U.S. patent number 3,853,186 [Application Number 05/340,639] was granted by the patent office on 1974-12-10 for drilling assembly deflection apparatus.
This patent grant is currently assigned to Continental Oil Company. Invention is credited to Hilbert D. Dahl, Tibor O. Edmond, Gordon R. Haworth.
United States Patent |
3,853,186 |
Dahl , et al. |
December 10, 1974 |
DRILLING ASSEMBLY DEFLECTION APPARATUS
Abstract
An apparatus for deflecting the axis of a drill assembly has a
housing and a central shaft inside said housing where the shaft has
spaced surfaces contoured into the outer surface of the shaft.
Means are included for yieldably attaching one end of the shaft to
the outer housing. Engaging means are mounted rigidly to the
interior of the outer housing and in slidable contact with the
contoured spaced surfaces. Means are also provided for moving the
shaft along the length of its axis so that the contoured variations
will cause a change in the alignment of the outer housing with
respect to the axis of the shaft.
Inventors: |
Dahl; Hilbert D. (Ponca City,
OK), Haworth; Gordon R. (Glencoe, IL), Edmond; Tibor
O. (Ponca City, OK) |
Assignee: |
Continental Oil Company (Ponca
City, OK)
|
Family
ID: |
23334305 |
Appl.
No.: |
05/340,639 |
Filed: |
March 12, 1973 |
Current U.S.
Class: |
175/73; 175/24;
175/61 |
Current CPC
Class: |
E21B
7/068 (20130101) |
Current International
Class: |
E21B
7/04 (20060101); E21B 7/06 (20060101); E21b
007/04 () |
Field of
Search: |
;175/24,26,41,61,62,73 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: Miller; William J.
Claims
We claim:
1. An apparatus for deflecting the axis of a drill assembly
comprising:
a. an outer housing;
b. a piston means having spaced surfaces contoured into the surface
of said piston means;
c. means for slidably mounting said piston means;
d. engaging means mounted between said housing and said piston
means and in slidable contact with said spaced surfaces;
e. means for moving said piston means along the length of its axis;
and
f. means for yieldably attaching one end of said housing to said
means for slidably mounting said piston means, whereby longitudinal
movement of said piston means along its length will communicate the
variations in said contoured surfaces to the axial position of said
housing with respect to the axis of said piston means.
2. An apparatus as defined in claim 1 wherein said spaced surfaces
comprise three contoured surfaces spaced equal distance from each
other around the circumference of said piston means and having
interrelationship as defined in Tables 1 through 6.
3. An apparatus as defined in claim 2 wherein said engaging means
comprises a ring having three rollers positioned to engage said
three contoured surfaces and wherein the outer circumference of
said ring is mounted to said outer housing.
4. An apparatus as defined in claim 3 wherein said means for moving
said piston means along the length of its axis comprises a
hydraulic piston formed at the end of said piston means, a cylinder
wall coaxially mounted around said piston means to form a hydraulic
cylinder, hydraulic inlet means to said hydraulic piston, and
biasing means at the opposite end of said piston means.
5. An apparatus for deflecting the axis of a drill assembly
comprising:
a. a mandrel;
b. a tubular piston having an inner diameter dimensioned to
slidably fit over said mandrel;
c. a tubular piston cylinder having one end attached to said
mandrel and the other end extending over said tubular piston;
d. a first sealing means at one end of said tubular piston between
said piston and said piston cylinder;
e. a second sealing means between said tubular piston and said
mandrel;
f. hydraulic fluid inlet means to said first-mentioned end of said
tubular piston;
g. spring biasing means between said mandrel and the remaining end
of said tubular piston;
h. outer housing means;
i. means for yieldably attaching said outer housing means to said
mandrel;
j. contour means formed in the outer surface of said tubular
piston; and
k. engaging means mounted to said housing means and moveably
engaging said contour means whereby hydraulic pressure applied to
the end of said tubular piston will force said tubular piston along
the length of said mandrel against the force created by said
biasing means, said engaging means following the contour means
thereby positioning the axis of said outer housing with respect to
the axis of said mandrel in accordance with the configuration of
said contour means.
6. An apparatus as defined in claim 5 wherein said contour means
comprises two surfaces placed directly opposite each other on said
tubular piston.
7. An apparatus as defined in claim 5 wherein said contour means
comprises three surfaces formed in the outer surface of said
tubular piston, said contour means being spaced equal distance from
each other about the outer circumference of said tubular
piston.
