U.S. patent number 3,749,166 [Application Number 05/257,405] was granted by the patent office on 1973-07-31 for well packer apparatus.
This patent grant is currently assigned to Schlumberger Technology Corporation. Invention is credited to David E. Young.
United States Patent |
3,749,166 |
Young |
July 31, 1973 |
WELL PACKER APPARATUS
Abstract
In accordance with an illustrative embodiment of the present
invention, a well packer apparatus includes a mandrel that carries
normally retracted slips and packing elements that can be expanded
to provide an anchored pack off in a well. Separate lock systems
are provided to lock the slips and the packing in set positions,
and the lock systems can be disabled by selectively operable means
to enable retraction of the packing and the slips so that the
apparatus can be retrieved, intact, to the surface.
Inventors: |
Young; David E. (Friendswood,
TX) |
Assignee: |
Schlumberger Technology
Corporation (New York, NY)
|
Family
ID: |
22976185 |
Appl.
No.: |
05/257,405 |
Filed: |
May 26, 1972 |
Current U.S.
Class: |
166/123;
166/134 |
Current CPC
Class: |
E21B
23/06 (20130101); E21B 33/1293 (20130101) |
Current International
Class: |
E21B
33/12 (20060101); E21B 33/129 (20060101); E21B
23/00 (20060101); E21B 23/06 (20060101); E21b
023/06 (); E21b 033/128 (); E21b 033/129 () |
Field of
Search: |
;166/120,123,134,135,237,238,216,217 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Claims
I claim:
1. A well packer apparatus comprising: a body member; normally
retracted slip means on said body member that can be shifted
outwardly thereof into anchoring contact with a well casing;
expander means for shifting said slip means outwardly; packing
means surrounding said body member and adapted to be expanded into
sealing engagement with a well casing; first one-way lock means for
locking said slip and expander means with said slip means in outer
positions; second one-way lock means for locking said packing means
in expanded condition; and means movable relative to said body
member for inactivating said first and second lock means to enable
retraction of said slip means and said packing means so that said
apparatus can be retrieved from a well.
2. The well packer apparatus of claim 1 wherein said expander means
includes opposed expander members movable relatively toward each
other to shift said slip means outwardly, said first lock means
comprising instrumentalities coacting with one of said expander
members and said body member to prevent movement of said expander
members away from each other.
3. The well packer apparatus of claim 2 wherein said
instrumentalities include a lock member surrounding said body
member and having gripping engagement therewith, said lock member
being movable relatively along said body member in one direction
during movement of said expander members relatively toward each
other, and means engaged between said lock member and said one
expander member for preventing movement of said expander members
away from each other.
4. The well packer apparatus of claim 3 wherein said inactivating
means includes means to disengage said least mentioned means to
enable said expander members to move away from one another.
5. The well packer apparatus of claim 1 wherein said packing means
comprises elastomeric elements, and abutments movable relatively
toward each other to compress and expand said elements, said second
lock means comprising instrumentalities coacting with said body
member and one of said abutments to prevent movement of said
abutments away from each other.
6. The well packer apparatus of claim 5 wherein said
instrumentalities include a lock member surrounding said body
member and having gripping engagement therewith, said lock member
being movable relatively along said body member in one direction
during movement of said abutments relatively toward each other, and
means engaged between said lock member and said one abutment for
preventing movement of said abutments away from each other.
7. The well packer apparatus of claim 6 wherein said inactivating
means includes means to disengage said last-mentioned means to
enable said abutments to move away from each other.
8. A well packer apparatus comprising: a body member; a sleeve
structure movable relatively along said body member and providing a
fixed first abutment; packing means surrounding said sleeve
structure and having one end engaged by said first abutment; a
second abutment movable relatively along said sleeve structure and
engaging the other end of said packing means, whereby movement of
said first and second abutments relatively toward each other causes
compression and expansion of said packing means; normally retracted
slip means on said body member below said packing means, said slip
means being shiftable outwardly into anchoring engagement with a
well casing; an expander member movable downwardly along said body
member to shift said slip means outwardly, said expander member
being coupled to said second abutment by means including an
intervening sleeve; first one-way lock means for preventing upward
movement of said expander member to lock said slip means in outward
positions; second one-way lock means for preventing movement of
said abutments away from each other to lock said packing means in
expanded condition; and means movable relative to said body member
for inactivating said first and second lock means to enable
retraction of said packing means and said slip means.
