U.S. patent application number 12/198086 was filed with the patent office on 2010-02-25 for well tool latching system.
This patent application is currently assigned to Baker Hughes Incorporated. Invention is credited to Elias Pena.
Application Number | 20100044055 12/198086 |
Document ID | / |
Family ID | 41695272 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100044055 |
Kind Code |
A1 |
Pena; Elias |
February 25, 2010 |
Well Tool Latching System
Abstract
A system for securing well tools, such as gas lift valves, into
a latching profile within a wellbore. A gas lift valve is provided
having a latching arrangement wherein an apertured back-up ring is
used to provide stability for the locking lugs throughout the
process of latching and unlatching the gas lift valve.
Inventors: |
Pena; Elias; (Houston,
TX) |
Correspondence
Address: |
Shawn Hunter / Baker Hughes Filings
P.O. Box 270110
Houston
TX
77277-0110
US
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
41695272 |
Appl. No.: |
12/198086 |
Filed: |
August 25, 2008 |
Current U.S.
Class: |
166/381 ;
166/216; 166/316 |
Current CPC
Class: |
E21B 23/03 20130101;
E21B 43/123 20130101 |
Class at
Publication: |
166/381 ;
166/216; 166/316 |
International
Class: |
E21B 23/01 20060101
E21B023/01 |
Claims
1. A latching arrangement for releasably securing a well tool
within a bore in a wellbore, the latching arrangement comprising:
an outer radial housing defining a window therein; a locking lug
that is at least partially disposed within the window and is
moveable radially inwardly and outwardly with respect to the
housing to removably lock the well tool within the bore; and a
backup ring disposed within the housing, the backup ring having a
ring body having an aperture disposed therein, the aperture
presenting first and second axially facing walls; and the locking
lug being at least partially disposed within the aperture of the
backup ring and presenting first and second axial surfaces which
adjoin the first and second walls of the backup ring, thereby
precluding substantial rotation of the locking lug with respect to
the backup ring.
2. The latching arrangement of claim 1 wherein the well tool is a
gas lift valve.
3. The latching arrangement of claim 1 wherein the locking lug
comprises a lug body and an ear portion which extends radially from
the body, the ear portion preventing the locking lug from being
moved entirely radially outwardly through the window.
4. The latching arrangement of claim 1 wherein: the backup ring has
three apertures; and there are three locking lugs.
5. The latching arrangement of claim 1 further comprising a
mechanism for moving the locking lug radially outwardly with
respect to the housing.
6. The latching arrangement of claim 5 wherein the mechanism for
moving the locking lug comprises a generally cylindrical expander
shaft disposed radially within the valve housing, locking lug and
backup ring, the expander shaft presents: a first section having a
first diameter; a second section having a second diameter that is
larger than the first diameter; and wherein the expander shaft is
axially moveable with respect to the locking lug to cause the
locking lug to move radially outwardly as the lug is moved radially
outwardly as the locking lug contacts the second section of the
expander shaft.
7. The latching arrangement of claim 6 wherein the expander shaft
is releasably secured to the outer radial housing by a frangible
shear member.
8. A gas lift valve for use in a side pocket mandrel within a
wellbore, the side pocket mandrel having a bore, the gas lift valve
comprising: a valve housing defining a window therein; a locking
lug that is moveable radially inwardly and outwardly through the
window with respect to the valve housing for removably locking the
gas lift valve into a latching profile in the bore; a backup ring
disposed within the valve housing, the backup ring comprising a
ring body having an aperture disposed therein, the aperture
presenting first and second axially facing walls; and the locking
lug being at least partially disposed within the aperture of the
backup ring.
9. The gas lift valve of claim 8 further comprising a generally
cylindrical expander shaft disposed radially within the valve
housing, locking lug and backup ring, the expander shaft presents:
a first section having a first diameter; and a second section
having a second diameter that is larger than the first
diameter.
10. The gas lift valve of claim 8 wherein the locking lug comprises
a lug body and an ear portion which extends radially from the body,
the ear portion preventing the locking lug from being moved
entirely radially outwardly through the window.
11. The gas lift valve of claim 9 wherein the expander shaft is
releasably secured to the valve housing by a frangible shear
member.
12. The gas lift valve of claim 9 wherein the expander shaft is
axially moveable with respect to the locking lug to cause the
locking lug to move radially outwardly as the lug is moved radially
outwardly as the locking lug contacts the second section of the
expander shaft.
