U.S. patent number 3,888,319 [Application Number 05/419,157] was granted by the patent office on 1975-06-10 for control system for a drilling apparatus.
This patent grant is currently assigned to Continental Oil Company. Invention is credited to Henry A. Bourne, Jr., Rondon L. Schroeder.
United States Patent |
3,888,319 |
Bourne, Jr. , et
al. |
June 10, 1975 |
Control system for a drilling apparatus
Abstract
A roll control and deflection device for a drilling apparatus
which may include a hydraulic drive mechanism, an instrumentation
unit, a drill motor, and a drill bit. The deflection unit is
mounted between the drill motor and the drill bit and includes a
foot which is extendible against the drill hole wall, forcing the
drill to deflect from the previous drilling axis. A roll control
apparatus is coupled between the drive mechanism and the mounting
for the deflection unit and will roll the deflection unit to any
angular position about the axis of the drill unit.
Inventors: |
Bourne, Jr.; Henry A. (Ponca
City, OK), Schroeder; Rondon L. (Shinnston, WV) |
Assignee: |
Continental Oil Company (Ponca
City, OK)
|
Family
ID: |
23661023 |
Appl.
No.: |
05/419,157 |
Filed: |
November 26, 1973 |
Current U.S.
Class: |
175/76; 175/61;
175/24; 175/94 |
Current CPC
Class: |
E21B
4/20 (20130101); E21B 23/04 (20130101); E21B
7/04 (20130101); E21B 7/068 (20130101); E21B
4/18 (20130101) |
Current International
Class: |
E21B
23/04 (20060101); E21B 4/18 (20060101); E21B
7/04 (20060101); E21B 23/00 (20060101); E21B
7/06 (20060101); E21B 4/20 (20060101); E21B
4/00 (20060101); E21b 007/08 (); E21b 003/08 () |
Field of
Search: |
;175/61,62,73,74,76,24,26,94,95,104,107,106 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: Miller; William J.
Claims
We claim:
1. A roll control and deflection device for a drilling apparatus
having a hydraulic drive mechanism, an instrumentation unit, a
drill motor and a drill bit connected axially to form said drilling
apparatus, comprising:
a. a deflection unit;
b. means for mounting said deflection unit between said drill motor
and said drill bit, said deflection unit including a foot, means
for extending said foot normal to the axis of said drilling
apparatus, and
c. roll control means coupled between said hydraulic drive
mechanism and said means for mounting said deflection unit, to roll
said deflection unit to any angular position about the axis of said
drilling unit.
2. An apparatus as described in claim 1 wherein said deflection
unit includes a hydraulic cylinder and piston mounted between said
drilling mechanism and said foot, spring biasing means mounted to
bias said piston into said hydraulic cylinder and means to
controllably apply hydraulic fluid into said hydraulic
cylinder.
3. An apparatus as described in claim 1 wherein a first hydraulic
line is connected to said roll control means and a second hydraulic
line is connected from said first hydraulic line to said deflection
unit.
4. An apparatus as described in claim 3 wherein a check valve means
and orifice means are parallelly connected and in series with said
second line and wherein said check valve means operates to release
pressure buildup in said deflection unit upon reduction of pressure
in said first hydraulic line and wherein said orifice means is
timed to permit full operation of said roll control means without
substantial pressure buildup in said deflection unit.
5. In a drilling apparatus having at least a drilling motor having
a rotational axis and a drill bit connected through a shaft to said
drilling motor a deflection unit comprising a:
a. mounting means attached between said drilling motor and said
drill bit;
b. pressure application means slidably attached to said mounting
means normal to the rotational axis of said drill motor; and means
for axially positioning said pressure application means by axially
rotating said mounting means.
6. A deflection unit as described in claim 5 wherein said mounting
means is rigidly attached to said drilling motor.
7. A deflection unit as described in claim 6 wherein said means for
positioning said pressure application means comprises a cylinder
mounted on said mounting means and having its axis normal to the
axis of rotation of said drilling motor, piston means sealably
mounted inside said cylinder in contactual relation with said
pressure application means, hydraulic inlet means connected to said
cylinder for using said piston out of said cylinder and spring
biasing means for returning said piston into said cylinder along
with said pressure application means into said cylinder.
8. A deflection unit as described in claim 6 wherein said pressure
application means comprises first and second feet mounted on
diametrically opposite sides of said mounting means, side plates
attached to opposite sides of said feet, slidably mounted to said
mounting means, piston means positioned between said mounting means
and one of said feet and spring biasing means positioned between
said mounting means and said remaining foot.
