U.S. patent application number 10/712866 was filed with the patent office on 2004-07-15 for releasable wireline cablehead.
This patent application is currently assigned to Baker Hughes Incorporated. Invention is credited to Brewer, James E., Castillo, Homero C., Rogers, James O..
Application Number | 20040134667 10/712866 |
Document ID | / |
Family ID | 32329135 |
Filed Date | 2004-07-15 |
United States Patent
Application |
20040134667 |
Kind Code |
A1 |
Brewer, James E. ; et
al. |
July 15, 2004 |
Releasable wireline cablehead
Abstract
An apparatus for releasably connecting a wireline to a downhole
tool comprises a connector having a first member adapted for
connection to the downhole tool and a second member adapted for
connection to the wireline. A plurality of locking elements are
constrained to engage the first and second members by a moveable
release member, where the plurality of locking elements maintain
the first and second members in a connected position when the
moveable release member is in a first locked position. An
electromechanical actuator moves the moveable release member to a
second released position, releasing the plurality of locking
elements from engagement with the first and second members. This
allows the first and second members to release the wireline from
the tool.
Inventors: |
Brewer, James E.; (Houston,
TX) ; Castillo, Homero C.; (Kingwood, TX) ;
Rogers, James O.; (Spring, TX) |
Correspondence
Address: |
PAUL S MADAN
MADAN, MOSSMAN & SRIRAM, PC
2603 AUGUSTA, SUITE 700
HOUSTON
TX
77057-1130
US
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
32329135 |
Appl. No.: |
10/712866 |
Filed: |
November 13, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60426897 |
Nov 15, 2002 |
|
|
|
Current U.S.
Class: |
166/380 ;
166/242.6 |
Current CPC
Class: |
E21B 17/023 20130101;
E21B 17/04 20130101; E21B 17/028 20130101; E21B 17/06 20130101 |
Class at
Publication: |
166/380 ;
166/242.6 |
International
Class: |
E21B 017/00 |
Claims
What is claimed is:
1. A system for use in a wellbore, comprising: a. a wireline
extending from a surface location to a predetermined location in
the wellbore; b. a tool string having at least one tool adapted to
perform at least one downhole operation; and c. a cable head for
releasably connecting said wireline to said tool string.
2. The system of claim 1, wherein the cable head includes: i. a
first member adapted for connection to the downhole tool and a
second member adapted for connection to the wireline; ii. a
plurality of locking elements constrained to engage said first
member and said second member by a moveable locking sleeve, said
plurality of locking elements maintaining said first member and
said second member in a connected position when said moveable
locking sleeve is in a first position; and iii. an actuator adapted
to move said moveable locking sleeve to a second position releasing
said plurality of locking elements from engagement with said first
member and said second member allowing said first member and said
second member to release said wireline from said tool.
3. The system of claim 2 wherein the plurality of locking elements
are balls.
4. The system of claim 2 wherein the actuator includes a
solenoid.
5. The system of claim 2 wherein the actuator includes a motor
drive.
6. The system of claim 2 further comprising a breakable tensile
link.
7. The system of claim 2 wherein the plurality of locking elements
includes locking fingers.
8. The system of claim 7 wherein the locking fingers pivot about a
hinge.
9. The system of claim 7 wherein the locking fingers comprise
collet type elements.
10. The system of claim 2, wherein the plurality of locking
elements move inwardly when said moveable locking sleeve is moved
to the second position.
11. The system of claim 1, wherein the wireline is a
multi-conductor wireline.
12. The system of claim 1, wherein the at least one tool is a
logging tool.
13. The system of claim 1, wherein the cable head is remotely
operated by a surface controller.
14. An apparatus for releasably connecting a wireline to a downhole
tool, comprising: a. a cable head having a first member adapted for
connection to the downhole tool and a second member adapted for
connection to the wireline; b. a plurality of locking elements
constrained to engage said first member and said second member by a
moveable locking sleeve, said plurality of locking elements
maintaining said first member and said second member in a connected
position when said moveable locking sleeve is in a first position;
and c. an actuator adapted to move said moveable locking sleeve to
a second position releasing said plurality of locking elements from
engagement with said first member and said second member allowing
said first member and said second member to release said wireline
from said tool.
15. The apparatus of claim 14 wherein the plurality of locking
elements are balls.
16. The apparatus of claim 14 wherein the actuator includes a
solenoid.
17. The apparatus of claim 14 wherein the electromechanical
actuator includes a motor drive.
18. The apparatus of claim 14 further comprising a breakable
tensile link.
19. The apparatus of claim 14 wherein the plurality of locking
elements includes locking fingers.
20. The apparatus of claim 19 wherein the locking fingers pivot
about a hinge.