9. The well packer apparatus of claim 8 wherein each of said lock
means includes a lock member having gripping engagement with said
body member, and cam means causing said lock member to grip said
body member when in one position and movable to another position to
enable said lock member to pass longitudinally therethrough.
10. The well packer apparatus of claim 9 wherein said inactivating
means comprises longitudinally shiftable members for enabling said
cam means to move from said one position to said other
position.
11. The well packer apparatus of claim 10 wherein said members
comprise a release sleeve mounted for longitudinal movement
relative to said sleeve structure, and said intervening sleeve
being movable longitudinally with respect to said body member.
12. The well packer apparatus of claim 11 wherein said release
sleeve and said intervening sleeve each have a locking surface for
positioning a respective cam means in said one position, and a
recess adjacent said locking surface that enables movement of a
respective cam means to said other position.
13. A well packer apparatus comprising: a body member; a sleeve
structure movable relatively along said body member and providing a
fixed first abutment; packing means surrounding said sleeve
structure and having one end engaged by said first abutment; a
second abutment slidable with respect to said sleeve structure and
engaging the other end of said packing means, whereby movement of
said abutments relatively toward each other causes compression and
expansion of said packing means; first one-way lock means for
enabling movement of said abutments relatively toward each other
but normally preventing movement of said abutment away from each
other to lock said packing means in expanded condition; means for
releasing said first lock means including a release sleeve slidable
upwardly with respect to said sleeve structure from a locking
position to a releasing position; normally retracted slip means on
said body member below said packing means, said slip means being
shiftable outwardly into anchoring engagement with a well casing;
expander means including an upper expander and a lower expander
movable relatively toward each other to shift said slip means
outwardly, said lower expander being fixed to said body member,
said upper expander being movable relatively along said body
member; second one-way lock means for enabling movement of said
upper and lower expanders relatively toward each other but normally
preventing movement of said expanders away from each other to lock
said slip means in anchoring position; and means for releasing said
second lock means including an intervening sleeve that couples said
upper expander to said second abutment, said intervening sleeve
being slidably upwardly relative to said upper expander from a
locking position to a releasing position.
14. The well packer apparatus of claim 13 wherein each of said lock
means includes a lock member having gripping engagement with said
body member, and cam means causing said lock member to grip said
body member when in one position and movable to another position
disengaged from said lock member.
15. The well packer apparatus of claim 14 wherein said releasing
sleeve and said intervening sleeve each provide a locking surface
for holding a respective cam means in said one position, each
sleeve having a recess that is positioned by sliding said sleeves
to said releasing position to enable movement of said cam means to
said other position.
16. The well packer apparatus of claim 15 wherein each lock member
is constituted by a circumferentially discontinuous ring having
internal teeth that grip said body member, and wherein each cam
means has downwardly and inwardly inclined internal cam surfaces
that engage upwardly and downwardly inclined external cam surfaces
on said ring, whereby upward force on each cam means results in the
application of inward force on said ring.
17. The well packer apparatus of claim 16 wherein said release
sleeve, sleeve structure and intervening sleeve are coupled
together such that upward movement of said release sleeve disposes
both recesses in position to enable movement of said cam means to
said other position.
18. The well packer apparatus of claim 17 further including
lost-motion connection means for coupling said release sleeve to
said sleeve structure and said sleeve structure to said intervening
sleeve.
19. The well packer apparatus of claim 18 further including means
on said release sleeve to enable connection thereof with a
retrieving tool to cause upward movement.
20. The well packer apparatus of claim 19 further including a latch
sleeve disposed within said release sleeve and having means to
enable connection thereof with a production string of pipe that
extends upwardly to the surface.
Description
This invention relates generally to well packers used in well
bores, and more particularly to a new and improved permanent or
retrievable well packer that can be used to isolate a producing
zone of a well bore.