8. An apparatus as defined in claim 7 wherein said contour surfaces
are formed in accordance with the mathematical interrelationship as
defined in Tables 1 through 6.
9. An apparatus as defined in claim 8 wherein said engaging means
comprises a ring having its outer periphery rigidly attached to
said outer housing and three rollers journaled on the inner
periphery of said ring and dimensioned to engage said three contour
surfaces.
10. An apparatus for deflecting the axis of a drill assembly
comprising:
a. an outer housing;
b. a deflection means having a contoured surface means;
c. engaging means mounted between said outer housing and said
deflection means and in slidable contact with said contoured
surface means;
d. means for positioning said contoured surface means with respect
to said engaging means to cause a resultant deflection in the
housing axis with respect to said deflection means; and
e. means for yieldably attaching said outer housing to said
deflection means.
11. An apparatus for deflecting the axis of a drill assembly as
described in claim 10 wherein said deflection means comprises a bar
having a rectangular cross-section and wherein said contoured
surfaces are opposite each other.
12. An apparatus for deflecting the axis of a drill assembly as
described in claim 10 wherein said deflection means comprises a
cylinder having an outer circumference in the configuration of a
helix.
13. An apparatus for deflecting the axis of a drill assembly as
defined in claim 10 wherein said deflection means comprises a
plurality of contoured surfaces, means for attaching said contoured
surfaces to said outer housing means, and wherein said engaging
means is mounted to said means for positioning the said contoured
surface means with respect to said engaging means.
14. An apparatus for deflecting the axis of a drill assembly as
described in claim 10 wherein said deflection means comprises a
cylinder having three contoured surfaces spaced 120.degree. apart
around the circumference of said cylinder.
15. A device as described in claim 14 wherein said contoured
surfaces have the mathematical inner relationship as defined in
Tables 1 through 6 when said contoured surfaces are formed by a
milling cutter having a diameter of 0.25 inch and wherein said
engaging means comprises a plurality of rollers in contact with
said contoured surfaces and wherein the diameter of said rollers is
0.25 inch.
16. An apparatus for deflecting the axis of a drill assembly
comprising:
a. a mandrel;
b. a tubular piston having an inner diameter dimensioned to
slidably fit over said mandrel;
c. a tubular piston cylinder having one end attached to said
mandrel and the other end extending over said tubular piston;
d. a first sealing means at one end of said tubular piston between
said piston and said piston cylinder;
e. a second sealing means between said tubualr piston and said
mandrel;
f. hydraulic fluid inlet means to said first-mentioned end of said
tubular piston;
g. spring biasing means between said mandrel and the remaining end
of said tubular piston;
h. outer housing means;
i. means for yieldably attaching said outer housing means to said
mandrel;
j. contour means attached to said housing means;
k. engaging means mounted to said tubular piston and movably
engaging said contour means whereby hydraulic pressure applied to
the end of said tubular piston will force said tubular piston along
the length of said mandrel against the force created by said
biasing means, said engaging means following the contour means
thereby positioning the axis of said outer housing with respect to
the axis of said mandrel in accordance with the configuration of
said contour means.
17. An apparatus for deflecting the axis of a drill assembly as
defined in claim 16 wherein said contour means comprises two
surfaces placed directly opposite each other on said outer housing
means.
18. An apparatus for deflecting the axis of a drill assembly as
defined in claim 16 wherein said contour means comprises three
surfaces formed in the inner surface of said outer housing means,
said contour means being spaced 120.degree. from each other as
measured from the axis of said mandrel.
19. An apparatus for deflecting the axis of a drill assembly as
defined in claim 18 wherein said contour surfaces are formed in
accordance with the mathematical inner relationship as defined in
Tables 1 through 6 by a milling cutter having a diameter of 0.25
inch and wherein said engaging means comprises a roller in contact
with each surface having a diameter of 0.25 inch.
Description
BACKGROUND OF THE INVENTION
In drilling either a vertical or horizontal bore hole, it may
become necessary to divert the direction of the drill. In the case
of a vertical bore hole, the diversion is generally accomplished by
mechanical means, such as a whipstock. Such devices are acceptable
when only a few diversions are required to drill the hole; however,
when the drill must be continuously guided, the use of a mechanical
diverter, such as a whipstock, becomes uneconomical, since the
drill and its associated equipment must be removed from the bore
hole each time the whipstock is inserted.