13. A method for releasably securing a well tool within a bore in a
wellbore, the method comprising the steps of: disposing the well
tool within the bore proximate a latching profile in the bore, the
well tool having a latch housing which defines a window therein;
urging a locking lug radially outwardly through the window and into
the latching profile; and providing sliding contact between the
locking lug and at least two axially facing walls of a backup ring
lying radially within the latch housing to prevent substantial
axial rotation of the locking lug with respect to the latch housing
during radial outward movement of the to locking lug.
14. The method of claim 13 further comprising the steps of: moving
the locking lug radially inwardly with respect to the latch
housing; and providing sliding contact between the locking lug and
at least two axially facing walls of a backup ring lying radially
within the latch housing to prevent substantial axial rotation of
the locking lug with respect to the latch housing during radial
outward movement of the locking lug.
15. The method of claim 14 wherein the locking lug is moved
radially inwardly by compressive contact between the locking lug
and the backup ring, which causes the locking lug to be moved
inwardly by sliding contact against a shoulder within the bore.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to devices and methods for
securing a well tool within a tubular portion of a wellbore. In
particular aspects, the invention relates to a latching arrangement
for releasably securing a gas lift valve within a side pocket
mandrel.
[0003] 2. Description of the Related Art
[0004] Secure and reliable latching arrangements are important for
releasably securing devices within wellbore arrangements. Gas lift
valves are one such device that is used to assist the flow of
hydrocarbons to the surface in a wellbore. The gas lift valve
transmits a gas, such as air which has been pumped down the
annulus, into the flowbore of the production tubing to increase the
flow of hydrocarbons through the production tubing and toward the
surface of the well. Typically, a gas lift valve is inserted into a
side pocket mandrel in a production string using a kickover tool,
as is well known in the art. A latching arrangement is needed to
secure the gas lift valve within a latching profile in the side
pocket mandrel. If the valve is not properly latched into place, it
may not function properly. In addition, a latching arrangement that
malfunctions may cause the valve to become stuck in the side pocket
mandrel so that it cannot be removed without significant damage to
the valve or the surrounding wellbore components.
[0005] Prior art latching arrangements for gas lift valves are
shown in U.S. Pat. No. 4,265,306 issued to Stout and U.S. Pat. No.
4,554,972 issued to Merritt.
SUMMARY OF THE INVENTION
[0006] The invention provides a system for securing well tools,
such as gas lift valves, into a latching profile within a wellbore.
In a described embodiment, a gas lift valve is provided having a
latching arrangement wherein an apertured back-up ring is used to
provide stability for the locking lugs throughout the process of
latching and unlatching the gas lift valve. In addition, the
structure of the backup ring provides a positive retractive force
for urging of the locking lugs radially inwardly during withdrawal
of the gas lift valve. An axially facing wall of the aperture of
the backup ring exerts a compressive force upon the lower axial
side of the locking lug, causing a sliding contact between a
chamfered surface on the lug and a shoulder on the latching
profile. This sliding contact moves the locking lug radially
inwardly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The advantages and further aspects of the invention will be
readily appreciated by those of ordinary skill in the art as the
same becomes better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings in which like reference characters designate
like or similar elements throughout the several figures of the
drawing and wherein:
[0008] FIG. 1 is a side, cross-sectional view of an exemplary side
pocket mandrel and gas lift valve having an improved latching
system, in accordance with the present invention.
[0009] FIG. 2 is a side, cross-sectional view of the devices shown
in FIG. 1, now with the gas lift valve being inserted into the side
pocket mandrel.
[0010] FIG. 3 is a side, cross-sectional view of the devices shown
in FIGS. 1-2, now in a fully latched position.
[0011] FIG. 4 is a side, cross-sectional view of the devices shown
in FIGS. 1-3, now beginning to be withdrawn from the side pocket
mandrel.
[0012] FIG. 5 is a side, cross-sectional view of the devices shown
in FIGS. 1-4, now further withdrawn from the side pocket
mandrel.
[0013] FIG. 6 is a side, cross-sectional view of the devices shown
in FIGS. 1-5, now withdrawn from the side pocket mandrel.
[0014] FIG. 7 is an axial cross-sectional view of the gas lift
valve 12 taken along lines 7-7 in FIG. 1.
[0015] FIG. 8 is an isometric view of an exemplary back-up ring
used in the gas lift valve shown apart from other components.
[0016] FIG. 9 is an axial cross-sectional view of the gas lift
valve 12 taken along lines 9-9 in FIG. 2.
[0017] FIG. 10 is an enlarged cross-sectional detail view depicting
a locking lug member and the back-up ring.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The general operation of gas lift valves and side pocket
mandrels is well known in the art and described in further detail
in U.S. Pat. No. 7,360,602 issued to Kritzler et al. and U.S. Pat.
