U.S. patent number 3,631,926 [Application Number 04/889,540] was granted by the patent office on 1972-01-04 for well packer.
This patent grant is currently assigned to Schlumberger Technology Corporation. Invention is credited to David E. Young.
United States Patent |
3,631,926 |
Young |
January 4, 1972 |
WELL PACKER
Abstract
An improved well packer having upper and lower slips and
expanders for permanent anchoring, is further provided with
separate upper and lower mandrel sections. After the packer is
permanently anchored in a well casing or tubing, the packer may be
retrieved by pulling the upper mandrel section to disconnect a
segmented nut assembly which couples the upper expander to the
lower mandrel section, and which also keeps the upper expander
wedged between the upper slips and the upper mandrel section. When
the nut is released, the compression loading on the packing is
relieved to enable its relaxation, and the setting pressure on the
upper and lower slips is also achieved. Further upward travel of
the upper mandrel section carries the upper slip out of engagement
with the well casing, and thereafter draws the lower cone upward
and out from between the lower slip and the lower mandrel
section.
Inventors: |
Young; David E. (Houston,
TX) |
Assignee: |
Schlumberger Technology
Corporation (New York, NY)
|
Family
ID: |
25395315 |
Appl.
No.: |
04/889,540 |
Filed: |
December 31, 1969 |
Current U.S.
Class: |
166/134;
166/123 |
Current CPC
Class: |
E21B
33/1293 (20130101); E21B 23/06 (20130101) |
Current International
Class: |
E21B
33/12 (20060101); E21B 23/06 (20060101); E21B
23/00 (20060101); E21B 33/129 (20060101); E21b
023/06 (); E21b 033/129 () |
Field of
Search: |
;166/134,135,123,120 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Claims
What is claimed is:
1. A well packer apparatus comprising
an upper mandrel adapted to be passed longitudinally through a well
casing or the like,
a lower mandrel adapted to be passed longitudinally through a well
casing or the like and releasably secured to said upper
mandrel,
a resilient packing body arranged about said lower mandrel and
longitudinally compressible into fluidtight engagement with the
inside surface of said casing,
lower expander means slidably mounted on said lower mandrel,
lower slip means slidably mounted on said lower mandrel for urging
said lower expander means into compressive engagement with said
packing body and adapted for upward wedged engagement between said
casing and said lower expander means,
upper expander means slidably mounted on said upper mandrel,
upper slip means slidably mounted on said upper mandrel and
cooperable with said upper expander means for anchoring against
movement and for maintaining said fluidtight engagement of said
packing body with said casing, and
locking means fixedly interconnecting one of said mandrels with
said upper expander means for opposing upward movement of said one
mandrel and disabled by movement of the other of said mandrels
independent of said one mandrel.
2. The packing assembly described in claim 1, wherein said locking
means is disabled by upward movement of said upper mandrel from and
independent of said lower mandrel.
3. The packing assembly described in claim 2, wherein said locking
means is slidably disposed relative to said upper mandrel and
fixedly disposed between said lower mandrel and said upper expander
means.
4. The packing assembly described in claim 3, wherein said locking
means is disposed between the adjacent ends of said mandrels and
between the exterior surface of said upper mandrel and the interior
surface of said lower mandrel.
5. The packing assembly described in claim 4, wherein said locking
means collapses relative to said interior surface of said lower
mandrel upon upward movement of said upper mandrel from said lower
mandrel and said locking means, and
wherein said collapse of said locking means enables disengagement
of the anchoring of said upper slip means and said upper expander
means.
6. The packing assembly described in claim 5, wherein said collapse
of said locking means releases the fluidtight engagement of said
packing body with said casing.
