Hoffmann! gives several instances of its successful
application. |
10Op. cit., p. 9:
186 DEEP BOREHOLE SURVEYS AND PROBLEMS
Haussmann’s Apparatus.—This apparatus was invented
by Prof. Karl Haussmann at the Technical High School in
Aix la Chapelle in 1907. It is essentially a double magnetic
needle, spirit level and photographic device and has com-
Surface
6160) N60 eee fizon
6030 N40°E~
5900! Nate Z
3100/1
MN NN 2080/Noa"e
f 2600 N55°E
/4850' N50°E
£--\600' N58°E
~..1350' N102°E
Norte: All Bearings
Magnetic
58124/Commencement of Deflection '
6000' 4 ‘
6656°Bo¢tom of Hole
Fie. 125.—Course of a South African drill-hole, vertical and horizontal views.
(After J. I. Hoffmann by permission of the Institution of Mining and Metallurgy,
London.)
manded such respect for a long time on the Continent
that we shall enter into some detail regarding it.
Figure 126 shows the assembled plumbing cylinder with
guide springs and an attachment for the core cather below
and one for the rope or rods above. The conductor cable
runs along the rods and down into the interior of the cylin-
PHOTOGRAPHIC METHODS 187
der. On the right is an accumulator with cells and on the
left, on the tripod, a current switch connected to the accu-
mulator and coupled to the cable reel.
The plumbing cylinder has a non-magnetic casing 40
mm. wide, 10 mm. thick and 750 mm. long and is in three
Fic. 126.—Haussmann’s apparatus assembled.
parts; the lower one for taking the plumbing apparatus,
the middle one the registering apparatus and the upper
one the connection to the electric conductor. At the ends
of the middle section are two corresponding graduated
circles divided into 10-deg. intervals; the two other sections
carry reading marks. The upper mark lies in the plane
of symmetry of the suspension device and the lower one
corresponds with channels in the lower casing in which
188 DEEP BOREHOLE SURVEYS AND PROBLEMS
the plumbing frame with the registering apparatus is
inserted. Thus one can screw up the casing
without nut surfaces and still if needed be Ry
able to read the position of the registering
apparatus against a guide rod.!
The Guide Springs —The longitudinal guides
above and below the cylinder are of steel and
ringed at their ends, the rings being rotat-
able about the plumbing cylinder. The outer
ring can be adjusted up and down it. ‘These
springs (Fig. 127) must act simi-
larly together so that the most
outer points always lie on a f
conical surface through the axis
of the apparatus.
The Inclination Measurer.—
Figure 128 shows the internal
construction of the dip meas-
urer. One of the three bars
forming the frame has a lamp
(4 volts, 0.45 amp.) with a
reflecting parabolic mirror 6
res 12 below, 1b (Big, 128). lheusident™
conductor wires leading up from the lamp are
well coiled about one another in order not to |g
influence the neighboring magnets. Next ff
above the lamp is a plain glass plate c witha |F
swinging magnetic needle d held by arme. A
little above this an adjustable level f is pro-
vided with a glass floor on the cover of which
a second magnet swings. The glass plate may
be removed so that both magnets, oppositely
influenced, may give a suitable intersection
angle. Above the level on its glass cover are
concentric rings 2 mm. apart, then come the
lenses g and h (Fig. 128). Some convex
1 Gliickauf, No. 7, p. 233, Feb. 15, 1908; Mitt. Markschei-
derwesen, Heft 9, p. 53, 1908.
PHOTOGRAPHIC METHODS 189
lenses can also be set here. On the upper surface of the
level is a mark a a (Fig. 129) representing the abscissa
Pia. 129.
axis on which the direction of the throw is taken. The
two convex lenses g and h from
which the latter is screened throw
the image of the level with the con-
centric rings, the abscissa axis, and
the upper needle ns (Fig. 129) on to
a sensitive paper strip 7 (Fig. 128)
working on rolls R, and R, and
shafts 7, r. This is the headpiece
with registering device shown in Fig.
128. Below the frame (not visible
in Fig. 128) is a central lug for stick-
ing in the casing. ‘There are connec-
tion screws for the level and the
whole frame, for connection and
screwing in the frame to the cylin-
drical casing.
The Registering Apparatus.—This
is shown in Fig. 130 on a greater
scale than in Fig. 128. A long strip
of paper very sensitive to light winds
from a roll R, over two guide roll
shafts r in the image plane of the
level and lens system. From here it Fre. 130.—Haussmann’s
runs on over the fixed drive roll R,. - Te##*eTing apparatus.
There is a solenoid e above the rolls provided with a clutch n
190 DEEP BOREHOLE SURVEYS AND PROBLEMS
which engages in a cog wheel z on the upper roll. If the cur-
rent to the solenoid is shut off the core rises and the clutch
turns the upper roll one tooth further, thus drawing the
paper strip a corresponding piece forward. On interrup-
tion of the current the clutch is snapped into the next
tooth by a small spiral spring f. The base of the registering
device is fitted exactly to the end plate of the plumbing
frame.
The Current Supply.—The conductor wires go from the
lamp and solenoid to three concentric measuring rings
which are in the cover of the registering apparatus insulated
from each other. One of the rings is connected to both
the lamp and solenoid. From here on the cable is led
into the upper part of the casing and terminates in three
spring rods sliding on three rings in the cover of the register-
ing device when screwed up. ‘This gives an easy connec-
tion between cable and lamp or solenoid. From the rods
the cable goes through the neck of the plumb cylinder
casing with suitable screw nut tightening and protection
from water. It is a three-wire cable, but two will do if a
suspension rope is used or rods, and, if there is a reversing
device, one will do.
The Switch—This apparatus is switched in between the
source and the cable roll. It is used for cutting off, inter-
rupting, regulating, and reversing the current. It carries
a variable resistance in a wooden frame with an ammeter
and voltmeter between, which is an attachment for switch-
ing in a control lamp in the circuit. The plugging arrange-
ment is for closing or reversing the current to either the lamp
or solenoid of the plumbing apparatus. There is a press
button for the supply to the lamp as well as a moving
measuring arm which slides over a toothed measuring
plate which has spaces filled with a non-conducting
substance.
A numbered rotating ring is fitted for the number of
teeth. The plate is connected to the registering apparatus.
If the accumulator is switched in and the arm turned the
registering roll turns correspondingly. The functioning
PHOTOGRAPHIC METHODS 191
of the apparatus depends on the action of the solenoid
armature.
The Guide Rods.—If magnetic orientation fails, as, for
instance, with lined holes, a mechanical means must be
resorted to for obtaining a definite direction,
and his is done by means of the guide
rods. These are made of stiff-membered
cross links as in Fig. 131. In the end of
equal lengths of tube taps are fitted which
are crosswise to one another and have
alternate interior and exterior guide surfaces.
The several members are bolted in right-
angled planes immovable; thus the rods can
press against a winding borehole without
turning their members in shear. Over the
borehole the guide jack or trestle is set up
which gives a definite orientation to the rod Brae de
members as they are let into the hole and
for adding fresh members. Haussmann used members 75
em. long, 1 em. thick, and 4 cm. wide, strengthened above.
_ The Level—The level is used instead of a plumb bob
and cuts out much inconvenience; the plumb oscillates a
lot and slowly comes to rest and is also not so exact as the
level in such a narrow space. The level on the other hand
comes to rest quickly and its sensitiveness is quite inde-
pendent of the length of the plumbing cylinder and no
magnification of readings is necessary.
The Crossed Magnets——Magnetic needles are suited to
undisturbed regions, unlined holes, and iron-free places,
but one has no control over a magnetic needle. Two
needles close together, swinging in parallel planes, cross
when under contrary influences; we thus have a means
of locating disturbances and preventing false readings.
If a magnetic deflection is present the cross angle of the two
magnets will vary and on the vertical turning axis of the
magnetic needles is a differential variometer for horizontal
intensity. In some cases cutting out faulty orientation
survey spots will not give a correct notion of the survey
SSossSy
[2 |
3 ios
SiS> Saba GS
7
192 DEEP BOREHOLE SURVEYS AND PROBLEMS
as a whole, and in such cases mechanical means must be
used.
The Mechanical Guide of the Rods.—The above-mentioned
rods of stiff members with cross links are movable on all
sides in their long axis but not at all in the cross direction,
so that they can follow a winding hole without losing their
orientation. Thus the borehole course is resolved into
short pieces. The correct working of these guides is an
important preliminary of all surveys. Trial of rods
through 180 deg. before every test is considered a good
check.
| Meridian
omica
ee
\
Astron
3.0m.
Fic. 132.—Borehole survey by Haussmann’s method.
In plumbing a hole in undisturbed conditions, first
arrange marks for depth measurements on the rope or
use a measuring wheel, or, if using rods, mark the rods for
a given direction on the scale of the registering apparatus.
Now when ready switch in the resistance for the lamp and
solenoid and read with the ammeter and voltmeter. The
first survey is made with the plumb cylinder hanging
free in the hole. By means of the switch lever we can
PHOTOGRAPHIC METHODS 193
bring a new piece of photographic paper strip into the
picture plane and by pressure on the middle button of the
switch box illuminate the lamp. We have now to get
the depth which is got from the rope or rods and in this way
ean carry out hundreds of surveys without pulling the
plumbing cylinder out of the hole. A dark room is impro-
vised in which to develop the sensitive figures of Fig. 129.
The results can be evaluated by means of a polar coordinate
sealer or a rectangular coordinate tracer.
Figure 132 shows an actual survey by this method of a
borehole with a 2.9 per cent deviation off vertical, the small
circles being the horizontal sections of the borehole at the
respective depths in meters, the axes numbers being the
lateral displacement in meters.
For Haussmann’s apparatus the following advantages
over previous devices have been made and they appear to
be well founded:
1. A higher degree of accuracy is obtained with a sensi-
tive level than with a plumb bob or pendulum. The level
permits of a reading accuracy of 0.1 to 0.01 per cent.
2. It provides a sure reading in magnetically disturbed
regions, giving reliable direction determinations.
3. Repeated measurements can be made, each giving a
sharp photographic indication.
4. Good centering.
5. Simple and rapid assembling and measuring, which
holds also for great depths.
Owens’s Apparatus.—This is an illuminated clinometer
and compass device, invented by Dr. J. 8S. Owens in 1925,
and having an external and internal casing like Gallacher’s
apparatus. The inner one bearing two corner tubes is
free to rotate on the long axis pivots. This, of course,
keeps the inner casing with the clinometer and compass
always swinging into the vertical and horizontal planes,
respectively; the other inner carrier tube holds mechanism
which controls the length, number and interval of expo-
sures. This mechanism is a clock-operated controller
making and breaking circuit with electric lamps. The
194 DEEP BOREHOLE SURVEYS AND PROBLEMS
clinometer is an eccentrically weighted drum bearing a
strip of sensitized paper which rocks close to a diaphragm
with apertures in it.
The magnetic needles and apertures move on one spider
and they are encircled by a strip of sensitized paper on a
drum and all light is excluded except at the apertures.
On top of this is an opal glass lit up by the lamps which
flood the inside with subdued light, and this gives the
photographic record of the needles. When horizontal
each lamp lights up half of the dome, and when the instru-
ment is vertical one lamp lights up the whole dome, so that
illumination is constant at all angles. The instrument is
best understood if taken part by part.?
Figure 1 (Plate XII) shows the complete instrument.
At the ends of the external casing 3 are screwed two similar
watertight plugs 1 and 55 of non-magnetic material,
the latter having the hauling rope eye. ‘The two separate
internal carrier tubes 5 and 39 are bayonet jointed for easy
removal. In Figs. 1 and 2, on pivots 6 and 21, is a cradle
26 with a compass, clinometer and two lanterns. By way
of cap bolt 21 a stud 25 makes electrical contact with a dry
battery. The weight of the cradle 26 keeps the clinometer
in a vertical plane, as in Bawden’s method. It is borne
on end pivots 7 and 19, and there are two lamps at 35 on
the central line of the cradle in front of and behind the com-
pass, the one always throwing light on the clinometer
holes. These lamps are connected in parallel to bolts 20
and contact finger 57.
The clinometer 27 (Figs. 2, 3) is a drum on a spindle free to
revolve at right angles to the cradle pivots and has oil
damping in its bearing sleeves; and behind are spring clips
9 for the record paper 10. On its side next to the compass
is the aperture plate 11.
The magnetic compass is spherical and borne on pivots
63 at right angles to the cradle pivots (Figs. 2, 4). Its
lower half 33 is solid, thus being the righting weight which
1 Dr. J. S. Owens’s paper read before the Institute of Mining and Metal-
lurgy, Jan. 21, 1926.
195
PHOTOGRAPHIC METHODS
quoUINIysUL SUIAVAINS sjoyas1og 8,SueEMGO “IQ—I]IX ALvIg
EOUe| SUL wy pub JUdUUNI{sUl Jo JUaWebUbIUY
ssadui07 21, dUb_yy
Sponig YBNosY, UOI49aG p91 4
SMAAK ai =) SS : SSS
YI SH HH ch tb Ib Ob Le
SSS inh
i
SS SESS
WOl9S6lL9 Ss ¥
$2 82 72
Jofewoul|) LSP T SSS
SS
UOlJOAI|J [OUO!LIaS ¢'914 Wan rats Sor Ni
SCZ 9u © Y) | ann | gun (l= SF =a
;
Sy Ly SvSb rh chtb Ih Ov 6c at
gsc vE 72 Ie OL GZ BZ LZ
SS
“ne 4
BS a
oes ce
ENS UL
=
SN
GZ
LLLLLLLS Ss SLLSELS SD:
I
UMMM,
Le) G # ¢ Z i
196 DEEP BOREHOLE SURVEYS AND PROBLEMS
keeps it horizontal, and the upper half 15 is a hollow dome.
In an annular recess inside the bow] 33 is a strip of sensitized
paper fixed relative to the bowl in which the needles move.