No. 7,228,897 issued to Holt, Jr. et al. Each of these patents is
owned by the assignee of the present application and each is hereby
incorporated by reference in its entirety. As is known in the art,
the side pocket mandrel 10 is a pocket or recess which lies
substantially parallel to and alongside of the central flowbore of
a string of production tubing within a wellbore.
[0019] FIG. 1 illustrates an exemplary side pocket mandrel 10 and a
gas lift valve 12 that can be removably latched within the mandrel
10. The side pocket mandrel 10 includes a housing 14 that defines a
central axial bore 16. It is noted that, within the context of this
discussion the terms "axial" and "axially" will refer to the
direction defined by the longitudinal axis of the axial bore 16,
and which is illustrated by the arrows 79 in FIGS. 1 and 2 as well
as arrows 82 in FIGS. 4-6. The bore 16 of the side pocket mandrel
10 has an enlarged diameter latching profile 18. It is noted that
the transition between the bore 16 and the latching profile 18
presents sloped shoulders 20, 22. Fluid openings 24 are disposed
through the housing 14 proximate the lower end of the bore 16 to
permit a gas that is pumped down into the external annulus 26 to
enter the bore 16.
[0020] In FIG. 1, the gas lift valve 12 is depicted in an initial
run-in position prior to being disposed into and latched within the
bore 16. Those of skill in the art will understand that a kickover
tool, of a type known in the art is used to dispose the gas lift
valve 12 into the bore 16. For clarity, the kickover tool is not
depicted in the drawings.
[0021] The gas lift valve 12 includes a latch head 28 that is
threadedly affixed to a generally cylindrical expander shaft 30.
The shaft 30 features a primary shaft portion 32 which presents a
substantially uniform diameter along its length and an enlarged
diameter annular portion 34. The lower end of expander shaft 30 is
affixed to a bottom sub 36. A latch housing 38 radially surrounds
the expander shaft 30 and is secured to the expander shaft 30 by a
frangible shear member, such as shear pin 40, which passes through
both the shaft 30 and the latch housing 38. A radially enlarged
spring chamber 42 is defined between the latch housing 38 and the
primary shaft portion 32. An axially compressible spring 44 is
disposed within the spring chamber 42.
[0022] A further enlarged lug chamber 46 is defined below the
spring chamber 42 between the shaft 30 and the latch housing 38. In
a preferred embodiment, a number of openings (one shown) 48 are
disposed through the latch housing 38 within the lug chamber 46. A
back-up ring 50 is disposed within the lug chamber 46 immediately
below the spring 44. The back-up ring 50 contains apertures 52. In
a presently preferred embodiment, there are three apertures 52,
although there may be more or fewer than three, if desired. A
locking lug 54 is disposed within each of the apertures 52. It can
be seen from FIG. 1 that, during initial run-in to the side pocket
mandrel 10, the locking lugs 54 (one show) also reside partially
within the window 48 of the latch housing 38 and abut the radially
enlarged portion 34 of the expander shaft 30.
[0023] The structure and operation of an exemplary back-up ring 50,
apertures 52 and locking lugs 54 are better understood with further
reference to FIGS. 7-9. As depicted in FIG. 8, the ring 50 features
a generally cylindrical ring body 56 with an inwardly directed
flange 58 at one axial end. The apertures 52 are entirely defined
within the ring body 56 so is as to each present a pair of axially
facing walls 60, 62 and a pair of angularly facing walls 64, 66. In
a currently preferred embodiment, the apertures 52 are generally
rectangular in shape.
[0024] Each of the locking lugs 54 includes a central lug body 68
with a substantially flat radially outward face 67 and chamfered
edge portions 69 (see FIG. 10). Each of the lugs 54 also has a pair
of ears 70 which extend radially outwardly from the body 68. The
locking lugs 54 are shaped and sized to reside within the apertures
52 in a complimentary fashion. The lug members 54 each have a
curved radially inner surface 71 which will abut the outer radial
surfaces 34 or 32 of the expander shaft 30, as FIGS. 7 and 9 show.