9. A roll control device for a drilling apparatus having a pressure
mechanism and a drill means comprising a fractional-rotation torque
motor attached to said pressure mechanism and having its output
connected through a drive means and an antitorque means to said
drill means, and means for applying power to said torque motor to
fractionally rotate said drill means a predetermined number of
degrees.
10. A torque motor as described in claim 9 comprising:
a. a piston block and a spring block each comprising cylindrical
tubular portions formed of oppositely facing quadrants, each of
said quadrants forming said spring block forming an angle from the
axis of said cylindrical tubular portion of at least
83.degree.;
b. means for mounting the quadrants of said piston and spring
blocks to form a subtantially contiguous tubular surface;
c. piston means mounted in at least one of said quadrants of said
piston block, said piston means in contactual relation with one of
said quadrants of said spring block;
d. spring means retained in at least one of said quadrants of said
spring block and in contactual relation with one of said quadrants
of said piston block;
e. means for supplying power to said piston means;
f. means for mounting one of said blocks to said pressure
mechanism; and
g. means for coupling said remaining block to said drive means and
antitorque means.
11. A device as described in claim 9 wherein said drive and
antitorque means comprises a drive ratchet rigidly coupled with
respect to said drill means and a plurality of cooperating pawls
coupled to said torque motor, an antitorque ratchet, means for
rigidly mounting said antitorque ratchet to said pressure mechanism
and means for rigidly mounting a plurality of antitorque pawls to
said drill means.
12. Drill control apparatus comprising directional drilling
apparatus for a drill adapted to form a borehole, said drill having
a drill motor coupled substantially adjacent a drill bit
comprising:
a. roll control apparatus coupled to said drill motor, and
b. pressure deflection means mounted between said roll control
apparatus and said drill bit to apply force against the wall of
said borehole, thereby deflecting the axis of said drilling
apparatus.
13. An apparatus as described in claim 12 wherein said pressure
deflection means includes a hydraulic cylinder and piston mounted
between said roll control apparatus and said drill motor and a
yieldable coupling between said pressure deflection means and said
drill motor.
14. An apparatus as described in claim 13 additionally including
stabilizing means between said yieldable coupling and said drill
bit.
15. An apparatus as described in claim 14 wherein said stabilizing
means is located on said drill motor.
Description
BRIEF DESCRIPTION OF THE PRIOR ART
Horizontal drilling may require three essential features: first, a
drill; second, a means of forcing the drill into the ground; and
third, a means of controlling the drill during its operation
underground. The guidance systems used for controlling the
underground operation of a drill generally comprise two type. The
first type comprises surface-generated signals and means for
conveying the signals to the horizontal drill. Such means can be,
for example, an antenna. The horizontal drill includes means for
receiving the signal and following some predetermined path in
accordance with the signals.
Patents to James C. Coyne, U.S. Pat. Nos. 3,589,454 and 3,712,391
describe a horizontal drill having such a control system. Means can
also be provided in the drill for controlling its operation. Such
means can be, for example, a radiation detector or radiation
transmitter and detector. The drill can be controlled internally in
accordance with the radiation detected, or information can be
transmitted out of the hole being drilled and controlling
information redirected to the drill from outside the hole.
Such an apparatus is described in U.S. patent application Ser. No.
246,297 now U.S. Pat. No. 3,823,787 filed Apr. 21, 1972, by Haworth
et al and assigned to the same assignee as this invention.
The above-related patents also describe means for deflecting the
drill, the deflection means comprising a pivotal joint which is
mechanically deflected. The position of the hinged joint is varied
by a rotary actuator which is not described in detail in the
patents.
BRIEF DESCRIPTION OF THE INVENTION
This invention describes a specific roll control mechanism or
rotary actuator in combination with a unique deflection device. The
roll control mechanism comprises a unit which is actuated by
pistons which operate on a ratchet assembly. The ratchet assembly
provides a means of transmitting the movement of the roll control
mechanism to the outside body of the drill. The deflection unit is
mounted near the drill bit and comprises a single shoe which is
forced against the drill hole wall in any position necessary to
provide force against the drill, thereby controlling its direction.
The same hydraulic system provides both operation of the roll
control mechanism and the deflection unit.
The invention further features a deflection unit that can be
operated either in conjunction with the roll control mechanism
above described or as an individual unit in a system that does not
contain a roll control mechanism but where control of the drill is
desired.