21. The apparatus of claim 19 wherein the locking fingers comprise
collet type elements.
22. The apparatus of claim 14, wherein the plurality of locking
elements move inwardly when said moveable locking sleeve is moved
to the second position.
23. The apparatus of claim 14, wherein the wireline includes
multiple conductors.
24. The apparatus of claim 14, wherein the wireline includes at
least one optical fiber.
25. A method of releasably connecting a wireline to a downhole
tool, comprising; a. locking a first member coupled to the wireline
to a second member coupled to the downhole tool by using a locking
sleeve to constrain a plurality of locking elements to engage said
first member and said second member when said locking sleeve is in
a first position; and b. using an actuator to move said locking
sleeve from said first position to a second position releasing said
plurality of locking elements from engagement with said first
member and said second member for releasing said first member from
said second member and releasing said wireline from said downhole
tool.
26. The apparatus of claim 25 wherein the plurality of locking
elements are balls.
27. The apparatus of claim 25 wherein the actuator includes a
solenoid.
28. The apparatus of claim 25 wherein the actuator includes a motor
drive.
29. The apparatus of claim 25 further comprising a breakable
tensile link.
30. The apparatus of claim 25 wherein the plurality of locking
elements includes locking fingers.
31. The apparatus of claim 30 wherein the locking fingers pivot
about a hinge.
32. The apparatus of claim 30 wherein the locking fingers comprise
collet type elements.
33. The apparatus of claim 25, wherein the plurality of locking
elements move inwardly when said moveable locking sleeve is moved
to the second position.
34. The apparatus of claim 25, wherein the wireline includes at
least one optical fiber.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/426,897, filed Nov. 15, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to wireline operations in a well and
more particularly to a cable head system for remotely releasing a
wireline from a downhole tool.
[0004] 2. Description of the Related Art
[0005] Wireline operations are carried out in oil and gas wells for
conveying tools downhole in the well. A wide variety of downhole
tools may be supported on a wireline including tools to perform
logging, perforating, and setting and retrieving operations. The
tools typically comprise a combination of different tubular members
threaded together to form a working unit which is manipulated and
controlled from the surface via the wireline. Although tools may be
conveyed downhole on a tubing string which can withstand
substantially higher extraction forces than a wireline, oftentimes
a wireline is preferred because it saves substantial rig time in
conveying tools downhole and positioning them within the well. A
cable head, which connects the tools to the wireline, is typically
provided with a release mechanism to permit the wireline to be
disconnected from the tools, such as when the tools become stuck
downhole.
[0006] The commonly accepted safe operational pull of the wireline
is a pull which does not exceed one-half the breaking strength of
the wireline. When a tension is placed on the wireline which is
over 50% of its break point, then problems begin to occur with the
electrical conductors in the wireline. Also, there is the danger of
breaking the wireline.
[0007] A typical wireline release utilizes a mechanical weak point
in the connection between the wireline and the cable head.
Typically this is a metal member which is designed to break upon a
predetermined pull on the wireline. The correct conventional
mechanical weak point must be calculated and installed prior to
running the cable head and tools into the borehole on the
wireline.
[0008] There are two limitations in using the typical mechanical
weak point release, one is the strength of the wireline itself and
the other is the strength of the mechanical weak point. For
example, when the tool is stuck, the operator will fish for the
tool with the wireline still attached to the tool in the hole. The
operator lowers a grapple on a separate line, such as a slick line,
which grabs the top of the cable head or the tool body. Once the
tools are grabbed, the operator wants to release the wireline from
the tool and remove it from the hole. Removing the wireline makes
it easier to pull the tools and pipe out of the well. In order to
effect the release, the operator places a large tension on the
wireline to activate the typical mechanical release. If the cable
head and tools are in a deviated hole, the effects of friction on
the wireline may prevent the mechanical link at the cable head from
receiving sufficient tension to break the link. In fact, the
wireline may break at some uphole location before the mechanical
link breaks. The presence of the broken wireline substantially
impairs the fishing operation for the stuck tool.
[0009] Various other apparatus and methods have been provided for
releasing the wireline from the cable head and tools. One common
method of releasing the wireline includes the use of a spring set
at a particular tension. Once the force on the spring is exceeded,
the wireline is released. This release still requires that the
amount of load required to release the wireline be predetermined
prior to lowering the cable head into the well. If the spring
tension is exceeded, there can be a premature release of the cable
head.
[0010] Another typical release relies primarily on shear pins or
shear screws. Problems are encountered with shear screws having a
low failure point because they are exposed to various cyclical
forces which tend to affect their ultimate shear rating. The shear
screws are exposed to fluids in the well which over time can affect
the inherent strength of the shear screws or pins making them
susceptible to failure at stresses below their rated failure point.
