U.S. patent number 3,570,599 [Application Number 04/832,046] was granted by the patent office on 1971-03-16 for liner hanger.
This patent grant is currently assigned to Brown Well Service & Supply Company. Invention is credited to Fletcher Andrew Anderson, Ben Rodney Groce, Truman Foy Wilson.
United States Patent |
3,570,599 |
Wilson , et al. |
March 16, 1971 |
LINER HANGER
Abstract
A liner hanger for down-hole suspension of a liner pipe from a
well casing. Toothed slips are used to engage the casing wall when
allowed to slide up over a conical slip expander. Bow springs
attached to the slips frictionally engage the casing wall, and
cause the slips to move up onto the slip expander when a latch
mechanism is released. An hydraulically operated latch release
device is disclosed, employing a sleeve biased away from the
latches but forced toward the latches by hydraulic pressure.
Control is provided by increasing the pressure in the tubing string
compared to the annulus between the casing and the tubing. The
latching arrangement may be both hydraulically and manually
operated, according to one embodiment.
Inventors: |
Wilson; Truman Foy (Odessa,
TX), Anderson; Fletcher Andrew (Odessa, TX), Groce; Ben
Rodney (Odessa, TX) |
Assignee: |
Brown Well Service & Supply
Company (Odessa, TX)
|
Family
ID: |
25260523 |
Appl.
No.: |
04/832,046 |
Filed: |
June 11, 1969 |
Current U.S.
Class: |
166/208;
166/216 |
Current CPC
Class: |
E21B
23/01 (20130101); E21B 43/10 (20130101) |
Current International
Class: |
E21B
23/01 (20060101); E21B 23/00 (20060101); E21B
43/10 (20060101); E21B 43/02 (20060101); E21b
023/00 (); E21b 043/10 () |
Field of
Search: |
;166/138,208,216,217 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Calvert; Ian A.
Claims
We claim:
1. A liner hanger of the type used in a well casing,
comprising:
a generally tubular body for supporting the parts of the liner
hanger;
a plurality of slips slidably mounted on the exterior of the body
for gripping a well casing;
conically shaped, downwardly facing, slip expanding means mounted
on said body for causing the slips to move radially into gripping
engagement with the well casing, as the slips are displaced axially
upward into engagement with the expanding mean;
a plurality of bow springs for resiliently and frictionally
engaging the well casing, connected to the slips and axially
movable with the slips;
elongated latch spring means including a plurality of elongated
flat springs depending from and coupled to the slips and bow
springs, and radially movable between hold and release positions,
the slips being held away from engagement with the slip expanding
means when the latch spring means is in the hold position, the
slips being permitted to move axially into engagement with the slip
expanding means when the latch spring means is in the release
position, each of the latch spring means including a hook
positioned to engage a catch ring when in the hold position and to
disengage the catch ring upon outward radial movement;
hydraulically operated axially movable means positioned for
mechanical engagement with the latch spring means and effective to
radially displace the latch spring means from the hold to the
release position, the lower end of each of the latch spring means
including a slanted surface engageable by a mating slanted surface
on the hydraulically operated means; and
the hydraulically operated means including a hydraulic piston
provided at one end of an elongated sleeve, means including the
sleeve defining a chamber, and means are provided for admitting
fluid into the chamber to operate the piston when the pressure
within the liner hanger exceeds the pressure in the annulus between
the liner hanger and the well casing.
2. A liner hanger according to claim 1 wherein the hydraulically
operated means includes an elongated sleeve defining a hydraulic
piston and defining a chamber whereby a hydraulic piston and
cylinder function is provided.
3. A liner hanger according to claim 2 wherein the latch spring
means extend axially above the elongated sleeve, and include hook
means each having a lower end operatively engageable by the upper
end of the elongated sleeve.
4. A liner hanger according to claim 3 wherein detents are provided
on said body and the hook means are spring-biased inward and are
releasable from said detents upon outward radial movement.
5. A liner hanger according to claim 1 wherein the catch ring
includes a plurality of slots for engaging the hooks of the latch
spring means, and also a plurality of hook expanding surfaces
adjacent the slots adapted to move the hooks to the release
position upon rotation of the slips with respect to the liner
hanger.
6. A liner hanger according to claim 1 wherein the sleeve is biased
in a direction away from engagement of the hydraulically operated
means with the latch spring means.
7. A liner hanger according to claim 6 wherein biasing of the
sleeve is provided by a flat helical spring within the sleeve.
8. A liner hanger according to claim 6 wherein biasing of the
sleeve is provided by means including a second hydraulic piston
provided at the other end of the sleeve, and means for admitting
fluid into a chamber to operate the piston when the pressure within
the line hanger is less than the external pressure in the annulus
between the liner hanger and the well casing.