The needle pivot in the bottom part of the bowl 33 holds
the needle, which is a standard sewing needle, on carrier
62. There are four of these rectangular needles; two 30
flat, and two 31 on edge on the bearing spider 29. This
spider has two opposite holes at right angles to the center
lines of the needles, and two white paper reflectors 65
opposite the holes. In the cradle on the compass side of
each lantern is a diaphragm 34 (Fig. 2) with a bell-mouthed
hole with clip held screens. A number of screens of tracing
cloth are placed in these to adjust the intensity of light
on the dome. The compass has a sliding cover 13 over
the upper half and is finished dead white inside for even
lighting. This all provides uniformly diffused light of
suitable intensity within narrow limits.
The controller is for determining the length and interval
of exposures which may be two or four per hour, dependent
on the setting of contact finger 44. A control screw 50
(Fig. 1) insulated from the control base 49 is prolonged into
a spring plunger 38 by means of which a good contact is
made to the dry battery. Owing to the high-pitch, left-
hand thread on this small diameter screw the drum retreats
from the clock when it is revolved by the crank. This
crank is fixed to the minute-hand spindle of the clock and
drives the drum through the insulated pin 50 projecting
from the spider 52 carrying drum 51. This drum has four
longitudinal metal contact strips 45 in electrical connection
with the spider for giving two or four exposures per hour.
The circumferential width of these strips is such that a
series of exposures of increasing length are got during each
revolution of the drum, and this enables the records to be
identified. The drum contacts, as shown by the finger 44,
on slide 41.
At the end of carrier tube 39 is the clock 48 withits minute-
hand spindle extended to carry a crank 47 with a milled
setting knob 54 on opposite ends. It is readable from the
PHOTOGRAPHIC METHODS 197
opening over the controller. The standard dry battery 37
in carrier 39 bearing on plunger 38 presses its central stud
on to the contact bolt 21.
The insulation rod 59 (Fig. 5, Plate XII) is attached
when the instrument is in use and coupled to the drill
rods or rope for lowering. Before making the survey
the device is taken to a dark room where the two carrier
tubes are taken out and uncoupled and record strips of
bromide printing paper are fitted to the clinometer and
-Magnetic
Needle
Inside View from above of Compass Apertures and Needle
Fra. 183.—Inside view of compass apertures and needle from above.
No.1 No.1
$s W N E 6)
No.2 No.1 2 i
(Datum) (Datum)
See ae a
(Datum) y ) Datum) _ (c)
907 45° 0% 45% 90% 1357 1807 135° 90"
um) 5 “ara: (d)
Bots
Fig. 134.—Compass record.
compass drums. The datum record from which deviations
are measured is arranged in the dark room, this being a
standard datum such as the horizontal instrument casing
with the controller end toward the magnetic north. Now
set the record strips with controller to give one exposure and
reassemble the carrier tubes in the casing. After time
sufficient for exposure the controller automatically stops and
it is taken to the hole to be surveyed when the controller is
reset. The eyed plug 55 is now unscrewed and the carrier
198 DEEP BOREHOLE SURVEYS AND PROBLEMS
tube withdrawn sufficient to expose the controller, which is
set for the desired number of records and required interval
between time of setting and first exposure. The watch
of the operator is synchronized with the instrument clock
and the whole apparatus assembled, screwed up tight, and,
with the insulation rod attached to the instrument, lowered
to the spot to be surveyed. Depth and time are noted,
and time for exposure at the spot exceeded, it is lowered
to the next spot and so on for the number of spots being
Nola
(a)
Typical Record
showing progressive
increase in Dip
Fig. 135.—Clinometer record.
surveyed, after which the instrument automatically ceases
working and is withdrawn from the hole. It is now taken
to the dark room where the record strips are withdrawn and
developed.
Assuming that the instrument is horizontal and the con-
troller end points toward the magnetic north, which is
datum line direction, we get a record as in Fig. 134a.
If the said end be pointed northeast, the record is as in
Fig. 1346; if southwest, it would be as in Fig. 134c, the dis-
placements being typical for these positions. The drums
are designed so that 300 deg. equals 3.6 in. on the record
strip surface, or 1 deg. equals 0.01 in. Thus by dividers
and a diagonal scale we may read hundredths of an inch,
PHOTOGRAPHIC METHODS 199
as seen in Fig. 134d, where distances b, c and d are for
records 2, 3 and 4, respectively. Similar reasoning applies
to Fig. 185 showing clinometer records. Figure 136 shows a
92m) Floor
wee ew ww ww me eee i i =
7 265'260' 200', of Hole 30
7 ICEL, OES oper Zen" 293°
Plan
Fie. 136.—Actual survey of a Portuguese borehole.
typical borehole survey from Portugal constructed from
such records. We are indebted to the proprietors of
Engineering, and C. F. Casella & Co., London, the makers,
ne, WB7/
for the photographic views showing (Fig. 137) the compass
and clinometer, (Fig. 138) the casing and inner parts ready
for assembly and (Fig. 139) the clinometer and contact
drum.
200 DEEP BOREHOLE SURVEYS AND PROBLEMS
Anderson’s Apparatus.—We have had no personal oppor-
tunity of examining this method, the full details of which
Fig. 138.—Compass and clinometer.
are not accessible. However, it is known to be another
application of the orientated drill-stem method, the survey
Fie. 139.—Clinometer and contact drum.
principle being that of the multiple-photograph method
wherein one or more pendulums are photographed for
each position. It has been widely and_ successfully
PHOTOGRAPHIC METHODS 201
employed in California. It is about 31% in. in diameter
and about 7 ft. long (Fig. 140) and is capable of taking 88
records each trip, the distance between each setting being
at the control of the operator. The survey can thus be
made in a normal round trip and usually at the rate of 1,000
ies tad (CO oaveay
Fie. 140.—Anderson oil-well Fig. 141.—Demonstration frame with
survey apparatus about to be the machine set for certain inclination
lowered in hole, with stands of from the vertical.
drill pipe set back in the derrick.
The apparatus, including the pendulums, photographic
equipment, timing and actuating devices, is all contained
in a watertight welded casing which is constructed to
be run into the well on the end of a string of drill pipe or
tubing. Thus it can be used in mud and water. It is
generally run on tubing or drill pipe, although in the case
of one Pan-American well it was run on a sand line. In
202 DEEP BOREHOLE SURVEYS AND PROBLEMS
Anderson’s sand-line method a set of expansible steel-spring
guides is run both above and below the instrument in its
shell to prevent rotation in azimuth. A _ practically
frictionless swivel connection is made from the end of the
sand line to the instrument container.
Readings are taken at each stand length and the station
distances measured on the drill lengths, the operator taking
the instrument as delivered from the well and interpreting
End of Survey __
at 6948 ft a ae
5 W
Plan of Underground Course
of Rotary Hole
C=C. Mi. ©. Go:
Olinda No.96 i
0' 20'40'60' 80 100' 6/4, Casing Cemented
, at 5596 Fre
3 Drill Pipe used
below this depth
S
2
\- Derrick Floor
% 7] :
Als 15> Conductor 8/p Casing Cemented
“20 + Cemented at 9/2 Ft. at 469] Ft. LS
Ay 2677 aa
1000" “Bg, Ba Akrag sip.
7 b 50p
20001” cee of |
we Los HODES Nu Bottom of 48
we Ist. Ov] ped
7] 5 QS
Il Casing Cemented 8
at 3800 Ft.----? 48 “
Fic. 142.—Plan of very deep borehole surveyed by Anderson.
the results on a special orientating stand (Fig. 141).
Orientation is thus measured mechanically the direction
of drift being referred to a north-south line on the derrick
floor so that at each exposure the directional deflection
is known at the surface.
Interpretations will average within about 7 ft. of arc
of being correct for vertical angles and 30 ft. for azimuth.
The instrument is also self-checking in that all recorded
points must fall on a curve when plotted. Various surveys
PHOTOGRAPHIC METHODS 203
with this instrument have been published,! while Fig.
142 shows the course of the first 6,948 ft. of the deepest
well as surveyed by this device. Goodrich? quotes an
instance of one survey by this device in a well 6,522 ft.
deep taking 6 hr. 45 min.
1§$mitn, F. M., Oil Gas Jour., p. 120, Dec. 2, 1926; Eng. Min. Jour.
Press, Feb. 6, 1926; ANDERSON, A., Oil Age, p. 20, September, 1926.
2 Oil Gas Jour., p. 38, Nov. 15, 1928.
CHAPTER IX
GYROSCOPIC COMPASS METHODS OF SURVEYING
BOREHOLES
Introductory Note.—The gyroscope being uninfluenced
by local attraction is well suited to the survey of boreholes.
The physicist, Foucault, whose pendulum researches are
well known, instituted in the middle of last century the law
that a spinning wheel with three directions of freedom, 7.e.,
one which is free to move in all three dimensions, is unin-
fluenced by the force of gravity and
is suited to indicate the rotation of
the earth. In order to have a freely
moving wheel it must have Cardan
suspension. In order that the action
of gravitation be removed the three
axes must all meet in the center of
gravity of the system (Fig. 143).
Such a gyroscope is called an azimuth
gyroscope and then if no external
force acts on it—whether at rest or
rotating—it keeps its position in
space unchanged. The term ‘‘azi-
Fre. 143.—Wheatstone’s muth gyroscope” is not happily
Pies chosen because the magnetic compass
also has an azimuth, only this is not optional but zero
(meridian).
Foucault has also shown that a gyroscope which is com-
pelled to move in a horizontal plane endeavors to adjust
itself to the north-south line. Such an arrangement is
called a gyroscopic compass or gyrocompass. In England
and France experiments have been undertaken since well
into last century, with the purpose of utilizing the gyroscope
as a compass. In Germany experiments have been under-
204
GYROSCOPIC COMPASS METHODS OF SURVEYING 205
taken mainly by the firm of Siemens and Halske. Owing
to insufficient technical assistance and faulty knowledge
these experiments were more or less abortive.
A gyroscope! consists of a heavy wheel mounted on bear-
ings free to spin about different axes, usually symmetrical
axes perpendicular to the equatorial plane (Fig. 148).
When the conditions of dynamical symmetry are not obeyed
we get bad static balance, as when
a. The center of mass of the gyroscope O does not lie
on the spinning axis; as in the case of an eccentrically
mounted disc.
b. The principal moment of inertia is not coincident
with the spinning axis, a torque being thrown on the bear-
ings; as when we get oblique but central mounting.
c. The moments of inertia about all axes through O
are not normal to the axis of spin; as when we have an
elliptical centrally mounted disc.
These are corrected mainly by distribution of small
masses on the disc. When all the axes rx, yy and zz are
as in Wheatstone’s gyroscope shown in Fig. 148, it is said
to be ‘‘free,’”’ and if any one is locked it is said to be ‘‘con-
strained.” This latter feature sets up certain phenomena
applied in borehole surveys.
Degrees of Freedom.—The spin of the disc about zz
is known as the first degree of freedom, the rotation of the
disc about yy axis the second and that about the xz axis
the third degree of freedom. When the disc spins about
zz there is an instantaneous angular movement of the axis zz
known as ‘‘precession.”’ It can be noted if a heavy
cycle wheel is held vertically in front of the body with
the left hand by means of an axle and spun clockwise
with the right. The bearing pressure on the left palm
tends to vanish and the wheel under the influence of the
spin and gravitation rotates anticlockwise about the experi-
menter’s body. The free gyroscope tends to keep the axis
1 GLAZEBROOK, SiR R., ‘‘ Dictionary of Applied Physies,’”’ Vol. 1, p. 421.
Ross, J. F. 8., ‘‘Introduction to the Principles of Mechanics,’’ Cape, 1923.
Haussmann, K., ‘‘ Der Kreiselkompass in Dienste des Bergbau,”’ 1914.
206 DEEP BOREHOLE SURVEYS AND PROBLEMS
about which it spins unaltered in direction whether rotating
or not. If spinning it resists any attempt to alter the direc-
tion of its axis, and the gyroscopic torque dominates when
the gyroscope is given a very high speed as is common in
borehole practice. This precession is so important in
borehole gyrocompasses that it appears to merit fuller
detail.
At the beginning of this century several trials were made
to establish a gyrocompass. Doctor Anschiitz-Kaempfe
succeeded in bringing out a gyroscopic compass which
maintained its direction for a long time—24 hr.—in the
laboratory. He however recognized that it was extra-
ordinarily difficult, perhaps impossible, to create a gyro-
scope complete and perfect in equilibrium; he therefore,
in 1906, added to the gyroscope with three degrees of
freedom one with two degrees of freedom and in this way
arrived, by progressive simplification, at his first gyroscopic
compass with only one high-speed wheel and with damped
oscillations. In the most recent form of the Anschitz
compass for nautical purposes there are three similar wheels
which compensate the regular oscillations of the ship.
Precession.—When a simple wheel disc rotates and no
lateral force or torque is exerted upon it, it persists in its
position because every particle of mass in the disc endeavors
to remain in the plane set up. This inertia grows with the
mass of the dise and with the angular velocity of the rota-
tion. If a torque is exerted on the quiescent disc (which
can be imagined as an upward pull on one axis end or a
downward pressure on the other end) the plane will incline
laterally.
If a torque or lateral pressure be now applied to the disc
when rotating, we have the inertia of the dise on the one
hand and the inclination of the tilt on the other, so that it is
a question of what will be the result in the motion due to
these two factors acting simultaneously. Let us consider
Haussmann’s! simple presentation of these important
facts, which we have slightly modified for our purpose.