Unexpected release can significantly delay operations, causing
additional operating expense. An unexpected release can also result
in the loss of downhole tools and in extreme cases can cause severe
damage to the wellbore requiring substantial time and money to
repair.
[0011] Major problems occur if the cable head and tools get stuck
in the well and the wireline breaks upon pulling on the wireline
with too much tension. Breaking the wireline and dropping the
wireline in the well greatly complicates the fishing operation to
retrieve the tools.
[0012] Therefore, there is a demonstrated need for a remotely
actuated cable release system that does not primarily rely on
pulling a tension on the wireline to break a mechanical link.
SUMMARY OF THE INVENTION
[0013] The present invention addresses the above-noted and other
deficiencies of conventional release mechanisms and provides a
releasable wireline cable head.
[0014] In one embodiment of the present invention, a system for use
in a wellbore, comprises a wireline extending from a surface
location to a predetermined location in the wellbore. A tool string
has at least one tool adapted to perform at least one downhole
operation. A cable head releasably connects the wireline to the
tool string.
[0015] In one aspect of the present invention, an apparatus for
releasably connecting a wireline to a downhole tool comprises a
first member adapted for connection to the downhole tool and a
second member adapted for connection to the wireline. A plurality
of locking elements are constrained to engage the first member and
the second member by a moveable release member, where the plurality
of locking elements maintain the first member and the second member
in a connected position when the moveable release member is in a
first position. An actuator moves the moveable release member to a
second position, releasing the plurality of locking elements from
engagement with the first member and the second member. This allows
the first member and the second member to release the wireline from
the tool.
[0016] In another aspect of the present invention, a method of
releasably connecting a wireline to a downhole tool comprises
locking a first member to a second member by using a release member
to constrain a plurality of locking members to engage the first
member and the second member, when the release member is in a first
position. This maintains the first and second in a locked position.
The release member is moved from the first position to a second
position, thereby releasing the plurality of locking members from
engagement with the first member and the second member. This
releases the first member from the second member and allows the
wireline to be released from the downhole tool.
[0017] Examples of the more important features of the invention
thus have been summarized rather broadly in order that the detailed
description thereof that follows may be better understood, and in
order that the contributions to the art may be appreciated. There
are, of course, additional features of the invention that will be
described hereinafter and which will form the subject of the claims
appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For detailed understanding of the present invention,
references should be made to the following detailed description of
the preferred embodiment, taken in conjunction with the
accompanying drawings, in which like elements have been given like
numerals, wherein:
[0019] FIG. 1 shows an elevation view of a well logging instrument
being deployed in a wellbore;
[0020] FIG. 2 shows a cross section of a cable head according to
one embodiment of the present invention;
[0021] FIG. 3A shows a cross section of a latching mechanism in the
locked position according to one embodiment of the present
invention;
[0022] FIG. 3B shows a cross section of a latching mechanism in the
released position according to one embodiment of the present
invention; and
[0023] FIG. 4 shows a cross section of a latching mechanism
according to another preferred embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Referring initially to FIG. 1, there is shown a cable head
10 supported by a wireline 12 from a rig 14 at the surface 16. The
releasable cable head 10 supports a tool string 18 disposed
adjacent a production zone 22 located, as for example, near the
bottom 24 of borehole 20, also called a wellbore. The wireline 12
is deployed from the reel 29 on the wireline vehicle 28 around one
or more sheave wheels 26 down the borehole 20. The wireline vehicle
28 has instrumentation, well known in the art, for communication
and control of the cable head 10 and the tool string 18. Such
instrumentation may include a surface controller for remotely
operating the cable head 10.
[0025] The wireline 12, sometimes referred to as a cable, typically
includes a plurality of electrical conductors extending from the
wireline vehicle 28 to the cable head 10, all well known in the
art. One such type of multi-conductor wireline 12 includes an inner
core of seven electrical conductors covered by an insulating wrap.
An inner and outer steel armor sheath is then wrapped in a helix in
opposite directions around the conductors. The electrical
conductors are used for communicating power and telemetry between
the wireline vehicle 28 and the tool string 18. Alternatively, the
wireline cable may contain a combination of electrical conductors
and optical fibers. A single electrical conductor cable may also be
used. The tool string 18 may include logging tools, perforating
guns, packers, and/or any other device suitable for running on a
wireline and performing downhole operations.
[0026] FIGS. 2 and, 3A,B show one preferred embodiment of the
releasable cable head 10. The cable 12 is inserted in the
releasable cable head 10 through an elastomeric cap 13. The cap 13
extends inside the housing 15. Commonly, the cap 13 is sized to be
compressed around the cable 12 as the cap 13 is inserted in the
housing 15 thereby acting as a seal against the entry of wellbore
fluid into the housing 15. The housing 15 is commonly filled, after
assembly, with a non-conductive grease 41 through the fill port 40.