Packers of the type shown in U. S. Pat. No. 3,229,767, are adapted
to be permanently set in a well casing to isolate the upper end of
a producing zone. The packer is made of drillable materials and
includes upper and lower slip and expander combinations to either
side of an expansible packing structure, and is considered to be
permanently set because the only way to clear the well bore is to
drill the packer away with a drill bit. Although this type of
packer has the advantage of simplicity of structural combination,
it does require the considerable expense of a drilling operation in
the event it is desired to remove it from the well.
Several attempts therefore have been made to design a well packer
that approaches the simplicity of the permanent set type, but with
provision for releasing the slips and the packing so that the tool
can be recovered intact when it is desired to remove it. One such
packer is disclosed in U. S. Pat. No. 2,714,931, and includes
normally retracted slips located between opposed expanders and
below a packing element that can be expanded against the casing.
The slips are locked in set positions by ratchet teeth on the upper
expander, and the packing is locked in expanded condition by a lock
ring between the upper abutment and the mandrel. To release the
tool, a nose piece at the bottom of the mandrel is sheared off by
pulling upwardly on the mandrel, and with the nose piece dropped
away the mandrel can supposedly be pulled upwardly through the
surrounding parts to release the slips and the packing. However, it
is thought that the releasing procedure taught in this disclosure
is not sufficiently positive in operation and reliable under actual
conditions to provide assurance of retrievability. Moreover, a
certain amount of junk is left in the well after the tool is
retrieved, due to the manner in which release is achieved. This is,
of course, undesirable.
A more recent effort is shown and described in U. S. Pat. No.
3,398,795. Here, the general structural arrangement is somewhat
similar to that described in the patent disclosure mentioned first
above, except that a collet lock at the lower end of the mandrel
can be released, and the slip and expander combination above the
packing element is constructed in such a manner that the expander
can be collapsed to release the slips in response to upward mandrel
movement. This enables releasing the tool for recovery to the
surface, provided of course that the releasing structure is
operational.
However, a production packer is normally left in set position for a
considerable period of time, for example several years, before it
might become desirable to retrieve it. In that length of time, it
is quite likely that a large amount of debris such as sand, scale
and the like will have settled out on top of the tool, making
release of the parts located above the packing very difficult if
not impossible. Of course it is still possible to drill the packer
away, however the feature of retrievability has become
meaningless.
It is the leading object of this invention to provide a new and
improved well packer usable in production operations that is either
permanent or retrievable, and is constructed so that release can be
achieved in a simple and reliable manner even after the packer has
been in the well for a long period of time.
This and other objects are attained in accordance with the concepts
of the present invention through the provision of a well packer
apparatus that includes a body member or mandrel carrying normally
retracted slips located between opposed expanders and below
settable packing that can be expanded to seal off the well bore.
The packing assembly includes expansible elements mounted around a
sleeve that is provided with a fixed abutment engaging the upper
end of the packing elements. A movable abutment is fixed to a
sleeve that is coupled to the upper one of the opposed expanders,
and engages the lower end of the packing elements. Both the
abutments and the expanders can be advanced relatively toward each
other to expand the packing elements and the slip elements into
contact with the casing.
A first one-way locking means is provided to prevent movement of
the abutments away from one another and a second one-way locking
means is provided to prevent movement of the expanders away from
one another, thus locking the packer in set condition until it is
desired to remove it from the well. To enable the packer to be
retrieved, means are provided to conveniently and positively
disable the first and the second lock means to permit movement of
the expanders and the abutments away from each other so that the
packing element and the slip elements can be again retracted,
whereupon the tool can be removed from the well intact.
The present invention has other objects and advantages which will
become more clearly apparent in connection with the following
detailed description of a preferred embodiment thereof, taken in
conjunction with the accompanying drawings in which:
FIGS. 1A and 1B are longitudinal sectional views, with portions in
side elevation, of a well packer according to the present
invention, with parts in the relative positions they occupy during
running into a well bore, FIG. 1B forming a lower continuation of
FIG. 1A;
FIGS. 2 and 3 are cross-sections taken on lines 2--2 and 3--3 of
FIGS. 1A and 1B, respectively;
FIGS. 4A and 4B are views similar to FIGS. 1A and 1B except with
parts in relative positions where the tool is set in a well casing;
and
FIGS. 5A and 5B are views similar to the foregoing except showing
the parts in position for retrieving the tool from a well.