1 Ibid., p. 51,
GYROSCOPIC COMPASS METHODS OF SURVEYING 207
Figure 144 shows a plan and elevation of a rotating disc
I with a force acting partially on its axis; also its imagined
neighboring position II into which the disc is for the time
being inclined. (For clarity the drawing is much exag-
gerated.) In the plan the narrow ellipse I gives the original
position and II the inclined position of the disc. The direc-
tion of the disc in plane I in the plan is shown by the hori-
zontal diameter AB of the ellipse. Any mass particle m
of the rotating disc I will remain in this position in conse-
quence of its inertia, even if the disc inclines a little due
Elevation Plan
Fig. 144.—Precession.
to a lateral torque. ‘This direction of persistence must
thus also be present when the particle m rotates in the
inclined plane II. If the particle is now compelled to
rotate in plane IT it still has the tendency to remain in the
direction of plane I. The tangents to plane II give the new,
those to I the old, directions of movement. These direc-
tions are only equal in C and D, also in E and F; in all other
points they differ. Let the divergence of corresponding
tangents be indicated by 6 and the angle between planes I
and II by A and further let the angular rotation of the
particle proceeding from D be w, then we get the relation
5. © eae OF
smM5 = sins sino (12)
208 DEEP BOREHOLE SURVEYS AND PROBLEMS
For small angles 6 = Asinw. The value of 6 is nil in points
D and F, a maximum in A and a minimum in B.
Corresponding to the divergence of the tangents there
appears a force acting at right angles to the disc, which is
nil in D and grows to A and from here on again declines to
nil at F then back to D in the same manner but taking a
course in the contrary direction.
These lateral components effect a rotation of the spinning
disc about the diameter DF or in relation to the original
position I about the normal diameter CH; and this turning
annuls at every moment the tendency to lateral inclina-
tion. This turning motion at right angles to the direc-
tion of the applied force is called precession. We shall
not go into the lesser motion appearing in the periodic
repeated dip and rise of the axis known as nutation. The
preceding construction applies very fully to a gyroscope
imagined as frictionless. In practice the axis of the
gyroscopic disc will, in the course of time, show more and
more marked inclination owing to the action of friction.
As a proof that a force applied to the axis of a rotating
gyroscope brings about a lateral movement we have but to
consider the common spinning top or child’s hoop.
The Action of the Gyroscopic Compass.—Imagine a
gyroscope wheel suspended at the equator so that its axis
A,A,. (Fig. 145) is horizontal and it goes round from west
to east. Regarded from west or south the wheel has a
clockwise direction of rotation as shown by I in (Fig. 145).
Next instant the wheel, owing to the earth’s rotation, is in
position IT (much exaggerated in the drawing).
Owing to the inertia of the disc the axis A,,’A.’ stays in
position IT parallel to its former position A,,A., while the
direction line of gravity in II makes an angle of w») = 15¢
with that in I, owing to the interval ¢ in time between
positions I and II and the fact that gravitation acts toward
the earth’s center. Thus the disc axis is no longer at right
angles to the direction of gravity; its east end is too high,
so that the force of gravity acts unequally on the axis.
On the west end an upward pull is exerted and on the east
GYROSCOPIC COMPASS METHODS OF SURVEYING 209
end a down pull acts. The force of gravity thus gives
rise to the precession motion of the gyroscope whereby
the east extremity of the axis moves toward the north.
When the axis comes into the plane of the meridian the
effect of gravitation on both ends of the axis is similar and
balances. The gyroscope remains in this position because
the meridians at the equator run parallel, and thus it is
independent of the earth’s rotation. The meridian is
the position of equilibrium which the gyroscope tends to
attain in consequence of the earth’s rotation. On the equa-
tor the turning axes of the earth and the gyroscope are
Horizon
Fig. 145.
parallel and their rotational senses are the same. In
general all rotating bodies tend so to place themselves
that in similar turning senses their turning axes are similarly
directed. If now we hang the rotating wheel not on the
equator but on any other chosen spot on the earth’s surface
the gyroscope will still tend to set its axis in the same direc-
tion as that of the earth. This can not occur completely
owing to the line of gravitation being here no longer normal
to the earth’s axis as at the equator, but being inclined
to it. The gyroscope will now, as far as is possible, set its
axis in the line of the earth’s axis, and it attains its greatest
proximity to this when its axis lies in the meridian. If
at any place of latitude ¢ the axis of the gyroscope makes
210 DEEP BOREHOLE SURVEYS AND PROBLEMS
an angle @ with the earth’s axis, this is then the smallest
of all possible angles between a horizontal line and the
earth’s axis. For a horizontal line of any azimuth Awe
get the corresponding angle of inclination a, from Napier’s
laws. Thus
cos a = cos ¢ cos A (13)
Angle a is greater than ¢ because its cosine is smaller.
In Fig. 146 point I, rotates, owing to the earth’s rotation
in time ¢, to position II,. The gravity direction lines in
Fie. 146.
I, and II, do not now make an angle of wo = 15% as at
the equator, but a smaller angle w, which can be computed
from
sin a = Si = COs ¢ (14)
Thus for small intervals of time we may write 15¢ cos ¢.
The directing force of the gyroscope thus decreases with
latitude, it being only a half in 60 deg., a quarter in 75
deg., and a tenth at 85 deg. latitude, of the force at the
equator. It is nil at the pole where all great circles are
meridians. On the gyroscope axis swinging into the merid-
ian plane from the east, the east end of the axis is somewhat
GYROSCOPIC COMPASS METHODS OF SURVEYING 211
too high and the gyroscope oscillates over the meridian
out again. As the north axis then dips below the horizon
a back oscillation sets in. To decrease these oscillations
sufficiently rapidly a damping device is provided with
the gyrocompass. In Anschiitz’s method the suspension
of the compass is obtained by having it connected to a
body which floats in quicksilver. Then at any azimuth
of the gyrocompass the buoyancy of the mercury takes up
the gravitational force, acting through the earth’s rotation
on the one extremity of the axis, in the form of a pull
upward, and that on the other end is compensated as a
pull downward by its proper weight.
The Kiel Nautical Instrument Company’s Gyroscopic
Compass for Borehole Surveys.—This apparatus! was
formerly introduced for warships and
submarines by the firm Anschiitz of
Kiel. Indeed, it alone made long-
distance underwater navigation
possible.
It is let into the hole on a cable and
2-m. measurements are taken with it.
It is held centrally by guide brushes to
maintain always the same vertical in
the hole. A measuring box (Fig. 147)
has two pendulums arranged to rotate
about the axis of the apparatus; they
Swing in two planes at right angles to
one another and a small gyrocompass
adjusts the measuring case so that one
pendulum swings in the east-west and
the other in the north-south direction
regardless of how the apparatus turns
on being let down. Figure 148 is a
schematic view of the measuring box
with an east-west pendulum which hangs vertical while the
box is inclined with the hole. (The dip here is exaggerated
Fie. 148.
1 MarTIENSSEN, O., Electrotechnische Ztschr., Heft 24, p. 462, 1920; p.
694, 1919; and pp. 862, 887, 1911.
212 DEEP BOREHOLE SURVEYS AND PROBLEMS
being seldom more than 1 deg.) Below the point of the
pendulum is the midline m, m, of the apparatus, and,
owing to the dip, the pendulum deviates a little way a
from this line east or west. This amount a is measured
and if, say, the deviation is a mm. and the pendulum 20
em. long, then in a length of 2 m. the hole is displaced 2 cm.
to the west. If we carry all measurements at 2 m. and add
all the deflections a we get the total deviation of the hole
toward the west in centimeters. Similarly the north-south
pendulum point may give deflections 6 at the same times
and these are also added as above algebraically. Both
displacements are plotted on coordinate paper which
permits the position of the hole with respect to its origin
being easily found. Thus, for example, for a 300-m. depth
in a hole, we employ 150 measurements on the north-south
and east-west pendulums and add them for the resulting
displacement, say west and south.
Figure 1 (Plate XIII) shows the interior of the apparatus
which is protected by a steel casing, for loosening which a
nut at the bottom can be drawn out. It is tightened with
India-rubber gaskets which will suit pressures of 150 atm.
The most important part of the device is the gyrocompass
hanging under the inclination measurer, the action of which
is based on Foucault’s law that the earth exerts, on every
horizontal rotating shaft, by its revolution, a force which
turns the shaft in the north-south direction, so that the
turning of the earth is of the same sense as that of the shaft.
The directing force we have discussed on page 208 to
be the product of the moment of inertia of the wheel, its
angular velocity, the angular velocity of the earth, the
cosine of the geographical latitude and the sine of the angle
between the meridian and the wheel axis.!
If the suspension is free enough this directing force lets
the axis of the wheel swing into the north-south line, for
then the sine of the angle is nil, but in order to attain suff-
cient force the velocity of the wheel must be great.
1MartTieNnsseN, O., Die Theorie des Kreiselkompasses, Zéschr. f.
Instrumentenkunde, 1913.
GYROSCOPIC COMPASS METHODS OF SURVEYING 213
The gyroscopic compass constructed to meet these
demands is shown in Fig. 2 (Plate XIII) and set in the
lowest part of the apparatus (Fig. 1). A ring-shaped vessel
a filled with mercury is fixed on the rotatable measuring
case in a housing with the aid of bows 6. A ring-shaped
float c in the mercury vessel holds the wheel cap e by a neck
d. In this cap or case runs the gyrowheel on ball bearings,
the wheel itself being of nickel steel and having a short-
circuit rotor pressed on it. ‘The stator of the small alter-
nating-current motor which drives the wheel is fixed in the
wheel case, and it is supplied with a 400-cycle per second
current, by means of fine silver wiring, causing the wheel
to make 25,000 r.p.m.
The construction of such a quick running alternating-
current motor with short-circuit armature is extremely
skillful; the high number of revolutions demands much
copper in the rotor so that the turning moment be small,
otherwise the wheel will not exceed a definite speed range.
The wheel hangs in its case as deep as possible below
the float compatible with the tube width against which it
would bump if very deep. In this position gravitation
tends to hold the axis horizontal and the axis adjusts itself
to the meridian by Foucault’s principle, stated above,
because the entire floating system is arranged rotatable
about the center rod f. A directing force of some tenths
gram-centimeter suffices to turn this small gyrocompass
but not the whole measuring box, so for that reason the
following arrangement is adopted. On the floating system
is fixed a contact bead g which, when the float with the wheel
turns right or left, makes contact with a contact spring
on right or left and in this way a so-called ‘‘turning,
take-up, or compensating motor” changes its rotational
sense. This is to be found in the uppermost part of the
inclination measurer (Fig. 3). It is a small direct-current
motor with double armature winding and commutators
on both sides; and by the contact bead one or the other
of the windings is cut out causing the armature to rotate
in the opposite way.
214 DEEP BOREHOLE SURVEYS AND PROBLEMS
This take-up motor turns the measuring box with the
mercury vessel and contact springs to the rotations of the
gyrocompass, for the bead is only out of contact when it
hangs free between the contact springs on the mercury
vessel. Consequently, the measuring box is always in a
definite position with respect to the gyrocompass and
thus also to the meridian. In Fig. 2 (Plate XIII) the lower
bearing of the compass box is shown at / and in Fig. 3 L
is the upper bearing of it. The box itself is shown in Fig. 4.
The east-west pendulum a swings in the picture plane
and the north-south pendulum 6 at right angles to this.
Under each pendulum is a registering casket kk with a
registering strip running close under the points. Over
the pendulum points lie the cores or armatures dd of two
small electromagnets as broad as the strips. When taking
measurements the current is sent into the electromagnet
by a telegraph key on the surface; the core strikes the
pendulum and presses a fine needle on the end of the pendu-
lum into the registering paper thus perforating it. Break-
ing the circuit the electromagnet operates a catchwork
driving the registering strip 5 mm. forward ready for the
next measurement.
On opening the apparatus at bank and taking the strips
out from the casket and reading the deflection of the several
holes from the midline of the paper, two separate tables are
entered up with the data from the two strips. The sum
of the entries in the two tables, east-west and north-south,
gives the displacement at the depth concerned.
Figure 1 shows the head of the apparatus; the various
leads of the cable are tightened with India-rubber the
winding cable itself being of medium steel and held by bolts
b. Eight lines encased in gutta-percha and jute yarn
take the current to the wheel, take-up motor and electro-
magnets. The rope is also covered with gutta-percha to
distribute the load at the bearing guide roll.
The cable drum and motor are in a special lorry as also
are the current source and transformer for the direct-
current portion and also the necessary controls for the gyro-
GYROSCOPIC COMPASS METHODS OF SURVEYING 215
Fig. 2.—The
gyrocompass.
Fie.1— Fic. 3.—The dip Fic. 4.—Registra-
Complete measurer. tion section.
instrument.
Puate XIII.—The Kiel Nautical Instrument Co.’s gyroscopic compass borehole
apparatus.
216 DEEP BOREHOLE SURVEYS AND PROBLEMS
wheel current, the take-up motor current, keys, etc. The
method has been frequently applied in measuring the devia-
tion of freezing shaft boreholes. The makers
claim the remarkable accuracy of about 1 in 2,000.
Anschiitz Borehole Deviation Instrument.—
, Doctor Anschiitz' employs the gyroscopic compass
for fixing the direction of deviation and a rigid
plumb bob for the amount of deviation. He
equips both with transmitting apparatus and
a combines these with a receiving apparatus on the
surface so that one can read there at once the
position of the plumbing apparatus at any chosen
position in the borehole. The plumbing device is
let into the hole with a cable from which the depth
is read.
Since the results are given directly on the merid-
ian, the astronomical north and the direction of
gravity the apparatus is free from partial measure-
ment errors. Each individual observation is com-
pletely independent of the others, thus obviating
the transference of errors. The superiority of this
method will thus be greater at greater depths.
Since an opening of the tube throughout the appli-
cation is not necessary, the dip measurer is always
» ready for use and yields unvarying data. Figures
149 to 152 show the constructional parts of the
inclination measurer. They are made up of the
transmitter (Figs. 149-151) and the indicator or
receiver aboveground (Fig. 152).
The Transmitter: Plumbing Cylinder and Chief
4 Parts——This is shown in Fig. 149 as a pressure-
rig. 149, Proof steel cylinder a bearing a gyrocompass 6
The trans- giving the direction, and a rigid plumb c with
aaa @ardan suspension for giving the amount of incli-
nation of a borehole at any position. This cylinder has
steel feeler brushes d above and below and is let into the
_
=
)
>
i
/
hf
ena!
ys
(=
Gal
{|
=|
AA
1 Haussmann, K., Glickauf, July 4, p. 1076, 1914, also BERGaASSESSOR
Wimmetmann, Kohle und Erz, Nos. 13-15, pp. 323-379, 1924.