The invention further features means for launching the horizontal
drill horizontally into the stratum to be bored.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side view of a horizontal drill incorporating the
hydraulic pressure mechanism, the instrument package including the
roll control mechanism, the drill motor and associated gear
reduction box, the deflection unit, and the drill bit;
FIG. 2 is a cross-sectional view of the roll control mechanism;
FIG. 3 is an expanded view of the piston block and the spring block
used in the roll control mechanism;
FIG. 4 is a cross-sectional view of FIG. 2 taken through lines
4--4;
FIG. 5 is a cross-sectional view of FIG. 2 taken through lines 4--4
and used to illustrate the operation of the roll control
mechanism;
FIG. 6 is a cross-sectional view of FIG. 2 taken through lines
6--6;
FIG. 7 is a cross-sectional view of FIG. 2 taken through lines
7--7;
FIG. 8 is a cross-sectional view of the slipring assembly for the
electrical circuitry and the rotary assembly of the hydraulic
circuitry for the roll control mechanism;
FIGS. 9A, 9B, and 9C show the cam arrangement for inserting the
electrical plugs for mating electrical plugs in a blind assembly
used in the device illustrated in FIG. 8;
FIG. 10 is a side cross-sectional view of the deflection control
mechanism;
FIG. 11 is a partial cross-sectional top view of the deflection
control mechanism shown in FIG. 10;
FIG. 12 is a cross-sectional view of FIG. 10 taken through lines
12--12;
FIG. 13 is another embodiment of the roll and deflection control
mechanism;
FIG. 14 illustrates the operation of the embodiment shown in FIG.
13;
FIG. 15 is an embodiment illustrating the deflection control
mechanism used for drilling horizontal holes without the use of a
roll control mechanism;
FIG. 16 is a hydraulic drive unit and external roll control
mechanism useful in the device illustrated in FIG. 15;
FIG. 17 is an end view of the apparatus illustrated in FIG. 16;
FIG. 18 is a launch control device useful in launching the
apparatus illustrated in FIG. 1;
FIG. 19 is an enlarged side view taken through lines 19--19 of FIG.
18; and
FIG. 20 is a cross-sectional view taken through lines 20--20 of
FIG. 18.
GENERAL DESCRIPTION
Referring to FIG. 1 a horizontal drill is illustrated and
essentially comprises a hydraulic pressure mechanism generally
referred to by the number 10. Mechanism 10 provides force for a
drill 11. Mechanism 10 comprises a hydraulic cylinder 12 which has
a plurality of pressure feet 13 attached on the outside thereof.
Pressure feet 13 are adapted to be hydraulically forced against the
drill hole wall when the unit is applying pressure to drill 11 and
released during the retraction stage. Unit 14 provides a mounting
for a second set of pressure feet 15 which are selectively engaged
against a drill hole wall by hydraulic pressure during the
retraction stage. A shaft 16 extends through hydraulic cylinder 12
and into instrument package 17. A hydraulic piston (not shown) is
mounted inside cylinder 12 and rigidly attached to shaft 16. An
electrical drill motor 18 (which may also be hydraulic) is attached
to instrument package 17 and has a deflection mounting end 19
attached to a deflection unit 20. A drill shaft 21 is rigidly
attached to drill 11 by any suitable means, such as tapered
threads. Hydraulic pipes, generally referred to by the number 21,
provide control to the hydraulic pressure mechanism 10, to the roll
control unit (not shown), and to deflection control unit 20.
Electrical wires 22 provide power for the instrument package 17 and
drill motor 18. Pipe 23 provides drilling fluid for drill 11.
OPERATION
The device disclosed in FIG. 1 essentially functions as follows:
Hydraulic pressure of the pipes 21 expands pressure feet 13 against
the drill hole wall. Additional hydraulic pressure is applied
inside cylinder 12 against the hydraulic piston. Hydraulic pressure
then applies force against shaft 16 which will force the drill in
the direction of arrow 24. When the hydraulic piston has traveled
as far as it can inside cylinder 12, pressure feet 15 are expanded
against the drill hole wall, pressure feet 13 are retracted,
hydraulic fluid is applied to the opposite side of the piston, and
the cylinder 12 will move back toward drill 11. The reverse
procedure is then followed, and the unit will again drive the drill
in the direction of arrow 24. If roll control is needed, hydraulic
pressure (from 350 to 1,500 pounds depending on the amount of
friction encountered) can be applied through one of the pipes 21
which is connected to the roll control mechanism. The mechanism
will be actuated causing instrument package 17, motor 18,
deflection unit 20, and drill 21 to be rotated a predetermined
number of degrees. If deflection of the drill is necessary,
hydraulic fluid pressure to the roll control mechanism is sustained
until an orifice permits sufficient fluid to cause an increase in
deflection unit 20, resulting in deflection unit 20 moving against
the wall of the bore hole, thereby deflecting the drill 11.