This invention relates to a method for drilling a horizontal bore
hole wherein the drill axis may be altered many times before the
bore hole is completed. In patent application Ser. No. 246,297,
filed Apr. 21, 1972, for "Drill Hole Guidance System" by
Haworth-Edmond-Poundstone. A system is described for determining
the locaton of a drilling assembly in relationship to the top and
the bottom of a seam of coal. Means are provided to guide the drill
by deflecting the axis of the drill so that the assembly will
always maintain a predetermined distance from the top or the bottom
of the seam. This invention relates to an improved method for
deflecting the axis of a drilling assembly through 360.degree.,
that is, the assembly cannot only be deflected up or down but in
any other direction as well.
BRIEF DESCRIPTION OF THE PRIOR ART
The patents relating to the above system generally fall into two
categories. The first category is those patents which permit
deflection through a single plane and accomplish the deflection by
some mechanical piston, arm, or the like. An example of this type
patent is U.S. Pat. No. 3,326,008 to Baran et al. The second
category of patents relates to devices for changing the direction
of the drill through 360.degree.. These inventions generally
accomplish the change by the movement of pistons and the like which
contact the bore hole wall. The amount of extension of each of the
pistons will determine the direction the drill will take. Patents
illustrative of the above are issued to Gaskell et al., U.S. Pat.
No. 3,141,512; Kostylev et al., U.S. Pat. No. 3,677,354; and
Fields, U.S. Pat. No. 3,593,810. In the second category also falls
most large tunneling machines which have adjustable supports for
orienting the axis of the drilling head of the machines with
respect to the axis of the previous tunnel drilled. This disclosure
illustrates a method for providing a 360.degree. control over the
drilling axis with a minimum control system which greatly
simplifies the apparatus over that disclosed in any of the prior
art patents.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1, 2, and 3 represent a complete drilling assembly. FIG. 1
illustrates a thrust system for forcing a horizontal drilling
assembly into the formation. FIG. 2 illustrates that portion of the
drilling assembly which provides directional control for the drill.
FIG. 3 illustrates the motor and drilling head for the
assembly;
FIG. 4 is a detailed drawing of the directional control
apparatus;
FIG. 5 is a perspective view of the preferred embodiment of the
control surface;
FIG. 6 is a cross-sectional view taken through lines 6--6 of FIG.
4;
FIG. 7 is a perspective view of a second embodiment of the control
surface illustrated in FIG. 5;
FIG. 8 is a two-dimensioned control surface embodiment; and
FIG. 9 is a cross-sectional portion of FIG. 4 illustrating a
modified placement of the contoured surfaces.
The same numbers will be used for identical parts throughout all of
the drawings.
Referring to all of the drawings but in particular to FIGS. 1
through 3, a horizontal thrust unit having a first portion 10 and a
second portion 11 is interconnected by means of hydraulic piston
shafts 12 and 13. Interconnecting hollow shaft 13 is connected
axially and rigidly to directional control apparatus 14. Drilling
apparatus 15 is rigidly coupled to position sensing appratus 17 and
contains a drill 16 at its terminus.
The thrust unit comprising first portion 10 and second portion 11
provides a means for applying pressure to drill 16. Thrust unit 10
comprises a plurality of pressure pads 20 on first portion 10 and
21 on second portion 11. Unit 11 contains internally, a hydraulic
piston (not shown) which is coupled to shaft 13. A plurality of
similar hydraulic pistons is also coupled to each of the pads 20
and 21. Drilling assembly 15 comprises an electric motor 22 and an
output shaft 23 which is coupled to the drill shank 24. A mud
source 25 is connected through a pipe 26 through an opening 27 in
the thrust units 10 and 11, through an opening 28 in deflection
unit 14 and through opening 29 to outlet holes 30. Flowing out of
outlet holes 30, the mud passes between the motor 22 and the
housing 31 to the opening 32 in the drill shaft. The mud is
expelled in openings at the terminus of the drill (not shown).