GYROSCOPIC COMPASS METHODS OF SURVEYING 217
borehole by the cable e. Compass and plumb are both
provided with a transmitter, which are connected by elec-
tric conductors in the interior of the holding cable to the
receiver aboveground. The two principal parts of the
plumbing cylinder are the gyrocompass and :
the hanging plumb bob.
The Gyrocompass.—Under the steel cover
there is a lead to the compass (Fig. 150).
The capped compass case a carries a three-
phase motor with a short-circuit rotor.
This consists of iron sheets with aluminum
rods and star plates. Over the axis a two-
pole alternating-current winding is_ slid.
At an alternating current of 0.25 amp. and
120 volts, 500 periods, the body wheel of
the compass is made to rotate about its
horizontal axis at 30,000 r.p.m. The wheel
is closed about by a cap which hangs on a
floating ball bearing. The ball floats in a
vessel of mercury b (Fig. 150). On the float
body a small contact ball ¢ is sprung. This
rotates with the wheel independent of the
mercury bath and the tube. Contact paths
d are fixed on the mercury bath and they
have slits. These turn independent of the Rana eae
wheel with the bath and lamp e in the casing ratus. The
jacket. The mercury bath hasa Cardan sus- ®77°comPSS8-
pension, 7.e., gimbals, in the lamp e and is connected to the
transmitter motor g by means of a spur wheel drive f through
a shaft. This motor g rotates the bath and lamp as long as
the contact bead slides on one of the contact pathsd. As
soon as the bead has reached the slit the electrical circuit is
interrupted and the turning ceases. ‘Then the transmitter
motor has reached its previously known normal position
compared with the wheel. The motor of the transmitter is
connected electrically to the receiver motor, the graduated
scale of which turns back. Here one may read off the
position of the transmitter motor respecting the compass
218 DEEP BOREHOLE SURVEYS AND PROBLEMS
wheel and therewith respecting the meridian (by providing
a meridian line or azimuth line through the borehole).
Thus we get the lateral angle aboveground. The damping
of the circle is easily obtained by chambers between which
some oil runs in and out on the oscillations of
the wheel axis.
Above in the steel shell comes the plumbing
device (Fig. 151). The rigid plumb bob a
hangs by Cardan suspension in a guide and is
prolonged in a rod 6b as far above as it hangs
below. The plummet carries above and below
a small contact bead or ball. Each of these
two balls runs in a slit between contact tracts
c and d on a lateral support capable of tipping
e and f. In space the slits stand at right
anglestooneanother. 'Theuppersupport turns
about an axis which is in a position at right
angles to that of the lower one. ‘The inclina-
tion is resolved into two components at right
angles to one another. Naturally the same
action can be obtained as well by two sepa-
rate pendulums. When the contact balls fit
laterally into their slits the current is cut off and
the parts concerned will be so far displaced
Fic. 151 laterally that no further side contact can take
Anschiitz ap- place until the rigid plummet hangs free. The
paratus. The 5 % :
plumbing de- contact chariot of the transmitter is, however,
mice: connected to the corresponding parts of the
receiver by means of the electrical conductor in the cable.
As long as the transmitter parts are in lateral motion
the current to the receiver is cut off and it there displaces a
motor contact carriage in the same manner. Both compo-
nents are compounded in the receiver yielding the total
motion of a magnet bar whose deviation from a mean
position is shown on the concentric rings of a graduated
plate by means of a small iron ball on a rod which moves
accerding to the magnitude of the inclination of the bore-
GYROSCOPIC COMPASS METHODS OF SURVEYING 219
hole. Amount and direction of inclination are read off
the receiver in tenths of a degree.
The Receiver.—The mode of action of the receiver (Fig.
152) has already been described. The alternating motor a
in the receiver runs synchronously with the motor in the
gyrowheel chamber in the plumbing apparatus and turns
the counter 6b (detached in the figure) back in the direction
for reading the inclination. Another motor c displaces a
Fig. 152.—Anschiitz apparatus. The surface receiver.
main carriage d on a horizontal spindle on which a second
carriage e turns, also horizontal, but can be displaced
90 deg. to the main carriage. On the carriage e sits a
' bar magnet f with an end pointed upward 90 deg. which
reaches close under the scale plate b and on it pulls asmall
iron ball. By this ball, on concentric circles, the magnitude
of the inclination is read. Doctor Anschiitz has investi-
gated the possibility of a coupling table on which the course
of the borehole is automatically indicated on the plumbing
apparatus being let into the hole. With such a device one
would only have to draw in the depth indicated by the cable
on the line of course of the borehole.
The Transport Lorry.—A lorry carries the cable on a drum
as well as a switch plant and all accessories. The cable is
marked in 2.5 to 25 m. for reading depths. It carries
inside it the conductor cable from transmitter to receiver.
220 DEEP BOREHOLE SURVEYS AND PROBLEMS
The apparatus suffices for plumbings up to 700 m. and can,
with corresponding cable lengths, be used for any depth.
Test Plumbings.—Tests with the above dip measurer
in a pipe in a shaft of the Deutscher Kaiser works were
carried out to a depth of 350 m. and have yielded the same
results on insertion and extraction and on repetition.
These have been checked by surveys and give agreeable
results as far as comes into general practice. Since in this
method partially active errors are avoided, which would
make repetition results false, the conclusions to be drawn
from the tests are that for a well thoughtout, ingenious and
rapid working apparatus it is quite accurate and satisfies
all the demands of practice. It should still be mentioned
that the dip measurer is also applicable as a stratameter
for cores. Speaking of this instrument, after observing a
test, Prof. Haussmann of Aix says,! ‘‘The mathematical
and physical basis on which the appliance is constructed
permits us to recognize that it is free from inherent errors;
thus must it also yield correct results with increasing
depths.”’ This accuracy fulfills the preliminary conditions
for the success of freezing shafts, 7.e., by proving the course
of the boreholes.
Surwel Gyroscopic Clinograph.—This remarkable device
marks the most recent practice in the adaptation of the
gyroscopic principle to the survey of borehole deflection.
The principal features of the well-known Sperry” gyroscope
of navigation are applied.
This apparatus consists of three main parts: (1) the box
lerel gage (Fig. 2, Plate XIV)* for ascertaining the vertical
inclination, which is placed uppermost of the three in the
apparatus; (2) the film camera (Fig. 3) making simultaneous
moving-reel records above and below; and (3) the lowermost
1 HaussMANN, K., Mitt. Markscheiderwesen, p. 60, Sonderdruck, 1914.
2 GLAZEBROOK, Sir R., ‘‘ Dictionary of Applied Physics,’”’ Vol. 1, p. 421;
Vol. 4, p. 255; also British Patent No. 15,669/15; Rawuines, A. L., ‘‘The
Theory of the Gyroscopic Compass,’ p. 18, Macmillan & Co., Ltd., 1929.
3 By the courtesy of the Sperry-Sun Well Surveying Company, Phila-
delphia.
GYROSCOPIC COMPASS METHODS OF SURVEYING 221
Wire Line
Socket
1 Ball Bearing
J Swivel
Fie. 2.—The box Fig. 4.
level gage.
- Batteries
-Battery
Protective
Casing
Shock
Absorber
laine ile Fic. 3.—The camera. Fic. 5.—The pointer compass.
Fic. 6.—Specimen photo strip from borehole.
Puate XIV.—The Sperry-Sun Well Surveying Co.’s gyroscopic compass device.
222 DEEP BOREHOLE SURVEYS AND PROBLEMS
unit, the gyroscope itself (Fig. 4). These three units are
assembled, screwed tight, in a high steel jacket 514 in.
external diameter, the apparatus itself being about 414 in.
in diameter. The lower joints carry dry batteries operating
the gyroscope and illuminating the film camera. The top
joint ends in a ball-bearing swivel which enables the appara-
tus to be sent into the hole either on the drill stem or on a
wire line. It is thus independent of many of the objection-
able torsional features which render the results of so many
devices unacceptable for accuracy. This latter feature
plus the north orientating tendency of the gyroscope (and
here the special restraining appliances) make this class of
instrument independent of the effects due to twist on
insertion and extraction of the apparatus. It is claimed
that the casing of steel will withstand the mud pressures
encountered in holes down to 10,000 ft. deep. The gyro-
scope, maintaining the features of rigidity and precession
discussed mathematically at the beginning of this chapter,
offers great resistance to any attempt to alter the direction
of its axis by being caused to spin, by means of the electric
motor self-contained, at a very high speed, as in the case
of Anschiitz model and that of the Kiel Nautical Instru-
ment Company previously described. The direct-trans-
mitting motor rotates the gyroscopic disc at about 10,000
r.p.m., and this latter is specially balanced to maintain
its axis in the geographical meridian! when once set there.
A pointer coinciding with and controlled by the gyroscope
(Fig. 5) is set above the gyroscope on its axis over a grad-
uated are. To this latter is attached a non-magnetic
watch with large minute and second hands giving readings
to 14 sec. This enables computations of depth to be made
for each site recorded in the hole. A thermometer may
also be added here for reading the temperatures encountered
which yields data not only on direct thermal conditions
but for computation corrections if desired.
1See Rawlings, op. cit., p. 124, for mathematical discussion on balancing
the disc.
GYROSCOPIC COMPASS METHODS OF SURVEYING 223
The camera! (Fig. 3) which is of special design employs
a 16-mm. perforated motion-picture film and has a capacity
of 50 ft. There are two lenses recording pictures simultane-
ously in opposite directions, up and down. One lens
photographs the compass scale and gyroscopic pointer
below with the watch and thermometer (if any), while
the other photographs the position of the bubble in the
graduated level gage box above. These lenses have to be
very accurately aligned on the same optical axis and focus,
thus superimposing two pictures on one film as shown in
Fig. 6, Plate XIV. This enables one to read off the amount
and direction of deflection at the same time, while the time
for the depth computation is given as well. The film
take-up is worked through gears by a small electric motor,
which also operates a synchronized and adjustable contact
device providing the necessary light flashes for taking the
pictures. The camera motor is controlled by an accurate
timing device guaranteed to vary less than 7 sec. per day.
Thus the camera has a capacity for taking up to 1,000
photographs, giving a practically continuous record of the
hole. It also records going into, and coming out of, the
hole.
The box level gage (Fig. 2) is a ring with top and bottom
of ground special glass, the former disc being spherical and
having concentric graduations. The position of the bubble
relative to these graduations gives the amount of vertical
inclination as in the depthometer of a previous chapter.
Three different levels are provided with each instrument
having maximum inclinations of 20, 40 and 55 deg.,
respectively. This range of registration of dip angle far
transcends that of any other device employing the gyro-
static principle. Preliminary runs with an acid-bottle
apparatus decide which of these box level gages to select
for a particular case. To ensure rapid response of the
bubble to quickly altering inclinations the nature and
size of the bubble are specially allowed for in the material
1 We are indebted here for some notes kindly supplied by the makers,
The Sperry-Sun Well Surveying Company, Philadelphia.
224 DEEP BOREHOLE SURVEYS AND PROBLEMS
of the fluid. Lag and oscillation of the bubble have also
to be provided against while temperature effects are com-
pensated by expansion coils.
For operation with a wire line a line meter is applied
to the derrick reel starting from zero, and a watch syn-
chronized with the gyroscope watch is used for making
time readings every 25 or 50 ft., according to the depth
of the hole. Thus the depths are easily obtained. The
apparatus is run at a fairly constant speed of 150 to 180 ft.
per minute in cased holes, thus taking about 1 hr. for a
5,000 ft. hole, but this speed does not apply equally to open
holes.
h=+ABsin Qo tan d----------.
eh ENN)
Fig. 167.
3. The Borehole Is on the Downstream Side of the Out-
crop and the Strata Dip toward It (Fig. 167).—Here we
get
L=h—-—H
or
L = AB’ sin ® tan 6 — H (21d)
250 DEEP BOREHOLE SURVEYS AND PROBLEMS
Norre.—In this case H must be less than A and if the strata dip in the
other direction no location is possible.
These will cover all cases of vertical boreholes.
b. INCLINED BOREHOLES: LENGTHS, DISPLACEMENTS AND DEPTHS
In these cases the boreholes may have an infinite number
of dips in amount in two directions at 180 deg. from one
another, 7.e., corresponding opposed and “together”
dips, and still be at right angles to the strike of the stratum,
provided the hole does not leave the plane normal to the
stratum strike, 7.e., its full dip or rise direction plane (Figs.
168, 169). The angle 6 of Eq. (20) is 90 deg., making it
Jal ae AUB tam
a tan a + tan 6 (22)
according to the relations of the dips of borehole and
stratum. It will be found more convenient to measure
the surface slope y in these cases.
Fig. 168.
1. The Borehole and Stratum Dip in the Same Direction
with the Borehole Upstream of the Outcrop (Fig. 168).
la. The Length of the Borehole.
H
sin a
BB” =
PROBLEMS 251
ee — OH COt) a
mn He BC sin (a — 6)
pe Ly A Bin
Rat cini(a— 5) > sin (@ =)
AB” = H (cot y + cot a)
" a AUB
eee + 8 OO are Gai OR ee
a il cot y + cot a
= itl (= all Conyac cos | (22)
If the borehole is downstream of the outcrop the first
term in the bracket is negative; on a level surface H van-
ishes, also y, and since then AB’’ = AB’ = AB, the above
form is not applicable, a modification of either Eqs. (216),
(21c) or (21d) being then most suitable, which will yield
the length, thus
AB sin 5
sin (6 — a)
aC = L= (24)
and so on for other dimensions which need not be repeated
here.
16. The Displacement of the Borehole-—This is the shift
of the hole and will be in the full dip direction here (Fig.
168).
Displacement = DC = B’B” + FC.