The ears 70 of each locking lug 54 function to prevent the locking
lug 54 from being moved radially outwardly through the windows 48
of the latch housing 38. When the locking lug 54 is disposed within
the aperture 52, the axially facing walls 60, 62 prevent the lug
member 54, as depicted in FIG. 10. The axially facing walls 60, 62
abut axial faces 72, 74, respectively of the lug member 54. As a
result, the lug member 54 can move radially inwardly and outwardly
with respect to the backup ring 50 (as illustrated by the phantom
lines of 54' in FIG. 10 illustrating a radially outwardly extended
position). However, the lug member 54 is prevented from appreciably
rotating away in any substantial manner from the axially facing
wall 62, (in the direction illustrated by arrow 76) by the presence
of the axially facing wall 60. The lug member 54 is also prevented
from appreciably rotating away from the wall 60 (in the direction
indicated by arrow 78) in any substantial manner by the presence of
wall 62. A substantial rotation of the lug member 54 with respect
to the walls 60 or 62 would be an amount of rotation that would
preclude the lug member 54 from operating properly to move radially
inwardly or outwardly to selectively latch the gas lift valve 12
into the side pocket mandrel 10. In addition, the angularly facing
walls 64, 66 prevent angular rotation of the lug members 54, as
FIGS. 7 and 9 illustrate.
[0025] The operation to insert the gas lift valve 12 into the side
pocket mandrel 10 and latch it within is illustrated by FIGS. 1-3
as well as 7 and 9. Beginning with the configurations shown in
FIGS. 1 and 7, a downward compression force (illustrated by arrow
79) is applied to the latch head 28 and latch housing 38. This
downward force 79 compresses the spring 44 between the latch
housing and the backup ring 50, as FIG. 2 depicts. The latching
lugs 54 are moved from the lower end of windows 52, as illustrated
in FIG. 1, to the upper end of the windows 52, as shown in FIG. 2.
In addition, the downward force moves the lug members 54 from
abutting the diametrically expanded section 34 of the expander
shaft 30 (as shown in FIGS. 1 and 7) to a position wherein the
curved faces 71 of the lug members 54 abut the reduced diameter
portion 32 of the shaft 30 (see FIGS. 2 and 9). This permits the
lug members 54 to be moved radially inwardly by sliding contact
between a chamfered edge 69 of the lug with a sloped shoulder 80
(see FIG. 2) within the bore 16 of the side pocket mandrel 10. Once
the lug members 54 have been moved radially inwardly, the
compression force gas lift valve 12 is moved downwardly to the
position depicted in FIG. 3 wherein the latching lug members 54 are
located within the latching profile 18 of the gas lift mandrel 10.
At this point the downward force 79 is removed. The compression
spring 44 will move the backup ring 50 axially downwardly with
respect to the latch housing 38 and expander shaft 30. The inner
radial surfaces 71 of the lug members 54 will once again be
abutting the expanded diameter portion 34 of the expander shaft 30.
As a result, the lug members 54 will extend outwardly into the
latching profile 18, thereby latching the gas lift valve 12 in
place against inadvertent removal during operation.
[0026] FIGS. 4-6 illustrate removal of the gas lift valve 12 from
the side pocket mandrel 10. When it is desired to remove the gas
lift valve 12, an upward pulling force, or removal force) is
applied to the latch head 28 (illustrated by arrow 82). As is
known, the removal force is typically applied to the latch head by
a suitable pulling tool (not shown). It is noted that the removal
force 82 must be sufficient to shear the shear member 40. The force
82 first moves the gas lift valve 12 upwardly to the position shown
in FIG. 4 wherein the upper chamfered edge 69 of the locking lugs
54 comes into contact with the shoulder 20 of the latching profile
18. However, the lugs 54 cannot be moved radially inwardly at this
point due to their abutting relation with the expanded diameter
portion 34 of the expander shaft 30. The removal force 82 then
shears the shear pin 40, as shown in FIG. 5. When this occurs, the
latching head 28 and expander shaft 30 are freed to move with
respect to the surrounding latch housing 38. The radially expanded
portion 34 of the expander shaft 30 will engage the flange 58 of
the backup ring 50, thereby drawings it axially upwardly. The
radially expanded portion 34 of the expander shaft 30 is also moved
above the locking lugs 54, thereby allowing them to be moved
radially inwardly to the position shown in FIG. 5, due to sliding
contact with the shoulder 20. It is noted that the lower axially
facing wall 60 of the backup ring 50 will exert a positive
compressive force against the lower axial face 72 of the locking
lugs 54. This compressive force will ensure that there is sliding
contact between the upper chamfered edge 69 of the lugs 54 and the
shoulder 20 of the bore 16. This sliding contact will move the lugs
54 radially inwardly. As the lugs 54 are moved inwardly, they are
prevented from axial rotation with respect to the latch housing 38
by sliding contact with the axially facing walls 60, 62 of the
backup ring 50. At this point, the gas lift valve 12 is freed to be
removed completely from the side pocket mandrel 10, as further
depicted in FIG. 6.
[0027] 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 and the spirit of the invention.
* * * * *