US3631927A

US3631927A - Well packer

Info

Publication number: US3631927A
Application number: US889562A
Authority: US
Inventors: David E Young
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 1969-12-31
Filing date: 1969-12-31
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04

Abstract

An improved packer is provided which is adapted to be anchored in a well casing against longitudinal movement in either direction, but which is also retrievable without damage to either the packer or the casing. The packer is equipped with conventional slips and cones located on opposite sides of a conventional elastic packing body. Separate upper and lower mandrel sections are provided with their ends abutting each other adjacent the packing body. The packer is anchored by conventional setting techniques and equipment, and may be retrieved by drawing the upper mandrel away from the lower mandrel. The compressed packing body then relaxes inwardly into the gap separating the ends of the mandrels, thereby releasing backup pressure on the cones. Thereafter, first the upper slip is drawn out of engagement with the casing, and then the lower cones and slip is carried out of engagement with the casing by further upward travel of the upper mandrel.

Description

waited States Patet New York, N.Y.

App]. No. Filed Patented Assignee WELL PACKIER 12 Claims, 4 Drawing Figs.

US. Cl

[52] 166/134, 166/125 Int. Cl E2lb23/06,

E21b 33/ l 29 Field 01 Search 166/134,

[56] References Cited UNITED STATES PATENTS 166/125 166/125 l66/134X 166/134 166/134X 3,434,538 3/1969 Kilgore et a].

Primary ExaminerDavid H. Brown Attorneys-Ernest R. Archarnbeau, William J. Beard,

Stewart F. Moore, David L. Moseley, Edward M. Roney and Wm. R. Sherman ABSTRACT: An improved packer is provided which is adapted to be anchored in a well casing against longitudinal movement in either direction, but which is also retrievable without damage to either the packer or the casing The packer is equipped with conventional slips and cones located on opposite sides of a conventional elastic packing body. Separate upper and lower mandrel sections are provided with their ends abutting each other adjacent the packing body. The packer is anchored by conventional setting techniques and equipment, and may be retrieved by drawing the upper mandrel away from the lower mandrel. The compressed packing body then relaxes inwardly into the gap separating the ends of the mandrels, thereby releasing backup pressure on the cones. Thereafter, first the upper slip is drawn out of engagement with the casing, and then the lower cones and slip is carried out of engagement with the casing by further upward travel of the upper mandrel.

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2 or 2 no.3 F164 David E.Younq INVENIUR BY g I ATTORNEYS WELL IPACKER 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 wherein 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 so 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 or tubing. 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 either to the casing or to the packer.

It is 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 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 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

7 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 instzdl 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 US. 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 complicated and expensive.

These and other disadvantages of the prior art are completely overcome with the present invention, however, and novel packer means is provided herein which may be anchored immovably in a well casing or the like by conventional setting techniques, but which may also be 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, an improved packer assembly is provided which is equipped with a conventional elastic packing body located intermcdiately of a generally conventional assembly of upper and lower slips and cones. Thus, the packer assembly may be anchored permanently in the well casing against longitudinal movement in either direction in the borehole.

An essential difference in the subject packing assembly is that the mandrel has separate upper and lower sections with abutting ends. Further, the elastic packing element or body is preferably positioned adjacent the butting ends of the two mandrel sections, when the packing assembly is installed or set in the well.

In the preferred embodiment of the invention, the upper cone is releasably secured to the upper mandrel section, and the lower cone is advanced toward the upper cone to compress the elastic packing body. This, in turn, squeezes the packing body circumferentially outward of the packing assembly and into fluidtight engagement with the inside circumference of the casing (as well as circumferentially inward against the exterior surfaces of the abutting ends of the two mandrel sections). The upper and lower slips are shifted into engagement with the inside surface of the casing in a conventional manner.

In retrieving the packer assembly, the upper mandrel is initially engaged by a retrieving tool and an upward pull is used to release the connection between the upper cone and mandrel section. The upper mandrel section is then raised a limited distance through the borehole from and independently of the lower mandrel section and the other components of the packer assembly. The compressed packing body will thereupon expand inwardly into the gap established by the separated ends of the mandrel sections, and as the packing element expands into this widening gap, this in turn releases or reduces the longitudinal back pressure against the cones.