= H cota + B’C cosa
VAN
(tan a cot 6 — 1)
cot y + cot a
tan a cot 6 — 1
= H cota +
IDG, = 16! (cot a + (25)
Wherein the first term on the right is negative if the bore-
hole is downstream of the outcrop; and if the surface is
level
IDG = IKC Cos) a (26)
252 DEEP BOREHOLE SURVEYS AND PROBLEMS
lc. The Total Depth of the Borehole.—This is the distance
to the base, v.e., BD.
BD=H-+h
Bi) sin; a
sin (a — 6)
=
and since
BNI INI SO
we get
AB”
cot 6 — cota
cot y + cot =)
=H+
cot 6 — cot a (27)
BD = H(1+
2. The Borehole and Stratum Dip in Opposite Directions
against One Another with the Borehole Upstream of the
Outcrop (Fig. 169).
Fic. 169.
2a. The Length of the Borehole.
BB” — H/sin a
he — er COt a:
and
AB” = H (cot y — cot a).
ii — aC — bil =| BO,
PROBLEMS 253
BNC = Bais See sin: 6
~ sin (180 —6— a) sin (6 + a)
ja H AB"
~ sina cot dsina-+ cosa
of it cot y — cot a
lh oe (a 2 lcaworsne + cos -) (28)
Compare with Eq. (23) above where similar remarks
apply respecting the altitudes of the derrick floor and the
outcrop.
When the surface is flat AB’’ = AB’ = AB and then
AB sin 6
sin (6 + a)
Compare with Eq. (24) above.
2b. The Displacement of the Borehole.
DC = B’B”’ + FC
L= BC =
(29)
AB”
tan a cot6+1
cot y — cota
tan a cot 6 + 1
2c. The Total Depth of the Borehole.
BD=H+h
Bb= ae AB H(1 + Sete (31)
= H cota +
DC =H (cot ae (30)
COE ee cot 6+ cota
The reason for choosing the persistent term AB’ is
because it is the dimension most likely to give the least
trouble in obtaining in practice.
Cc. HORIZONTAL BOREHOLES
Here the inclination of the borehole is nil, so that in
Kq. (20) a = 0 deg., making the expression for the displace-
ment x (Fig. 170).
H — AB’ sin 6,tané6 AB’ sin 6. — H cot 6
MO 5 = 5 ALG sin 6,
and
or
tan 5 = tan @ cosee 61 (62)
Given Three Deviated Boreholes to Determine the Dip
and Strike of the Stratum.—Having surveyed three bore-
Fie. 183.
holes A, B and C and found their net horizontal displace-
ments and depths a line may be drawn in a direction
connecting the source and end of each. This line will
usually be the shortest line between these points and will
have the average deflection of the hole throughout.
Let us consider a concrete case of three holes set vertically
but now deviated until when reduced as above we get their
bases data also. Let the surface and borehole data be:
Coordinates Dip from
Net bearing | Length of |horizontal (90 —
: of hole hole, feet | off vertical),
x Y degrees
A 1,000.00 500.00 N.50°E. 1,200 60
B 100.00 | —800.00 S.80°E. 300 75
G — 600.00 200.00 | N.10°E. 400 80
These points are set out in ABC (Fig. 184).
PROBLEMS 275
Set off from A a line at the hole bearing N. 50°E. and on
it the dip angle of the hole, 7.e., 60 deg., setting off on the dip
line AA; = 1,200 ft. the borehole length. Drop a per-
pendicular A,A» to meet the direction line from A in A», and
A» will be the plan position of the end of the borehole from
A. Ina similar manner, using the relevant data, get B,
I
1
-*
\ aw) ly
a
od
/
A@
Fie. 184.—The three slanting borehole problem.
and C,.A»2B2C;, is the actual area encompassed by the bore-
hole bases. On line A.C, set off the depths of A, and Cy
at these points, respectively, at right angles to this line,
so getting A; and C3. Join A; to C3 and produce to meet
AC, produced in x. (Note that A.A; is the depth of A»
and B.B; is that of B. and CC; that of C2.) Similarly set
off A2A’;, the depth of A», and B.B3, the depth of Bz,
at right angles to A.B, as shown. Connect A’; to B3
and produce to meet A.B, produced in y. «wand y are on
the strike of the stratum. Drop a perpendicular C,D
on to the strike line zy and erect one, C,H, at C2 equal to its
depth. Join ED and the angle EDC, is the amount of dip
and its direction is DC;. Check by B» GF using the same
reasoning.
276 DEEP BOREHOLE SURVEYS AND PROBLEMS
NOMOGRAPHIC AND ALIGNMENT METHODS
These simple and easily understood charts are becoming
more and more popular because they can, as a rule, be
manipulated by the boring personnel and others who wish
to save time.
Figure 185! shows the well-known versed-sine relation
which can be applied to a hole the deviation of which is
either regular or can be approximately meaned throughout
its course, giving a straight deflection; that is to say, a
constant off-vertical angle. The alignment chart itself
A (Fig. 186) is constructed by putting on the left
the logarithmic scale A with the scale of versed
sines B, or C, on its right and the vertical
correction scales corresponding at B, and C».
To get a correction, place a straightedge
at the desired depth of hole on A scale, say
100 ft., and at the proper off-vertical angle on
B, scale; continue and read off the correction
on Bz or Cy scale. If the straightedge falls
off scale B., then use scales C, and C,. If the
measured depth is greater than scale A divide
dL TerFical it by 10 and multiply the corresponding results
Connection on Bo or C.by 10. Thus if the depth is 2,500
Fic. 185. ft and the off-vertical angle 10 deg. use
250 ft. and multiply the resultant vertical correction of
3.75 ft. by 10, giving 37.5 ft. Use a transparent cellu-
loid straightedge with a fine black parallel line near one
edge.
Based on Fig. 185 Mr. Brindel? discusses a simple employ-
ment of mathematical tables and formula, noting that
1. By the Cosine Method.
The corrected measurement = (actual measurement) X
(cosine of off-vertical angle),
1.€., In Rigs 185) Aue
cos BAD.
1 BRINDEL, H. F., Oil Gas Jour., p. 41, Apr. 11, 1929.
2 Tbid., p. 41.
Position if Hole were vertical
PROBLEMS 277
2. By the Versed Sine Method.
The corrected measurement = (actual measurement) —
(actual measurement X ver-
sine of off-vertical angle)
1.e., BC — AD vers BAD.
saiiddo ajbuy yaiym gate ul [OAJaLUy
1000
900
800
100
600
500
400
350 :
BSNS
SSS i
SINAN 3
Shy S
mNINNA >
oKNN IN °
SUKNANWS <
BRAINS ee
EN NNAN Bg
“RQQnay Me
iS XN = =
BNC S
SSN Sb ts
$ EN ANS Be
aN SSN oc .s
£ aN SN ISSN oes
ive) LAIN No
es ~~ aS S SS SOF8 :
\ “Ss \ ak RSIS ESSN aed
ore ae
=e es:
- Bg
52 ete
> =|
So IO a
a a |
ioe) foe) 4
a SIE Sa g
mm WJ eae Nar i
iS!
ANS SW LIE SS 2
pes a RRS SE) INS
el LTT TT TTT NSS El
17 UTRIITHENAISNN IE s
CIT SSN
EEN
Vertical correctron
for 1000 Ft. of interval
ie
1s as follows
by 2
278 DEEP BOREHOLE SURVEYS AND PROBLEMS
A table of natural cosines and another of natural versines
should be kept, the latter being the simpler to use having
least multiplying figures. A check on each of these
methods would be always advisable; e.g., in a 200-ft. hole
A 5: C; Bo Co
1000 Oris! 01 1
900 3°
800
700
600
500 2
A400
3
300
4
8 200 Sat
rte 5
Le
ie is
g 3 8
> 100 103
ty 90 =
=| (30) (Ss)
S 70 3
= iS)
=> 60 =
50 208
40 Examples:
100 Ft. Measured Depth 30
30 1° Slope
0/5 Ft. Vertical Correction 4 40
99.985 Fi. True Depth a
20 100 Ft, Measured Depth Bs 5 50
50°Slope a is Ge
35.7 Ft. Vertical Correction > 7 0
64.3 Ft. True Depth ak 's 80
Be A) 90
10 10 100
Fig. 186.—Alignment chart for determining vertical corrections in crooked
holes.
5 deg. off the vertical the cosine rule will give a correct
vertical distance of 199.24 ft. and the versine rule will
give the same. Table IX! shows tabulated data, the
results of several such examples as the above.
Plate XVII shows Miuilliken’s chart? for the graphic
determination of vertical corrections in crooked holes. It
is drawn on logarithmic paper, the off-vertical angles being
1 By the courtesy of R. Van A. Mills, of Petroleum Engineering.
2 Charles V. Milliken, of the Amerada Petroleum Corporation, in Oil
Gas Jour., p. 102, 1930.
PROBLEMS 279
represented by diagonal lines. The measured interval
scales are shown on the left and right margins. Pick off
the proper measured interval on the left or right margin
and follow the horizontal line from this point on the meas-
ured interval scale to its intersection with the proper
off-vertical line. From here follow a vertical line to the
upper or lower margin, as the case may require, where
the vertical correction in feet is indicated.
TaBLeE [X.—EXAMPLE AND Form or Notes For VERSINE VERTICAL
CorRECTION METHOD
“ease Off-vertical REGO, Vertical | Corrected | Total true
from point of natural 5
angles, ‘ correction, | measure- depth,
last measure- versine
degrees feet ment, feet feet
ment, feet of angle 2
200 5 0.0038 — 0.76 199.24 199.24
190 10 0.0152 — 2.89 AS etal 386.35
195 24 0.0865 —16.77 178.23 564.58
220 6 0.0055 — 1.21 218.79 783 .37
240 15 0.0341 — 8.18 | 231.82 1,015.19
238 a 0.0075 — 1.79 | 286.21 1,251.40
242 9 0.0123 — 2.98 | 239.02 1,490.42
256 6 0.0055 — 1.41 254.59 1,745.01
239 30 0.1340 —32.03 | 206.97 1,951.98
250 25 0.0937 —23.43 226.57 2,178.55
Total 2,270 ENT ngs een ea: == Ia ale 2178.05
BIBLIOGRAPHY
ABBREVIATIONS IN THE LITERATURE INDEX
Ja iaa\ oJ EM Gel Bop
A.I.M.M.E.
A.I.M.E.B.
A.M.B.
A.M .P.
Bulletin of the American Association of Petroleum
Geologists, Tulsa, Oklahoma.
American Institution of Mining and Metallurgical
Engineers, New York.
American Institution Mining Engineers Bulletin, New
York.
Annales des Mines, Belgique, Brussels.
Annales des Mines de Paris, Paris.
Analele Minelor din Romania, Bucharest.
American Patent, Washington.
American Petroleum Institution Bulletin.
British Association Report.
Bergbaukunde.
Berg-und Hiittenmannische Jahrbuch, Loeben.
Berg-und Hiittenminnische Zeitung.
Canadian Mining Journal, Gardenvale, Canada.
Colliery Engineering, London.
Colliery Guardian, London.
German Patent.
Engineering, London.
Engineering and Mining Journal, New York.
Elektrotechnische Zeitschrift, Berlin.
Gliickauf, Essen.
Institution of Petroleum Technology, London.
Internationale Zeitschrift fur Bohrtechnik, Erdélbergbau,
und Geologie, Vienna.
Tron and Coal Trades Review, London.
Jernkontorets Annaler, Stockholm.
Journal of Geology.
Journal of the Institute of Petroleum Technologists,
U.S.A.
Journal of the South African Association of Engineers,
Johannesburg.
Journal of the South African Institute of Mining Engin-
eers, Johannesburg.
Kali, Halle, Saale.
Kohle und Erz, Berlin.
Mining Journal, London.
Mining Magazine, London.
Mitteilungen aus dem Markscheiderwesen, Freiberg.
281
282 DEEP BOREHOLE SURVEYS AND PROBLEMS
NEPENG
N.S.K.
0.A.
O.B.
O.B.Z.
O.F.E.
0.G.J.
O.V.B.
O.W.
ats
P.AG.
Pet.
P.E.
Proc. L.S.M.I.
IPip, Ake
Pie
P.W.O.A.
S.A.M.J.
TAI.M.E.
DP IEMeE:
T.I.M.M.
U.S.B.M. Bull.
U.S.B.M.R.
U.S.GS.
Z.DGG.
ZI.B.Y.
Z.1IV.B.B.
National Petroleum News, Cleveland, Ohio.
Neftianoe i Slantzenoe Khoziaistvo, Moscow.
Oil Age.
Oil Bulletin.
Osterreichische
Vienna.
Oil Field Engineering, Philadelphia.
Oil and Gas Journal, Tulsa, Oklahoma.
Organ des Verein der Bohrtechniker, Vienna.
Oil Weekly, Houston, Texas.
British Patent, London.
Pan-American Geologists.
Petroleum, Berlin.
Petroleum Engineer.
Proceedings of the Lake Superior Mining Institute.
Preussisch Zeitschrift, Berlin.
Petroleum Times, London.
Petroleum World and Oil Age.
South African Mining Journal, Johannesburg.
Transactions of the American Institution of Mining
Engineers, New York.
Transactions of the Institution of Mining Engineers,
London. ,
Transactions of the Institution of Mining and Metallurgy,
London.
Bulletin of the United States Bureau of Mines.
United States Bureau of Mines Report.
United States Geological Survey, Washington.
Zeitschrift der deutschen geologischen Gesellschaft,
Stuttgart.
Zeitschrift des Internationalen Bohrtechniker Verbandes,
Berlin.
Zeitschrift des Internationalen Vereines der Bohringen-
ieure und Bohrtechniker, Vienna.
Zeitschrift. Berg-und Hiittenwesen,
BIBLIOGRAPHY
ApaM, D.: Shaft Sinking by the Freezing Process, C. Hng., Notes on Tele-
clinograph, p. 409, November, 1924.
AmBRONN, R.: ‘“Methoden der Angewandten Geophysik,’’ Steinkopff, Leipzig,
1926.