Thrust Unit
The thrust apparatus which comprises units 10 and 11, pads 20 and
21, and piston shaft 13 has thrust control inlet pipes 35 and
thrust control outlet pipes 36. Said pipes are connected to thrust
control system 37. The unit operates as follows:
Hydraulic pressure is applied to inlet pipes 35, applying hydraulic
pressure to the piston contained in unit 11, said piston being
attached to shaft 13. Simultaneously, the pads 21 are forced
outwardly against the side of the bore hole. Hydraulic fluid will
then increase the pressure against the piston inside unit 11,
moving shaft 13 through the unit in a direction to apply power to
drill bit 16. When shaft 13 has moved its maximum distance,
pressure is removed from the inlet pipes 35 and applied to the
second of the inlet pipes 35. Pressure in the second pipes 35 will
cause pads 20 to move outwardly and engage the wall, rigidly
securing unit 10. Pressure will then be simultaneously applied to
the other side of the piston inside unit 11. Pads 21 will be in the
retracted state, causing unit 11 to move back into the original
position so that it can reapply pressure to hollow shaft 13.
Position Sensing Apparatus
Position sensing apparatus 17 is illustrated as being attached to
the housing of directional control apparatus 14. No particular
location is absolutely necessary for the placement of the position
sensing apparatus, however; and it may be placed before or after
the directional control apparatus. Position sensing apparatus 17
contains a horizontal sensor 40, a vertical sensor 41, and a roll
sensor 42 along with the necessary control modules 43 and 44. The
equipment used in the position sensing apparatus is well known and
will not be further described.
The vertical sensor, however, may be a radioactive source capable
of detecting the position of the drilling assembly in the coal
seam. The preferred embodiment utilizes a vertical sensor which
detects secondary radiation caused by radioactive shale above and
below the coal seam. Suitable electrical cables 45 connect the
position sensing apparatus to an instrumentation readout panel
46.
DRILLING APPARATUS
The drilling apparatus 15 comprises, in the embodiment shown, an
electric motor 22 which is connected through a shaft 23 to the
shank 24 of a drill bit 16. The electric motor is powered by
suitable electric cables 47 to a motor power source 48.
DIRECTIONAL CONTROL APPARATUS
The directional control apparatus is illustrated in detail in FIG.
4 and essentially comprises an inner hollow mandrel 50 attached to
a tapered mandrel 51 which in turn is used to mount the directional
control apparatus to the preceding unit which, in the
above-disclosed embodiment, is the thrust unit. An outer tubular
piston cylinder 52 is attached to tapered mandrel 51 by any
suitable means such as threads or pins, for example. Mounted
between tubular piston cylinder 52 and hollow mandrel 50 is a
tubular piston 53 having a plurality of contoured surfaces 54
formed in its outer periphery. Enclosing the directional control
apparatus is an outer casing or housing 55 which is yieldably
attached to tubular piston cylinder 52 at one end by means of
screws 56 which pass through enlarged openings 57 and are secured
by means of flexible-type washers 58. Between housing 55 and
tubular piston 53 is mounted an engaging means 60. Engaging means
60 essentially comprises a ring 61 which is attached to housing 55
by means of a screw 62. A plurality of rollers 63 (one for each
contoured surface 54) is journaled in ring 61 by a shaft 64. A
biasing spring 70 is mounted between an end flange 71 which is
attached to mandrel 50 at its terminus and a secondary flange 72
which engages the end of tubular piston 53 and is free to slide
over the outer surface of mandrel 50. The end of tubular housing 55
is sealed by an end plate 75. A tubular portion 76 is axially
attached to end plate 75 and has an extension 77. Flange 71
likewise has an extension 78. A flexible rubber pipe 79 seals
extension 78 to extension 77 and is retained by bands 80 and 81,
respectively. Tubular piston 53 has a plurality of outer seals 82
and inner seals 83. A hydraulic inlet pipe 90 is connected by means
of a "V" groove 91 in tubular piston cylinder 52 to a conduit 92 to
the end of tubular piston 53.
It should be noted that the outer diameter of tubular piston
cylinder 52 is tapered from its mounting to its terminus 93 to
provide for freedom of movement of the housing 55 through
360.degree. without striking the outer diameter of tubular piston
cylinder 52, and providing an axial movement of approximately 0.8
of a degree.
Contoured surfaces 54 in the preferred embodiment are formed in
three places around the circumference of piston 53. The surfaces
are designed so that axial movement along the mandrel 50 will cause
deflection of the outer housing continuously from an axially
aligned position to a 360.degree. rotation. The preferred
embodiment accomplishes the above by generating flat surfaces which
are the mathematical equivalent of a helix. Tables 1 through 6
provide the mathematical development of each of the surfaces as
measured along the length of the mandrel from point 95 to point
96.
