U.S. patent number 3,840,128 [Application Number 05/377,321] was granted by the patent office on 1974-10-08 for racking arm for pipe sections, drill collars, riser pipe, and the like used in well drilling operations.
Invention is credited to John J. Swoboda, Jr., Norman L. Swoboda.
United States Patent |
3,840,128 |
Swoboda, Jr. , et
al. |
October 8, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
RACKING ARM FOR PIPE SECTIONS, DRILL COLLARS, RISER PIPE, AND THE
LIKE USED IN WELL DRILLING OPERATIONS
Abstract
The specification discloses a racking arm having a telescoping
boom with a supported end and a free cantilevered end. A pipe
gripping head is secured to the cantilevered end of the boom for
clamping about elongated members such as pipe sections, drill
collars, riser pipes or the like. The supported end of the boom is
mounted for pivotal movement about a vertical axis and a motor is
provided to selectively rotate the boom about the vertical axis.
Hydraulic cylinders are provided to selectively raise and lower the
free cantilevered end of the boom. Hydraulic cylinders also are
provided to extend and retract the boom to selectively vary the
length thereof. In operation, the boom is disposed on a drilling
rig with the supported end spaced above the working platform of the
drilling rig and the vertical axis spaced away from the well bore
axis. The boom may then be employed to move elongated pipe members
from various storage positions to the well bore or other areas and
vice-versa. The pipe gripper head is normally automatically
maintained horizontal during vertical movement of the boom. A first
embodiment of the pipe gripper head clamps pipe sections, drill
collars and the like for lateral movement while allowing the pipe
sections and drill collars to slide vertically along their axes. In
a second embodiment of the gripper head, riser pipe having an
irregular cross-section may be tightly gripped by the gripper
head.
Inventors: |
Swoboda, Jr.; John J.
(Victoria, TX), Swoboda; Norman L. (Victoria, TX) |
Family
ID: |
23488636 |
Appl.
No.: |
05/377,321 |
Filed: |
July 9, 1973 |
Current U.S.
Class: |
414/728; 212/203;
212/231; 294/104; 414/700; 414/732; 901/20; 901/37; 294/86.4;
414/22.65; 414/708; 901/18; 901/22; 901/39; 182/2.11 |
Current CPC
Class: |
B25J
9/045 (20130101); E21B 19/14 (20130101); B25J
15/0206 (20130101) |
Current International
Class: |
B25J
15/02 (20060101); B25J 9/02 (20060101); B25J
9/04 (20060101); E21B 19/00 (20060101); E21B
19/14 (20060101); B65g 047/08 () |
Field of
Search: |
;214/1BC,1BD,2.5,3,3.1,1P,147R,147G,147T,763,771 ;175/85 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Werner; Frank E.
Attorney, Agent or Firm: Richards, Harris & Medlock
Claims
What is claimed is:
1. A racking arm for mounting on a drilling rig at a point spaced
above the working platform of the drilling rig and spaced away from
the well bore axis and for being employed to move elongated members
such as pipe sections, drill collars, riser pipe and the like used
in rotary drilling of earth formations and being in combination
with said dulling rig comprising:
a pedestal for being mounted on said working platform away from
said well bore axis,
a multisection telescoping boom having a supported end pivotally
connected to said pedestal and having a cantilevered end,
gripping means secured to said cantilevered end of said boom for
engaging the exterior surface of ssaid elongated members,
means for mounting said supported end of said boom for pivotal
movement about a vertical axis,
power means connected between said pedestal and said boom for
selectively rotating said boom about said vertical axis,
means connected between said pedestal and said boom for selectively
raising and lowering said cantilevered end, and
means in said boom for extending and retracting said boom to
selectively vary the length thereof.
2. The racking arm of claim 1 and further comprising:
an automatic parallel arm interposed between said free cantilevered
end of said boom and asid gripping means, said parallel arm
operable to maintain said gripping means in a constant position
relative to the horizontal during vertical movements of said
boom.
3. The racking arm of claim 1 wherein said gripping means is
adapted to grip pipe for lateral movement while permitting such
pipe to slide vertically on its own axis, and wherein said boom is
mounted to swing to a different vertical position if said pipe
becomes stuck in said gripping means so that said pipe cannot so
slide axially.
4. The racking arm of claim 1 wherein said gripping means is
constructed to grip riser pipe having a generally irregular
cross-sectional shape.
5. The racking arm of claim 1 and further comprising:
means operatively associated with said raising and lowering means
for allowing floating movement of said boom when a force is applied
to said boom through said elongated member being gripped.
6. The racker arm of claim 1 wherein said means for raising and
lowering comprises:
a first hydraulic cylinder mounted between said pedestal and said
boom for raising and lowering said boom,
a second hydraulic cylinder mounted to sense the vertical load
applied to the free cantilevered end of said boom, and
control valve means operable in response to said second cylinder to
cause said first cylinder to move said boom up or down upon the
occurrence of a predetermined load.
7. The racker arm of claim 1 and further comprising:
means attached between said gripping means and said boom for moving
said gripping means vertically relative to said boom.
8. The racker arm of claim 7 and further comprising:
means for sensing the vertical position of the cantilevered end of
said boom, said means for sensing being slaved to said means for
moving said gripping means vertically.
9. A racker arm system for guiding elongated pipe members used in
well drilling operations comprising:
a pedestal for being rigidly mounted on a drilling platform,
an extendable boom pivotally mounted at one end portion on said
pedestal and having a free cantilevered end,
a pipe gripper mounted on said cantilevered end for encircling pipe
members,
means for selectively pivoting said boom about a vertical axis
relative to said pedestal,
means for selectively raising and lowering said cantilevered
end,
means for selectively extending and retracting said boom, wherein
pipe members may be encircled by said gripper and guided by said
boom to desired locations,
a supply of pressurized fluid connected to a plurality of supply
lines in said pedestal,
a swivel assembly having an inner housing rigidly connected to said
pedestal and an outer housing pivotally movable with said boom,
conduits formed through said inner housing and communicating with
said supply lines,
ports in said outer housing communicating with said conduits,
and
fluid lines connected to said ports for supplying pressurized fluid
to said means for pivoting, raising and lowering, and extending and
retracting.
