U.S. patent application number 11/678067 was filed with the patent office on 2008-08-28 for pressure activated locking slot assembly.
Invention is credited to Matt Howell, Kevin Manke.
Application Number | 20080202766 11/678067 |
Document ID | / |
Family ID | 39416232 |
Filed Date | 2008-08-28 |
United States Patent
Application |
20080202766 |
Kind Code |
A1 |
Howell; Matt ; et
al. |
August 28, 2008 |
Pressure Activated Locking Slot Assembly
Abstract
A locking slot assembly may include a slot, a lug configured to
move within the slot, and a lock configured to prevent the lug from
moving within the slot until a triggering event occurs. The lock
may be further configured to allow the lug to move within the slot
after the triggering event has occurred, so long as a predetermined
condition is maintained. The triggering event may be the
application of a predetermined pressure, and the predetermined
condition may be a minimum pressure.
Inventors: |
Howell; Matt; (Duncan,
OK) ; Manke; Kevin; (Martow, OK) |
Correspondence
Address: |
John W. Wustenberg;Halliburton Energy Services, Inc.
2600 S. 2nd Street
Duncan
OK
73536
US
|
Family ID: |
39416232 |
Appl. No.: |
11/678067 |
Filed: |
February 23, 2007 |
Current U.S.
Class: |
166/381 ;
166/240; 166/242.6; 166/386 |
Current CPC
Class: |
E21B 23/006 20130101;
E21B 23/04 20130101 |
Class at
Publication: |
166/381 ;
166/386; 166/240; 166/242.6 |
International
Class: |
E21B 23/00 20060101
E21B023/00 |
Claims
1. A locking slot assembly comprising: a slot; a lug configured to
move within the slot; and a lock configured to prevent the lug from
moving within the slot until a triggering event occurs; wherein the
lock is further configured to allow the lug to move within the slot
after the triggering event has occurred, so long as a predetermined
condition is maintained.
2. The locking slot assembly of claim 1, wherein the triggering
event is the application of a predetermined pressure, and wherein
the predetermined condition is a minimum pressure.
3. The locking slot assembly of claim 2, further comprising: an
inner mandrel disposed at least partially within the lock; and a
fluid chamber disposed between the lock and the inner mandrel;
wherein the fluid chamber is configured to expand upon application
of the predetermined pressure, moving the lock and allowing the lug
to move within the slot.
4. The locking slot assembly of claim 2, wherein the slot comprises
a J-slot.
5. The locking slot assembly of claim 4, wherein the J-slot is a
continuous J-slot.
6. The locking slot assembly of claim 2, wherein the lock comprises
one or more rupture disks configured to rupture at the
predetermined pressure, allowing the lug to move within the
slot.
7. The locking slot assembly of claim 2, wherein the lock comprises
one or more shear pins configured to shear at the predetermined
pressure, allowing the lug to move within the slot.
8. The locking slot assembly of claim 2, wherein the lock is
further configured to once again prevent the lug from moving within
the slot if the minimum pressure is not maintained.
9. The locking slot assembly of claim 2, wherein the predetermined
pressure is a hydrostatic pressure.
10. The locking slot assembly of claim 2, wherein the minimum
pressure is a hydrostatic pressure.
11. A downhole tool assembly comprising: a sleeve having a slot; a
lug rotator ring configured to move axially relative to the sleeve,
the rotator ring having a lug configured to move within the slot;
and a lock configured to prevent the lug from moving within the
slot until a predetermined pressure is applied; and wherein the
lock is further configured to allow the lug to move within the slot
after the predetermined pressure has been applied, so long as a
minimum pressure is maintained.
12. The downhole tool assembly of claim 11, further comprising: an
inner mandrel disposed at least partially within the lock; and a
fluid chamber disposed between the lock and the inner mandrel;
wherein the fluid chamber is configured to expand upon application
of the predetermined pressure, moving the lock and allowing the lug
to move within the slot.
13. The downhole assembly of claim 1 1, wherein the slot comprises
a J-slot.
14. The downhole assembly of claim 12, wherein the J-slot is a
continuous J-slot.
15. The downhole assembly of claim 11, wherein the lock comprises
one or more rupture disks configured to rupture at the
predetermined pressure, allowing the lug to move within the
slot.
16. The downhole assembly of claim 11, wherein the lock comprises
one or more shear pins configured to shear at the predetermined
pressure, allowing the lug to move within the slot.
17. The downhole assembly of claim 11, wherein the lock is further
configured to once again prevent the lug from moving within the
slot if the minimum pressure is not maintained.
18. The downhole assembly of claim 1 1, wherein the predetermined
pressure is a hydrostatic pressure.
19. A method of activating downhole tool assembly comprising a
sleeve having a slot, a lug rotator ring configured to move axially
relative to the sleeve, the rotator ring having a lug configured to
move within the slot, and a lock configured to prevent the lug from
moving within the slot until a predetermined pressure is applied,
the method comprising: providing a downhole tool assembly in a well
bore; applying a predetermined pressure to the downhole tool
assembly; and moving the downhole tool assembly upward.