Referring initially to FIGS. 1A and 1B for a detailed description
of a permanent or retrievable well packer constructed in accordance
with the principles of the present invention, an elongated mandrel
10 having a full opening throughbore 11 carries a set 12 of
normally retracted slip elements 13 that are disposed between an
upper expander 14 and a lower expander 15. The lower expander 15 is
fixed to the mandrel 10 by virtue of being threaded to a ring 16
which is threaded to the mandrel, whereas the upper expander 14 is
movable relatively therealong. A nose piece 17 is fixed to the
mandrel 10 below the lower expander 15. The slip elements 13 are
maintained in the same horizontal plane by a band 18 that encircles
the elements and engages within an inwardly directed recess 19 in
each slip element. Each slip element 13 has spaced upper and lower
sets of wickers or teeth 20 and 21, and has inner inclined surfaces
22 and 23 that are engaged by companion outer surfaces 24 and 25 on
the respective expanders in order to cause outward shifting of the
slip elements in response to movement of the upper expander 14
relatively toward the lower expander 15. Each end of each slip
element 13 may be provided with a retractor structure including
slidable connections to the adjacent expander so that movement of
the upper expander 14 relatively away from the lower expander 15
will cause inward movement of the slip elements to retracted
positions. For further detail of the slidable connections,
attention is invited to Application Ser. No. 257,086, filed
concurrently herewith and assigned to the assignee of this
invention.
The mandrel 10 also carries a packing assembly 30 that comprises
several elastomeric packing rings 31, 32 and 33 mounted around a
tubular compression sleeve 34 that is movable relatively along the
mandrel. The upper packing ring 31 is engaged by a downwardly
facing abutment 35 that is fixed to the sleeve 34, and the lower
ring 33 is engaged by an upwardly facing abutment 36 that is
movable relatively along the sleeve above an enlarged section 37
thereof provided at its lower end. Of course it will be recognized
that movement of the abutments 35 and 36 relatively toward one
another will cause the packing rings 31, 32 and 33 to be compressed
and expanded into sealing contact with a well casing wall.
The lower abutment 36 is coupled to the upper expander 14 through
the medium of an intervening sleeve 38. Within limits, the sleeve
38 can move longitudinally relative to both the upper expander 14
and the compression sleeve 34. Limited movement with respect to the
upper expander 14 is afforded through the provision of one or more
outwardly extending plugs 39 that are threaded within openings in a
reduced diameter upper section 40 of the expander, and which extend
into elongated slots 41 through the wall of the sleeve 38, whereas
limited movement with respect to the compression sleeve 34 is
afforded by similar arrangement including a plug 42 on the section
37 that extends into an elongated slot 43 through the wall of the
sleeve 34. Of course the respective plugs and slots also function
to prevent relative rotation of the parts. Moreover, in the initial
positions of the parts, the intervening sleeve 38 is relatively
fixed by shear pins 44 and 45 that extend through the wall of the
sleeve and into the enlarged section 37 and the upper portion 40 of
the expander 14, respectively. With the parts in the running-in
position shown in FIG. 1B, the lower end surface 46 of the sleeve
38 engages an upwardly facing shoulder 47 on the upper expander 14
so as to be able to drive the upper expander downwardly along the
mandrel 10.
A releasable, one-way lock system indicated generally at 50 is
disposed above the upper end surface 51 of the upper expander 14,
and between the mandrel 10 and the intervening sleeve 38. The lock
system 50 includes a split ratchet or lock ring 52 that normally is
surrounded by a split cam ring 53 which is adapted to be held in an
inner position as shown by an internal locking surface 54 on the
intervening sleeve 38. The ratchet ring 52 has internal teeth 55
that can mesh with external teeth 56 formed, for example, by
threads on an adjacent section of the mandrel 10. Moreover, the
ring 52 has upwardly and outwardly inclined cam surfaces 57 on its
outer periphery that are engaged by companion cam surfaces 58
formed interiorly of the cam ring 53. The ratchet ring 52, by
virtue of its split construction as shown in FIG. 2, has the
capability for lateral expansion and contraction and can therefore
ratchet downwardly along the mandrel teeth 56 in response to
downward force imposed upon the cam ring 53 by the inwardly
directed shoulder 59 on the intervening sleeve 38 during downward
movement of the latter, however the ratchet and cam rings cannot be
moved jointly upwardly along the mandrel 10 by the expander 14 due
to the camming action of the surfaces 57 and 58 which causes the
ratchet ring to be forced inwardly and to tightly grip the mandrel.