ROLL CONTROL MECHANISM
A more detailed explanation of the roll control mechanism is
illustrated by reference to FIGS. 2 through 7.
The roll control mechanism provides an essential means for
deflecting the drill in any predetermined direction. The roll
control mechanism will also counter any tendency to roll caused by
the hydraulic pressure mechanism 10. The deflection device will
then permit controlled deflection of the longitudinal axis of drill
bit 11 and its associated equipment in a long-hole drill train so
that the hole axis remains either horizontal or deflected by an
amount necessary to maintain the horizontal drill in some
predetermined prescribed path.
Referring to FIG. 2 but with particular reference to FIG. 3, a
mandrel 31 is attached to shaft 16 through an end portion 32 by
means of threads 33. A piston block 34 is attached to mandrel 31 by
means of cap screws 35. A spring block, generally referred to by
number 36, is slidably positioned over mandrel 31. The entire block
assembly comprising piston block 34 and spring block 36 is retained
on mandrel 31 by means of a nut 37 secured to mandrel 31 by threads
38.
The open end of piston block assembly 34 is machined so that there
are two opposed quadrants 40 and 41 remaining, each having an
included angle of 90.degree.. The open end of spring block assembly
36 is machined so that there are two opposed quadrants 42 and 43
remaining, each having an included angle of 83.degree.. Thus, when
spring block assembly 36 is rotatably engaged with piston block
assembly 34 on mandrel 31, there is 7.degree. of rotational freedom
between blocks 36 and 34. Piston block assembly 34 is bored and
counterbored in six locations to accommodate six pistons 47. The
spring block assembly 36 is bored in six locatons to receive six
springs 48 which, when assembled, are preloaded in compression and
secured with spring keepers 49 which are in turn held in position
by a keeper rod 50. Keeper rod 50 is inserted through holes 51 in
spring block 36 and holes 52 in keepers 49. Each of the keepers
also includes a threaded portion 53 used to compress the springs
during the assembly procedure, thereby permitting the insertion of
the keeper rods 50 into holes 52 (see FIGS. 4 and 5). On the end of
spring block assembly 36, opposite the quadrants 42 and 43, are
mounted nine pawl pins 61 which are press-fitted into holes
40.degree. apart which are drilled into the end of spring block
assembly 36 (see FIGS. 6 and 7). Nine ratchet pawls 62 are
rotatably mounted on pawl pins 61 and are urged inwardly against a
drive ratchet 63 by an elastic member 64 which encircles pawls 62
and applies biasing pressure toward drive ratchet 63 by exerting
pressure against a pin 65 rigidly secured normal to the surface of
pawls 62. Pins 65 are press-fitted into holes drilled into ratehet
pawls 62. Drive ratchet 63 is rotatably mounted over mandrel 31 and
is rotatably locked to a bearing housing 66 by a plurality of drive
ratchet pins 67 which are press-fitted into holes drilled into
bearing housing 66. Bearing housing 66 is secured axially and
rotatably with respect to instrument package 17 by four countersunk
cap screws 68. An antitorque ratchet 76 fits over mandrel 31 and is
keyed to mandrel 31 by key 77. A plurality of pawls 78 is rotatably
secured to a plurality of pawl pins 79. Pawl pins 79 are
press-fitted into bearing housing cap 80. Bearing housing cap 80 is
secured to bearing housing 66 by means of a plurality of screws 81.
Each pawl 78 carries a pin 65. An elastic member 82 encircles the
pawls and engages pins 65 in a manner to bias the pawls into the
antitorque ratchet 76.
A thrust bearing race 83 and a radial bearing race 84 provide free
movement for rotation and thrust of the housing with respect to the
mandrel 31. The entire roll control mechanism is secured to the
mandrel by means of an end plate 84 and tubular housing 85. A
radial bearing 86 provides freedom of movement of the mandrel with
respect to the outer housing. Seals 87 throughout the unit prevent
entrance of drilling fluids into the roll control mechanism. Screws
88 secure the housing 85 to end plate 84. The entire unit is
enclosed in a second tubular housing 89. Fluid movement into and
out of the unit is provided by several passages and channels.