9. A liner hanger according to claim 6 wherein the slips, bow
springs, latch spring means and the elongated sleeve are all
slidably mounted on a tubular body for the liner hanger, and the
slip expanding means and the catch ring are fixedly mounted on the
tubular body.
10. A liner hanger comprising:
a plurality of slips for gripping a well casing;
conically shaped, downwardly facing, slip expanding means for
causing the slips to move radially into gripping engagement with
the casing wall, as the slips are displaced axially upward into
engagement with the expanding means;
a plurality of bow springs for resiliently and frictionally
engaging the casing wall, connected to the slips and axially
movable with the slips;
elongated latch spring means coupled to the slips and bow springs,
and radially movable between hold and release positions, the slips
being held away from engagement with the slip expanding means when
the latch spring means is in the hold position, the slips being
permitted to move axially into engagement with the slip expanding
means when the latch spring means is in the release position;
and
hydraulically operated, axially movable means positioned for
mechanical engagement with the latch spring means from the hold to
the release position, the hydraulically operated means being held
from engaging the latch spring means by frangible shear pin means,
the hydraulically operated means including an elongated sleeve
having a shaped upper end for engaging the latch spring means, and
said frangible shear pin means being positioned between said shaped
upper end of the sleeve and the latch spring means.
11. A liner hanger comprising:
a generally tubular body for supporting the parts of the liner
hanger;
a plurality of toothed slips positioned on the tubular body in
sliding relationship for gripping the interior cylindrical wall of
a well casing or the like;
wedgelike slip expanding means positioned on the tubular body in
fixed relationship for causing the slips to move radially against
the wall as the slips are displaced axially upward into engagement
with the expanding means;
a plurality of bow springs slidably positioned on the tubular body
for frictionally engaging the casing wall, the bow springs being
connected to the slips and axially movable with such slips;
latch means coupled to the slips and bow springs, and movable
between hold and release positions, the slips being held away from
engagement with the slip expanding means when the latch means is in
the hold position and being permitted to move axially into
engagement with the slip expanding means when the latch means is in
the release position; and
hydraulically operated means, including an elongated sleeve
surrounding the tubular body, slidably positioned on the tubular
body and axially movable between hold and release positions, and
effective when in the release position for engagement with the
latch means to displace the latch means from the hold to the
release position, the latch means being positioned above the
elongated sleeve and including hook means having a lower end
operatively engageable by the upper end of the elongated
sleeve.
12. A liner hanger according to claim 11 wherein the hook means are
spring biased inward and are releasable from detent means fixed to
the tubular body, upon outward radial movement of the hooks caused
by engagement of the upper end of the elongated sleeve.
13. A liner hanger according to claim 12 wherein the hook means
includes downwardly facing slanted surfaces, and wherein the upper
end of the elongated sleeve includes a mating slanted surface.
14. A liner hanger according to claim 11 wherein the latch means
include a plurality of elongated flat springs depending from the
bow springs, and the lower end of each such latch spring includes a
slanted surface engageable by a mating slanted surface on the
hydraulically operated means.
15. A liner hanger according to claim 14 wherein each of the latch
springs includes a hook positioned to engage a catch ring which is
fixed to the tubular body.
16. A liner hanger according to claim 15 wherein a second ring is
positioned on the tubular body above the catch ring for engagement
by the hooks after a given distance of axial movement by the bow
springs and slips.
17. A liner hanger according to claim 11 wherein the hydraulically
operated means includes a hydraulic piston provided at one end of
an elongated sleeve, means including the sleeve defining a chamber
behind the piston, and means for admitting fluid into the chamber
to operate the piston when the pressure within the liner hanger is
different from the pressure in the annulus between the liner hanger
and the well casing.
18. A liner hanger according to claim 17 wherein the sleeve is
biased in a direction away from engagement of the hydraulically
operated means with the latch means.
19. A liner hanger according to claim 18 wherein biasing of the
sleeve is provided by flat helical spring means within the
sleeve.
20. A liner hanger according to claim 18 wherein biasing of the
sleeve is provided by means including a second hydraulic piston
provided at the other end of the sleeve, and means for admitting
fluid into a chamber to operate the second piston when the pressure
within the liner hanger is different from the external pressure in
the annulus between the liner hanger and the well casing, and the
differential is opposite that for operating the first-mentioned
hydraulic piston.