After the upper mandrel section has been raised a substantial portion of the maximum distance it can travel from the lower mandrel section, it engages the upper slip carrier and carries it upward from the upper slip or slips. The upper slip carrier is preferably loosely interlinked with the upper slips by some conventional means such as by a dovetail or l-connection. Thus, upward movement of the upper slip carrier will carry the upper slips away from between the casing and the canted outer surface of the upper cone or cones. Since back pressure has previously been removed or released from the upper cone, the upper slips are no longer jammed or wedged between the upper cone and the inside surface of the casing. Thus, the upper slips are easily pulled from between the casing and the upper cone without the slightest damage to the inside surface of the casing.

Like the upper slips, cone, and slip carrier, the lower slips, cone, and carrier are also slidably mounted on the exterior surface of the lower mandrel section, and are also linked together in tandem by dovetail or T-connections or the like. Also, the lower cone is relieved of back pressure by relaxation of the elastic packing body, the same as with the upper cone. Thus, when the upper mandrel section is raised the full distance from the lower mandrel section, the lower mandrel section is engaged by the retrieval tool. Thereafter, further upward movement of the upper mandrel section will be accompanied by corresponding upward movement of the lower mandrel section.

As the lower mandrel section is carried up the casing, it first engages the lower cone and carries it up through the borehole. Thereafier, the lower cone engages and carries up the lower slips which have been disengaged from the casing wall by relaxation of the packing body followed by upward movement of the lower cone away from the lower slips. Finally, the lower slips engage and carry the lower slip carrier up the borehole.

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.

It is a specific object of the present invention to provide an improved packing assembly having upper and lower slips and cones separated by an elastic packing body and mounted on a pair of abutting mandrels which are separable to permit relaxation of the packing body and release of the cones and slips for retrieval from a well casing or the like.

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. I 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 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 against longitudinal movement in either direction through the casing.

FIG. 3 is a pictorial representation, also partly in cross section, of the apparatus depicted in FIGS. I and 2, and illustrating release of the upper slips from the casing during retrieval of the packer assembly from the casing.

FIG. 4 is a pictorial representation, partly in cross section, of the apparatus depicted in FIGS. 1-3, and illustrating release of the lower slips from the casing during retrieval of the packer assembly from the casing.

DETAILED DESCRIPTION Referring now to FIG. 1, there may be seen a pictorial representation, partly in cross section, of an improved packing assembly such as a production packer embodying an exemplary fonn of the present invention. In particular, there is depicted a simplified representation of a steel well casing 2 or the like, containing a packing assembly composed of an upper mandrel section 8 and a lower mandrel section 10 slidably disposed about the exterior surface of a portion of conventional setting equipment which will hereinafter be described. As may further be seen, the upper and

lower mandrel sections

8 and 10 are arranged in abutting end-to-end relationship one to the other, with an annular elastic packing body 18 disposed about the abutting ends of these two components.

As may further be seen in FIG. 1, the upper end of the upper mandrel section 8 is preferably provided with inside ratchet threads 9 and an annular exterior shoulder 24. An upper slip carrier 20 of generally conventional configuration, but with an inside upper shoulder portion 21, is slidably positioned about the upper end of the upper mandrel section 8, and preferably fixedly attached thereto by means of a shear pin 36 or other frangible link of conventional design. In addition to the upper annular shoulder 21, the upper slip carrier 20 may further be seen to preferably include a lower annular shoulder 22, with an annular space 23 therebetween for accommodating longitudinal movement of the exterior annular shoulder 24 of the upper mandrel section 8.

An upper cone or expander 16 of conventional configuration is preferably slidably mounted about the upper mandrel section 8, and in abutting engagement with the upper edge of the packing body 18. A shear ring 40, or other frangible linking device of suitable design, is provided for temporarily fixedly securing the upper cone 16 to the exterior surface of the upper mandrel section 8. Upper slips [4 of conventional design may be slidably positioned about the upper mandrel section 8, between the upper slip carrier 20 and the canted surface of the upper cone l6, and may be temporarily secured to the upper cone 16 by means of shear pins 37 or the like. In addition, the upper end of the upper slips 14 are preferably linked loosely to the upper slip carrier 20 by means of a T-connection 25, or the like, and the lower end of the upper slips 14 may be'loosely linked to the upper expander 16 by means ofa dovetail connection or the like.