Basically the fluid movement comprises a hydraulic input to control
the roll control mechanism and the deflection control unit 20 and a
drilling fluid passage for supplying liquid to the drill bit so
that the chips will be washed away from the bit and out of the hole
as drilling progresses. The hydraulic input comprises a pipe 90
which has an opening 91 into a circumferential groove 92 in mandrel
31. Groove 92 has a passage 93 into passage 94, through passages 95
and 96 to passage 97, which connects to passage 98 into piston 47
and passage 99 into pipe 100 which eventually is connected to the
deflection control unit. Drilling fluid enters pipe 105 out holes
106, into passage 107 through holes 108, and into the space 109
between housing 89 and housing 85.
The electrical connections to the instrument package 17 and to
drill motor 18 are made through pipe 110 to the inside 111 of
mandrel 31 which is formed of a pipe 112.
OPERATION OF ROLL CONTROL MECHANISM
When it is desired to rotate the instrument package 17, which by
construction includes drill motor 18, deflection unit 20 and drill
11, hydraulic pressure is applied to pipe 90 which is transferred
through hole 91, circumferential groove 92, passages 93, 94, 95,
96, 97, and 98 to the back of pistons 47. The system is designed so
that, at approximately 350 pounds per square inch, the
precompression on springs 48 will be overcome and block quadrants
42 and 43, which are connected to spring block 36, will begin to
rotate (see FIG. 5). Full hydraulic pressure of 500 pounds per
square inch will cause full rotation of 7.degree. of spring block
assembly 36 with respect to piston block assembly 34. The system is
designed to operate up to 1,500 pounds per square inch to provide
sufficient torque to overcome friction when the drilling unit is in
the hole. The 7.degree. rotation of spring block assembly 36 is
transmitted through pawl pins 61 to ratchet pawls 62. Three of the
nine ratchet pawls 62 (see FIG. 6), which are spaced 120.degree.
apart, will be engaged with drive ratchet 63 causing it to turn
counterclockwise through an angle of 7.degree.. The 7.degree.
rotation of drive ratchet 63 is transmitted to bearing housing 66
through drive ratchet pins 67 and to instrument package 17 through
bolts 68. The 7.degree. rotation is also transmitted through bolts
81 to bearing housing cap 80 to pawl pins 79 to pawls 78 (see FIG.
7). At the end of the 7.degree. rotational stroke, two of the pawl
pins 79 (shown in FIG. 7), which are spaced 180.degree. apart, will
become engaged with antitorque ratchet 76 which is rotatably locked
to mandrel 31 by key 77. When hydraulic pressure in pipe 90 and
subsequently to passage 98 is lowered, from 500 pounds per square
inch to about 375 pounds per square inch, the relationship of the
internal parts will return to that shown in FIG. 5. With continued
reduction in pressure, springs 48 will cause spring block assembly
36 to rotate 7.degree. clockwise to the position shown in FIG. 4,
with driving pistons 47 having returned to their initial position.
Ratchet pawls 62 will move in a clockwise direction with respect to
drive ratchet 63. At this time a different set (3) of ratchet pawls
62 will engage with the teeth of drive ratchet 63.
It should be noted that drive ratchet 63 and antitorque ratchet 76
each have 30 teeth which are on a 12.degree. spacing. Drive ratchet
pawls 62 are located with 40.degree. angular spacing. Consequently,
during each cycle of operation, only three drive ratchet pawls 62,
which are spaced 120.degree. apart, are engaged with drive ratchet
63. Thus, for each continued rotation, a new set of pawls 62 is
engaged. Similarly, as shown in FIG. 7, there are three pairs of
ratchet pawls 78, each pair being 180.degree. apart. Each pair is
angularly spaced from adjacent pairs by 30.degree.; therefore, each
pair is engaged during every third cycle. Although each cycle of
operation produces 7.degree. of relative rotation between piston
block assembly 34 and spring block assembly 36, only 4.degree. of
the 7.degree. is "caught" and held prior to the initiation of the
next cycle. Thus, for each cycle of operation, instrument package
17 is rotated 4.degree. with respect to mandrel 31. The use of six
power pistons was required to obtain the desired torque capability
in the roll device to overcome frictional drag of the instrument
package 17, drill motor 18, deflection unit 20 and drill 11. The
net torque output at 1,500 pounds per square inch hydraulic
pressure (after subtracting torque required to further compress
springs 48) is about 300 foot pounds.