AMBRONN, R., and MarGareT Coss: ‘‘Elements of Geophysics,’’ MeGraw-
Hill Book Company, Inc., New York.
AnppRSoN, A.: Crooked Work Shown in Survey of 2,000,000 ft. of Rotary
Hole, P.W.O.A., p. 64, April, 1929; O.A., April, 1929.
: Underground Survey of World’s Deepest Well. Shows Deviation
of Hole, 0.A., p. 20, September, 1926; P.W., September, 1926; O.G../.,
p. 29, Sept. 9, 1926.
: Notes on Underground Surveys of Oil Wells, New York Meeting
A.I.M.M.E., February, 1929.
: Progress in Straight-hole Drilling, O.G.J., p. 34; May 1, 1930;
O.F.E., p. 16, May, 1930.
Atwoop, J. T.: Photographic Survey of Boreholes, #.M.J., p. 944, May 18,
1907.
Baxgmr, C. L.: Geological Cross Section of Isthmus of Tehuantepec, P.A.G.,
Vol. 53, No. 3, pp. 161-174, April, 1930.
Baxur, W.: New Machine for Determining Vertical Direction of Oil Tests:
Driftmeter, O.W., p. 40, Mar. 28, 1930.
BauLoues, J. C.: A New Well-surveying Instrument, O.B., p. 156, Febru-
ary, 1930.
Barton, D. C., and E. Summers : Review of the Geophysical Methods of
Prospecting, Geographical Review, pp. 288-300, New York, April, 1930.
Becker, C. M.: Structure and Stratigraphy of Southwest Oklahoma,
A.A.P.G.B., Vol. 14, No. 1, pp. 37-56, January, 1930.
BIGNELL, L. G. E.: Electric Coring, O.G.J., p. 33, Feb. 6, 1980.
: Symposium on Straight-hole Problem, O.G.J., pp. 49, 167-74, June
6, 1929.
Buack, L. J.: Discussion of Crooked-hole Problem, O.G.J., p. 30, Nov. 29,
1928.
Buumer, E.: ‘‘ Die Erdéllagerstatten,”’ p. 337, Enke, Stuttgart.
Boyp, R. R.: Danger of Crooked Holes, O.F.H., p. 49, May, 1927.
BRINDEL, H. F.: Corrections for Crooked Holes, 0.G.J., pp. 41, 101-104,
Apr. 11, 1929.
Brown, C. B., and F. DrsEnuam: ‘“‘Structure and Surface,” Chap. XI for
block diagrams, Edward Arnold, 1929.
Busk, H. G.: ‘‘Harth Flexures,’’ Chaps. I-IV for graphical problems,
Cambridge University Press, 1929.
Case, J. W.: “‘Boreholes and Borehole Machinery,” London.
Cartwricut, R. 8.: Discussion of Crooked-hole Problem, 0.G.J., p. 39,
Sept. 6, 1928,
283
284 DEEP BOREHOLE SURVEYS AND PROBLEMS
———: Rotary Drilling Problem, A.I.M.M.E., pp. 9-29, 1929; O.W., p.
41, Nov. 2, 1929.
Carney, S. C.: National Gas, /.P.T., Vol. 16, No. 80, pp. 118-24, March,
1930.
CavaLuier, M., and M. Dausine: Basket Method of Plumbing, A.M.P.,
Vol. 18, p. 392.
Cuatmers, R. M.: ‘“‘Geological Maps,” Chaps. VIII and IX for problems,
Oxford University Press, 1926.
CuauMErsS, T. W.: ‘‘The Gyroscopic Compass,’”’ D. Van Nostrand Com-
pany, Inc., New York, 1920.
CHAMBERLAIN, R. T.: Injustice of Misleading Citations, A.A.P.G.B., Vol.
14, No. 4, pp. 521-522, April, 1930.
: Appalachian Folds of Central Pennsylvania, J.G., Vol. 18.
CHANNING-PaRKE, L.: Deviations in Lake Superior District, Proc. L.S.M.I.,
Vol. 2, p. 23, 1894.
Cueney, M. G.: Pre-Mississippian Production in Texas, O.G.J., p. 31,
Apr. 12, 1928.
Cuupp, G. T.: Crooked-hole Problem, Ploesti, Rumania, O.G.J., p. 104,
Feb. 7, 1929.
Coss, S. W.: Making Oil Wells Straight, O.G.J., pp. 7-8, May,
1929.
Cooxg, L. H.: Magnetism of Drill Rods, 7.J.M.M., Seventeenth Session.
p. 126, 1907.
Coxes, E. B.: A New Method of Sinking Shafts, 7.4./.M.E., Vol. 1, pp.
216-276.
Cummines, W. R.: The Crooked-hole Problem, 0.G.J., p. 41, Sept. 13, 1928.
Curtiss, L. S.: Theory of Borehole Deflections, S.A.M.J., Vol. 8, Part 1,
p. 425; J.S.A.I.M.E., Vol. 9, No. 8, p. 199, 1911.
Davis, Watutacre: Crooked-hole Problem Minimized in Burma, O.W.,
p. 31, May 17, 1929.
Deime., R. F.: ‘‘Mechanics of the Gyroscope,’ Macmillan & Co., Ltd.,
1929.
Dickinson, J.: Deviation of Boreholes, 7.1.M.E., Vol. 35, p. 396.
Doves, J. E.: Straight-hole Drilling Practice in California, N.P.N., p. 45,
Dec. 11, 1929; O.B., p. 30, January, 1930; A.P.7.B., Vol. 11, No. 1,
p. 438, Jan. 2, 1930.
Dwyer, J. L.: Crooked Holes Cost Industry Vast Sum, O.G.J., p. 29,
Aug. 23, 1928.
: Little River Wells Run Together, O.G.J., pp. 78, 202, Dec. 29, 1927.
Epson, F. A.: Use of Diamond Drill in Oil Fields, 0.G.J., Dec. 24, 1920.
: Diamond Drilling for Production, A.A.P.G.B., Vol. 6, No. 2, p. 91,
1922.
: Diamond Drilling, U.S.B.M. Bull. 248.
Euuiott, R. D.: Straight Drilling of Rotary Holes, O.G.J., p. 49, May 9,
1929; O.B., pp. 590-591, June, 1929.
ERLINGHAGEN O.: Die Feststellung des Fallens und Streichens von Tiefbohr-
léchern durch Messung, Gl., June 8, 15, 1907.
Estaprook, E. L.: An Alibi for Geologists, A.A.P.G.B., Vol. 9, p. 1295.
Farnswortu, H. R.: The Relation of Boreholes to the Vertical and the
Effect of Geological Conclusions, O.B., p. 384, April, 19380.
BIBLIOGRAPHY 285
Fauck, A.: Konstatierung von Kohle in Bohrléchern, 0.V.B., p. 274, Nov.
20, 1910.
FeTrKs, C. R.: Recent Developments in Flooding Practice in the Bradford
and Richburg Oil Fields, A.J.M.M.E., p. 30, New York, 1930.
FLorIn, JEAN: Compass and Camera Survey, #.M.J., Vol. 87, p. 854.
: Enregister l’orientation des strates au fond des trous de sondage,
A.M.B., Vol. 18, p. 781, 1908.
: Abstract from Annales des Mines de Belgique, H.M.J., Vol. 47,
p. 854, 1909.
Foraky, Company: Sociétié Anonyme Belge d’entreprise de forage et
foncage, Prospectus Brussels.
Forpuam, W. H.: Geophysics, J.P.T., Vol. 16, No. 80, pp. 97-107, March,
1930.
Freisg, F.: Die Entwicklung der Stratameter, O.B.Z., Nos. 41, 42, 48,
October, 1906.
FRIEDENREICH, O. L.: Le Téléclinographe Denis Foraky pour la mesure de
la deviation des surdages, A.M.R., p. 698.
Fuuier, M. L.: Magnetic Wells, U.S.G.S., Water Supply Paper 341.
GaALLAcHER, W.: Instrument for Surveying Boreholes, Pat. No. 158,937.
GLAZEBROOK, R.: Gyroscopic Notes, ‘‘Dictionary of Applied Physics,”’
Vol. 1, p. 42.
Goutpman, O. B.: Modern Well Drilling Is Straightening Our Crooked-hole
and Twist-off Evils, P.W.O.A., pp. 46-7, 121, January, 1929.
: The Torque Question, O.G.J., p. 34, Jan. 24, 1929.
Goopman, J.: Apparatus for Determining the Inclination and Direction of
Boreholes, Pat. No. 23,003.
GoopricH, H. B.: Pioneers Had Crooked-hole Problems, O.G.J., p. 109,
Apr. 4, 1929.
: Crooked-hole Problem Being Studied, O.G./., p. 38, Nov. 15, 1928;
Importance of Crooked-hole Problem, O.G.J., p. 165, Nov. 15, 1928.
GoTHAN, H.: Improvements in Apparatus for Borehole Deflection, Pat.
Nos. 21,183 and 2,220.
Happock, M. H.: ‘‘Location of Mineral Fields,’’ Chaps. IV and V, Crosby
Lockwood, London, 1926.
: ‘Disrupted Strata,’’ Chap. II, Crosby Lockwood, London, 1929.
: The Development and Present Status of Geophysical Methods of
Prospecting, C.G., May to September, 1927.
Hauper, W.: Verfahren zur Messung des Abweichens der Bohrlécher von
der Senkrechten, GJ., p. 108, Feb. 15, 1919.
Hat, O., and V. P. Row: Wedging Diamond Drilling, A.J.M,.M.E., Vol.
63, p. 413, for notes on Maas’ Method.
Haropison, H. C., and W. W. Warnzr: Frequent Surveys Check Crooked
Hole, 0.G.J., pp. 104, 191, 192, Apr. 4, 1929; O.W., pp. 49-96, Apr. 12,
1929.
Harris, H. M.: Acid-bottle Method of Surveying Holes, O. W., pp. 47, 48,
May 3, 1929.
Haseman, W. P.: Drill-pipe Flexure and Crooked Holes, P.E#., p. 49,
October, 1929.
Hatcu, F. H.: Oehman’s Instrument, A.P., 1905.
286 DEEP BOREHOLE SURVEYS AND PROBLEMS
Haussmann, K.: M.M., Heft 9, 1908; Der Borhléchneigungsmesser von
Anschiitz, Gl., No. 27, p. 1074.
: Ein neuer Lot-Apparat fur Bohrlécher, Gl., p. 217, February, 1908. :
Haywoop, J. T.: Mud Fluid Pressures and Their Relation to Straight-hole
Drilling, P.E., p. 45, December, 1929. O.G.J., p. 51, Dec. 5, 1929;
WY PINs os (Sy Lies WLS EPL
: Theory of Tension in Drill Pipe in the Drilling of Straight Holes,
OG I. p. L477, Octs 71929:
: Torque Indicator Problem Discussed, p. 30, Ploesti, Rumania,
Nov. 29, 1928.
Heap, K. C.: Determination of Geothermal Gradients, O.G.J., Dec. 5,
1929.
Heatu, H. F.: On Recording Borehole Data: Legal Notice, M.J., Nov. 27,
1926.
HernricnH, O. J.: Diamond Drill for Deep Boring Compared with Other
Systems, 7.A.I.M.E., Vol. 2, p. 241.
HeEmpELL, B.: Plumbing Apparatus, J.Z.B., p. 73, Apr. 15, 1930.
Hesetpin, G.: Drilling and Production Methods in the Greater Seminole
Field, Oklahoma, J.J.P.T., Vol. 14, pp. 7834824, December, London.
Hiuu, E. F.: Recommendation for Better Drilling, O.G.J., p. 126, Apr. 10,
1930.
HorrMann, J. I., Oehman’s Instrument, 7.J.M.M., Apr. 18, 1922.
Hornocyu, A.: B.H.J., Bd. 73, Heft. 2, for problem notes, 1925.
Howe tu, J. V.: Notes on the Prepermian Paleozoics of the Wichita Moun-
tain Area, A.A.P.G.B., Vol. 6, No. 5, pp. 413-425, September, October,
1922.
Hupson, F. 8., and N. Tattarerro: An Interesting Example of a Survey
of a Deep Borehole, A.A.P.G.B., pp. 775-785, August, 1926.
Ickes, L. E.: The Determination of Formation Thicknesses by the Method
of Graphical Integration, A.A.P.G.B., Vol. 9, p. 451, May, June, 1925.
Inuinc, V. C.: Petroleum Geology, /.P.T., Vol. 16, No. 80, pp. 91-96,
London, March, 1930.
JauR, E.: Der Stratigraph, M.M., Heft 7, p. 1, 1905.
Janson, C.: Notes on Horizontal Boreholes, Proc. L.S.M.I., Vol. 2, p. 48;
Vol. 2, p. 26, 1894.
JENNINGS, J.: On Magnetism of Rods, J.S.A.A.#., Vol. 12, p. 7, 1906.
Jones, H. H.: Drilling Straight Holes by Gravity, O.B., p. 591, June, 1929.
JusticE, J. N.: Demerara Ore Deposits, T7.1.M.M., Oct. 27, 1921.
KEGEL, K.: Verfahren und Vorrichtung zur Erzielung geradliniger Bohrlécher,
D.R.P. No. 317,663; Z.7.V.B.B., No. 8, p. 61, Apr: 15, 1920:
Kenpauu, P. F.: Determination of the Direction of the Dip of Rock in
Deep Boreholes, Pat. No. 5470.
Kitcuen, J.: The Deviation of Rand Boreholes, J.S.A.A.H., March, 1907.
Kuiewitz, O.: Das Ausfuhrungsgesetz, das Erdél, Pet., No. 49, p. 1638.
Korsricu, A.: Notes on Kind’s Method, Pr. Zt., Vol. 36, p. 256, 1888.
Koerner, G.: Improvements Relating to Measuring Devices for Deep
Boring Apparatus, Pat. No. 7797.
Kouter, A.: Basket Method of Plumbing, Vol. 1, p. 634; B.H.Z., p. 276,
1901.