As may further be seen in FIG. 1, the lower mandrel section 10 may include a series of exterior threads or grooves 13 adjacent its upper end for fixedly positioning the packing body 18 relative to the other components in the depicted packing assembly and may further include an inside annular latching groove II adjacent its lower end, for reasons which will hereinafter be explained. Further, the lower mandrel section 10 preferably includes an exterior shoulder 12 located generally intennediately of the upper and lower ends of the lower mandrel section 10.

As depicted, a lower slip carrier 26 is preferably slidably mounted on the lower end of the lower mandrel section 10, and temporarily fixed thereto by means of a shear pin 39, or the like. The lower slip carrier 26 preferably includes an inside annular latching groove 27 for engaging the lower end of the setting tool. A lower expander 17 of conventional design is preferably positioned in abutting engagement with the lower surface of the packing body 18, and lower slips 15 of conventional design are preferably positioned between the upper end of the lower slip carrier 26, and the canted lower surface of the expander 17. Shear pins 38 or the like may be provided for temporarily securing the lower slips l5 and expander 17 together, and the lower slips 15 are preferably loosely linked to the lower slip carrier 26 by means of a T-connection 29 or other suitable means. In addition, the lower slips and cones may be loosely linked together by means of a dovetail connection or the like.

As may be seen, the packing assembly depicted in FIG. I is represented as being in a relaxed condition prior to being anchored in the casing 2. In setting the packing assembly, conventional setting equipment may be used such as the cylindrical tension member or mandrel 3 having a setting sleeve 4 slidably disposed about its circumference and anchored at the upper end by means of a shear pin 5. The lower end of the setting sleeve 4 may be seen to include a plurality of collet fm gets 6 which are each provided with outwardly directed or extended tips 7 for engaging the groove 27 in the lower end of the lower slip carrier 26. The setting tool mandrel 3 may further include an annular collar 30 mounted on its exterior at a preselected location immediately below the shear pin 5. The setting tool will further be seen to include a suitable compressional member 32 (not depicted in FIG. I, see FIG. 2).

During the setting operation, the setting tool mandrel 3 and sleeve 4 are positioned substantially as illustrated in FIG. I, with the tips 7 of the collet fingers 6 engaging the groove 27 of the lower slip carrier 26 to prevent downward movement of the packingassembly. The mandrel 3 and sleeve 4 are raised through the casing 2, while the compressional member 32 is urged downwardly against the upper end of the upper slip carrier 20, thereby urging the upper slip carrier 20 downwardly against the upper slips l4, and the lower slip carrier 26 upwardly against the lower slips 15. When sufficient force has been applied in this manner, shear pins 37 and 38 will be sheared, and the upper and

lower slip carriers

20 and 26 will be urged toward each other along the exterior surfaces of the upper and

lower mandrel sections

8 and 10, respectively. This will urge the upper and lower slips I4 and 15 together against the upper and lower cones l6 and 17, respectively, thus shifting them outwardly into gripping engagement with the casing. Since the upper cone 16 is fixed to the mandrel section 8, the lower cone 17 will be advanced toward the upper cone to compress the packing element 18. Thus the packing element 18 will be squeezed outwardly against the inside surface of the casing 2. In this respect, it is convenient to provide the packing element 18 with antiextrusion springs 19 to restrict deformation of the packing element 18 to the direction of the casing 2.

When the packing element 18 has been squeezed sufficiently against the casing 2 and the upper and lower slips I4 and I5 firmly set in locking engagement with the inside surface of the casing 2, further tension force on the setting tool mandrel 3 will cause the shear pin 5 to sever, and the setting tool mandrel 3 to slide upwardly within the setting tool sleeve 4 until the tips 7 of the collet fingers 6 are disengaged from the groove 27 in the lower slip carrier 26, whereupon the collar 39 will engage the upper end of the setting sleeve 1 at the shoulder 31 and carry the setting tool sleeve 4 out of the upper and

lower mandrel sections

8 and 10. The packing assembly depicted in FIGS. 1 and 2 will then be completely installed in the casing 2, and anchored against longitudinal movement in either direction.