SLIP-RING ASSEMBLY
The instrument package requires both a source of power to operate
and a return connection for transmitting multiplex information from
the instrument package to the operator controlling the drill unit.
Since the mandrel supplying the electric power through pipe 110 and
into pipe 100 (see FIG. 2), is stationary and since instrument
package 17 is capable of rotation, because of the previously
described roll control mechanism, some form of slip-ring assembly
must be utilized to transmit hydraulic fluid through the unit to
the deflection unit 20, electrical power to, and return signals
from the instrument package. The apparatus for accomplishing the
above is illustrated in FIGS. 8, 9A, 9B, and 9C. One of the
problems in assembly of the roll control mechanism and the
slip-ring unit is the inaccessibility of the slip-ring unit. Thus
the unit shown in FIG. 8 is assembled essentially "blind." Pipe 100
fits into mounting block 115 through an opening 116 centrally
located in block 115. Pipe 100 has a pointed end 117 to assist in
making the blind insertion into opening 116. Hydraulic fluid from
the inside of pipe 100 passes out of a hole 118 through the tube
wall and into a circumferential groove 119. A passage 120 leads to
a hydraulic coupling 121 and to a pipe 122 which eventually
connects with deflection unit 20. Electrical connection is made to
a slip-ring unit 123 through a female plug 124 and male plug 125.
Wires 126 from male plug 125 are connected to a plurality of
slip-rings 127. Brushes 128 in contact with slip-rings 127 have a
plurality of wires 129 coupled to the instrument package. In order
to mate plug 124 with plug 125 in a blind situation, a camming
arrangement is provided and is illustrated in FIGS. 9A, 9B, and
9C.
Referring to these figures, a first cam 128, which carries female
plug 124, is attached to an extension 129 of pipe 112 and is
rigidly secured thereto. Female plug 125 is attached to cam 130
which in turn is attached to tubular mounting 131 which carries
slip-rings 127. Screws 132 are attached between tubular mounting
131 and plug 125. Both cams 128 and 130 are guided axially by pipe
100 illustrated in dotted lines in FIGS. 9A, 9B, and 9C. Each cam
128 and 130 carries a caming surface 133 and 134, respectively.
Thus, as surface 133 strikes surface 134, cam 130 will rotate in
either direction as illustrated by arrow 135 until the final
position shown in FIG. 9C is accomplished, at which time the plugs
will be properly mated.
DEFLECTION CONTROL UNIT
The deflection control unit is illustrated in detail in FIGS. 10,
11 and 12. In the drawing illustrated the deflection unit is
located between the drill motor 18 and the drill bit 11 and
provides a mechanical means for causing the drill bit to drill
ahead, upwardly, downwardly, or in any other predetermined
direction. The deflection unit essentially comprises a main body
140 which is bolted to the bearing housing 141 by means of a
plurality of bolts 142. Drill motor 18 has a threaded shaft 143
connected to a shaft extension 144 connected to a second shaft
extension 145 which is coupled through threads (not shown) to drill
11. Outside tubular housing 89 is sealed from bearing housing 141
by a plurality of O-ring seals 87. Bearings 148 provide rotational
support between shaft extension 144 and bearing housing 141. The
upper part of the main body 140 is machined with a cylindrical
section 149 which is bored to provide a cavity for a spring 150.
The lower part of main body 140 is machined with a cylindrical
section 151 which is coaxial with the cylindrical section 149. A
piston 152 fits over cylindrical section 141 and is sealed by an
O-ring seal 153. A piston 154 fits over cylindrical section 149 and
is sealed by an O-ring seal 155. Pistons 152 and 154 function as
pressure shoes for the deflection unit. Side plates 156 (see FIG.
12) couple piston 154 to piston 152 and are secured by means of a
plurality of screws 157. Hydraulic fluid is supplied to piston 151
from pipe 122 through coupling 158, passage 159, coupling 160, pipe
161, coupling 162, and passage 163. The distance measured from the
top of piston 154 to the bottom of piston 152 is slightly less than
the diameter of the hole formed by drill bit 11.
OPERATION OF DEFLECTION UNIT
By proper regulation of the hydraulic pressure applied to the
cavity between cylindrical section 151 and piston 152, pressure can
be applied between piston 151 and the bore hole wall to control the
direction of the drill axis. Because of gravity a drilling unit
will normally tend to drill downwardly. Hydraulic fluid applied to
piston 152 by a proper amount will maintain the drill properly
oriented along a straight axis. If it is desired to drill
downwardly, the hydraulic pressure level is lowered. The force
exerted by spring 150 plus the force exerted by gravity produced by
the cantilevered loads of the instrument package 17, motor 18, and
the drill bit 11 will cause the bit to drill downwardly.