Description
A liner hanger is a tool employed in oil wells when the well is
being completed, and functions to suspend a liner pipe within a
well casing which has been previously set within the well bore. In
one typical well completion sequence, a liner pipe is attached to
the bottom of the liner hanger, the liner pipe is run into the oil
production zone, and the liner hanger is actuated to grip the
casing wall. Then the tubing string used to run the liner and liner
hanger down into the well is released and withdrawn. The hanger may
be thus required to support long lengths of liner pipe, sometimes
weighing many tons. Yet, the liner hanger must occupy only a very
narrow radial distance because a casing diameter is selected for
maximum economy consistent with the production capability of the
well, while the liner will be selected as the maximum which will
fit within the casing. The liner hanger preferably has the same ID
(inside diameter) as the liner pipe to permit tools for other
completion operations to pass through.
Liner hangers have been provided which are actuated by mechanisms
such as a so-called J-hook or other mechanical means which require
certain rotary or reciprocating motions of the string to cause the
hanger to be actuated to grip the casing wall. These devices are
widely used, but yet have been found to inadvertently actuate the
hanger due to motion of the string while running in, or to be
inoperative after run-in. Further, many of these mechanically
operated devices are found to cause difficulty in releasing the
hanger, when it is desired to remove the liner for resetting into
another protection zone or if it is erroneously set.
Hydraulically set liner hangers have been provided which operate by
circulating the well, i.e., applying fluid pressure to the tubing
string and withdrawing liquid from the annulus between the string
and the casing. Usually pressure is permitted to build up only
after a ball is dropped down the string to seat in a catcher. This
type of hanger avoids the problem of prematurely setting the hanger
when running in, since impact, rotation or vertical movement will
not cause it to set. However, these hydraulically set hangers do
not provide the same degree of positive operation such as results
from the use of bow springs to move the slips, as in the
mechanically set devices. Further, release of the hanger after it
has been set is not facilitated in the hydraulically set devices
currently available.
It is therefore an important feature of this invention to provide a
liner hanger which is set by hydraulically operated latching means
that cannot be inadvertently actuated by rotation, reciprocation or
impact, while at the same time employing positive mechanical means,
such as bow springs which frictionally engage the casing walls, for
the purpose of providing the axial mechanical movement of the slips
when the hanger is being set. Another feature of the invention is
the provision of a liner hanger wherein the actuating and setting
mechanism requires a very narrow radial thickness. Another feature
is the provision of a liner hanger which may be set and also
released in a positive manner, but yet is relatively free of
inadvertent setting while running in or the like.
In accordance with this invention, a liner hanger is provided which
includes slips which are caused to move onto a slip expander by bow
springs, but the slips and bow springs are latched by mechanical
detents which may be released by a hydraulically operated
mechanism. This latch release arrangement includes a sleeve movable
axially along the tubular body of the liner hanger, with latch
spring expanders positioned at one end of the sleeve to force the
latches out away from the detents. The sleeve is caused to move by
a pressure differential applied between the interior and exterior
of the tubing string. In this manner, mechanical operation of the
bow springs and slips is provided, but the latch release mechanism
is hydraulically operated.
Novel features which are believed characteristic of the invention
are set forth in the appended claims. The invention itself,
however, as well as further features and advantages thereof, may
best be understood by reference to the following detailed
description of illustrative embodiments, when read in conjunction
with the accompanying drawing, wherein:
FIG. 1 is a vertical sectional view of a portion of a well bore
having a casing therein, and including a liner hanger according to
the invention shown in elevation, with parts thereof broken away or
in section;
FIG. 2 is an enlarged detail view in vertical section, of a portion
of the liner hanger of FIG. 1, showing in particular the
hydraulically operated latching mechanism;
FIG. 3 is an enlarged detail view in section similar to that of
FIG. 2, but showing another embodiment of the invention;
FIG. 4 is a pictorial view of a catch ring which may be used in the
liner hangers of FIGS. 1--3, according to one embodiment of the
invention; and
FIGS. 5a and 5b are enlarged detail views, in vertical section, of
the operation of the latching mechanism using the catch ring of
FIG. 4.
Referring now to FIG. 1, a liner hanger according to the invention
is shown within a well casing 10 which has been set in a well bore.
The liner hanger is shown in an unactuated condition, although it
is in a position where it would be actuated and set, since a
depending liner 11 is shown in a producing formation 12. The liner
hanger, and the liner pipe 11 attached below it, are lowered into
the casing by a tubing string or drill pipe 13 which is connected
to the upper end of the liner hanger mechanism by a releasable
connector or setting tool 14 which may be any one of a number of
conventional devices. The setting tool will not be described in
detail here as the releasable mechanism forms no part of this
invention. After the liner hanger has been actuated and set in the
well casing 10 to suspend the liner pipe 11 in the proper location
in the well bore, the tubing string 13 is appropriately operated to
actuate the releasable connector 14 so that the tubing string may
be withdrawn from the well, leaving the liner and liner hanger in
place for production.