__________________________________________________________________________
TABLE 1 TABLE 2
__________________________________________________________________________
Surface "A" Surface "B" Surface "C" Surface "A" Surface "B" Surface
"C" X Y X Y X Y X Y X Y X Y
__________________________________________________________________________
0.000 1.375 0.000 1.562 0.000 1.375 0.900 1.329 0.900 1.437 0.900
1.545 .025 1.370 .025 1.561 .025 1.380 .925 1.332 .925 1.432 .925
1.547 .050 1.366 .050 1.561 .050 1.385 .950 1.335 .950 1.427 .950
1.550 .075 1.361 .075 1.560 .075 1.390 .975 1.338 .975 1.421 .975
1.552 .100 1.357 .100 1.560 .100 1.395 1.000 1.342 1.000 1.416
1.000 1.554 .125 1.353 .125 1.559 .125 1.400 1.025 1.345 1.025
1.410 1.025 1.556 .150 1.349 .150 1.557 .150 1.405 1.050 1.349
1.050 1.405 1.050 1.557 .175 1.345 .175 1.556 .175 1.410 1.075
1.353 1.075 1.400 1.075 1.559 .200 1.342 .200 1.554 .200 1.416
1.100 1.357 1.100 1.395 1.100 1.560 .225 1.338 .225 1.552 .225
1.421 1.125 1.361 1.125 1.390 1.125 1.560 .250 1.335 .250 1.550
.250 1.427 1.150 1.366 1.150 1.385 1.150 1.561 .275 1.332 .275
1.547 .275 1.432 1.175 1.370 1.175 1.380 1.175 1.561 .300 1.329
.300 1.545 .300 1.437 1.200 1.375 1.200 1.375 1.200 1.562 .325
1.327 .325 1.542 .325 1.442 1.225 1.380 1.225 1.370 1.225 1.561
.350 1.324 .350 1.539 .350 1.447 1.250 1.385 1.250 1.366 1.250
1.561 .375 1.322 .375 1.536 .375 1.453 1.275 1.390 1.275 1.361
1.275 1.560 .400 1.320 .400 1.532 .400 1.458 1.300 1.395 1.300
1.357 1.300 1.560 .425 1.318 .425 1.529 .425 1.464 1.325 1.400
1.325 1.353 1.325 1.559 .450 1.317 .450 1.525 .450 1.469 1.350
1.405 1.350 1.349 1.350 1.557 .475 1.315 .475 1.521 .475 1.474
1.375 1.410 1.375 1.345 1.375 1.556 .500 1.314 .500 1.517 .500
1.479 1.400 1.416 1.400 1.342 1.400 1.554 .525 1.314 .525 1.513
.525 1.484 1.425 1.421 1.425 1.338 1.425 1.552 .550 1.313 .550
1.508 .550 1.489 1.450 1.427 1.450 1.335 1.450 1.550 .575 1.313
.575 1.504 .575 1.494 1.475 1.432 1.475 1.332 1.475 1.547 .600
1.312 .600 1.499 .600 1.499 1.500 1.437 1.500 1.329 1.500 1.545
.625 1.313 .625 1.494 .625 1.504 1.525 1.442 1.525 1.327 1.525
1.542 .650 1.313 .650 1.489 .650 1.508 1.550 1.447 1.550 1.324
1.550 1.539 .675 1.314 .675 1.484 .675 1.513 1.575 1.453 1.575
1.322 1.575 1.536 .700 1.314 .700 1.479 .700 1.517 1.600 1.458
1.600 1.320 1.600 1.532 .725 1.315 .725 1.474 .725 1.521 1.625
1.464 1.625 1.318 1.625 1.529 .750 1.317 .750 1.469 .750 1.525
1.650 1.469
1.650 1.317 1.650 1.525 .775 1.318 .775 1.464 .775 1.529 1.675
1.474 1.675 1.315 1.675 1.521 .800 1.320 .800 1.458 .800 1.532
1.700 1.479 1.700 1.314 1.700 1.517 .825 1.322 .825 1.453 .825
1.536 1.725 1.484 1.725 1.314 1.725 1.513 .850 1.324 .850 1.447
.850 1.539 1.750 1.489 1.750 1.313 1.750 1.508 .875 1.327 .875
1.442 .875 1.542 1.775 1.494 1.775 1.313 1.775 1.504
__________________________________________________________________________
TABLE 3 TABLE 4
__________________________________________________________________________
Surface "A" Surface "B" Surface "C" Surface "A" Surface "B" Surface
