U.S. patent application number 15/147423 was filed with the patent office on 2017-11-09 for heave compensator for constant force application to a borehole tool.
This patent application is currently assigned to BAKER HUGHES INCORPORATED. The applicant listed for this patent is BAKER HUGHES INCORPORATED. Invention is credited to Jason L. Cullum, William A. Hered.
Application Number | 20170321495 15/147423 |
Document ID | / |
Family ID | 60203462 |
Filed Date | 2017-11-09 |
United States Patent
Application |
20170321495 |
Kind Code |
A1 |
Hered; William A. ; et
al. |
November 9, 2017 |
Heave Compensator for Constant Force Application to a Borehole
Tool
Abstract
The compensating device has a through passage that goes to the
borehole tool. There is a lateral passage to a piston housing.
Through the use of a differential piston area on the outer housing,
a net uphole force results from backpressure as a result of flow
pumped through a section mill that mills in an uphole direction. If
the vessel goes down the mill is just pushed away from the tubular
being cut. If wave action takes the vessel up fluid is displaced
back into the mandrel but the constant force up that is dependent
on the existing backpressure in the tubing keeps a steady uphole
force on the mill. The tool can be reversed for applications that
require a net down force during milling. Rotational locking between
the mandrel and the outer housing can be used. Ports are sized to
prevent damping responses.
Inventors: |
Hered; William A.; (Houston,
TX) ; Cullum; Jason L.; (League City, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BAKER HUGHES INCORPORATED |
Houston |
TX |
US |
|
|
Assignee: |
BAKER HUGHES INCORPORATED
Houston
TX
|
Family ID: |
60203462 |
Appl. No.: |
15/147423 |
Filed: |
May 5, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 29/12 20130101;
E21B 17/076 20130101; E21B 19/09 20130101 |
International
Class: |
E21B 17/07 20060101
E21B017/07; E21B 29/12 20060101 E21B029/12 |
Claims
1. An apparatus for applying force to a borehole tool from a moving
source, comprising: a mandrel having a passage therethrough and an
upper and lower ends; an outer housing slidably mounted to said
mandrel for predetermined relative movement in opposed directions,
said outer housing comprising an outer housing passage which
continues said mandrel passage; said mandrel and outer housing
defining a first variable volume chamber which communicates with
said passage such the pressure in said first variable volume
chamber results in a force applied to the borehole tool that is
insensitive to said predetermined relative movement.
2. The apparatus of claim 1, wherein: pressure in said chamber
arises from flow resistance in the borehole tool.
3. The apparatus of claim 1, further comprising: a second variable
volume chamber communicating to outside said outer housing; said
variable volume chambers comprise opposed piston faces to create a
net force on the borehole tool.
4. The apparatus of claim 1, wherein: said mandrel and said outer
housing are rotationally locked.
5. The apparatus of claim 4, wherein: said rotational locking
comprises a keyway on one of said mandrel and said outer housing
engaged to a tab on the other of said mandrel and said housing.
6. The apparatus of claim 3, wherein: said first variable volume
chamber is closer to said uphole end of said mandrel than said
second variable volume chamber.
7. The apparatus of claim 3, wherein: said first variable volume
chamber is further from said uphole end of said mandrel than said
second variable volume chamber.
8. The apparatus of claim 6, wherein: pressure in said first
variable volume chamber creates a tensile force on the borehole
tool.
9. The apparatus of claim 7, wherein: pressure in said first
variable volume chamber creates a compressive force on the borehole
tool.
10. The apparatus of claim 6, wherein: one of said mandrel and said
outer housing comprising opposed surfaces that define said
predetermined relative movement.
11. The apparatus of claim 7, wherein: one of said mandrel and said
outer housing comprising opposed surfaces that define said
predetermined relative movement.
12. The apparatus of claim 3, wherein: said first and second
variable volume chambers defined by an upper seal, a middle seal
and a lower seal.
13. The apparatus of claim 12, wherein: said first variable volume
chamber communicating with said passage between said upper and
middle seals and said second variable volume chamber communicating
with outside of said outer housing between said middle and lower
seals.
14. The apparatus of claim 12, wherein: said first variable volume
chamber communicating with said passage between said middle and
lower seals and said second variable volume chamber communicating
with outside of said outer housing between said upper and said
middle seals.
15. The apparatus of claim 10, wherein: said mandrel and said outer
housing move in tandem after one of said opposed surfaces are
engaged.
16. The apparatus of claim 11, wherein: said mandrel and said outer
housing move in tandem after one of said opposed surfaces are
engaged.
17. The apparatus of claim 10, wherein: said opposed surfaces are
located in said first variable volume chamber.
18. The apparatus of claim 11, wherein: said opposed surfaces are
located in said first variable volume chamber.
19. The apparatus of claim 1, wherein: said mandrel is connected to
the borehole tool and said outer housing is connected to the moving
source.
20. The apparatus of claim 1, wherein: said first variable volume
chamber is located between said outer housing passage and said
mandrel passage.