10. The racking arm of claim 1 and further comprising:
relief protection means operatively associated with said raising
and lowering means for allowing said boom to pivot independently of
said means for pivoting upon the occurrence of a predetermined
overload condition.
11. The racking arm of claim 1 wherein said means for pivoting
comprises:
a motor mounted for movement with said boom,
first gear means carried by said motor,
second gear means carried by said pedestal, said first and second
gear means meshing to provide rotation of said boom relative to
said pedestal.
12. A racking arm for guiding elongated pipe members used in rotary
drilling of wells comprising:
a pedestal for being affixed to a working platform of a drilling
rig,
a swivel platform pivotally mounted above said pedestal,
means for pivoting said platform about a vertical axis relative to
said pedestal,
a telescoping boom pivotally connected at a supported end about a
horizontal pivot axis to said platform, said boom having an
outwardly extending free cantilevered end,
a first hydraulic cylinder connected at the lower end to said
platform and at the upper end to a location on said boom between
said pivot axis and said cantilevered end,
a second hydraulic cylinder connected at the lower end to said
platform and at the upper end to said boom opposite said pivot axis
from said first hydraulic cylinder,
a gripper assembly pivotally connected on said cantilevered end of
said boom, and
a third hydraulic cylinder connected between said cantilevered end
and said gripper assembly, said second and third cylinders being
slaved together wherein said gripper assembly may be maintained at
a desired constant attitude.
13. The racker arm system of claim 9 wherein said means for raising
and lowering comprises:
a first hydraulic cylinder mounted between said pedestal and said
boom for raising and lowering said boom,
a second hydraulic cylinder mounted to sense the vertical load
applied to the free cantilevered end of said boom, and
control valve means operable in response to said second cylinder to
cause said first cylinder to move said boom up or down upon the
occurrence of a predetermined load.
14. The racker arm system of claim 9 and further comprising:
means for moving said gripper vertically relative to said boom.
15. The racker arm system of claim 14 and further comprising:
means for sensing the vertical position of the cantilevered end of
said boom, said means for sensing being slaved to said means for
moving said gripper vertically.
16. The racking arm system of claim 9 and further comprising:
relief protection means operatively associated with said raising
and lowering means for allowing said boom to pivot independently of
said means for pivoting upon the occurrence of a predetermined
overload condition.
17. The racking arm system of claim 9 wherein said means for
pivoting comprises:
a motor mounted selectively movement with said boom,
first gear means carried by said motor,
second gear means carried by said pedestal, said first and second
gear means meshing to provide rotation of said boom relative to
said pedestal.
18. The racking arm system of claim 9 and further comprising:
an automatic parallel arm interposed between said free cantilevered
end of said boom and said pipe gripper, said parallel arm operable
to maintain said pipe gripper means in a constant position relative
to the horizontal during vertical movements of said boom.
19. The racking arm system of claim 9 wherein said pipe gripper is
adapted to grip pipe for lateral movement while permitting such
pipe to slide vertically on its own axis, and wherein said boom is
mounted to swing to a different vertical position if said pipe
becomes stuck in said gripper so that said pipe cannot so slide
axially.
20. The racking arm system of claim 9 wherein said pipe gripper is
constructed to grip riser pipe having a generally irregular
cross-sectional shape.
21. The racking arm of claim 9 and further comprising:
means operatively associated with said raising and lowering means
for allowing floating movement of said boom when a force is applied
to said boom through the pipe member being gripped.
22. A racking arm for mounting on a drilling rig at a point spaced
above the working platform of the drilling rig and spaced away from
the well bore axis and which may be employed to move elongated
members such as pipe sections, drill collars, riser pipe and the
like used in rotary drilling of earth formations and being in
combination with said drilling rig comprising:
a multisection telescoping boom having a supported end and a
cantilevered end,
pipe gripping means secured to said cantilevered end of said boom
for engaging the exterior surface of said elongated members,
means for mounting said supported end of said boom for pivotal
movement about a vertical axis,
power means for selectively rotating said boom about said vertical
axis,
power means for selectively rotating said boom about said vertical
axis,
power means secured to said boom for selectively raising and
lowering said cantilevered end,
means operatively associated with said power means allowing
floating movement of said boom when forces are applied through
elongated member being gripped, and
means for extending and retracting said boom to selectively vary
the length thereof.
23. A racking arm for mounting on a drilling rig at a point spaced
above the working platform of the drilling rig and spaced away from
the well bore axis and which may be employed to move elongated
members such as pipe sections, drill collars, riser pipe and the
like used in rotary drilling of earth formations and being in
combination with said drilling rig comprising:
a multisection telescoping boom having a supported end and a
cantilevered end,
means secured to said cantilevered end of said boom for engaging
the exterior surface of said elongated member and limiting lateral
movement of said member while permitting said member to vertically
move in the direction of its axis,
means for mounting said supported end of said boom for pivotal
movement about a vertical axis,
power means for seectively rotating said boom about said vertical
axis,
means secured to said boom for selectively raising and lowering
said cantilevered end, and
means for extending and retracting said boom to selectively vary
the length thereof.
Description
FIELD OF THE INVENTION
This invention relates to well drilling operations, and more
particularly relates to a device for assisting in the handling of
vertical sections of pipes, drill collars, riser pipes and the like
in a well drilling rig.