7. A well packer apparatus comprising
upper mandrel means adapted to be passed longitudinally through a
well casing or the like,
lower mandrel means also adapted to be passed longitudinally
through said well casing and having its upper end provided with an
external annular shoulder and adapted to encompass the lower
adjacent end of said upper mandrel means,
a lower expander means slidably mounted on said lower mandrel
means,
an annular resilient packing body disposed on said lower mandrel
means between said shoulder and said lower expander means and
compressible into fluidtight engagement with said casing,
a lower slip means slidably mounted on said lower mandrel means for
driving said lower expander means into compressive engagement with
said packing body and upwardly wedgeable between said casing and
said lower expander means to oppose downward relaxation of said
packing body,
locking means fixedly disposed between said adjacent ends of said
mandrel means and releasable by upward movement of said upper
mandrel means from and independent of said lower mandrel means,
upper expander means slidably movable on said upper mandrel means
and supported by said locking means, and
upper slip means slidably movable about said upper mandrel means
and downwardly wedgeable between said casing and said upper
expander means to oppose upward relaxation of said packing
body.
8. The packer apparatus described in claim 7, wherein said locking
means is slidably disposed about the encompassed lower end of said
upper mandrel means and releasably fixed within said encompassing
end of said lower mandrel means.
9. The packer apparatus described in claim 8, wherein said locking
means is threadedly engaged with said encompassing upper end of
said lower mandrel means and is further adapted to collapse and
disengage from said threaded upper end thereof upon withdrawal of
said lower end of said upper mandrel means from said encompassing
upper end of said lower mandrel means.
10. The packer apparatus described in claim 9, wherein said locking
means is a segmented nut assembly having external threads for
engaging said upper end of said lower mandrel means and a
relatively smooth internal surface for slidable engagement with
said lower end of said upper mandrel means.
11. The packing assembly of claim 6 wherein said upper mandrel has
means engageable with said upper slip means upon upward movement of
said upper mandrel to permit retrieval of said upper slips and
upper expander with said upper mandrel and wherein said lower
mandrel has means engageable with said lower expander means upon
upward movement of said lower mandrel to release said lower slip
means from said wedged engagement with the casing and to permit
retrieval of said lower expander and lower slips with said lower
mandrel.
12. The packing assembly described in claim 11, further
including
pin means having one end fixedly connected to said upper end of
said lower mandrel and having the other end inserted in a
longitudinal slot in the lower end of said upper mandrel for
limiting upward movement of said upper mandrel from said lower
mandrel.
13. A well packer assembly for use in a well bore comprising:
telescopically arranged tubular members movable between
longitudinally spaced positions,
means for releasably latching said members in one of said
positions,
packing means disposed on one of said members,
first anchor means on said one member operable for gripping
engagement with the wall of a well bore and for providing a support
for said packing means,
second anchor means on said other member operable for gripping
engagement with the wall of a well bore and for providing a support
for said packer assembly, said second anchor means when in
engagement with the wall of a well bore preventing release of a
compressed packing means, said second anchor means including slip
means and expander means, means for normally interlocking said slip
means to said other member, and cooperable means between said
members for releasably supporting said expander means when said
slip means are interlocked to said other member.
Description
BACKGROUND OF INVENTION
This invention relates to well packers and the like, and more
particularly relates to permanently anchored packers which are
adapted to be retrieved without damage to either the well or the
packer.
There are many instances, such as production operations, where it
is desirable to define and segregate one portion of a borehole from
another. In those instances wherein the borehole is lined with a
steel casing or the like, this is achieved by setting a packer
assembly in the casing at such depth as may be desired.
In some instances, it may be desired that the well be "packed off"
only temporarily, wherein in many other instances it is intended
that the packer be permanently set in the well. So-called
"temporary packers" are usually designed to be wedged in the casing
in such manner as to resist movement in only one direction. This is
because retrieval of a temporary packer is usually achieved by
shifting in the opposite direction to disengage it from the
interior of the casing. On the other hand, "permanent" packers are
wedged in the casing in a manner opposing movement in either
direction. Hence, most permanently anchored packers cannot be
dislodged without damage to either the casing or the packer.