"C" X Y X Y X Y X Y X Y X Y
__________________________________________________________________________
1.800 1.499 1.800 1.312 1.800 1.499 2.700 1.545 2.700 1.437 2.700
1.329 1.825 1.504 1.825 1.313 1.825 1.494 2.725 1.542 2.725 1.442
2.725 1.327 1.850 1.508 1.850 1.313 1.850 1.489 2.750 1.539 2.750
1.447 2.750 1.324 1.875 1.513 1.875 1.314 1.875 1.484 2.775 1.536
2.775 1.453 2.775 1.322 1.900 1.517 1.900 1.314 1.900 1.479 2.800
1.532 2.800 1.458 2.800 1.320 1.925 1.521 1.925 1.315 1.925 1.474
2.825 1.529 2.825 1.464 2.825 1.318 1.950 1.525 1.950 1.317 1.950
1.469 2.850 1.525 2.850 1.469 2.850 1.317 1.975 1.529 1.975 1.318
1.975 1.464 2.875 1.521 2.875 1.474 2.875 1.315 2.000 1.532 2.000
1.320 2.000 1.458 2.900 1.517 2.900 1.479 2.900 1.314 2.025 1.536
2.025 1.322 2.025 1.453 2.925 1.513 2.925 1.484 2.925 1.314 2.050
1.539 2.050 1.324 2.050 1.447 2.950 1.508 2.950 1.489 2.950 1.313
2.075 1.542 2.075 1.327 2.075 1.442 2.975 1.504 2.975 1.494 2.975
1.313 2.100 1.545 2.100 1.329 2.100 1.437 3.000 1.499 3.000 1.499
3.000 1.312 2.125 1.547 2.125 1.332 2.125 1.432 3.025 1.494 3.025
1.504 3.025 1.313 2.150 1.550 2.150 1.335 2.150 1.427 3.050 1.489
3.050 1.508 3.050 1.313 2.175 1.552 2.175 1.338 2.175 1.421 3.075
1.484 3.075 1.513 3.075 1.314 2.200 1.554 2.200 1.342 2.200 1.416
3.100 1.479 3.100 1.517 3.100 1.314 2.225 1.556 2.225 1.345 2.225
1.410 3.125 1.474 3.125 1.521 3.125 1.315 2.250 1.557 2.250 1.349
2.250 1.405 3.150 1.469 3.150 1.525 3.150 1.317 2.275 1.559 2.275
1.353 2.275 1.400 3.175 1.464 3.175 1.529 3.175 1.318 2.300 1.560
2.300 1.357 2.300 1.395 3.200 1.458 3.200 1.532 3.200 1.320 2.325
1.560 2.325 1.361 2.325 1.390 3.225 1.453 3.225 1.536 3.225
1.322
2.350 1.561 2.350 1.366 2.350 1.385 3.250 1.447 3.250 1.539 3.250
1.324 2.375 1.561 2.375 1.370 2.375 1.380 3.275 1.442 3.275 1.542
3.275 1.327 2.400 1.562 2.400 1.375 2.400 1.375 3.300 1.437 3.300
1.545 3.300 1.329 2.425 1.561 2.425 1.380 2.425 1.370 3.325 1.432
3.325 1.547 3.325 1.332 2.450 1.561 2.450 1.385 2.450 1.366 3.350
1.427 3.350 1.550 3.350 1.335 2.475 1.560 2.475 1.390 2.475 1.361
3.375 1.421 3.375 1.552 3.375 1.338 2.500 1.560 2.500 1.395 2.500
1.357 3.400 1.416 3.400 1.554 3.400 1.342 2.525 1.559 2.525 1.400
2.525 1.353 3.425 1.410 3.425 1.556 3.425 1.345 2.550 1.557 2.550
1.405 2.550 1.349 3.450 1.405 3.450 1.557 3.450 1.349 2.575 1.556
2.575 1.410 2.575 1.345 3.475 1.400 3.475 1.559 3.475 1.353 2.600
1.554 2.600 1.416 2.600 1.342 3.500 1.395 3.500 1.560 3.500 1.357
2.625 1.552 2.625 1.421 2.625 1.338 3.525 1.390 3.525 1.560 3.525
1.361 2.650 1.550 2.650 1.427 2.650 1.335 3.550 1.385 3.550 1.561
3.550 1.366 2.675 1.547 2.675 1.437 2.675 1.332 3.575 1.380 3.575
1.561 3.575 1.370
__________________________________________________________________________
TABLE 5 TABLE 6
__________________________________________________________________________
Surface "A" Surface "B" Surface "C" Surface "A" Surface "B" Surface
"C" X Y X Y X Y X Y X Y X Y