THE PRIOR ART
As is well known, it is necessary during the drilling of oil wells
to transport elongated pipe members in a vertical position to and
from various locations on the oil drilling rig. For example,
additional sections of drill pipe must be periodically moved from a
setback area to the well hole as the well is extended further into
the ground, or when a drill bit needs replacement, the drill pipe
sections must be removed and temporarily stored in the setback
area. Moreover, during drilling operations, drill collars must be
removed from a setback area and transported to the drilling area.
In addition, when drilling is being done on an offshore platform,
riser pipes having an irregular cross-sectional area must be moved
to the blowout preventers from a racking area.
Generally, such elongated pipe members as pipe sections, drill
collars or riser pipes are lifted in a generally vertical position
by means of a traveling block on a derrick hoist. When such pipe
members are being transported in a vertical position, the lower end
of the pipe members tend to sway. Not only does such swaying
movement of the pipe members tend to present a safety problem to
the drilling rig and personnel, but such movement of the pipe
members may make it difficult to guide the pipe members to the
desired location which may comprise a relatively small opening. The
problem of swaying of pipe members is particularly critical when
the drilling is being performed from a floating offshore vessel
which is subject to severe pitching and rolling due to high winds
and waves.
Heretofore, it has been known to manually attempt to restrain such
pipe members from swaying during transport. Manhandling the pipe
has not been particularly successful due to the large mass and
unpredictable movement of the pipe members, and in some instances
the attempt to manually restrain the pipe members has presented
safety problems to personnel. A number of mechanical systems have
thus been heretofore developed in an attempt to restrain the
swaying of vertical pipe and to guide the pipe to the desired
location in an oil drilling rig. As an example, U.S. Pat. Nos.
2,828,024, 2,829,783 and 3,467,262 disclose extendable pipe
engaging members which may be operated to position a suspended pipe
over a well borehole. However, such prior devices are limited to
movement in a single horizontal plane and are provided only with
extremely limited pivotal movement about a vertical axis, and are
thus not practical for use in a well drilling environment to move a
variety of different types and sizes of pipe members to a plurality
of locations. In addition, such prior art devices have been subject
to overload damage in case of sudden vertical or lateral movement
of the pipe member. Previously developed systems have also not
heretofore enabled the selective guiding of riser pipes, due to the
various irregular shapes and configurations of the riser pipes.
SUMMARY OF THE INVENTION
In accordance with the present invention, a racker arm is provided
which substantially reduces or eliminates many of the problems
heretofore experienced in prior systems. The present racker arm
includes an extendable boom which may be moved to any desired
extent about a vertical axis and which may be selectively raised
and lowered to operate in a variety of different horizontal planes.
The system includes a first gripper head which may loosely clamp
about pipe sections or drill collars and a second gripper head
which may be tightly clamped about riser pipe having an irregular
cross-section. The gripper head is automatically maintained at all
times in a predetermined horizontal position regardless of the
vertical position of the boom. The present system includes overload
protection so that the boom is not damaged when the torque applied
to the bottom is exceeded by movement of the pipe member. The
extendable boom first extends the larger and strongest boom
sections and first retracts the smaller and weaker boom sections in
order to maintain optimum stability of the boom in all stages of
extension and retraction.
In accordance with a more specific aspect of the present invention,
a racking arm is provided for guiding elongated members such as
pipe sections, drill collars and riser pipe used in the rotary
drilling of earth formations. The racking arm includes a
telescoping boom having a supported end and a free cantilevered
end. A pipe gripper is secured to the cantilevered end of the boom
for clamping about elongated pipe members. Structure mounts the
supported end of the boom for pivotal movement about a vertical
axis and a motor is provided to selectively rotate the boom about
the vertical axis. Structure is secured to the supported end of the
boom for selectively raising and lowering the free cantilevered
end. Structure is provided for extending and retracting the boom to
selectively vary the length thereof. The boom may be disposed on a
drilling rig with the supported end spaced above the working
platform of the drilling rig and the vertical axis spaced away from
the well bore axes. The racking arm may be employed to move
elongated pipe members from various storage positions to the
wellbore or other areas and vice-versa.
In accordance with another aspect of the invention, a racker arm
system guides elongated pipe members used in well drilling
operations and includes a pedestal for being rigidly mounted on a
drilling platform. An extendable boom is pivotally mounted at one
end portion on the pedestal and includes a free cantilevered end. A
pipe gripper is mounted on the cantilevered end in order to
encircle pipe members. Structure is provided to selectively pivot
the boom about a vertical axes relative to the pedestal. Structure
is provided to selectively raise and lower the cantilevered end.
Structure is provided for selectively extending and retracting the
boom wherein pipe members may be encircled by the gripper and
guided by the boom to desired locations.
In accordance with another aspect of the invention, a racker arm
assembly includes an extendable boom having a supported end pivotal
about a vertical axis and having a free end movable upwardly and
downwardly. A pipe gripper is located on the free end of the boom.
The boom includes an outer housing having a plurality of
telescoping sections relatively movable from the housing to extend
and retract the boom. Structure is provided to control the movement
of the telescoping sections such that the outer sections are first
outwardly extended prior to the outwad extension of the innermost
sections.
In accordance with another aspect of the invention, a racaker arm
assembly is provided to grip and guide riser pipe having an
irregular cross-section. An extendable boom is movable to and from
a plurality of locations in the region of a well drilling platform.
A gripper head is mounted on the end of the boom and includes a
cutout portion for receiving an inner peripheral portion of the
riser pipe. A flexible chain is attached at one end to the gripper
head and has a free end. The chain is of sufficient length to be
wrapped around an outer peripheral portion of the riser pipe.
Structure is provided to attach the free end of the chain to the
gripper head so that the riser pipe is securely gripped for
movement in a vertical position to the desired locations in the
region of a well drilling platform.