It is a common occurrence for it to become desirable to remove a
packer that has been permanently installed. Since this usually
requires a drilling operation and consequent destruction of the
packer, this may be quite costly. Moreover, it has become common
practice to construct permanent packers of drillable materials so
that they can be easily shattered by the drill bit. Although this
provides a substantial saving insofar as drilling time is
concerned, it has the disadvantage that a frangible packer may be
an inherently weaker packer. Furthermore, the fragments and other
debris from the shattered packer tend to clutter the bottom of the
borehole, and may interfere with subsequent operations. In
addition, a permanent packer is an expensive piece of equipment as
such.
There have been many attempts to provide a packer which is adapted
to be anchored immovably in the borehole, but which is also adapted
to be retrieved whenever desired without damage to either the
packer or the interior of the borehole or casing. However, none of
these retrieval permanent packers have met with complete acceptance
by the oil and gas industry.
In many cases, the packers have been both anchorable and
retrievable, but either special setting techniques or equipment
have been required to install the packer, or else special retrieval
techniques and equipment have been necessary. In these cases, it
has often cost more to retrieve such a packer than it would have
cost to drill through and destroy it. Other packers such as that
depicted in U.S. Pat. No. 3,398,795, have been capable of being
installed and retrieved by special setting and removal equipment,
however, such equipment and the packer itself are quite
expensive.
These and other disadvantages of the prior art are completely
overcome with the present invention, and novel packer means is
provided herein which is adapted to be anchored immovably in a well
casing or the like by conventional setting techniques, and which is
also adapted to be selectively retrieved by conventional retrieval
techniques and equipment without damage to either the packer
assembly or the casing.
THE INVENTION
In a preferred embodiment of the invention, a packer assembly is
provided which has a conventional elastic packing body located
intermediately of upper and lower slips and expanders. Thus, the
packer may be anchored permanently in a well casing or the like by
setting the upper slips in a conventional manner to oppose upward
movement of the packer, and by setting the lower slips in a
conventional manner to oppose downward movement of the packer in
the casing.
The packer assembly is provided, however, with a mandrel assembly
having separate upper and lower mandrel sections which may be moved
to and from each other to a limited extent. The mandrel sections
are initially held together by one or more shearpins or the like,
whereby the packer may be set in the casing in a conventional
manner. If the packer is to be retrieved, however, the upper
mandrel section is preferably drawn upward from the lower mandrel
section until means, such as a segmented nut, becomes disengaged in
a manner to thereby release the compression loading in the packing
and setting force on the upper expander and slips. Further upward
movement of the upper mandrel section will then carry the upper
slips completely free of the upper expander.
As hereinbefore stated, the upper mandrel section can be raised
independently of the lower mandrel section only a limited distance.
Thus, further upward movement of the upper mandrel section will
engage and carry the lower mandrel section with it upward through
the borehole. Since the lower slips and expander are slidably
mounted on the lower mandrel section, the lower mandrel section
will travel upward independently of the lower slips and expander a
limited distance. After this limited distance has been transversed,
however, the lower mandrel section preferably engages the lower
expander to carry it upward away from the lower slips until the
lower slips are disengaged from the casing. Thereafter, further
upward movement of the upper mandrel section will raise the entire
packing assembly through the casing without damage to or loss of
any portion of the packing assembly (except for shearpins and the
like which are severed when the packing assembly is initially set)
and without damage to the casing.
Accordingly, it is an object of the present invention to provide an
improved packing assembly which is adapted to be immovably anchored
in a casing or the like, and which is also retrievable without
damage to or loss of any portion of the assembly and without damage
to the casing.
It is further an object of the present invention to provide an
improved packing assembly which is adapted to be immovably or
permanently anchored in a casing by conventional setting
techniques, and which is also adapted to be retrieved by
conventional retrieval techniques and equipment without damage to
or loss of any portion of the packing assembly and without damage
to the casing.
These and other objects and features of the present invention will
become apparent from the following detailed description, wherein
reference is made to the figures in the accompanying drawings.
IN THE DRAWINGS
FIG. 1 is a pictorial representation, partly in cross section, of a
packing assembly embodying one form of the present invention,
wherein the packing assembly is depicted in a relaxed condition
prior to being anchored in a casing.