__________________________________________________________________________
3.600 1.375 3.600 1.562 3.600 1.375 4.475 1.429 4.475 1.452 4.475
1.429 3.625 1.376 3.625 1.558 3.625 1.376 4.500 1.431 4.500 1.449
4.500 1.431 3.650 1.378 3.650 1.555 3.650 1.378 4.525 1.432 4.525
1.446 4.525 1.432 3.675 1.379 3.675 1.552 3.675 1.379 4.550 1.434
4.550 1.443 4.550 1.434 3.700 1.381 3.700 1.549 3.700 1.381 4.575
1.435 4.575 1.440 4.575 1.435 3.725 1.382 3.725 1.546 3.725 1.382
4.600 1.437 4.600 1.437 4.600 1.437 3.750 1.384 3.750 1.543 3.750
1.384 4.625 1.437 4.625 1.437 4.625 1.437 3.775 1.386 3.775 1.540
3.775 1.386 4.650 1.437 4.650 1.437 4.650 1.437 3.800 1.387 3.800
1.537 3.800 1.387 4.675 1.437 4.675 1.437 4.675 1.437 3.825 1.389
3.825 1.533 3.825 1.389 4.700 1.437 4.700 1.437 4.700 1.437 3.850
1.390 3.850 1.530 3.850 1.390 4.725 1.437 1.725 1.437 4.725 1.437
3.875 1.392 3.875 1.527 3.875 1.392 4.750 1.437 4.750 1.437 4.750
1.437 3.900 1.393 3.900 1.524 3.900 1.393 4.775 1.437 4.775 1.437
4.775 1.437 3.925 1.395 3.925 1.521 3.925 1.395 4.800 1.437 4.800
1.437 4.800 1.437 3.950 1.396 3.950 1.518 3.950 1.396 4.825 1.437
4.825 1.437 4.825 1.437 3.975 1.398 3.975 1.515 3.975 1.398 4.850
1.437 4.850 1.437 4.850 1.437 4.000 1.400 4.000 1.512 4.000 1.400
4.875 1.437 4.875 1.437 4.875 1.437 4.025 1.401 4.025 1.508 4.025
1.401 4.900 1.437 4.900 1.437 4.900 1.437 4.050 1.403 4.050 1.505
4.050 1.403 4.925 1.437 4.925 1.437 4.925 1.437 4.075 1.404 4.075
1.502 4.075 1.404 5.950 1.437 5.950 1.437 5.950 1.437 4.100 1.406
4.100 1.499 4.100 1.406 5.975 1.437 5.975 1.437 5.975 1.437 4.125
1.407 4.125 1.496 4.125 1.407 5.000 1.437 5.000 1.437 5.000
1.437
4.150 1.409 4.150 1.493 4.150 1.409 5.025 1.437 5.025 1.437 5.025
1.437 4.175 1.410 4.175 1.490 4.175 1.410 5.050 1.437 5.050 1.437
5.050 1.437 4.200 1.412 4.200 1.487 4.200 1.412 5.075 1.437 5.075
1.437 5.075 1.437 4.225 1.414 4.225 1.483 4.225 1.414 5.100 1.437
5.100 1.437 5.100 1.437 4.250 1.415 4.250 1.480 4.250 1.415 4.275
1.417 4.275 1.477 4.275 1.417 4.300 1.418 4.300 1.474 4.300 1.418
4.325 1.420 4.325 1.471 4.325 1.420 4.350 1.421 4.350 1.468 4.350
1.421 4.375 1.423 4.375 1.465 4.375 1.423 4.400 1.425 4.400 1.462
4.400 1.425 4.425 1.426 4.425 1.458 4.425 1.426 4.450 1.428 4.450
1.455 4.450 1.428
__________________________________________________________________________
The above tables are computed on the basis of roller 63 being 0.25
inch in diameter and the surfaces being formed by a milling cutter
having the same diameter as the rollers. If different diameter
rollers are utilized or a different diameter milling cutter used to
form the surfaces, then the tables must be modified to accommodate
the above set out variations.
Referring to Tables 1 through 6 (see FIG. 5), the three surfaces
are defined as Surface A, Surface B, and Surface C. Each of the
surfaces has its coordinates defined by "X" and "Y," "X" being the
distance in inches as shown between points 95 and 96. "Y" is the
sum of the distance 97 from the axis 98 of tubular piston 53 and
the radius of the .25 inch diameter milling cutter.