Referring now to FIGS. 3 and 4, there may be seen a pictorial representation of the apparatus depicted in FIGS. 1 and 2, and more particularly depicting the arrangement of various parts during retrieval of the packing assembly after it has been fully anchored as illustrated in FIG. 2. In particular, a retrieval tool 33 having provision for engaging the ratchet threads 9 at the upper end of the upper mandrel section 8, is slidably inserted within the upper and lower mandrel sections 8 and until its collet fingers 34 and gripping tips 35 extend below the lower end of the lower mandrel section 10. When the retrieval tool 33 is raised through the casing 2, the pin 40 is sheared and the upper mandrel section 8 initially moves upwardly from the lower mandrel section 10 and independently of the other components of the depicted packing assembly. As may also be seen, lifting the upper mandrel section 8 creates a gap between the abutting ends of the

mandrel sections

8 and 10, and the compressed packing element 18 accordingly relaxes laterally into this gap in the manner illustrated in FIG. 3. Expansion into the gap results in relaxation of the packing element 18, and this, in turn, removes the force which holds the upper and lower cones l6 and 17 apart. Thus, lifting the upper mandrel section 8 away from the lower mandrel section 10 releases the upper and lower cones l6 and 17 which are wedged under the upper and lower cones 16 slips 14 and 15, respectively, and this efi'ectively releases the

slips

14 and 15. After the packing element 18 is fully relaxed, however, it will revert to its normal configuration as illustrated in FIG. 4.

Further, upward travel of the retrieval tool 33 carries the upper mandrel section 8 upward through the casing 22, and independently of the upper cone 16, slips l4, and slip carrier 20, until the shoulder 24 engages the upper slip carrier 20 at the upper inside annular shoulder 21. Thereupon, upward movement of the upper mandrel section 8 will carry the upper slip carrier 20 with it. Since the upper slip carrier 20 is linked to the upper slips 14 by means of the T-connection 25, this will, in turn, carry the upper slips 14 out of engagement with the inside surface of the casing 2.

As may be seen, there is no direct link between the upper and

lower mandrel sections

8 and 10. However, when the retrieval tool 33 is moved a sufficient distance upwardly through the casing 2, the latching tips 35 of the collet fingers 34 of the retrieval tool 33 will engage the annular groove 11 inside the lower mandrel section 10, and thereafter upward travel of the retrieval tool 33 will also carry the lower mandrel section 10 with it through the casing 2.

As the lower mandrel section 10 is carried upwardly through the casing 2, it will move independently of the lower cone l7, slips 15, and slip carrier 26, until the shoulder portion 12 of the lower mandrel section 10 engages the lower cone 17 as depicted in FIG, 3. Thereafter, further upward movement of the lower mandrel section 10 will carry the lower cone 17 with it and out from under the lower slips 15. This, in turn, disengages the lower slips 15 from the inside surface of the casing 2, and since the lower cone l7 and slips 15 are preferably interconnected by means of a dovetail connection, or the like, upward movement of the lower cone 17 by the lower mandrel section 10, will carry the lower slips 15 with it. Further, the lower slips 15 are linked to the lower slip canier 26 by means of a ward movement of the lower slips 15 will carry the lower slip carrier 26 upwardly through the casing 2.

Referring to FIG. 3, there may be seen a pictorial illustration of the apparatus wherein the upper slips 14 have been disengaged from the inside of the casing 2 by upward movement of the retrieval tool 13, but wherein the lower slips 15 are still locked to the inside surface of the casing 2. Referring to FIG. 4, there may be seen an illustration of the general configuration of the apparatus depicted in FIGS. l-3, wherein both the upper and lower slips l4 and have been disengaged from the inside of the casing 2, but wherein all of the components of the depicted packing assembly are linked together to be fully recovered from the well without loss of or damage to any of the components of the depicted packing assembly.

The upper and lower slips l4 and 15 and cones l6 and 17 may be of any conventional configuration, except as hereinbefore specifically noted. The shear device 40 prevents inadvertent release of the packer due to tension force producted, for example, by the effects of temperature changes on a production stinger that is latched to the threads 9 during production operations.

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.

What is claimed is:

1. A well packer apparatus comprising:

a body member including upper and lower sections having abutting end portions;

an upper expander means and a lower expander means on said body member;

packing means on said body member and surrounding said abutting end portions and adapted to be compressed and expanded into sealing contact with a well casing by advancement of one of said expander means toward the other of said expander means;

upper and lower slip means cooperable respectively with said upper and lower expander means and adapted to be shifted outwardly thereby into gripping contact with the well casing; and

releasable means for attaching the other of said expander means to one of said sections, release of said releasable means enabling separation of said sections and release of the compression in said packing means.

2. The apparatus described in claim 1 wherein said releasable means includes a shearable member between said one expander means and said one body member section, said shearable means shearing only in response to a predetermined longitudinal force applied to said one body member section.