In accordance with yet another aspect of the invention, a racker
arm system is provided to guide elongated pipe members. The system
includes an extendable boom having a free end movable to a
plurality of locations in the region of the drilling platform. A
pipe gripper is mounted on the free end of the boom and includes a
gripper base having a semi-circular cutout portion for receiving a
first peripheral portion of a vertical pipe. A movable gripper jaw
is mounted on a side of the base and includes a curved portion for
receiving a second peripheral portion of the pipe. At least two
linear lengths pivotally interconnect the base and the jaw so that
the jaw may be moved to and from the base in a generally linear
path. A pressurized cylinder is connected between the base and the
jaw for selectively moving the jaw to and from the base.
DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for
other objects and advantages thereof, reference is now made to the
following description taken in conjunction with the accompanying
drawings, in which:
FIG. 1 is a top view of a typical installation of the present
racker arm on an offshore drilling platform;
FIG. 2 is a side view of the present racker arm;
FIG. 3 is a rear view of the racker arm shown in FIG. 2;
FIG. 4 is a top view of the pipe section gripper head in the closed
position;
FIG. 5 is a top view of the gripper head shown in FIG. 4 in the
opened position;
FIG. 6 is a top view of the gripper head shown in FIG. 4 with
inserts added to enable gripping of smaller diameter pipes;
FIG. 7 is a top view of the riser pipe gripper head of the
invention with a riser pipe gripped in a first position;
FIG. 8 is a top view of the riser pipe gripper head shown in FIG. 7
with a riser pipe clamped in a second alternate position;
FIG. 9 is a perspective view of the present racker arm in a
partially extended position including the gripper head shown in
FIG. 4;
FIG. 10 is a perspective view of the racker arm in a fully extended
position including the gripper head shown in FIG. 7;
FIG. 11 is a sectional view, partially broken away, of the boom of
the present invention;
FIG. 12 is a sectional view taken generally along section lines
12--12 in FIG. 11;
FIG. 13 is a side view, partially sectioned, of the swivel assembly
of the present racker arm; and
FIG. 14 is a schematic drawing of the hydaulic control circuitry
for operation of the boom.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a top view of a typical installation of the
present invention is illustrated on an offshore drilling platform
designated generally by the numeral 10. The platform includes a
conventional rotary table 12 having a well bore 14, with a
mousehole 16 and a rathole 18 located adjacent the table 12. A pair
of drill pipe setback areas 20 and 22 are positioned opposite the
rotary table 12, with a pair of drill collar setback areas 24 and
26 being positioned between the areas 20 and 22 and the table 12.
The platform includes a deadman anchor 28, a derrick leg bedplate
30 and a stand pipe manifold 32.
The racker arm of the invention is illustrated generally by the
numeral 34 and is positioned between the rotary table 12 and the
derrick leg bedplate 30. The racker arm 34 includes an extendable
boom 36 including an outer housing and three extendable boom
sections 38, 40 and 42. A control console 44 includes five manually
operable levers 46 to enable control and operation of the racker
arm. The boom 36 includes a supported end 48 which is pivotal about
a vertical axis 50. The vertical axis 50 is spaced away from
borehole 14 and is positioned to enable access by the boom 36 to
the various setback areas on the platform, while also enabling
access to the well bore 14, the mousehole 16 and the rathole
18.
A pipe gripper head 52 is mounted on the free cantilevered end of
the boom 36 and includes a gripper base 54 having a cutout portion
56 for receiving a portion of the periphery of pipe section 58. The
gripper head 52 also includes a movable gripper jaw 60 which is
pivoted relative to the base 54 and is movable relative thereto by
operation of a hydraulic cylinder 62. As will be subsequently
described in greater detail, the gripper head assembly 52 clamps
about a pipe section or a drill collar in order to guide the pipe
members to the desired location, while allowing movement of the
pipe members along their vertical axes. an alternate gripper head
may be utilized with the boom to enable rigid gripping of riser
pipe for transportation to the blowout preventers.
The boom 36 is the illustrated position is pivotal about the
vertical axis 50 to scribe a minimum arm radius illustrated by the
arc 64. When the boom is extended to the maximum extent by
selective operation of the levers 46, the racker arm 34 may be
operated about a maximum arm radius illustrated by the arc 66. It
will thus be appaent apparent the racker arm 34 may be operated
substantially over the entire area of the well bore and the setback
areas of the platform.
FIGS. 2 and 3 illustrate side elevational views of the racker arm
34, and like numbers will be utilized in the various drawings for
like and corresponding parts. The boom 36 comprises an outer
housing 70 which receives the three telescoping boom sections 38,
40 and 42. The gripper head 52 is pivotally connected at pivot 72
to the lower end of the housing 42. A hydraulic cylinder 74 is
mounted within the outer end of the housing 42 and includes an
extendable rod 76 which is pivotally connected at pivot 78 to the
upper portion of the gripper head 52. As will be later described,
cylinder 74 is operated by the hydraulic control circuit to
maintain the gripper head 52 in a selected position (usually
horizontal) regardless of the attitude of the boom 36. In this
manner, pipe members may be grasped at high or low positions
without causing binding of the pipe members within the gripper head
52.
The boom 36 is mounted at the supported end upon a pedestal 80
which includes a base 82 which may be rigidly bolted to the floor
of the well drilling platform. The opposite end of boom 36
comprises free cantilevered end which may be selectively moved in
any direction. A hydraulic power unit assembly, not shown, is
connected to the pedestal 80 in order to supply pressurized fluid
thereto. The upper portion of the pedestal 80 supports a gear 84,
best shown in FIG. 3, which meshes with a gear 86 driven through a
gear box 88 by a hydraulic drive motor 90. The gear box 88 and
motor 90 are mounted on a platform 92 supported by two spaced apart
flanges 94 and 96 connected to a side brace 98. A second side brace
100 is spaced apart from brace 98 and both braces 98 and 100 are
connected to a pivot platform above gears 84 and 86. Operation of
motor 90 causes rotation of gear 86 to thereby pivot the upper
assembly relative to the fixed pedestal 80.