The lock system 50 can be released, however, by moving the
intervening sleeve 38 upwardly relative to the mandrel 10 and the
expander 14 to position an enlarged diameter relief recess 60
adjacent the cam ring 53. When this occurs, the cam ring 53 due its
split or segmented construction as shown in FIG. 2, can expand
outwardly to a throughbore size such that the ratchet ring 52 can
pass freely therethrough. A counterbore 61 is formed within the
upper end section of the upper expander 14 and is sized so that
with the cam ring in its outer position the upper expander can move
to a considerable distance upwardly along the mandrel 10 without
encountering the ratchet ring 52. The advantages and purposes of
the counterbore 61 are discussed more fully in Application Ser. No.
257,367, Mullins, filed concurrently herewith and assigned to the
assignee of this invention, as well as being elaborated in more
detail herebelow.
Turning now to FIG. 1A, it will be seen that the upper abutment 35
is formed in part by the lower end surface of a sleeve extension 65
that is threadedly fixed to the compression sleeve 34. The sleeve
extension 65 extends upwardly along the upper end portion of the
mandrel 10, and the lower end portion 66 of a releasing sleeve 67
is telescoped over the extension 65. Hereagain, the release sleeve
67 has some capability for limited vertical movement relative to
the extension 65 due to the provision of opposed stop shoulder 68
and 69 that may be conveniently formed on the respective member by
threads as shown in cut-away elevation. Relative rotation is
prevented by virtue of a plug 70 fixed to the extension and
engaging within an elongated slot 71 through the wall of the
release sleeve. It will be appreciated of course that the release
sleeve 67 and extension 65 are initially fixed together by means of
a shear pin 72 or the like.
A second releasable one-way lock system 75 is disposed between the
upper end portion 76 of the mandrel 10 and the release sleeve 67,
and also comprises a split ratchet ring 77 (FIG. 3) having internal
teeth 78 that mesh with external teeth 79 on the mandrel. The outer
cam surfaces 80 of the ratchet ring 77 are engaged by internal cam
surfaces 81 formed on enlarged head portions 82 of a plurality of
circumferentially spaced spring fingers 83 that depend from the
lower end of a latch sleeve 84 fitted within the release sleeve 67,
the spring fingers being formed by slots 85 that are cut from the
lower end of the latch sleeve 84. Normally, the head portions 82
are held inwardly, as shown, by locking surfaces 86 and 87 that are
formed by stepped diameter inner wall portions of the release
sleeve 67. In a fashion similar to the first lock system described
above, the upper lock system 75 permits the release sleeve 67 and
the extension 65 to be moved jointly downwardly along the mandrel
10 as the ratchet ring 77 ratchets over the mandrel threads 79,
however the parts cannot return upwardly due to the coaction of the
cam surfaces 80 and 81 and the resultant inward camming action of
the ratchet ring. Consequently, the packing assembly 30 can be
locked with the rings 30, 31 and 32 in expanded condition and will
remain in such condition until it is desirable to retract them.
Retraction is accomplished through release of the lock system 75 by
lowering into the well an inside grapple type tool that engages the
internal threads 88 at the upper end of the release sleeve 67. An
upward pull on the sleeve 67 results in shearing of the pin 72 so
that the sleeve can telescope upwardly over the extension 65 and
the latch sleeve 84, thus removing the locking surfaces 86 and 87
from around the head portions 82. Unsupported against outward
movement, the head portions 82 are free to resile outwardly so that
the sleeve extension 65 and the compression sleeve 34 can move
upwardly along the mandrel 10 and relieve the compression loading
in the packing rings 30, 31 and 32. The extension 65 is also
provided with an internal annular recess 89 that is sized such that
the ratchet ring 77 can pass therewithin during such upward
movement. Upward movement of the release sleeve 67 along the
extension 65 is of course stopped by engagement of the inwardly
directed shoulder 68 on the sleeve with the outwardly directed
shoulder 69 on the extension.