OPERATION
The directional control apparatus illustrated in FIGS. 1 and 4
through 6 operates as follows:
Hydraulic pressure applied thorugh pipe 90 is applied to V-shaped
groove 91, conduit 92 and into the chamber formed by tubular piston
52 and hollow mandrel 50. Hydraulic pressure, when applied to the
face of piston 53, will cause the piston to move in the direction
of the spring. The distance it will move will be determined by the
frictional losses in the system and by the spring bias supplied by
spring 70. In the unpressured state, rollers 63 will be all equal
distance from the axis 98, thereby causing the axis of housing 55
to coincide with axis 98, resulting in the electric drill and bit
14 drilling a straight hole. If it is desired to deflect the
direction of the drill, hydraulic fluid filling tube 90 will be
pressured, forcing piston 53 to move by an amount necessary to
balance the bias on spring 70. Rollers 63 following contoured
surfaces 54 will be moved in accordance with these contoured
surfaces. As they are moved, this movement is communicated to ring
61 which, as previously mentioned, is rigidly secured to housing
55. Thus the axis of housing 55 will be deflected in a direction
corresponding to the contoured surfaces. The amount of the
deflection is fixed by the particular magnitude of the contoured
surface deviations. Since the contoured surfaces are mathematically
equivalent to a helix, the angular deflection will move through
360.degree.. The actual direction the drill is taking will be
indicated by the horizontal sensor 40, vertical sensor 41, and roll
sensor 42. If additional corrections must be made, the hydraulic
pressure can be increased or decreased by the amount necessary to
correct for the drill error. Flexible pipe 79 provides for movement
of housing 55 and end plate 75 by effectively decoupling the
mandrel from tube 76 but yet providing a closed conduit for the
flow of drilling fluids.
OTHER EMBODIMENTS
FIGS. 7 and 8 illustrate other embodiments following the teachings
of the above invention. FIG. 7 illustrates a helically formed pipe
100 which has a ring 63 confining a plurality of ball bearings 101.
Ring 63 is attached to housing 55 in the manner illustrated in
FIGS. 4 through 6 and functions in the identical manner.
FIG. 8 illustrates a surface following the teachings of FIGS. 4
through 7 and provides a two-dimensional movement rather than a
three-dimensional movement. FIG. 8 comprises a bar 103 having an
upper contoured surface 104 and a lower contoured surface 105.
Rollers 63 engage surfaces 104 and 105, respectively. A roller
mounting means 106 journals rollers 63 and transfers the movement
to a housing similar to the housing 55 disclosed in FIGS. 4 and
5.
Referring to FIG. 9, a cross-sectional portion of FIG. 4 is
illustrated. The contoured surface 54 of FIG. 4 is formed into a
plurality of strips 65 and attached to the inner wall 39 of housing
55 by a pair of screws or rivets 66. An engagement means, such as
roller 67, is attached to the end of piston 53 by a support surface
68. A pin 69 journals roller 67 in support surface 68. The
operation of the system is substantially identical to the operation
of the embodiment illustrated in FIG. 4. The contoured surface will
have the same mathematical interrelationship as that disclosed for
FIG. 4; however, it should be noted that as roller 67 moves toward
end 96, the angular displacement of the unit 14 with respect to the
axis of mandrel 50 will become less by an mount proportional to the
distance moved over the surface 54 toward point 96. In order to
maintain an equal angular displacement, the distance "Y" as defined
in Tables 1 through 6 should be increased by a linear amount
proportional to the distance "X" along surface 54.
CONCLUSIONS
The directional control apparatus incorporated in a drill assembly
has been disclosed which provides axial control and 360.degree.
deviation control for a drill bit. The embodiment disclosed herein
locates the directional control apparatus between the thrust unit
and the instrument module. It is obvious that other locations are
feasible for the control apparatus and that other methods of
utilizing same are possible. A flexible coupling, having at least
.4 of a degree flexing capability, is provided between the thrust
unit and the instrument package, stabilizers are attached to the
drilling unit. The stabilizers will provide a fulcrum for a force
generated by the deflection unit, thereby offering superior
directional control capabilities.
Other obvious modifications can be made in the embodiment as
disclosed in this specification and still be within the scope of
the invention as disclosed in the specification and the appended
claims.
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