20. The method of activating a downhole tool assembly of claim 19,
further comprising: moving the downhole tool assembly downward.
Description
BACKGROUND
[0001] The present invention relates to locking apparatus for
downhole tools, and more particularly, to a pressure activated
locking slot assembly.
[0002] Typically, when tools are run into the well bore, a mandrel
is held in the run-in-hole position by interaction of a lug with a
J-slot. To move the tool out of the run-in-hole position generally
involves the application of torque and longitudinal force. Such an
arrangement can be problematic in offshore or highly deviated
sections of a well bore, where dragging forces on the tool string
may create difficulty in estimating the proper torque to apply at
the surface to obtain the desirable torque at the J-slot. A
continuous J-slot wraps all the way around the mandrel and
typically has two lugs, so that the direction of torque applied
need not be reversed in order to actuate. Rather, the tool may
simply be picked up and put back down to cycle.
[0003] A problem may arise when running such a tool into an
offshore or highly deviated well bore. Dragging of the tool string
on the well bore may cause the mandrel move relatively upwardly and
rotate with respect to the drag block assembly sufficiently to
result in premature actuation of the J-slot assembly. If such
premature actuation occurs, subsequent downward load on the tool
string may rupture the tool elements, or the tool elements may be
damaged by dragging along the well bore. In addition, premature
actuation may result in the tool string jamming in the well
bore.
SUMMARY
[0004] The present invention relates to locking apparatus for
downhole tools, and more particularly, to a pressure activated
locking slot assembly.
[0005] In one embodiment of the present invention a locking slot
assembly comprises: a slot; a lug configured to move within the
slot; and a lock configured to prevent the lug from moving within
the slot until a triggering event occurs; wherein the lock is
further configured to allow the lug to move within the slot after
the triggering event has occurred, so long as a predetermined
condition is maintained. The triggering event may be the
application of a predetermined pressure, and the predetermined
condition may be a minimum pressure.
[0006] In another embodiment of the present invention a downhole
tool assembly comprises: a sleeve having a slot; a lug rotator ring
configured to move axially relative to the sleeve, the rotator ring
having a lug configured to move within the slot; and a lock
configured to prevent the lug from moving within the slot until a
predetermined pressure is applied; and wherein the lock is further
configured to allow the lug to move within the slot after the
predetermined pressure has been applied, so long as a minimum
pressure is maintained.
[0007] In yet another embodiment of the present invention a method
of activating a downhole tool assembly comprises: providing a
downhole tool assembly in a well bore; applying a predetermined
pressure to the downhole tool assembly; and moving the downhole
tool assembly upward; wherein the downhole tool assembly comprises
a sleeve having a slot, a lug rotator ring configured to move
axially relative to the sleeve, the rotator ring having a lug
configured to move within the slot, and a lock configured to
prevent the lug from moving within the slot until a predetermined
pressure is applied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a side cross-sectional view showing one
embodiment according to the present invention.
[0009] FIG. 1B is a side cross-sectional view of the embodiment
illustrated in FIG. 1A, showing an unlocked position.
[0010] FIG. 2A is a side cross-sectional view showing another
embodiment according to the present invention.
[0011] FIG. 2B is a side cross-sectional view of the embodiment
illustrated in FIG. 2A, showing an unlocked position.
[0012] FIG. 3A is a side view showing one embodiment according to
the present invention.
[0013] FIG. 3B is a side view of the embodiment illustrated in FIG.
3A, showing an unlocked position.
DETAILED DESCRIPTION
[0014] Referring now to the drawings and more particularly to FIGS.
1A and 1B, the locking slot assembly of the present invention is
shown and generally designated by the numeral 10. locking slot
assembly 10 is disposed adjacent to a lower end of a tool 12 (shown
in FIG. 2A), which is of a kind known in the art, such as a valve,
a packer, or any tool requiring different positions. Tool 12 may
connect to a tool string (not shown) and the entire tool string may
be positioned in a well bore. The well bore may be defined by a
casing (not shown) and may be vertical, or the well bore may be
deviated to any degree.
[0015] Locking slot assembly 10 is illustrated below the tool 12.
Tool 12 may include, or be attached to, an inner, actuating mandrel
14, which may be connected to the tool string. Locking slot
assembly may include the actuating mandrel 14, attached at a lower
end to bottom adapter 16. Actuating mandrel 14 and at least a
portion of bottom adapter 16 may be situated within a fluid chamber
case 18 and/or a lock 20. The fluid chamber case 18 and the lock 20
may be removably attached, fixedly attached, or even integrally
formed with one another. Alternatively fluid chamber case 18 and
lock 20 may be separate.