The latch sleeve 84 has threads 90 formed internally at its upper
end for reception of a typical latching mechanism on a seal mandrel
(not shown) that forms the lower end of a production string of
pipe, an exemplary structure that is suitable for this purpose
being shown in U. S. Pat. No. 2,737,248. The presence of a tensile
strain in the production string will not affect the locked
condition of the lock system 75, since upward force only causes the
ratchet ring 77 to grip the mandrel 10 more tightly. Since the seal
mandrel and associated latching system noted above are released by
relative rotation, a lock pin 91 on the release sleeve 67 extends
into a groove 92 at the upper end of the latch sleeve 84 to prevent
co-rotation of the latter mentioned part.
In operation, the parts are assembled as shown in the drawings and
the assembly is coupled to a conventional gas operated setting tool
(not shown) for lowering to the desired setting depth in a well
casing. The setting tool is releasably connected to the packer
through instrumentalities including a tension member 100 and an
adapter sleeve 101 shown in FIGS. 1A and 1B. The tension member 100
includes a central rod 102 having its lower end connected to a
frangible tension stud 103 having a reduced neck providing a weak
point 104, the lower end of the tension stud being threaded to a
bottom cap 105. The cap 105 has a coupling sleeve 106 extending
upwardly therefrom, and the coupling sleeve carries a split ring
107 operatively engaged between an upwardly facing shoulder 108
thereon and a downwardly facing shoulder 109 presented by the lower
end surface of the mandrel 10. A holding and releasing member 110
is received over the upper end portion of the coupling sleeve 106,
and comprises a skirt 111 having an external annular recess 112 in
which the split ring 107 is held. The member 110 also includes
inwardly directed flange portion 113 that is disposed in spaced
relation above an outwardly directed flange 114 on the rod 102.
Moreover, an upwardly facing shoulder 115 is arranged in vertical
alignment with a downwardly facing shoulder 116 on the coupling
sleeve 106. As long as the tension stud 103 remains intact, the
split ring 107 is engaged within the annular recess 117 formed in
the nose piece 17 below the shoulder 109.
The adapter sleeve 101 has a drive surface 120 which engages the
upper end face 121 of the latch release sleeve 67. As will be
appreciated by those skilled in the art, activation of the setting
tool will cause upward movement of the tension rod 102 and downward
movement of the adapter sleeve 101. In response to the resultant
movement in opposite longitudinal directions, the packer is set in
the following manner. Inasmuch as the latch release sleeve 67 is in
driving contact with the extension 65 of the compression sleeve 34,
the compression sleeve and its upper abutment 35 will be shifted
downwardly relatively along the mandrel 10, which is simultaneously
being pulled upwardly. As the release sleeve 67 and the compression
sleeve 34 move downwardly, the latch sleeve 84 is also driven
downwardly by virtue of the shoulder formed by the stepped locking
surfaces 86 and 87. As previously described, the ratchet ring 77
has capability of sufficient lateral expansion and contraction
within the head portions 82 whereby it can ratchet downwardly over
the mandrel threads 79.
As the compression sleeve 34 moves downwardly along the mandrel 10,
the intervening sleeve 38 between the lower abutment 36 and the
upper expander 14 is also moved downwardly, resulting in
advancement of the upper expander toward the lower expander 15
which is fixed to the mandrel. Thus the slip elements 13 are
shifted outwardly until their teeth 20 and 21 bite into and grip
the well casing wall as shown in FIG. 4B to anchor the tool against
longitudinal movement. As the intervening sleeve 38 and the upper
expander 14 move downwardly, the shoulder 59 drives the one-way
lock system 50 downwardly along the mandrel 10, and as described
above the ratchet ring 52 ratchets along the threads 56 and traps
the extent of downward movement of the upper expander 14. Since the
ratchet and cam rings cannot be moved jointly upwardly, it will be
apparent that the slip elements 13 are locked by the system 50 in
set or expanded positions.