FIG. 2 is a pictorial representation, also partly in cross section,
of the apparatus depicted in FIG. 1, wherein the packing assembly
is depicted in a set condition after being anchored in the
casing.
FIG. 3A is a pictorial representation, also partly in cross
section, of the upper portion of the apparatus depicted in FIGS. 1
and 2, wherein the packing assembly is depicted with the upper
slips and cones disengaged by and during retrieval of the packing
assembly.
FIG. 3B is a pictorial representation, also partly in cross
section, of the lower portion of the apparatus depicted in FIGS. 1
and 2, wherein the packing assembly is depicted with the lower
slips and cones disengaged by and during retrieval of the packing
assembly.
FIG. 4 is a cross-sectional representation of a portion of the
apparatus illustrated in FIG. 1.
DETAILED DESCRIPTION
Referring now to FIG. 1, there may be seen a pictorial
representation, partly in cross section, of a packing assembly
suitable for the purposes of the present invention, and more
particularly including an upper mandrel section 3 having a slotted
portion 4 and a cam shoulder portion 5. As may be further seen, the
upper mandrel section 3 is preferably provided with inside ratchet
teeth 6 for engaging the lower end of a conventional retrieval tool
42 (not depicted in FIG. 1) and is further provided with an upper
slip carrier 7 slidably positioned about its exterior surface and
adjacent its upper end. The upper slip carrier 7 is preferably
fixedly attached to the upper mandrel section 3 by means of a
conventional shearpin 8 or other suitable means.
As further illustrated in FIG. 1, a suitable slip or slips 12 are
preferably slidably disposed about the upper mandrel section 3 and
interconnected loosely with the lower end of the upper slip carrier
7 by means of a T-connection 11 or other conventional means. It may
thus be seen that downward movement of the upper slip carrier 7
about the upper mandrel section 3 will urge the upper slips 12
downwardly upon and outwardly of an expander 13 which is also
slidably positioned upon the upper mandrel section 3. It will be
noted in FIG. 1, however, that the upper expander 13 is located
adjacent the slotted portion 4 of the upper mandrel section 3, and
is provided with an interior groove to accommodate and receive the
cam shoulder portion 5 of the upper mandrel section 3, for reasons
which will hereinafter be explained in detail.
As may further be seen in FIG. 1, the upper slip carrier 7 is
preferably provided with an interior longitudinal recess 10 for
receiving and accommodating one or more splines 9 on the exterior
surface of the upper mandrel section 3. The purpose of these
splines 9 and recesses 10 is to permit limited longitudinal
movement of the upper slip carrier 7 relative to the upper mandrel
section 3, but to prevent rotation or circumferential travel of the
upper slip carrier 7 about the upper mandrel section 3.
As may be seen, the packing assembly illustrated in FIG. 1 further
includes a lower mandrel section 20 having an enlarged or upset
abutment portion 40 at its upper end, and having a resilient
packing element 21 of conventional design mounted immediately below
the lower shoulder of the abutment portion 40. As depicted in FIG.
1, antiextrusion springs 22 may be incorporated with the resilient
member 21 for conventional reasons.
Referring again to the upper mandrel section 3, it may be seen that
this member is provided with a longitudinal slot 19 at its lower
end, and that the upper end of the lower mandrel section 20 is
provided with a suitable pin 18 which is disposed in the slot 19.
The upper end portion of the abutment portion 40, of the upper
mandrel section 3, is also preferably provided with inside threads
15 for threadedly engaging the exterior surfaces of a segmented nut
assembly 14 having smooth inside surfaces slidably abutting the
exterior of the upper mandrel section 3. It will further be noted
that when the segmented nut assembly 14 is fitted between the upper
and lower mandrel sections 3 and 20, as indicated in FIG. 1, the
nut assembly 14 provides a stop against slidable downward movement
of the upper cone 13. In addition, it should be noted that the
annular spacing 16 between the confronting surfaces of the upper
and lower mandrel sections 3 and 20 is greater immediately below
the segmented nut 14, than it is between the surfaces of the upper
and lower mandrel sections 3 and 20 which are contacted by the nut
assembly 14. Further, it will be noted that the spacing or annular
recess 16 is normally large enough to receive the components of the
segmented nut assembly 14, as will hereinafter be explained in
detail.