The liner hanger includes a conically shaped slip expander FIG.
which is secured to the outside of a tubular body 16 that generally
supports all of the parts of the liner hanger. Located below the
slip expander 15, and functioning to ride up on the slip expander
and be forced out against the walls of the FIG. casing 10, are a
number of slips 17 which include teeth for gripping the wall of the
casing. Although three slips 17 are shown, spaced at 120.degree.,
it is also conventional and perhaps preferable to use four or six
such slips suitably spaced around the tubular body 16. Each of the
slips is secured to an extension 18 of a separate bow spring or
spring stabilizer 19. All three of the bow springs 19 are secured
by rivets to a collar 20 which slides freely along the tubular body
16 and merely functions to stabilize the slips with respect to
peripheral movement. The bow springs are shaped to normally assume
a position larger than the inside diameter of the well casing 10,
so that when lowered down into the casing the bow springs will
frictionally engage the casing wall. Thus when the latch release
mechanism is actuated as will be described, and the string with
attached liner hanger is further lowered, the frictional engagement
of the bow springs on the casing wall will cause the slips 17 to
move up into engagement with the slip expander 15, causing the
slips to move radially outward and grip the casing.
The lower ends of the bow springs 19 are all connected by rivets to
another collar 21 which moves freely along the tubular body 16 and
functions to guide the bow springs and keep them in place.
Connection to this collar also anchors the latch springs and
prevents inward deflection of the bow springs from unlatching the
hooks as discussed below. Extending below the bow springs and
integrally connected thereto, are elongated latch springs 22. Each
of these includes a hook or detent 23 formed on the lower end and
adapted to engage a catch ring 24. A safety ring 25 similar to the
catch ring 24 is positioned above the catch ring to prevent the
slips from moving too far in the event that the slips do not engage
the casing wall properly. The catch ring 24 and the safety ring 25
are both circular bands secured to the tubular body 16 by welding
or the like.
The latch springs 22 and hooks 23 are caused to disengage from the
catch ring 24 by a hydraulically operated mechanism including a
cylindrical sleeve 26 which is slidably disposed outside the
tubular body 16. At the upper end of the cylindrical sleeve is
conical or wedge-shaped latch expander 27 which, when the sleeve 26
is forced upward, moves under the hooks 23 and forces them outward
so that the hooks will clear the catch ring 24. Upward movement of
the sleeve 26 is caused by a hydraulic piston and cylinder-type
arrangement as will be described. Initially, during lowering of the
liner hanger and liner into the well, upward movement of the sleeve
26 is prevented by a set of three shear pins 28 which are disposed
beneath the latch hooks 23. These shear pins extend into holes
suitably provided in the tubular body 16, and are composed of a
material which is fairly rigid, but fails under the force produced
by the hydraulic actuating mechanism.
The hydraulic sleeve 26 is caused to move upward by admission of
liquid under pressure from the interior of the tubular body 16 into
a hydraulic chamber 29 through one of a plurality of hydraulic
injection holes 30 spaced around the tubular body. The sleeve 26 is
ordinarily held down against a stop ring 31 by a flat helical
spring 32 which surrounds the tubular body 16. The spring 32 may be
seen in FIG. 1 through open ports 33 which allow the pressure in
the annular space between the tubular body 16 and the hydraulic
sleeve 26 to be equalized with the pressure between the outer
periphery of the liner hanger and the well casing 10, except of
course within the chamber 29. Below the stop ring 31, the tubular
body 16 extends down to a suitable coupling mechanism 34 which in
turn is connected to the liner 11. Included within this section may
be a valve arrangement which permits the pressure within the tubing
string 13 and the tubular body 16 of the liner hanger to be greater
than the pressure within the annulus between the tubing string and
the well casing 10, in spite of the apertures in the liner 11 or
other outlets, but still permits subsequent production of oil.
Various setting tools are available which have elongated extensions
with packers or cups provided for this purpose.