Alternatively, a non-conductive oil may be used. The end of
wireline cable 12 is terminated and captured with a conventional
full-armor cone 52 and a basket 50 assembly. Alternatively, any
suitable cable termination known in the art may be used. The basket
is threadedly connected to the release sleeve 51. The release
sleeve 51 is connected to the latching assembly 17 and is
releasable under remote electrical control from the surface.
[0027] The latching assembly 17 (see FIGS. 3A,3B) comprises a
restraining sleeve 54 fixedly attached in the housing 15. The
sleeve 54 transfers wireline tension loading to the housing through
the shoulder 57. The sleeve 54 has an annular groove 60 (see FIG.
3B) on an inner surface. The release sleeve 51 has a plurality of
radial through holes 58 arranged around a circumference such that
the holes 58 are juxtaposed with the annular groove 60 when the
release sleeve 51 is inserted in the restraining sleeve 54. Both
the holes 58 and the annular groove 60 are sized to accept the ball
locking elements 53. In the locked position (see FIG. 3A), the
balls 53 are captured between the restraining sleeve 54 and the
release sleeve 51 by the locking sleeve 70. The number, size, and
material of the balls 53 are determined, using techniques known in
the art, such that the shear strength of the balls substantially
exceeds the tensile strength of the cable 12. Alternatively, the
locking elements may be axially aligned rollers with appropriately
shaped holes in the release sleeve.
[0028] The locking sleeve 70 is forced into the locked position by
the spring 55 that extends around a reduced diameter portion of
locking sleeve 70. The reduced portion of the locking sleeve 70
extends through an annular solenoid coil 56 disposed in the housing
sleeve 54.
[0029] When energized (see FIG. 3B), the solenoid 56 magnetically
interacts with the locking sleeve 70 to retract the locking sleeve
70, compressing the spring 55 and allowing the balls 53 to move
inwardly. This action releases the cable 12 from latching the
assembly 17, and allows the cable to be retrieved to the surface.
The solenoid 56 may be potted using a suitable material such as an
epoxy or elastomeric potting compound to protect the solenoid from
contaminants. The electrical conductors 80 are routed through the
passage 71 and connected to the connectors 72 at the pressure
sealed bulkhead 73 (see FIG. 2) for connection and operation of at
least one downhole tool. Power to actuate the solenoid 56 is
provided by an electronics controller (not shown) through the
connector 42. The connectors 72 and 42 are pressure sealed against
intrusion of downhole fluids by use of o-rings and elastomeric
boots known in the art. Such connectors are well known in the art
and are commercially available. The electronics controller may be
located in an atmospheric pressure sealed chamber 35 in the cable
head 10. Alternatively, the electronics may be located in a
separate module (not shown) connected between the cable head 10 and
the tool string 18. Electrical power and communications signals are
fed through the conductors 80 and passed through the electronics
controller to operate the tools in the tool string 18.
[0030] In another preferred embodiment, see FIG. 4, a cable 112 is
terminated in the termination 150. Electrical conductors 152
carried in cable 112 are connected to connectors 153 for
transmitting power and/or signals to a controller (not shown)
similar to that described previously. The termination 150 is
mechanically connected through the tensile link 151 to the release
anchor 120 that has an annular groove 123 and a flange 122.
Multiple locking fingers 121 are hinged at the hinge pins 124 and
arranged to engage the anchor head 122. The fingers 121 are forced
to remain engaged with the anchor head 122 by the locking sleeve
154 that is held in position by the spring 125. When the solenoid
coil 156 is actuated, the locking sleeve 154 is retracted,
compressing the spring 125 and releasing the restraint around the
fingers 121. The fingers 121 are allowed to pivot outward,
releasing the anchor 120 and allowing the cable 112 to be retrieved
to the surface. Alternatively, the locking fingers 121 may be
flexible, non-hinged collet-type fingers (not shown) of a type
common in the art.
[0031] A tensile link 151 is used as a fail-safe device in case of
failure of the electrically operated release. Such a fail-safe link
may be incorporated in any of the preferred embodiments described
herein.
[0032] In the preferred embodiments described above, a solenoid has
been used to retract a sleeve to release a cable. Alternatively, an
electric motor (not shown) may be used through a suitable
mechanical drive, such as a ball-screw mechanism (not shown), to
retract the release sleeve in the preferred embodiments.
[0033] The foregoing description is directed to particular
embodiments of the present invention for the purpose of
illustration and explanation. It will be apparent, however, to one
skilled in the art that many modifications and changes to the
embodiment set forth above are possible without departing from the
scope of the invention. It is intended that the following claims be
interpreted to embrace all such modifications and changes.
* * * * *