As best shown in FIG. 3, a ten-way hydraulic swivel assembly 102 is
mounted between the side braces 98 and 100 and serves to
communicate hydraulic pressure applied from the pedestal 80 to the
various hydraulic motors and cylinders of the racker arm. For
example, pressurized hydraulic fluid is applied through hydraulic
cables 104 and 106 from the swivel assembly 102 to the boom 36 in
order to operate the hydraulic cylinders which control the
extension and retraction of the boom. This pressurized fluid also
controls the operation of the hydraulic cylinders 74 in order to
control the attitude of the gripper head 52. A more detailed
description of the ten-way hydraulic swivel assembly 102 will be
described with respect to FIG. 13.
As shown in FIG. 2, a hydraulic cylinder 110 is pivotally connected
at a pivot 111 to the pivot platform located above the pedestal 80.
The cylinder rod 112 of the cylinder 110 is pivotally connected at
114 to the underside of the boom housing 70. Housing 70 is
pivotally supported between the side braces 98 and 100 by a pivot
pin 118. Cylinder 110 is slaved with cylinder 74 in order to
maintain the gripping head 52 in a selected position. Cylinder 110
senses the attitude of the boom 36 and varies the volume of oil in
cylinder 74 in order to maintain the gripper head 52 level at all
times.
A cylinder 120 is pivotally mounted at pivot 122 in base member
124. The rod 126 of the cylinder 120 extends upwardly to a pivotal
connection 128 with the underside of the boom housing 70. Hydraulic
fluid for operation of the cylinder 120 is applied from the swivel
assembly 102 via hydraulic lines. A counter balance 130 is provided
on the lower portion of cylinder 120 to provide a counter balance
to the system in case of failure of one of the hydraulic lines.
Cylinder 120 is utilized to raise and lower the boom 36 in a manner
to be described in detail with respect to the hydraulic circuitry
shown in FIG. 14.
The console 44 includes five levers 46 as previously noted to
enable operator control of the system. While the illustrated
embodiment shows a hydraulic valve control system it will be
understood that an electrical control system could alternatively be
utilized. In the preferred embodiment, the first lever moves the
boom up and down, the second lever moves the boom in and out, the
third lever pivots the boom left or right, the fourth lever opens
and closes the gripper head and the fifth lever moves the gripper
head up or down as desired. Each of the levers 46 comprises a
conventional hydraulic control lever system which controls the
application of pressurized fluid to the various cylinders and
motors of the system shown in FIGS. 2 and 3.
FIGS. 4-6 illustrate in greater detail the construction and
operation of the pipe section and drill collar gripper head
assembly 52. As previously noted, the gripper head 52 comprises an
integral unit which may be selectively pinned or unpinned to the
cantilevered free end of the boom 36. In this manner, different
types of gripper heads may be easily connected to the system for
use with different applications.
Referring to FIG. 4, the assembly comprises the gripper base 54
including a rear portion 140 having a generally triangular
cross-section as shown in FIG. 2. At the rear of the rear portion
140, a pair of lugs 142 and 144 are provided to enable pinning of
the assembly to the end of housing 42 at the pivot point 72 (FIG.
2). At the top center of the rear portion 140 is a lug 146 to
enable pinning of the assembly to the rod 76 at the pivot point 78
as shown in FIG. 2. Quick disconnect couplings 148 and 150 enable
disconnection of the hydraulic lines of the assembly. The quick
disconnect 148 connects hydraulic lines 152 and 154 to the lower
portion of the cylinder 62, while the quick disconnect 150 connects
the hydraulic lines 156 and 158 to the upper portion of the
hydraulic cylinder 62. As previously noted, hydraulic pressure is
applied to lines 154 and 158 via the ten-way hydraulic swivel
assembly 102 shown in FIG. 3.
The rod 160 of cylinder 62 is pivotally connected at 162 to the
gripper jaw 60. The gripper jaw 60 includes a curved cutout portion
164 for clamping about a portion of the periphery of a vertically
extending pipe section or drill collar. The jaw 60 is pivotally
connected to a rigid linkage 166 and is pivotally connected at a
spaced apart pivot point 168 to a second rigid linkage 170. Linkage
166 is shorter than linkage 170. Linkage 166 is connected at pivot
172 to the gripper base 54 and linkage 170 is connected at pivot
174 to the base 54. A lifting eye 176 is connected to the base 54
to assist in manual installation of the gripper head. As previously
noted, the base 54 includes a semi-circular cutout portion 56 for
clamping against one-half of the periphery of a pipe section or
drill collar.
FIG. 5 illustrates an important aspect of the gripper head 52 in
that the gripper jaw 60 moves away from the gripper base 54 is a
generally linear manner. This enables the gripper head 52 to clamp
about a pipe section with much less required space than if the
cutout sections 56 and 164 were directly hinged together. The
present gripper assembly may thus be used to clamp and unclamp pipe
sections or drill collars in a minimum space. The generally linear
action is provided by the fact that the short linkage 166 tends to
move the jaw inwardly, while the linkage 170 moves the jaw 60
outwardly away from contact with the base 54. The cylinder 62 is
operated to retract the rod 160 in order to open the gripper jaw as
illustrated in FIG. 5.
FIG. 6 illustrates the connection of clamp inserts 180 and 182 to
the gripper head in order to enable the assembly to clamp pipe
sections or drill collars of smaller diameters.