As indicated in FIG. 1, the upper and lower mandrel sections 3 and
20 are fixedly attached, one to the other, by means of a shear ring
17 or other suitable frangible connecting device, prior to being
run into the casing 2 which surrounds the packing assembly. As
further depicted in FIG. 1, the upper and lower mandrel sections 3
and 20 are telescoped together until the pin 18 is in abutting
relationship with the upper end of the slot 19. Accordingly, the
upper mandrel section 3 may be pulled upward by suitable means (as
will hereinafter be explained) and independently of the lower
mandrel section 20, by shearing the shear ring 17, whereupon the
upper mandrel section 3 may move upwardly until the lower surface
of the slot abuts the lower surface of the pin 18. This will create
a longitudinal enlargement of the annular recess 16, ans also
release the segmented nut assembly 14. Further upward movement of
the upper mandrel section 3 will then carry the lower mandrel
section 20 with it due to the engagement provided by the pin
18.
Referring now to the lower mandrel section 20, there may be seen a
lower expander 25 located immediately below the lower surface of
the elastic packing element 21, and in a reversed configuration
relative to the upper expander 13. The lower expander 25 differs,
however, in that it is provided with one or more splines or keys 23
which are accommodated in a suitable longitudinal slot or slots 24
in the exterior surface of the lower mandrel section 20.
Lower slips 26 are slidably positioned below the canted surface of
the lower expander 25, and are interconnected with a suitable lower
slip carrier 29 by means of a suitable T-connection 30 or the like.
As may be seen in FIG. 1, the lower slip carrier 29 is slidably
mounted on the lower end of the lower mandrel section 20, and is
preferably fixedly secured thereto by means of a snap ring 31 or
other suitable fastening device.
Although the lower slips and expander 26 and 25 are slidably
movable, one to the other, they are also preferably linked together
by a loose dovetail connection 27. Similarly, the upper slips 12
and expander 13 are preferably linked together by a loose dovetail
connection 28.
As hereinbefore stated, the packing assembly depicted in FIG. 1 is
represented as having been positioned in a suitable well casing 2,
preparatory to being anchored permanently in the casing 2.
Accordingly, conventional setting equipment comprising a tension
member 33 for pulling upward through the casing, and a compression
member 34 (shown in phantom lines) for pushing down through the
casing 2, may be utilized as illustrated. More particularly, it
will be seen that the tension member 33 is provided with a shear
ring 32 or other suitable means for engaging the lower end of the
lower slip carrier 29, while the lower end of the compression
member 34 is urged downwardly about the upper end of the upper
mandrel section 3, and against the upper end of the upper slip
carrier 7. The illustrated packing assembly may now be conveniently
installed or set in the casing 2 by driving the compression member
downwardly while pulling the tension member 33 upwardly in the
casing 2 and in opposition to downward movement of the compression
member 34.
Accordingly, when the tension member 33 is held in position,
downward pressure of the compression member 34 will urge the upper
slip carrier 7 slidably down the exterior of the upper mandrel
section 3. The shearpin 8 is first severed, and thereafter the
upper slip carrier 7 urges the upper slips 12 downwardly over the
canted surface of the upper expander 13, and outwardly into
engagement with the interior surface of the casing. Upward movement
of the tension member 33, at the same time, tends to pull the lower
slip carrier 29 upward about the lower end of the lower mandrel
section 20, thereby urging the lower slips 26 and expander 25
upwardly against the lower end of the packing element 21. In this
respect, it should be noted that the snap ring 31 is preferably
collapsible into a suitable annular groove about the lower end of
the lower mandrel section 20. Further, it should be noted that the
lower slip carrier 29 is preferably provided with an abutting
annular shoulder 39 which tends to ride over and compress the snap
ring 31 into its groove, until the shoulder 39 overrides and rises
about the snap ring 31. Upward pressure of the lower expander 25
against the packing element 21, tends to squeeze it against the
lower surface of the abutment portion 40 of the lower mandrel
section 20, to thereby expand the resilient packing element 21
outwardly and into fluidtight engagement with the inside surface of
the casing 2. During setting, the lower slips 26 are slid over the
canted surface of the lower expander 25, to urge the lower slips 26
into gripping engagement with the inside surface of the casing
2.