21. The apparatus of claim 20, wherein: said mandrel comprising a
seal to said outer housing to allow said mandrel to act as a piston
exerting a force on the borehole tool.
22. The apparatus of claim 21, wherein: said outer housing
comprising opposed surfaces that act as travel stops in opposed
directions for said mandrel.
23. The apparatus of claim 1, wherein: pressure in said passages is
created by flow restriction through the borehole tool which
communicates with said first variable volume chamber to put a force
on said mandrel in the direction of the borehole tool.
Description
FIELD OF THE INVENTION
[0001] The field of the invention is a compensating device that
maintains a constant axial force on a borehole tool responsive to
internal pressure in the tool created by fluid pumped through the
compensating device and bound for the borehole tool.
BACKGROUND OF THE INVENTION
[0002] Some borehole procedures such as section milling are
sensitive to load variations which could adversely affect the
cutting inserts on the mill. Floating vessels are subject to wave
action and frequently contain heave compensation devices to even
out the up and down motion of the vessel in response to wave
action. These systems are not sensitive enough to stop all the
force variations at the borehole tool, which can adversely affect
the longevity of the tool. Heave compensation systems are large and
very complex as illustrated in U.S. Pat. No. 3,905,580; US
2016/0039643; and U.S. Pat. No. 9,267,340. Thrusters are used as
compensation device during drilling as illustrated in US
2001/0045300 and U.S. Pat. No. 6,102,138. Still other tool
variations for force control during drilling applications are U.S.
Pat. No. 7,284,606 and U.S. Pat. No. 6,705,411.
[0003] What is provided by the invention is a system that can apply
a constant loading force in either a downhole or uphole direction
based on internal pressure. The tool has the needed telescoping
capability such that between opposed travel limits a predetermined
force is applied in tension or compression to the attached borehole
tool depending on the orientation of the compensation tool in the
tubular string. The fluid pressure that regulates the force applied
to the borehole tool is the same fluid pressure that is applied to
the borehole tool in the case of a milling tool. The pressure exits
nozzles and takes away cuttings. These and other aspects of the
present invention will be more readily apparent to those skilled in
the art from a review of the description of the preferred
embodiment and the associated drawings while recognizing that the
full scope of the invention is to be determined from the appended
claims.
SUMMARY OF THE INVENTION
[0004] The compensating device has a through passage that goes to
the borehole tool. There is a lateral passage to a piston housing.
Through the use of a differential piston area on the outer housing,
a net uphole force results from backpressure as a result of flow
pumped through a section mill that mills in an uphole direction. If
the vessel moves down the mill is just pushed away from the tubular
being cut. If wave action takes the vessel up fluid is displaced
back into the mandrel but the constant force up that is dependent
on the existing backpressure in the tubing keeps a steady uphole
force on the mill. The tool can be reversed for applications that
require a net down force during milling. Rotational locking between
the mandrel and the outer housing can be used. Ports are sized to
prevent damping responses.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a section view of the device in the lowermost
position of the vessel;
[0006] FIG. 2 is the view of FIG. 1 with the vessel having risen
due to wave action;
[0007] FIG. 3 is an alternative embodiment to FIG. 1 in the
lowermost position of the vessel;
[0008] FIG. 4 is the view of FIG. 3 in the uppermost position of
the vessel;
[0009] FIG. 5 is a section view through line 5-5 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] Referring to FIG. 1, there is a mandrel 10 having a passage
12 and lateral ports 14. An outer housing 16 surrounds the mandrel
10 and has ports 18 leading to a surrounding annular space 20. A
vessel is schematically illustrated as V rides on the water and
likely has a heave compensator on board to minimize the movement
seen at connection 22 to the mandrel 10. Seals 24 and 26 are
different diameters and define a variable volume chamber 28 between
the outer housing 16 and the mandrel 10. Pressure applied to
passage 12 communicates with chamber 28 to create a net force in
the direction of arrow 30 on the outer housing 16. This happens
because the piston areas 32 and 48 see passage 12 pressure for a
force in the direction of arrow 30 and that force is opposed by
pressure in the annulus 20 which is usually far lower acting on
surfaces 50 and 52. Ports 18 communicate variable volume chamber 38
with the annular space 20 so that the mandrel 10 does not get
liquid locked in housing 16. Seals 26 and 40 seal off chamber 38
from chamber 28 as well as sealing chamber 42 from chamber 38.
Chamber 42 has the same pressure as in passage 12 and a series of
keyways 44 between which are disposed keys 46 mounted to the
mandrel 10. Mandrel 10 is rotationally locked to housing 16 using
keyways 44 meshing with a key or keys 46.
[0011] Mill M can be of a type that mills under a tensile force.