The insert 180 includes a base 184 with a pair of spaced apart
apertures 186. Retainer pins 188 rigidly connected to the base 54
extend through the apertures in order to securely fasten the insert
to the base 54. Insert 182 includes an aperture 180 which receives
a retainer pin 192 in order to affix insert 182 to the jaw 60. It
will be understood that a variety of different sizes of insert sets
may be utilized to enable the present device to guide a wide range
of pipe member sizes.
An important aspect of the present racker arm is the ability to
clamp riser pipe having an irregular cross-section. The riser pipe
gripper head 200 is illustrated in FIGS. 7 and 8 and includes a
rigid base 202 having a pair of spaced apart lugs 204 and 206
operable to be pivotally pinned to the free cantilevered end of the
boom 36 in the same manner as the gripper head 52. A central lug
208 is also adapted to be pivotally pinned to the rod 76 of the
cylinder 74 as previously described. Operation of the rod 76
enables pivotal movement of the gripper assembly 200 about the lugs
204 and 206 in order to vary the attitude of the gripper assembly.
The base 202 includes a pair of semi-circular portions 210 and 212.
Riser pipe may be gripped in either of the cutout portions 210 or
212, depending upon the position of the riser pipe when clamped and
depending upon the desired arc of movement of the riser pipe.
FIG. 7 illustrates a riser pipe assembly 214 clamped in the cutout
portion 210. Riser pipe assembly 214 includes a plurality of pipes
216 which provide the riser pipe assembly with an irregular
cross-section. In use of the present gripper assembly, the riser
pipe is positioned within the cutout portion 210 and a flexible
rigid chain 218 is wrapped around the outer periphery of the riser
pipe in order to rigidly clamp the riser pipe within the gripper
head assembly 200. Chain 218 may comprise any suitable linkage such
as a chain, cable or the like. Chain 218 is connected to an end of
a cylinder rod 220 and passes around a roller 219. Operation of the
cylinder 222 causes the chain 218 to be tightened about the riser
pipe. Cylinder 222 is connected by a pivot 224 to the base 202. The
free end of the chain 218 is hooked about a hook 228 after being
wrapped around a riser pipe. In operation, the riser pipe assembly
214 is positioned within the cutout portion 210. The free end of
the chain 218 is then wrapped around the riser pipe assembly and is
hooked on the hook 228. The cylinder 222 is then energized in order
to tighten the chain 218 around the riser pipe assembly to securely
clamp the riser pipe to the gripper head 200.
FIG. 8 illustrates the use of the present gripping head to grip the
riser pipe assembly 214 in the cutout portion 212. In this mode of
operation of the gripping head 200, the chain 218 is passed around
the roller 219 and around the outer periphery of the riser pipe
assembly 214 and is hooked upon a hook 230 extending from the base
202. The cylinder 222 is energized in order to tighten the chain
218 about the riser pipe assembly 214. The irregular
cross-sectional shape of the riser pipe assembly may be
accommodated dur to the flexible nature of the chain or cable
218.
FIGS. 9 and 10 are perspective views of the racker arm 34 and
illustrate the operation of the extendable boom 36. Like numbers
are utilized for like and corresponding parts in this drawing
previously described. As previously mentioned, operation of the
hydraulic motor 90 operates through the gear train 88 to rotate the
upper housing relative to the pedestal 80. In this manner, the
extendable boom 36 may be rotated any amount about a vertical axis.
Further, upon energization of the hydraulic cylinder 120, the boom
housing 70 and consequently the entire extendable boom may be
selectively moved up and down to enable the pipe member to be
gripped at any desired height. By operation of the cylinder 74, the
cylinder rod 76 may move the gripper head 52 up or down. Normally
during operation, the gripper head 52 will be automatically
maintained in a horizontal position by operation of the hydraulic
control system which will be subsequently described. Operation of
the cylinder 62 enables the gripper jaw 60 to open and close
against the gripper base 54 as previously described.
Each of the telescoping boom sections 38, 40 and 42 include a
corresponding hydraulic cylinder which enables selective individual
operation of each boom section. For example, section 38 includes a
cylinder rod 240 which may be selectively extended or retracted in
order to move the section 38 into and out from the housing 70.
Similarly, sections 40 and 42 include separate hydraulic cylinders
which enables relative movement of the sections to one another. As
shown in FIGS. 9 and 10, the housing 70 has the largest
cross-sectional area and receives each of the sections 38, 40 and
42 in a telescoping manner. Similarly, section 38 has a larger
cross-sectional area than do the innermost sections 40 and 42.
Likewise, section 40 has a larger cross-sectional area than the
innermost section 42.
An important aspect of the present invention is that the outermost
sections are first extended prior to any extension of the innermost
sections. Similarly, during retraction, the innermost sections are
first retracted prior to any retraction of the outermost sections.
Thus, the boom is provided with the optimum stability and strength
at any point of extension or retraction. For example, FIG. 9
illustrates a mid-point in the extension of the boom 36. In this
position, section 38 is fully exended from the housing 70 and
section 40 is just beginning to be outwardly extended from section
38. Section 42 is not extended whatsoever from section 40. In
operation, section 40 will be fully extended from section 38 before
any extension is provided to the innermost section 42.
FIG. 10 illustrates the boom 36 is a fully extended position
utilizing the gripper head 200 for riser pipe clamping. To retract
the boom, the innermost section 42 is first retracted within the
section 40. Thereafter, section 40 and section 42 are retracted
within the outermost section 38, and then section 38 is retracted
within the housing 70. In this manner, the larger and therefore
stronger outermost sections are utilized to bear the load when at
all possible. This construction and operation differs from prior
extendable booms utilizing cables wherein all sections are extended
and retracted simultaneously.