When the lower slips 26 have been securely engaged with the inside
surface of the casing 2, further upward movement of the tension
member 33 causes the shear ring 32 at the end of the lower slip
carrier 29 to be severed, and the tension member 33 may then be
drawn out of the packing assembly, and out of the casing 2. At this
point, the compression member 34, which is also a part of the
entire setting tool assembly (not depicted) may also be removed
from the interior of the casing 2. It may then be seen that the
upper slips oppose upward travel of the packing assembly through
the casing 2, and that the lower slips 26 oppose downward travel of
the packing assembly, and that the packing assembly is accordingly
permanently anchored in the interior of the casing 2.
Referring now to FIG. 2, there may be seen a pictorial illustration
of the apparatus generally depicted in FIG. 1, except that the
tension and compression members 33 and 34 have now been removed,
and that the lower end portion of a suitable production stinger 35
has now been inserted into the upper and lower mandrel sections 3
and 20. As may further be seen, the production stinger is provided
with a wide annular exterior groove or shoulder 37, positioned so
as to prevent inward contraction or collapse of the slotted portion
4 of the upper mandrel section 3, when the production stinger 35 is
fully inserted within the packing assembly. In this respect, it
will be noted that the production stinger 35 is also provided with
a suitable exterior shoulder 38 for being landed on an internal
canted portion of the upper mandrel section 3, immediately below
the ratchet threads or teeth 6, to stop downward travel of the
production stinger 35 when it has been fully inserted within the
illustrated packing assembly. In addition, annular seal rings 36,
of suitable configuration are preferably disposed about the
exterior surface of the production stinger 35 at its lower end. It
will thus be noted that the position of the annular expansion
shoulder 37 provides that the cam shoulder portion 5 of the slotted
portion 4 of the upper mandrel section 3, is locked within the
internal annular groove of the upper expander 13.
Referring now to FIGS. 3A and B, there may be seen pictorial
illustrations of the upper and lower portions of the packing
assembly depicted generally in FIGS. 1 and 2, but wherein the
various components are depicted in relaxed condition for
disengagement and withdrawal of the packing assembly from within
the tubing 2. In particular, it will be noted that the production
stinger 35 depicted in FIG. 2 has now been removed, and that a
suitable inside grapple-type retrieval tool 42 has been inserted
downwardly within the upper end of the upper mandrel section 3.
More particularly, it may be seen that the exterior ratchet teeth
41 located at the lower end of the retrieval tool 42 has been
thrust downwardly into the upper end of the upper mandrel section 3
to engage the ratchet teeth or threads 6 located therein.
The packing assembly depicted in the drawings may be retrieved
simply by drawing the retrieval tool 42 upward through the casing 2
after it has engaged with the ratchet threads 6 of the upper
mandrel section 3. As the upper mandrel section 3 is drawn
upwardly, the shear ring 17 breaks to disengage the upper mandrel
section 3 from the lower mandrel section 20. Thus, the upper
mandrel section 3 may now be drawn upwardly through the casing 2
independently of the other components of the packing assembly,
until the lower end of the upper mandrel section 3 engages the
lower surface of the pin 18 which is fixedly positioned within the
upper end of the lower mandrel section 20. The annular recess 16
may now be seen to be enlarged to the extent that the segmented nut
assembly 14 has now become disengaged from the interior threads 15,
and has thereupon fallen to the lower end of the annular recess 16.