The objective is to maintain a constant tensile force on the mill M
during milling. Mill M also uses nozzles to clear milling debris
and the pressure drop through those nozzles accounts for the back
pressure in passage 12 during milling. With the opposed piston
areas 32 on one hand and 34 and 36 on the other hand, the
consistent back pressure from flow through passage 12 going to the
nozzles of mill M results in a consistent tensile force applied to
the mill M during milling. There can be some variation in the
annulus 20 pressure but it should not materially affect the net
force in the direction of arrow 30 on mill M. In most cases passage
12 pressure acting on area 48 will create a net force in the
direction of arrow 30 on housing 16 slightly offset by pressure in
annulus 20 acting on area 50.
[0012] When the vessel V moves downward due to wave action the
vessel's heave compensator can offset some of that motion but there
can be a net downward force on the mill in a direction opposite
arrow 30. Mandrel 10 has the ability to move down until it
shoulders out against shoulder 52. As this happens the pressure in
passage 12 continues to provide the net force to the mill M in the
direction of arrow 30 so that milling can continue with a uniform
uphole force independent of the movement of mandrel 10 until
mandrel 10 engages shoulder 52. At that point there is tandem
movement of the mandrel 10 and the outer housing 16 which simply
results in backing away the mill M from the object or tubular that
is being milled.
[0013] On the other hand, if the vessel V moves upward raising
mandrel 10, there is no effect on the mill M unless shoulder 54 on
mandrel 10 engages shoulder 56 on the outer housing 16. The outer
housing 16 is designed long enough to prevent these two shoulders
from contacting since doing so will increase the stress on the
outer housing 16 and the mill M that in the displayed configuration
in FIGS. 1 and 2 is already under tension when milling. Movement of
mandrel 10 from the FIG. 1 to the FIG. 2 position reduces the
volume of chamber 28 and increases the volume of chamber 38. To
enable the movement fluid flows into passage 12 through ports 14
and into chamber 38 through ports 18. The volume of chamber 42
increases as it holds at a steady pressure seen in passage 12. The
flows reverse when the movement is from the FIG. 2 position back to
the FIG. 1 position. As long as the mandrel 10 has room to move
between opposed surfaces 52 and 56 the pressure in passage 12 keeps
a constant force on the mill M which is determined by the mill
nozzle quantity and size and the delivered flow rate to those
nozzles that are not shown.
[0014] Those skilled in the art will appreciate that the internal
configuration of mandrel 10 and outer housing 16 can be changed so
that pressure in passage 12 will result in a net downhole force on
outer housing 16 if a mill M is used that operates with a
compressive load against the piece being milled rather than a
tensile force against the piece as shown in FIGS. 1 and 2. The mill
M can be operated with rotating drill pipe or equivalent driving
system connected to passage 12 on the uphole end and to the nozzles
of the mill M on the downhole end.
[0015] Those skilled in the art will appreciate that the described
device is able to maintain a constant force on a tool in a
designated direction whose magnitude depends on the internal
pressure pumped to the tool while compensating for vessel movements
as the mill operates consistently with a required applied force. As
long as the telescoping components have room to move relative, the
movement of the vessel will be immaterial to the operation of the
mill M. In some applications torque can be transmitted through the
tool as its telescoping components can be rotationally locked. The
device is simple in construction and needs just three seals for a
force to be generated in an uphole direction. To generate a steady
force in the downhole direction a single seal is needed. The tool
length can be configured to take into account the contemplated
movement of the mandrel 10 attached to the vessel V so that the
engagement with the travel stops is avoided.
[0016] While the layout of FIGS. 1 and 2 result in a tensile force
on the mill M, a resulting compressive force can result if the
locations of ports 14 and 18 are swapped about the middle seal 26.
When that happens the chambers 28 and 38 switch positions although
the travel stops 32 and 52 remain in position. Alternatively the
mill M can be simply connected at thread 22 and the vessel V
connected to the outer housing 16, essentially turning the tool of
FIGS. 1 and 2 up side down and the result will still be a tensile
force as is now shown.
[0017] FIGS. 3-5 show a simplified version of a mandrel 70
surrounded by an outer housing 72. The vessel V is connected at 74
and the mill M is connected at 76. Housing 72 has a passage 78 that
continues as passage 80 to the mill M. Pressure in passages 78 and
80 creates pressure in variable volume chamber 82 due to the
presence of seal 84. A force in the direction of mill M depicted by
arrow 86 is generated for a mill that operates under a compressive
force. Housing 72 moves with the vessel V. The FIG. 4 position is
reached if the vessel V moves up so that surface 90 hits travel
stop 88 on housing 72 although the length of housing 72 can be
provided to avoid jarring loads on the mill M. Ideally surfaces 92
and 94 should not contact when the vessel V moves down. As shown in
FIG. 5 the mandrel 70 and housing 72 are rotationally locked in
this case with matching non-round shapes in the form of hexagons.
Other non-round shapes or splined arrangements are also
contemplated as alternatives. Variable volume chamber 96 has no
seals near its lower end allowing fluid to enter or leave as the
volume changes to avoid liquid locking of mandrel 70.
[0018] The above description is illustrative of the preferred
embodiment and many modifications may be made by those skilled in
the art without departing from the invention whose scope is to be
determined from the literal and equivalent scope of the claims
below:
* * * * *