FIG. 11 is a sectional view, partially broken away, of the boom 36
illustrating the interconnection of the sections 38, 40 and 42 of
the housing 70. A first hydraulic cylinder 242 is rigidly connected
to the top of the housing 70 and includes the cylinder rod 240
which is pivotally connected at 244 to a lug 246 attached to the
top of the section 38. Section 38 includes a second hydraulic
cylinder 248 having a rod 249 connected by a clevis pin 250 to the
rear wall of section 38. Clevis pin 250 is mounted on a spacer 251
mounted across the back of section 38. A bracket 252 is connected
to the top rear of the section 38 and includes a roller 254 which
rolls against the underside of the housing 70.
Cylinder 248 is rigidly interconnected with a third cylinder 258
which is rigidly connected by a pin 260 to a bracket rigidly
connected to the rear of the section 40. A roller 262 is connected
to the lower rear of the section 38 to roll against the bottom of
housing 70, and a roller 264 is connected to the rear of section 40
in order to roll along the bottom of section 38. A roller 265 is
attached to section 40 for rolling along section 38.
A cylinder rod 266 extends from cylinder 258 and is connected by a
clevis pin 268 with a bracket 270 rigidly mounted within the
innermost section 42. Section 42 includes rollers 272 and 274
mounted on a rear thereof to roll within section 40. Housing 70
includes, at the lower front end thereof, a support roller 280.
Support rollers 282 and 284 are respectively mounted on the front
portions of sections 38 and 40.
Operation of the extendable boom 36 will be apparent in FIG. 11.
When the boom is in the retracted position, hydraulic fluid is
first applied to cylinder 242 and rod 240 causes the section 38 to
be fully extended. Pressure is then applied to cylinder 248 and the
rod 249 causes the section 40 to be fully extended from section 38.
Pressurized fluid is then applied to cylinder 258 which causes the
rod 266 to fully extend the innermost section 42. Upon retraction,
the operation is reversed with the innermost section 42 being first
retracted within section 40 as previously noted. The roller pins
provided by the present invention provide smooth operation of the
telescoping action of the boom at all times.
FIG. 12 is a sectional view of the boom 36 taken along section
lines 12--12. FIG. 12 illustrates that cylinder 242 and cylinder
rod 240 are mounted in the interior top of housing 70. As may be
seen, guide rollers are connected between the housing 70 and the
section 38 in order to provide smooth trouble-free operation of the
boom. As shown in FIG. 12, cylinders 248 and 258 extend through the
middle of the innermost section 42 and serve to operate both
sections 40 and 42 ad previously described.
FIG. 13 illustrates the ten-way hydraulic flexible assembly 102
previously shown in FIG. 3. The swivel assembly 102 includes a
central housing 290 which is fixedly attached to the top of the
pedestal 80 (FIG. 3). The assembly 102 further includes an outer
housing 292 which is attached to the pivotal base above the
pedestal 80 which rotates relative to the pedestal 80. Ten circular
ports 300 are formed in the bottom of the housing 290 and extend
upwardly through the length thereof. Each of the ports communicates
with one of ten circular grooves 302 for about the periphery of the
housing 290. For example, port 304 communicates with the bottom of
the housing 290 and extends upwardly into contact with the second
circular groove around the top of the housing 290.
Ten ports 306 are formed through the walls of the outer housing
292. Each of the ports 306 communicates with a different one of the
grooves 302. Hoses are attached to the ports 306 and are directed
to the extendable boom 36 and to the various cylinders and motors
of the system. Housing 290 remains stationary, while outer housing
292 rotates during pivoting of the boom 36.
FIG. 14 is a diagram of the hydraulic control system for the racker
arm. This system controls the operation of the cylinder 62 which
opens and closes the gripper assembly, controls cylinders 74 and
110 which maintain the gripper assembly in a horizontal position,
controls the cylinder 120 which raises and lowers the free
cantilevered end of the boom, and controls cylinders 242, 248 and
258 which controls the extension and retraction of the boom. The
power unit 310 of the hydraulic system includes a hydraulic pump
312 which is operated by a 60-H.P. electrical motor 314. Motor 314
also operates a second hydraulic pump 316. Pressurized fluid is
applied from pump 312 via pump lines 318 and 320. Relief valves 322
and 324 relieve the pump lines at 1200 psi and 1600 psi,
respectively. Pump line 318 is directed to a four-way control valve
328 which controls the swing of the boom about the vertical axis.
Line 330 connects the valve 328 with the hydraulic motor 90 which
operates the gears 84 and 86 in the manner shown in FIG. 3 in order
to pivot the boom. A dual relief valve 332 is connected across the
motor 90 in order to provide relief protection to the motor at 1000
psi.
The output of the motor 90 is applied through line 334 to valve
328. Line 336 is directed from the valve 328 to a fourway control
valve 338 which operates to control the desired angular orientation
of the gripper assembly. When the valve 338 is in the illustrated
position, pressurized fluid is provided through line 340 to a
four-way control valve 342 which operates to open or close the
gripper jaw of the gripper assembly. The valve 342 thus controls
the flow of pressurized fluid to the cylinder 62 connected on the
gripper head shown in FIGS. 4 and 5. A low pressure relief valve
344 is connected to the input line to the 342 valve to relieve the
valve at 600 psi. One output of valve 338 is applied through line
346 and through a needle valve 348 to a piloted control valve 350,
termed the boom float valve. Line 346 is also applied to a dual
relief valve 352 which provides crossover pressure relief at 1,000
psi. The output of valve 352 is applied to a counter balance valve
354 and to a reservoir 356 and is also applied via line 358 to
cylinder 74. Cylinder 74 is slaved with cylinder 110.
The second output from valve 338 is applied via line 360 and
through a needle valve 362 to the boom float control valve 350.
Line 360 is also connected through the dual relief valve 352 and
via line 366 to the cylinder 110 (FIG. 2). An output line 368 from
the valve 352 is applied to a 200 psi relief valve 370.