BIBLIOGRAPHY 287
Lanes, F. H.: Problems of Crooked Holes, A.A.P.G.B., pp. 1095-1164,
September, 1929; Bibliography, O.W., pp. 29-38, Mar. 29; pp. 27-34,
78-88, Apr. 5, 1929; O.G.J., pp. 38, 150-152, Mar. 28, 1929.
: Problem of Crooked Holes, O.W., p. 34, Aug. 31, 1928.
: Study of the Crooked-hole Problem, A.A.P.G.B., pp. 853-859,
July, 1929.
: Research Provinces in Crooked-hole Problem, p. 30, Nov. 29, 1928.
: Research Notes: Crooked-hole Problem, A.A.P.G.B., p. 635, May,
1930.
Lerernzon, L. 8.: Exploitation of Curves of Oil Wells, etc., N.S.K., Vol. 6,
No. 1, p. 40, 1924, Russian, English Summary.
Lerru, C. K.: ‘Structural Geology,” rev. ed., pp. 196-99, Henry Holt &
Company, New York, 1923.
Lescuot, J. R.: First Rotary Core Drill, U. S. Patent No. 39,235.
Ling, T. A.: Some Applications of the Strain Ellipsoid, A.A.P.G.B., Vol. 13,
No. 2, p. 1450, November, 1929.
: Author’s Reply, A.A.P.G.B., Vol. 14, No. 2, February, 1930.
Lockwoop, C. D.: Acid Tests Reveal-Crooked Holes in Winkler County,
Texas Oil Report, Fort Worth, Dec. 12, 13, 1928.
Lows, W. F.: New Electric Well Surveying Device Simplifies Long Opera-
tion, NV.P.N., Jan. 29, 1930.
LunpserG, Sven: Borehole Surveying by the Kiruna Method, #.M.J/.,
Feb. 8, 1923.
: Kiruna Borehole Instrument, H.M.J., p. 690, 1924.
Macreapy, G. A.: Orientations of Cores, A.A.P.G.B., May, 1930.
MaitiarD, G.: Plumbing Apparatus, D.R.P., No. 492,573.
Matampuy, M. C.: Seismic Method of Determining Deviation of Drill
Holes, O.W., Apr. 26, 1929.
MartTIENSSEN, O.: Der Kreiselkompass in Schachtbau, #.Z., p. 462, June
17, 1920; p. 694, 1919; pp. 862, 887, 1911.
Martin, W. R.: The Crooked-hole Problem Further Discussed, 0.G.J.,
p. 165, Nov. 15, 1928.
Marriott, H. F.: Deep Borehole Surveying, 7./.M@.M., Vol. 14, pp. 255-
270.
McKez, E. J.: Causes and Effects of Crooked Holes, 0.G.J., p. 51, Nov.
22, 1928; O.W., p. 60, Nov. 23, 1928.
McLaueuuin, R. P.: Accuracy of Borehole Surveying by Orientation from
the Surface, O.W., p. 28, Mar. 21, 1930.
: Borehole Surveying by Orientation, O.G.J., p. 102, Mar. 27, 1930.
A.A.P.G.B., May, 1930.
Meap, W. J.: Discussion, A.A.P.G.B., p. 236, Vol. 14, No. 2, February, 1930.
Mitts, B.: Underground Surveying New Standard Practice in California,
O.W., May, 16, 1928.
: Developments in Acid-bottle Surveying Aid Accuracy, O.W., p.
35, Feb. 14, 1930.
Mitts, R. Van: Discussion of Engineering Problems, O.G.J., p. 41, Sept.
13, 1928.
: Crooked Holes Discussed by Engineers, O.G..J., p. 30, Aug. 23, 1928.
Mintrop, L.: Der Lotapparat fur Bohrlécher von Prof Haussmann, M.M.,
Heft 9, p. 52, 1908.
288 DEEP BOREHOLE SURVEYS AND PROBLEMS
Morris, A. B.: Formulae for Acid-bottle Determinations in Crooked-hole
Tests, O.W., p. 30, Jan. 10, 1930.
Mouttor, F. G. D.: Much Trouble Caused by Crooked Holes, O.W., pp.
27, 29, 30, Apr. 19, 1924.
Morpuy, P. G.: Correcting Crooked Holes at Barbers Hill, O.W., p. 31,
July 19, 1929.
-and 8. A. Jupson: Crooked-hole Problems on Gulf Coast, 0.G.J.,
p. 106, Mar. 27, 1930. O.W., p. 28, Mar. 21, 1980. A.A.P.G.B., May,
1930.
Netson, T. M.: Crooked Holes, Popular Mechanics, pp. 760-765, May, 1929.
Owens, J. S.: A New Instrument for Surveying Boreholes, 7.J.M.M.,
Jan. 21, 1926; Eng., Jan. 15, 1926.
ParpEE, H. N.: Causes and Prevention of Crooked Cable Tool Holes,
P.E., p. 33, February, 1930.
Parsons, A. T.: Timeliness Important in Checking Deviation of Crooked
Holes, P.#., p. 118, March, 1930.
: Causes and Prevention of Crooked Holes, O.B., pp. 587—588, June,
1929.
PEELE, R.: Deviation of Boreholes and Methods of Surveys, ‘‘ Mining Engi-
neers’ Handbook,” pp. 369-376, 1918.
PrenNtNGTON, H.: Crooked-hole Problem, O.G.J., p. 32, Bibliography, Mar.
14, 1929.
Peterson, W.: Kiruna Instrument, J.A., p. 224, 1922.
Power, J.: Drilling Contractor Develops Method of Keeping Holes Straight,
N.P.N., p. 63, Apr. 10; 1929.
: Progress in Charting Bore Vagaries, p. 458, H.M.J., Sept. 21, 1929.
Repick, F.: Crooked Holes, Iraan. Tex., Jan. 24, 1929.
REDMAYNE, R. A. S.: ‘‘Modern Practice in Mining,” Vol. 1, p. 172,
REINHOLD, T.: Photographic Apparatus, Pat. No. 226,079; C.G., p. 570,
August, 1926; Pet., No. 19.
Risen, C. O. and J. R. Bunn: Petroleum Engineering in the Cromwell Oil
Field, U.S.B.M.R., Dec. 1, 1924.
Rosinson, J. F. and J. A. Montcomsry: Deep Drilling in the Appalachian
Field with Cable Tools, O.F.E., pp. 26-31, Aug. 1, 1928.
Rosinson, R. R.: Straightening Crooked Holes with Orientated Whipstock,
O.F.E., p. 19, March, 1930.
Rumpr, K. and P. KLernnHenn: Apparat fur Bestimmung von Abweichung
des innern Durchmesser von Rohren, Pet., No. 14, p. 430.
RussEuu, J. H.: Heavy Penalties of Crooked Hole, O0.G.J., p. 104, Apr. 4,
1929.
ScuaTer, K. C., and J. StepHENSON: Method of Obtaining Bottom-hole
Data, O.G.J., p. 114, Oct. 25, 1928; also N.P.N., p. 59, Oct. 31, 1928.
ScuaTer, K. C.: Straight-hole Drilling, P.E., p. 21, October, 1929.
SCHLUSSELBERG, M.: Einige Ursachen der Entstehung von krummen
Bohrléchern und davon Behebung, Pet., No. 49, p. 1628, 1930.
Scumipt, F.: On Basket Plumbing, 7.J.M.E., Vol. 52, No. 2, p. 178, 1916-
1917.
ScHuUEMANN, A.: ‘‘Die Baumaschinen,”’ Vol. 2, p. 119, Leipzig, 1924.
ScHNEIDER, A.: Der Stratameter von Gothan, M.M., p. 37, 1902.
BIBLIOGRAPHY 289
Scuwernitz: Neuere Verfahren zur Erlangung zuverlissiger Bohrergebnissc,
Gl., p. 418, Mar. 18, 1911.
SHaw, H.: Field Test with a new Seismograph, M. Mag., p. 201, April, 1930.
Sitent, R. A.: Drill-pipe Tension and Straight Holes, O.G.J., p. 110, Feb.
20, 1930.
Simons, T.: Calculation of Strike and Dip, #.M.J., p. 753, Apr. 4, 1914.
Smitey, T. F.: Committee Will Study Crooked Hole, 0.G./., p. 39, Nov. 22,
1928.
: New Invention Designed to Show Hole’s Deviation from Vertical,
0.G.J., pp. 44, 150-151, Apr. 25, 1929; Tulsa Geological Society Hears
Talks on Crooked-hole Problem, O.G.J., p. 232, Mar. 7, 1929.
Smitu, F. M.: Two California Companies Discover They Are Drilling in
Same Hole, 0.G.J., p. 181, Apr. 29, 1926.
: Lateral Drift of Holes in Deep Drilling Shown by New Apparatus,
O:G.J., pp. 120-123, 127, Sept. 2, 1926.
: Surveying Oil Wells with Anderson’s Apparatus, #.M.J., pp. 241—
246, Feb. 6, 1926; O.B., March, 1926.
Smitu, L. E.: Crookedness of Deep Holes Determined by Acid-bottle
Method, N.P.N., pp. 50-A, 50-B, July 21, 1926.
Snow, D. R.: Cause and Effect of Crooked Holes, 0.G.J., pp. 109, 218,
Apr. 4, 1929.
Stockman, L. P.: To Cut California 145,156 Barrels, 0.G.J., p. 44, Apr. 25,
1929.
SturzEr, O.: Uber zwei Gesteine aus Rumiinischen Olbohrungen, Z.D.G.G.,
p. 537, Heft 10, Bd. 81, 1928.
Svimonorr, Victor: Method of Checking Vertical Wells, P.W., p. 382,
London, September, 1925.
: Magnetism affecting Drilling, 0.G.J., p. 124, Feb. 7, 1924.
TERwILuIGER, H. L.: Discussion of Paper on Rock Drill and Drill Steel,
#.M.J., p. 1128, Dec. 29, 1923.
Tureve, P.: Horizontalbohrungen Abweichung, K., p. 32, Jan. 15, 1913.
Tuomas, C. S.: Crooked Holes and Other Crooks, 0.B., pp. 698, 767, July,
1929.
Tuompson, A. B.: Oil-field Practice in 1927, J.J.P.T., pp. 108-117, Vol. 16,
March, 19380.
TuHuRMANN, H.: Lotapparate fur Bohrlécher, O.V.B., p. 189, Sept. 1, 1909.
: The Gothan Stratameter, Gl., pp. 55-57, Jan. 18, 1902.
TREWARTHA-JAMES, W. H.: Discussion on Drill Holes, Twenty-first Session,
Seventh General Meeting, Institute Mining and Metallurgy, London.
Van Covuverine, M.: Courses of Drill Holes, A.A.P.G.B., pp. 109-116,
Vol. 18, February, 1929.
: O.A., p. 34, December, 1928; P.W.O.A., p. 47, November, 1928;
O.B., p. 1259, December, 1928.
: Why Good Holes Go Wrong, O.B., pp. 588-590, June, 1929.
Vance, H.: A Discussion of Methods Used in Interpretation of Crooked-
hole Data, P.E., p. 76, March, 1930.
Vienna Branch of the Society of Boring Technicians Conference, 1910
O.V.B., Nos. 5, 6, 7, 17, 19, 20, 1910.
Waaener, Pauu: Crooked Holes, How to Overcome Them Studied by
Enquiries, V.P.N., p. 29, Apr. 3, 1929.
290 DEEP BOREHOLE SURVEYS AND PROBLEMS
———:; Instruments Measure Declination of Drill Hole and Dips of Strata,
N.P.N., p. 61, Apr. 16, 1930.
Weer, M. J.: Cyclical Sedimentation of the Pennsylvanian Period: Its
Significance, J.G., Vol. 38, pp. 97-135.
Westsmitu, H. W. and L. R. Coox: Crooked and Drifting Holes, O.B.,
pp. 577-585, Bibliography, June, 1929.
: Its a Deep Well that Has no Turning, P.W.O.A., p. 67, February,
1930.
Wuetton, J. T.: Surveying of Boreholes, /.C.T.R., p. 1028, June 27, 19380.
Wuitsr, EK. E.: Dip of Bed from Drill Cores, H.M.J., Vol. 98, No. 12, p.524,
Sept. 19,
: Surveying and Sampling Diamond-drill Holes, 7.A.J.M.E., Vol.
44, pp. 69-90, 1912.
WHITEFORD, W. K.: Straight-hole Practice, N.P.N., pp. 37-41, June 5,
1929; pp. 56, 57, 59. June 12, 1929; O.W., pp. 21, 22, 99-101, June 7,
1929; Oil Producer, pp. 3, 4, 11, May, 1929.
WIMMELMANN, B.: Das Kreiselkompass, K.H., Nos. 138-15, p. 323, 1924.
Wour, A. G.: Measuring Depth Accurately in Rotary Drilling, #.M.J/.,
Dec. 29, 1923.
Wotr, M.: Core Orientor, D.R.P. No. 47,221.
WorzasEk, F.: Wearing of Boring Chisels and the Conclusions to be Inferred
Therefrom, Z.J.B.V., p. 178, July 20, 1928.
WyrserG, W.: Diamond Drilling in the Transvaal, 7.J.M.M., Vol. 6, pp.
164-174.
Zprit, A.: The Deflection of Boreholes in Diamond Drilling on the Rand,
T.1I.M.M., Vol. 14, p. 255.