Conversely, an increase in controlled hyraulic pressure will cause
piston 152 to thrust against the bottom of the bore hole and urge
the axis of the drill bit shaft 145 upwardly against spring 150,
causing the drill bit 11 to drill upwardly. In the event it is
desired to change the compass or azimuth heading of the drilled
hole, the entire drilling assembly can be rolled by use of the roll
device described previously so that the bottom piston 152 is
positioned against any predetermined portion of the drill hole
wall.
It has been found desirable for ease of operation in the
simultaneous use of both the roll control mechanism and the
deflection unit to provide an orifice and check valve 113 in pipe
122. The orifice will provide a means for the oil to reach piston
152 but at a rate which will normally take longer than four
seconds. It has been found that approximately four seconds will
provide ample time to operate the roll control mechanism. Thus,
pressuring the roll control mechanism to at least 500 pounds,
barring an excess amount of friction, will operate same. The oil
pressure will also be transferred through pipe 122 to piston 152.
Usually enough pressure will be provided to piston 152 to just
center the deflection control unit during the operation of the roll
control mechanism. When the oil pressure is released, the check
valve 113 will immediately release the pressure in the series of
pipes and passages between check valve 113 and piston 152.
ALTERNATE PLACEMENT FOR DEFLECTION
FIGS. 13 and 14 illustrate an alternate placement for deflection
unit 20. Referring to FIG. 13, hydraulic mechanism 10 is connected
to a roll control and deflection control unit 136 which contains
deflection unit 20. Unit 136 is connected to drill motor 18 through
a flexible joint 137. Drill motor 18 is connected directly to drill
11. A stabilizer 138 is mounted on drill motor 18 near the drill
end of motor 18 and provides a rotational pivot for the deflection
action.
The operation is described by referring to FIG. 14. When deflection
unit 20 moves in the direction of arrow 139, pivot section 137 will
force the drill downward in the direction of arrow 146 about
stabilizer 138 which will force the drill in an upward direction as
indicated by arrow 147. Since the deflection unit can be moved by
the roll control mechanism in any direction, the drilling axis can
be changed in any desired direction.
FIG. 15 shows a further alternate embodiment where the roll and
power control unit, generally referred to by number 164, is outside
the hole being drilled. The instrument package 17, drill motor 18,
deflection unit 20, and drill 11 are as described in FIG. 1.
Instrument package 17, however, is connected to power and roll
control unit 164 by a plurality of hollow drill rods 165 which are
supported in the hole, if desired, by stabilizers 166. Hydraulic
control pipes 21 are coupled to a hydraulic control unit 167 and to
the deflection unit 20. An electrical control system 168 is
connected through electrical wires 22 to the instrument package 17
and to supply power to drill motor 18. Drilling fluid is supplied
through pipe 23 down the center of drill rod 165 through drill
motor 18 to drill 11.
An apparatus useful in providing the power and roll control 164 for
the apparatus disclosed in FIG. 15 is illustrated in FIGS. 16 and
17 and essentially comprises a hydraulic cylinder 170 having a
piston rod 171 coupled to drill rods 165. A roll control mechanism
comprises a motor 172 mounted to a pair of bars 173 through a
sliding bearing 174. Bars 173 are attached to a suitable frame 175.
Motor 172 is coupled through gears 176 and 177 to piston rod 171.
Piston rod 171 has an internal passage 178 coupled to the hollow
drill rod 165 and to a rotatable coupling 179 which in turn is
connected to drilling fluid pipe 23. Hydraulic pipes 180 and 181
are connected to a hydraulic control unit 167. A collapsible sleeve
182 may be mounted over bars 173 to protect them from dirt and
other foreign objects. A hydraulically controlled vise 183 has a
cylinder 184 with hydraulic lines 185 coupled to hydraulic control
unit 167. A piston 186 is attached to piston rod 171 and suitably
sealed.
Operation of the above device is as follows:
Hydraulic pressure applied to pipe 180 applies pressure between the
end wall and piston 186, driving piston rod 171 forward. Roll
control unit 164, being attached to piston rod 171 and slidable on
bars 173, will move with the forward advance of piston rod 171. The
advance of piston rod 171 will be transmitted to drill rods 165 and
subsequently to drill 11. When the piston rod has advanced to the
point where a joint 187 has nearly reached vise 183, the proper
switch is activated and hydraulic pressure through pipes 185 will
cause cylinder 184 to close the jaws of vise 183. Roll control
motor 172, through gears 176 and 177, will rotate piston rod 171 to
break joint 187. The piston rod 171 is then retracted by applying
hydraulic pressure through pipe 181. A new drill rod is inserted
and the roll control motor reversed in direction which will tighten
the drill rod, whereupon vise 183 is then released.