This releases the compressive load on the packing 21 and releases
or removes opposition to downward travel of the lower expander 13
relative to the upper slips 12. In this respect, it should be noted
that after the production stinger 35 has been removed from within
the upper mandrel section 3 this also removes the backing which
prevents inward contraction or collapse of the slotted portion 4 of
the upper mandrel section 3. Accordingly, the upper expander 13 can
now move away from the upper slips 12, thereby disengaging the
upper slips 12 from the interior of the casing 2. Nevertheless,
true disengagement of the slips 12 from the casing 2 occurs only
when the splines 9 have moved to the upper end of the recess 10,
whereupon the splines 9 engage the upper slip carrier 7 and carry
it upwardly through the casing 2 with the upward moving upper
mandrel section 3. As hereinbefore stated, the upper slip carrier 7
is linked to the upper slips 12 by means of a suitable T-connection
11. Furthermore, the upper slips 12 are linked at their lower end
with the upper expander 13 by means of a suitable dovetail
connection 28. Accordingly, upward movement of the upper slip
carrier 7 will tend to carry the upper slips 12 and the upper
expander 13 upwardly through the interior of the casing 2, as the
upper mandrel section 3 is carried upwardly through the casing 2 by
the retrieval tool 42.
When the upper mandrel section 3 engages the pin 18 linking it to
the lower mandrel section 20, it will thereafter carry the lower
mandrel section 20 with it up through the casing 2. If the packing
21 has not fully retracted, it will be forced to do so when the
lower portion of the slot 24 engages the lower end of the key 23.
Thereafter, further upward movement of the upper and lower mandrel
sections 3 and 20 will carry the lower expander 25 out from under
the lower slips 26, thereby disengaging the lower slips 26 from the
interior of the casing 2. As hereinbefore explained, the lower
slips and expander 25 and 26 are linked together by a suitable
dovertail connection 27, and the lower slips 26 and the lower
carrier 29 are suitably linked together by means of a T-connection
30 or other suitable means. Accordingly, further upward travel of
the lower expander 25 will carry the lower slips 26 completely out
of engagement with the interior of the casing 2, and upward through
the casing 2. Upward movement of the slips 26 will, in turn,
thereupon carry the lower slip carrier 29 up through the casing
2.
Referring now to FIG. 4, there may be seen a cross-sectional
representation of a portion of the apparatus depicted in FIG. 1,
wherein there may be seen the outer or exterior surface of the
abutment portion 40 of the lower mandrel section 20 adjacent, but
spaced from the inside surface of the casing 2. As further
depicted, the segmented nut assembly 14 may be six separate nut
segments equally spaced apart and about the exterior surface of the
upper mandrel section 3, and disposed between the upper mandrel
section 3 and the inside surface of the abutment portion 40 of the
lower mandrel section 20. The tension member 33 of the setting tool
may, of course, be centrally located in the upper mandrel section 3
as depicted in FIG. 1.
It will be apparent that an important feature of the present
invention is a two-piece mandrel with a releasable support which
opposes downward travel of the upper expander 13, and that
separation of the two mandrel sections 3 and 20 disables this
support to remove the opposition to downward travel of the upper
expander 13 and to relieve compression in the packing 21.
The production stinger 35 depicted generally in FIG. 2 is generally
conventional in function and purpose, except that the expansion
shoulder 37 portion is provided for the purpose of supporting the
slotted portion 4 of the upper mandrel section 3 against collapse
when the upper slips 12 are wedged into engagement with the inside
surface of the casing 2. Accordingly, a production stinger 35 may
be used which has a special configuration for such purposes, or the
shoulder 37 may be provided as an addition to a stinger 35 of more
conventional design and function. The upper and lower slips 12 and
26 and expanders 13 and 25 may be of any conventional
configuration, except as hereinbefore specifically noted.
It will be apparent from the foregoing that many other variations
and modifications may be made in the structures and methods
described herein without substantially departing from the essential
concept of the present invention. Accordingly, it should be clearly
understood that the forms of the invention described herein and
depicted in the accompanying drawings, are exemplary only and are
not intended as limitations in the scope of the present
invention.
* * * * *