INDEX
A
Absolute check on surveys, 53
Accuracy of borehole surveys, 50
Acid-bottle record, 53, 95
Action of gyrocompass, 208
Advantages, of fluid methods of
survey, 97
of seismic methods, 245
Alignment charts for deviated holes,
276, 278
Ambronn, A., cited, 34, 229
Anderson, A., quoted, 5
Anderson’s apparatus, 200
Anschiitz apparatus, 216
Anschiitz-Kaempfe’s device, 10
Anschiitz-Kaempfe’s gyrocompass,
206
Apsidal angle and plane, 114
Atwood’s apparatus, 176
Audible or acoustic device, 11
Auxiliary registrations, 22
Axial dip in gyrocompass, 211
Azimuth gyroscope, 204
B
Bailing ropes, 1
Basket or lantern method of plumb-
ing, 41
Batteries, dry, 177, 179, 183
Bawdon’s apparatus, 134
Bearing of boreholes, 264
Benzine wash, 181
Bibhography, 283
Boreholes not at right angles to
strata strike, 255
to particular points, 261, 262
at right angles to strata strike,
248
Briggs’ clinophone, 141
Briggs’ horizontal clinoscope, 33
Briggs’ transmitter and receiver, 141
Brindel’s chart, 276
Bubble log and oscillations, 224
Burbach borehole pressure recorders,
31
C
Californian boreholes, 5
Camera devices, 78, 176, 179, 186,
223
Casing, 10
Centering devices, 153, 156, 164
Channing Park, cited, 8
Chanslor-Canfield borehole model,
39
Check surveys, 53
Circulating water, 10
Clinographs, 101, 220, 224
Clinometers, 104, 193, 198
Clinophone, 141
Clockwork, 59, 81, 87, 110, 123, 132,
137, 151, 156, 161, 220
Comparison of methods of survey,
52, 53
Compass methods, 121, 139, 181, 193
Conductivities of rocks, 230
Constrained gyroscope, 205
Continucus registrations, 22, 30,
36, 84, 94, 126, 145, 161, 166,
1938, 223
Controller, 196
Cooke, Prof. L. H., cited, 19
Copper sulphate method, 114
Core orientation, 48, 54
Core spin, 19
Correction device, 184
Cosine method, 276
Costs of borehole surveys, 50
Counter-dip borehole problems, 248,
249
291
292
Curvature, incipient, 10
Czuchow borehole, Upper Silesia, 25
D
Deep boreholes, 1, 8
Denis-Foraky teleclinograph, 166
Depth recorders, 26, 28
Deviation, angular, 2, 274, 275
causes of, 1, 15
factors influencing, 54
Diagrams, 170
Diameters of boreholes, 18, 28, 29
change in, difficulties due to, 29
irregularities in, 29
shrinkage, causes of, 29
Diamond-drilled holes, 3
Dickenson, J., cited, 18
Difficulties due to diameter change
in boreholes, 29
Dip, of boreholes, 49, 250, 260, 264
of strata, 22, 96, 177, 179, 256
Direction of beds, 256
Disadvantages of fluid methods of
survey, 97
Displacements, and depths of bore-
holes, 250, 251, 253, 264
horizontal and vertical, 2, 3, 6,
184, 203
Dixon’s gyrocompass device, 85
Double pendulums, 211, 162
Driftmeter, 151
Driftmeter record, 53
Drum devices, 190, 196
E
Electric coring, 231
Electrical geophysical methods, 225
Electrical liquefaction of gelatin, 109
Electrical methods of survey, 47,
111, 113, 156, 166, 127, 148
Electrolytic registration, 113
Electromagnetic examination of
ground, 226
Electromagnets, 158, 168
Equator and gyro-action, 209
Equi-potential lines, 145
and methods, 226, 227
DEEP BOREHOLE SURVEYS AND PROBLEMS
Equi-potential surfaces, 231, 232
Erlinghagen, O., quoted, 41, 76
Erlinghagen’s apparatus, 156
External photographic devices, 176,
179
F
Films, 175, 177, 179, 183, 189, 221
Fissured strata, 18, 182
Florin’s method, 77
Fluid methods, 47, 95
Foraky depth recorder, 26
Foucault’s law, 204, 212
‘“‘Freedom”’ of gyroscope, 205
Freezing-shaft holes, 7
Freise, F., cited, 62, 64, 76, 136
G
Gallacher’s apparatus, 137
Gelatine, 63, 102, 108
Geological causes of deviation, 17
Geophone, 240
Geophonic or seismographic meth-
ods, 48, 240
Geophysical methods of borehole
survey, 225
Goniometers, 105, 108
Goodman’s apparatus, 80
Goodrich, H. B., quoted, 6, 203
Gothan’s stratameter, 64
Graphical problem for boreholes, 271
Gravitation, 208
Ground wave coefficients, 234, 235
Gudgeon joints, 164
Guide rods, 191
Guide springs, 154, 188
Gyro-axis, 209, 210
Gyrocompass, 204, 211, 214, 217
Gyroscopic compass methods, 204
Gyrostatic methods of survey, 48,
83, 85, 204
H
Haddow’s method, 121
Hall and Armentrout’s device, 83
Hanna’s inertia-rotor apparatus, 87
INDEX
Hardness, of common minerals, 16
of strata, 15
Hatch, Dr. F. H., quoted, 182
Haussmann, Dr. K., quoted, 206,
216, 220
Haussmann’s apparatus, 185
Heiland, Dr. C., quoted, 245
Hillmer’s apparatus, 136
Hoffmann, J. I., quoted, 183, 185
Horizontal boreholes, 32
problems, 253
Hydrofiuoric acid, 97, 98, 108
I
Illumination of borehole walls, 177,
179
Inclined strata, 17
Incorrect centering at surface, 15
Incorrect plumbing adjustment, 45
Inclination measurer (Haussmann’s),
188
Inclined borehole problems, 250
Inclinometer, 171
Inertia-rotor method of survey, 48,
87
Inexpert tiller work, 29
Inking device, 174
Instrumental survey of boreholes, 46
Irregularities in borehole diameter,
29
J
Jahr’s depth and thickness method,
22
Jarring at core, 20
Jennings, J., quoted, 19
Justice, J. N., cited, 8, 31
K
Kegel’s apparatus, 146
Kendall’s apparatus, 58
Kiel Nautical Instrument Com-
pany’s apparatus, 211
Kind’s method, 55
Kinley’s apparatus, 171
Kiruna method, 112
293
Kitchen, Joseph, quoted, 2, 8, 17
Koebrich, A, cited, 55
Koebrich’s apparatus, 60
Koerner’s borehole survey device,
153
KXoerner’s core orientator, 74
L
Laboring of rig gear, 10
Lahee, Prof. F. H., quoted, 37, 54
Lame’s coefficient, 235
Lamps, 177, 188
Lapp’s core orientator, 74
Lapp’s stratigraph, 25
Latitude and gyro-action, 209, 212
Lengths of boreholes, 248, 250, 252,
263
Lesser deflection records, 41
Levels, 191, 220
Literature index abbreviations, 280
Log checks, 9
Love’s waves, 237
M
Maas’ method, 108, 109
Macfarlane’s apparatus, 111
MacGeorge’s clinograph, 101
MacGeorge’s clinometer, 104
MacGeorge’s core orientator, 63
MacGeorge’s guide tube, 107
Macready, G. A., quoted, 48, 55, 92
Macready’s method, 91
Magnetic needle methods, 47, 80,
88, 91, 99, 102, 118, 1382, 134,
138, 194
Magnetism of rods, 19
Magnets, 191
Maillard’s apparatus, 148
Malamphy’s seismic method, 240,
242
Manometer, 32
Marriott, H. F., cited, 15
Marriott’s continuously recording
device, 126
Marriott’s intermittently recording
device, 128
Martienssen, Dr. O., quoted, 216
294 DEEP BOREHOLE SURVEYS AND PROBLEMS
-Master borers, 9
Maximum and minimum thermom-
eters, 35
McCutchin, J. A., quoted, 36
McLaughlin, R. P., quoted, 52
Meine’s borehole survey apparatus,
109
Meine’s stratameter, 67
Meridian, true, 209, 212
Messenger weights, 67, 75
Methods of surveying, 47, 54
Milliken’s deviation chart, 277
Models of boreholes, 38
Moh’s hardness scale, 15
Méllmann’s apparatus, 131
Mommertz low temperature bore-
hole thermometer, 35
Moreni oilfield borehole, 1
Mud pressure, 54
Multiple photographic devices, 47,
94
Murphy, P. C., and 8. A. Judson,
cited, 50
N
Neighboring boreholes, 17
Nolten’s apparatus, 98
Nomographic methods, 276
North German Deep Boring Com-
pany’s stratameter, 71
Nutation, 208
O
Oehman’s apparatus, 182
““Off-vertical”’ angle, 50, 184, 276,
279
Ohm’s law, 232
Oil wells surveyed, 5, 6
Orientating, of cores, 48, 54
couplings, 117, 118, 158, 171
Otto-Gothan apparatus, 123
Oversetting diamond crowns, 18
Owens’ apparatus, 193
Ve
Packing rings, 179
Payne-Gallwey cited, 182
Pendulum methods, 47, 153, 166,
168, 173
Penetration distance from cores,
etc., 260
Penetration point
246, 262, 264
Petersson, Prof. W., cited, 113
Phials, 102, 108
Photographic methods, 47, 77, 93,
153, 166, 168, 173
Pilot wedges, 184
Plans of drill holes, 7, 38, 52, 172,
192, 202
Plastic cast method, 48
Plotted surveys of boreholes, 3,
7, 32, 38, 41, 52, 107, 119, 131,
162, 186, 199
Plotting borehole data, 37
Plumb-bob methods, 88, 121, 126,
128, 1384, 136, 1387, 141, 148,
182
Plumbing by lantern-basket method,
41
Plumbing cylinder, 187, 216
Plummet and magnetic needle meth-
ods, 47
Plungers, 77, 30, 147, 151
Poisson’s constant, 234
Polarization by Schlumberger, 228
Potential method, 226
Practical problems with boreholes,
262
Precession, 205, 206
Precipitation method, 112
Pressure on rods, 18
Pressure records, 31
Pricker or plunger methods, 48,
73, 75, 123, 186, U5iyelGie tas
Problems, 246
one borehole, 246
three boreholes, 269
two boreholes, 265
Profiles or sections of boreholes, 37
Progress records, 22
Progress reports, 10
Purposes of boreholes, 50
R
Rand boreholes, 2
Rankine, Dr. A. O., quoted, 238,
243
computations,
INDEX
Rapoport’s method, 76
Rayleigh waves, 237
Recorders, 160, 169, 172, 187, 219
Records, 192, 196, 198
Redmayne, Sir R. A. S., cited, 55,
64, 112
Reduction of borehole diameters, 18
Registering apparatus, 189, 219
Reinhold’s apparatus, 179
Requirements for successful survey,
46
Rigidity, of gyrocompass, 209, 222
of rods, 17
Rod abrasions, 10
Rods, 1
Rope recorders, 36
Rotation of rods, 20
Riihland’s apparatus, 100
Rumanian boreholes, 4
Rumpf and Kleinhenn’s apparatus,
29
Russian boreholes, 4
8
Sag of plumbing rope, 45
Schlumberger brothers quoted, 227
Schlumberger’s. method, 229
Schmidt, Prof. F., quoted, 41, 44
Scoring of core-box or casing, 10
Seismic methods, 233, 236, 242
Seismograms, 237, 239
Seismograph, 239
Seminole oilfield boreholes, 6, 52
Shaped notches, 47
Shortest borehole of all, 255
Shortest possible borehole at given
bearing, 254
Sinking shaft borehole, 262
Six’s thermometer, 35
Slanting boreholes, 255, 266, 274
Small boreholes, 18
Small diameter instrument (Kiruna),
113
Snow, D. R., cited, 6
Special joints, 162
Special three borehole problems, 273
Specific resistivity of rocks, 230
Sperry gyrocompass, 83, 220
295
Sperry-Sun apparatus, 220
Sperry-Sun Company’s
model, 40
Spin of boring tools, 20
Spinning axis, 205
Spontaneous polarization, 223
Static electricity of rods, 19
Strata profiles, 9
Stratameter, Gothan’s, 64
Meine’s, 67
North German Company’s, 71
Thurmann’s, 70
Stratigraph, Foraky’s, 27
Jahr’s, 22
Lapp’s, 25
Strike of bedding, 248, 256
Strip films, 91, 157, 173, 177, 179,
183, 189, 221
Stiitzer, Dr. Otto, quoted, 1
Surface receivers, 169, 219
Survey of boreholes, instrumental,
46
Surwel gyroscopic clinograph, 220
Swedish clinometer-goniometer, 105
Switches, 190
borehole
T
“Take-up”’ motor, 213
Teleclinograph, 166, 171
Temperature measuring devices, 34
Thermal surveys, 34
Thermometers for boreholes, 35, 222
Thickness of beds, 256, 260
Thiele, P., cited, 33
Three-borehole problems, 269, 271
all slanting, 274
special cases, 273
Thurmann’s borehole model, 39
Thurmann’s borehole survey appara-
tus, 162
Thurmann’s stratameter, 70
Time-travel curves, 244
Timing device, 200
Torque, 205, 206
Total depth problems, 252, 253
Transmitters, 171, 216
Transverse seismic waves, 235
True dip, 256
296
Two slanting boreholes, problem,
268
Two vertical boreholes, problem, 268
Types of surveys, 48
U
Upham and Dixon’s gyrostatic ap-
paratus, 85
Upstream boreholes, 250, 252
Upward deviation, 31
V
Van Orstrand, C. E., cited, 36
Versine method, 277
Vertical borehole problems, 248
Vertical correction, 6
by alignment chart, 279
DEEP BOREHOLE SURVEYS AND PROBLEMS
Vibrometer, 239
Vivian’s method, 57
WwW
Wache’s plumbing device, 42
Walls of borehole photographed,
hrs IEPA)
Waves, electrical, 226
seismic, propagation of, 235, 243
Weak core barrels, 18
Wheatstone’s gyroscope, 204
White, E. E., cited, 108
Wire plumbing, 42
Wiring diagrams, 142, 145
Wolff’s apparatus, 59
Z
Zenith angle and plane, 114
.) r
aes.
oh;
te af °
a
.
*
'*
‘
wd
®
*
%
LJ
J
.
%
be
«
a
*
a.
‘ed
Pry
.
*
. :
e
;
*
La
*
a
~
a > e
oP at Po” of Po?
*
ait
* DAI J
ae ee Se ae
s 3% 4
.