[0016] At least one fluid chamber 22 may be situated between
actuating mandrel 14 and lock 20. Fluid chamber 22 may be sealed
via one or more seals 24, along with a rupture disk 26 situated in
the lock 20. Air at atmospheric pressure may initially fill the
fluid chamber 22. As the tool 12 is lowered into the well bore,
hydrostatic pressure outside the tool 12 increases. Once the
hydrostatic pressure reaches a predetermined value, the rupture
disk 26 may rupture. After the rupture disk 26 has ruptured, the
fluid outside the tool 12 will enter the tool 12 through a port 28
formed therein. The resulting increased pressure within the fluid
chamber 22 will cause the fluid chamber 22 to expand (as shown in
FIG. 1B). This expansion causes the longitudinal movement of the
lock 20 with respect to the actuating mandrel 14, thus "unlocking"
the locking slot assembly 10. FIGS. 3A and 3B, which will be
discussed below, further show the locked position and unlocked
position respectively.
[0017] Referring now to FIGS. 2A and 2B, shown therein is an
alternate embodiment of the locking slot assembly 10. This
embodiment has no rupture disk 26. Instead, one or more shear pins
30 to prevent the lock 20 from moving until adequate pressure is
present. A spring 32 may be included to keep the locking slot
assembly 10 in an unlocked position. While the spring 32 shown is a
coil spring, the spring 32 may be any biasing member. Likewise, the
shear pin 30 may be a screw, spring, or any other shearable member.
Other than the use of a rupture disk 26 and/or a spring 32, the
embodiment of FIGS. 2A and 2B functions similarly to the embodiment
of FIGS. 1A and 1B. An increase in pressure causes the lock 20 to
move longitudinally with respect to the actuating mandrel 14,
resulting in the unlocking of the locking slot assembly 10 (as
shown in FIG. 2B).
[0018] Referring now to FIGS. 3A and 3B, one or more lugs 34 may
extend from a lug rotator ring 36 into a continuous slot 38 in a
sleeve 40, thus providing locking assembly 10. As previously
discussed, pressure may cause the lock 20 to become unlocked. In
the locked position, a locking portion 42 of the lock 20 occupies
space within the slot 38, keeping the lugs 34 in a run-in-hole
position, and preventing the lugs 34 from moving relative to the
slot 38. As the lock 20 moves downwardly because of increased
pressure, the locking portion 42 moves out of the slot 38, allowing
the lugs 34 to move relative to the slot 38 if there is an upward
or downward force acting on the sleeve 40.
[0019] In the run-in-hole, locked position, the lock 20 is in an
upward position, in which lugs 34 are engaged with locking portion
42 of the lock 20. As the tool string is lowered into well bore,
the locking slot assembly 10 will remain in the locked position
shown in FIGS. 1A, 2A, and 3A, with the lock 20 preventing relative
longitudinal movement of the lug rotator ring 36 with respect to
the sleeve 40.
[0020] Once pressure is applied and the locking slot assembly 10 is
unlocked (as shown in FIGS. 1B, 2B, and 3B), the locking slot
assembly 10 may be actuated, allowing the lug rotator ring 36 to
move longitudinally with respect to the sleeve 40. In other words,
the tool 12 may be set by pushing downward on the tool string,
which lowers lug 34. While any type of slot 38 may be used, the
embodiment shown uses a j-slot, and in particular, shows a
continuous J-slot. Depending on the specific application and the
type of slot, setting the tool may involve pushing downward on the
tool string multiple times. Thus, when a continuous j-slot is used,
the tool 12 may be set by up and down motion alone. This may
prevent the operator from cycling through the slot and setting the
tool 12 prematurely.
[0021] For retrieval, the tool string is simply pulled upwardly out
of the well bore. This will cause the lug 34 to re-engage the slot
38. Additionally, as the pressure outside the tool 12, and thus,
the pressure within the fluid chamber 22 is reduced, the lock 20
may move back into the locked position, preventing any subsequent
relative movement of the lug rotator ring 36 with respect to the
sleeve 40.
[0022] While the application of pressure is disclosed above as one
triggering event to allow the lug 34 to move within the slot 38,
other events may also occur to allow the lug 34 to move within the
slot 38. In this case, the lock 20 may be configured to allow the
lug 34 to move within the slot after the triggering event has
occurred, so long as a predetermined condition is maintained. For
example, but not by way of limitation, the triggering event may be
a timer reaching a predetermined value, and the predetermined
condition may be that the timer has not yet reached a second
predetermined value.
[0023] Therefore, the present invention is well adapted to attain
the ends and advantages mentioned as well as those that are
inherent therein. The particular embodiments disclosed above are
illustrative only, as the present invention may be modified and
practiced in different but equivalent manners apparent to those
skilled in the art having the benefit of the teachings herein.
Furthermore, no limitations are intended to the details of
construction or design herein shown, other than as described in the
claims below. It is therefore evident that the particular
illustrative embodiments disclosed above may be altered or modified
and all such variations are considered within the scope and spirit
of the present invention. Also, the terms in the claims have their
plain, ordinary meaning unless otherwise explicitly and clearly
defined by the patentee.
* * * * *