Once the slip elements 13 are set against the casing C, the
intervening sleeve 38 and the lower abutment 36 cannot be moved any
further downwardly. Consequently, continued downward movement of
the compression sleeve 34 and the upper abutment 35 results in
shearing of the pins 44, whereupon the upper abutment moves toward
the lower abutment 36 to compress the packing rings 31, 32 and 33
and expand them into sealing contact with the surrounding well
casing wall. The upper one-way lock system 75 prevents upward
movement of the compression sleeve 34 and thereby traps the packing
in expanded condition, whereby the packer is fully set in the
casing C.
At a predetermined magnitude of tensile strain in the rod 102,
which magnitude is somewhat above that required to fully set the
packer, the tension stud 103 fails at the weak point 104 as shown
in FIG. 4B. Upward movement of the rod 102 brings the flange 113
against the holding member 110 and moves it upwardly relative to
the mandrel 10, whereupon the split ring 107 is permitted to resile
inwardly and disengage from the recess 117. The result is to
disconnect the coupling assembly from the mandrel 10 as shown in
FIG. 4B, whereupon the setting tool is released from the packer and
can be withdrawn from the wall. The lower shoulder 115 on the rod
102 picks up the member 106 and the cap 105 so that nothing is left
in the well as a result of the setting procedure.
With the packer firmly set in the casing C as shown in FIGS. 4A and
4B, a production string can be lowered into the well and connected
to the packer. A seal mandrel and latch sleeve as referred to above
can be connected to the lower end of the production string, the
seal mandrel extending into the bore 11 of the packer mandrel 10
and being fluidly sealed with respect thereto, the latch engaging
the internal threads 88 at the upper end of the latch sleeve 84 to
provide a coupling. The packer isolates the producing zone and
confines the pressure of the production fluids to the production
string of tubing that extends upwardly to the surface.
To release the packer for retrieval to the surface, the production
string is removed, and an inside grapple-type retrieving tool 125
shown schematically in FIG. 5A is lowered into the well on a pipe
string and connected to the internal threads 90 at the upper end of
the releasing sleeve 67. A sufficient upward pull on the releasing
sleeve 67 will cause the pin 72 to be sheared to enable upward
movement of the release sleeve relative to the mandrel 10 until the
shoulder 69 thereon abuts the shoulder 68 on the extension 65. Such
movement removes the locking surfaces 86 and 87 from around the
latch heads 82, and enables the heads and the fingers 83 to resile
outwardly with respect to the ratchet ring 77. Consequently, the
ratchet ring 77 no longer functions as a lock against upward
movement, permitting upward movement of the compression sleeve 34
and relief of the compression loading in the packing rings 31, 32
and 33 so that they will inherently retract.
When the lower enlarged section 37 of the compression sleeve 34
engages the lower abutment 36, the pins 45 are sheared and the
intervening sleeve 38 is drawn upwardly relative to the mandrel 10
and to the upper expander 14. Accordingly, the lock surface 54 is
removed upwardly from around the cam ring 53 so that it can move
outwardly into the recess 60. This disables the ability of the
ratchet ring 52 to prevent upward movement since it can now move
through the bore of the cam ring 53, so that when the plugs 39
engage the lower ends of the slots 41, the upper expander 14 is
pulled upwardly with respect to the slip elements 13. Movement of
the upper expander 14 away from the lower expander 15 results in
retraction of the slip elements 13 as shown in FIG. 5B. With the
packing and the slips retracted, the packer can be retrieved intact
to the surface.
It will now be apparent that a new and improved well packer has
been provided having the structural simplicity of a permanent
packer but with provision for convenient and positive release if it
is desired to remove it from the well. The lower lock system 50 is
located below the packing so as to be isolated from settlements
that may be deposited on the upper end of the packer over a
prolonged period in a well, and the upper lock system 75 is also
substantially isolated by virtue of its unique arrangement. The
wall packer disclosed herein has particular utility as a production
packer, but of course other uses in connection with other well bore
operations also can be made.
Since certain changes or modifications may be made in the disclosed
embodiment without departing from the inventive concepts involved,
it is the aim of the appended claims to cover all such changes and
modifications falling within the true spirit and scope of the
present invention.
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