During the preceding operation, the vise has prevented the drill
from becoming disorientated. The proper switch will then put the
drill motor back into the roll mode if, for example, additional
gears are needed (not shown).
LAUNCH TUBE
Difficulties encountered with a horizontal drill are drilling the
first 24 feet of hole, because of lack of support for the drilling
assembly and lack of a drill hole wall for the hydraulic mechanism
to operate against. In order to overcome these difficulties, a
launch tube was invented and is illustrated in FIGS. 18, 19, and
20. The launch tube consists of sections of semicircular tubular
elements bolted together and supported on three height-adjustable
support stands. Provision is made for lateral movement of the
launch tube with respect to the support stands. Further provision
is made to anchor the launch tube against axial thrust.
Referring to the figures but in particular to FIG. 18, a launch
tube assembly comprises two halfsections 201 made from 6-inch
inside diameter aluminum pipe. Half-flanges 202 are welded to the
ends of halfsections 201 and are bolted together with bolts 203 to
form a continuous half-tube. A T-section 205 is welded to the
bottom of each half-section 201 to provide stiffness to the overall
unit. Shorter 6-inch inside diameter aluminum pipe half-sections
206 (four in number) are attached to the bottom sections 201 by
hinges 207. A bolt 208 forms a pivot for hinges 207. The adjustable
support stands are attached to bands 210 mounted in three locations
along the launch tube assembly. A cylindrical section 211 is
attached normal to each of the bands on the underside and fits into
a mating vertically tubular section 212 which is welded to a
sideplate 213 for a support assembly 214. A pair of rollers 204 is
journaled in support assembly 214. A parallel rod or support bar
215 is welded to a vertical tubular support 216 which fits over a
vertical tubular member 217. A support stand 218 supports vertical
tubular member 217. Each vertical tubular member is provided with a
plurality of holes 219 which permits positioning of horizontal
support bars 215 at various elevations. Pins 220 support short
tubular members 216 at the desired elevation. Conical half-sections
221 are welded to the ends of half-sections 201 and 206 to provide
smooth entry for hydraulic hoses and electric cables. The entire
assembly is anchored by means of cables 225 which are attached by
any suitable means to half-sections 201 and to an anchor 226 which
may be drilled and anchored to a rock face, for example.
Operation of the launch tube is as follows:
Each of the hinged half-sections 206 is opened to permit exposure
to the bottom half-tubular section 201. The horizontal drill shown
in FIG. 1 is then laid onto the cradle formed by half-section 201.
Each of the top half-tubular sections 206 is then closed and pinned
to form a continuous tube. When the horizontal drill is actuated,
the hydraulic mechanism will have the side walls of the tube for
applying driving force through pressure feet 13. Furthermore, the
particular location to be drilled can be properly oriented by
loosening pins 220 and adjusting the height of support bars 215 and
reinserting pins 220. Rollers 204 will accommodate any horizontal
adjustments necessary to properly align the tube with the area to
be drilled. Anchors 226 and cables 225 will restrain the assembly
from axial movement created when the drill enters the face being
drilled.
CONCLUSIONS
A roll control mechanism and deflection unit have been described
for a horizontal drill. It is obvious that changes may be made in
the particular manner of accomplishing the details of building the
roll control mechanism and still be well within the scope of the
invention as described.
A unique interconnection between the roll control mechanism and the
deflection unit has also been described which provides for
operation of the roll control mechanism essentially independent of
the deflection unit and operation of the deflection device
independently of the roll device.
It has also been illustrated that the roll control mechanism may be
outside the hole and the deflection unit inside the hole and either
located by the drill or at another location along the drill
train.
The preferred embodiment has been described as a horizontal
drilling apparatus. It is obvious that any use may be made of the
roll control or deflection device, for example, in a vertical
drilling operation, and still be within the spirit and scope of
this invention. Further, other fluids, such as air, can be used in
place of hyraulic fluid.
Changes may be made in the deflection control unit or its
combination with the roll control mechanism and the location in
which either is mounted with respect to the horizontal drill and
still be well within the scope of the invention as described in the
specification and appended claims.
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