Referring now in particular to FIG. 2, which is an enlarged detail
view of the latch arrangement and hydraulic setting mechanism
referred to with reference to FIG. 1, it will be noted that the
chamber 29 is defined between an enlarged collar 36 at the upper
end of and integral with the sleeve 26, and a cylindrical collar 37
secured to the body 16 by welding or the like. The chamber 29 is
sealed at top and bottom by O-rings 38 positioned in suitable
recesses in the collar 36 and O-rings 39 positioned in suitable
recesses in the collar 37. The helical spring 32 bears against the
lower side of the collar 37, while the lower end of the spring 32
bears against another collar 40 so that force is applied by the
spring against the collar 40 to hold the collar 40 against the stop
ring 31. However, when pressure inside the tubular body 16
increases, the liquid will push against the lower transverse face
of the collar 36 within the chamber 29, forcing the sleeve 26
upward and fracturing the shear pins 28. This will permit the
conical latch spring expander 27 to engage the mating surface of
the hooks 23 and force the hooks outward so that they will pass
over the catch ring 24. It is noted that a shoulder 41 is provided
at the top of the sleeve 26 to engage the ends of the latch springs
and hooks 22 and 23, functioning to force the latch springs upward
in case the conical expander 27 does not completely disengage the
hooks and thus the hooks do not freely pass over the catch ring 24.
The shoulder 41 also functions to prevent the latch springs from
passing down over the sleeve 26, when the hanger is disengaged and
is being retrieved.
After the latch hooks FIG. have been disengaged from the catch ring
24 as just described, the string is lowered further and the
frictional engagement of the bow springs on the casing wall causes
the bow springs and slips to move upward and thus the slips will
grip the casing wall. Later, if it is necessary to remove the
liner, the liner hanger is released by pulling up on the string so
the slip expander 15 is pulled away from FIG. slips. The bow
springs will then cause the latch spring to move downward and the
hooks 23 will again engage the catch ring. If the slips do not
readily break free of the wall, the weight of tubing string may be
used to free the slips by lowering the tubing string slightly.
Referring now to FIG. 3, an embodiment of the invention is shown
wherein the helical spring 32 which is used in the embodiment of
FIGS. 1 and 2, is replaced by a hydraulic arrangement for reversing
the direction of movement of the hydraulic sleeve 26. In the FIG. 3
embodiment, all of the parts are the same as discussed above, with
the hydraulic sleeve 26 surrounding the tubular housing 16 and
providing a chamber 29 which is sealed by O-rings 38 and 39 so that
a pressure differential forcing fluid into the hole 30 will cause
the hydraulic sleeve 26 to move upward. In addition however, the
sleeve 26 includes exterior ports 44 which admit fluid from the
annulus 45 between the well casing 10 and the sleeve, whereby a
pressure differential between the annulus and the interior of the
tubing string and tubular body 16 will cause the hydraulic sleeve
26 to move downward until the collar 40 engages the stop ring 31 in
a manner the same as the function provided by the spring 32 in the
previous embodiment. It is noted that a set of O-rings 46 are
provided in suitable recesses in the collar 40 in the FIG. 3
embodiment to provide sealing in the usual hydraulic piston and
cylinder arrangement. Although not shown in FIG. 3, the remainder
of the liner hanger would be the same as in FIGS. 1 and 2,
including the slip expander, slips, bow springs, and latching
arrangement, or a latching arrangement as seen in FIGS. 4 and 5 may
be used.
In reference to FIG. 4, another embodiment of the invention is
shown wherein a different form of catch ring 24 is used so that
both manual and hydraulic operation is provided. In the embodiment
of FIGS. 1 and 2, the catch ring 24 is a solid ring so that
regardless of where the hooks 23 are positioned around the ring,
the hooks will still engage the ring, and rotation of the tubing
string has no effect on the operation of the hanger. However, the
catch ring 24' of FIG. 4 is especially shaped to provide a "climb
out slot" 48 for each of the spring hooks 23. That is, if three bow
springs and latch springs are used, there would be three of the
slots 48 provided in the catch ring 24, spaced at 120.degree.. In
like manner, if four or six latch springs were used, four or six
climb-out slots 48 would be employed. As long as the latch spring
hook 23 is generally vertically aligned with the open part of the
slot 48, the hook will engage the ring 24'. However, if the tubing
string and liner hanger mechanism is rotated clockwise looking
down, a cam surface 49 engages the hook 23 and causes it to move up
onto the smooth cylindrical outer face of the catch ring to a
position 50 where it will then slide on over the catch ring and
allow the slips of the liner hanger to move up and grip as before.
The operation of the embodiment using the catch ring of FIG. 4, is
seen from FIGS. 5a and 5b where the latch hook is shown in the
engaged and in the disengaged positions, respectively. The
embodiments of the liner hanger of FIGS. 1 and 2, or FIG. 3, may be
adapted for manual as well as hydraulic operation by using the
catch ring of FIGS. 4 and 5.
Accordingly, although the invention has been described with
reference to particular embodiments, it is seen that modifications
of the disclosed embodiments, as well as other embodiments of the
invention, will occur to persons skilled in the art upon reference
to this disclosure.
* * * * *