The output line 320 from the pump 312 is applied to the boom lift
four-way control valve 374. In the illustrated position, the valve
374 applies the fluid via line 376 to the boom float control valve
350. An 800 psi relief valve 378 is connected to line 376. The
output of the control valve 374 is applied via lines 380 both to
the boom float control valve 350 and to the boom lift cylinder 120.
A counterbalance valve 382 set at 2,500 psi is connected in series
with lines 380.
The output from pump 316 is applied to an overcenter valve 388 and
through a check valve 390 to line 392. A high-pressure relief valve
394 is set at 2,000 psi and is connected to line 392. Line 392 is
directed to a boom extension four-way control valve 396. Valve 396
controls the flow of fluid through line 398 through a counter
balance 400 to the cylinder 242, 248 and 258 connected in series,
as illustrated. The output of cylinders 242, 248 and 258 is applied
through line 402 and through a 2500 psi counterbalance valve 404 to
the boom extension control valve 396. A pilot line 408
interconnects line 398 with the overcenter valve 388.
The power unit 310 will generally be mounted in a separate unit,
not shown in FIGS. 1-13, which is conventionally connected to
pedestal 80 to supply pressurized fluid thereto. The hydraulic
circuitry located within the dotted line 412 is located within the
control console 44 shown in FIG. 3. The remainder of the motors and
cylinders are located on the boom as previously described.
In operation of the hydraulic circuitry shown in FIG. 14, selected
ones of the manual control levers 46 shown in FIG. 3 will be
operated in order to manually control the position of the control
valves 328, 342, 338, 374 and 396. When it is desired to pivot the
boom about the vertical axis, control valve 328 is operated in
order to cause operation of the hydraulic motor 90. The motor 90
rotates gear 86 which operates against gear 84 in order to pivot
the boom relative to the fixed pedestal 80 as previously
described.
When it is desired to open or close the gripper head, valve 342 is
operated in order to selectively move the gripper clamp cylinder 62
as shown in FIGS. 4 and 5. In the case of the gripper head shown in
FIGS. 7 and 8, operation of the valve 342 controls the operation of
the cylinder 222 in order to tighten or loosen the flexible chain
218.
As previously noted, cylinder 74 and 110 interact to maintain the
gripper assembly in a desired position throughout all vertical
movement of the free cantilevered end of the boom 36. Cylinders 74
and 110 are thus slaved, so that the volume of hydraulic fluid in
cylinder 110 is changed when the boom is moved up or down. The
change of hydraulic fluid in cylinder 110 thus causes a
corresponding opposite change in the volume of hydraulic fluid in
cylinder 74, in order to change the angle of the gripper head with
respect to the boom in order to maintain the desired preset angle
of the gripper head. The preset angle of the gripper head is
adjusted by operation of control valve 338.
The relief valve 370 maintains a minimum of 200 psi in the lines on
the low pressure side of the cylinders. Valve 370 thus insures that
air is kept out of the system due to the maintenance of 200 psi and
thus compensates for the difference in area between cylinders 74
and 110. The counterbalance valve 354 is important in providing
overload release in case the boom is overloaded faster than
cylinder 110 can compensate for. Upon overload, fluid is dumped
into reservoir 356.
An important aspect of the invention is that the boom 36
automatically floats vertically up and down with the riser pipe
when the riser gripper head is engaged with the riser pipe. This
floating action is provided by the boom float control valve 350.
Thus, the boom 36 may float with vertical movements of the riser
pipe during movement from one location to another without harm to
the boom. This floating operation is not required when the pipe
section or drill collar gripping head is being utilized, as the
pipe section or drill collar are not tightly gripped, but are
allowed to move vertically with respect to the gripping head. Thus,
when pipe sections or drill collars are gripped, the pipe sections
or drill collars are able to move vertically along their axes and
the gripper head is maintained in a predetermined angle to prevent
binding up.
To explain the floating boom action, assume an upward force is
exerted on boom 36. As the pressure begins to build up due to
lifting on the cylinder 74, the hydraulic fluid supplied through
line 346 is applied through the boom float control valve 350 and
the cylinder 120 is allowed to raise the boom 36 to compensate for
the overload in pressure. If an excessive downward load is applied
to the boom, the cylinder 74 picks up the load and pressurized
fluid is applied through line 366 to the boom float valve 350 and
the cylinder 120 pulls the boom downwardly in order to
automatically compensate for the overload.
When it is desired to lift or lower the cantilevered free end of
the boom 36 to initially clamp onto a pipe member, the valve 374 is
actuated by the respective manual lever and pressurized fluid is
applied to the boom lift cylinder 120 in order to selectively raise
or lower the boom about the pivot point 118 as previously
described. Lifting of the boom 36 will cause pressurized fluid to
be transferred from cylinder 110 to cylinder 74 in order to
maintain the desired position of the gripper head relative to the
horizontal.
when it is desired to extend or retract the boom 36, the boom
extension valve 396 is selectively operated and pressurized fluid
is applied from the pump 316 to the cylinders 242, 248 and 258. Due
to the serial connection of the cylinders, the outermost sections
are initially extended prior to the extension of the innermost
section, as previously noted, in order to maintain the maximum
strength of the boom at all times.
While the present invention has been primarily disclosed with
respect to a manual control console, it should be understood that
automatic or preprogrammed controls could be provided to the
present racker arm. As an example, a limit switch system could be
provided so that the boom automatically swings to and from the well
bore, rathole or mousehole and predetermined setback areas.
Alternatively, a properly programmed digital computer could be
utilized in order to operate the boom according to preprogrammed
instructions.
Whereas the present invention has been described with respect to
specific embodiments thereof, it will be understood that various
changes and modifications will be suggested to one skilled in the
art, and it is intended to encompass such changes and modifications
as fall within the scope of the appended claims.
* * * * *