3. The apparatus described in claim 2, wherein said upper expander means is adapted for slidable movement relative to said upper section of said body member, said releasable means attaching said upper section to said upper expander means.

4. The apparatus described in claim 3, wherein said shearable member is adapted to shear in response to said predetermined longitudinal force upwardly applied to said upper section of said body member.

5. The apparatus described in claim 4, wherein said upper section of said body member includes means for moving said upper slip means from gripping contact with said well casing and thereby releasing said upper expander means from compressive engagement with said packing means.

6. A well packer apparatus comprising an upper mandrel section adapted to be longitudinally disposed in a well casing or the like,

a lower mandrel section also adapted to be longitudinally disposed in said well casing and disposed in abutting endto-end relationship with said upper mandrel section,

a resilient annular packing body disposed about said abutting ends of said mandrel sections and compressible into fluidtight engagement with said well casing,

upper expander means slidably mounted on and releasably secured to said upper mandrel section,

upper slip means slidably mounted on said upper mandrel section for downward wedged engagement between said upper expander means and said well casing,

lower expander means slidably mounted on said lower mandrel section, and

lower slip means slidably mounted on said lower mandrel section for urging said lower expander upwardly against said packing body to compress said packing body between said upper and lower expander means and further adapted for upward wedged engagement between said lower expander means and w'd well casing,

shear means for releasably coupling said upper expander means to said upper mandrel section, said shear means being releasable upon the application of sufiicient force to said upper mandrel section for moving said upper mandrel section relative to said lower mandrel section.

7. The apparatus described in claim 6 and including means on said upper mandrel section for moving said upper slip means out of wedged engagement between said well casing and said upper expander means after said shear means is operated to release said upper expander means from said upper mandrel section.

8. The apparatus described in claim 7, wherein said compressed packing body is located on said mandrel sections so as to expand into the space between the separated abutting ends of said mandrel sections upon upward movement of said upper mandrel section to reduce setting pressure on said upper slip means and enable release of said upper slip and expander means.

9. The apparatus described in claim 8, wherein said packing body is slidably connected to said upper mandrel section and fixedly connected to said lower mandrel section.

10. A well packer for use in a well bore comprising longitudinally extending body means which are normally functionally integral for setting of a well packer and are selectively separable for release of a well packer, packing means on said body means for sealing with respect to the wall of a well bore, said body means providing internal support for said packing means and being separable into spaced-apart sections to release such support,

anchor means on said body means above and below said packing means, said anchor means being movable relative to one another for compressing said packing means therebetween and for gripping engagement with the wall of a well bore to prevent release of compressive forces in a compressed packing means, and

means for selectively effecting a separation of said body means supporting said packing means to release compressive forces in said packing means subsequent to compression of said packing means and gripping of the wall of a well bore by said anchor means.

11. A well packer for use in a 'well bore and including longitudinally extending body means which are functionally integral during setting and sealing of said well packer and longitudinally separable for release of said well packer,

packing means on said body means for sealing with respect to a well bore,

anchor means on said body means above and below said packing means, said anchor means having expanders and slips and being movably mounted for relative movement toward one another to compress said packing means to seal with respect to a well bore and for anchoring to a well bore against movement in either direction in response to the compression forces in an expanded packing means, and

means for selectively effecting a separation of said body means after said packing means are compressed, said body means being separable in a location permitting release of the compression forces in a compressed packing means.

12. A well packer for use in a well bore comprising longitudinally extending body means which are functionally integral during setting and sealing of a well packer and are longitudinally separable into upper and lower sections for release of such well packer,

packing means on said body means for sealing with respect to a well bore, said packing means extending over said ugper and lower sections anc or means on said body means above and below said packing means, said anchor means being relatively movable between an inactive position and an active position compressing the packing means into sealing engagement with the wall of a well bore, said anchor means including slips movable between an inactive position and an active position engaging the wall of a bore well bore,

first means releasably retaining said anchor means and slips in an inactive position, said first means being releasable in response to opposing forces applied to said anchor means to permit compression of said packing means into sealing engagement with the wall of a well bore and engagement of said slips with the wall of a well bore,

second means releasably retaining one of said anchor means fixed relative'to said body means during sealing of a well packer and engagement of said slips, said second means being independently releasable to permit movement of one of said body sections relative to said one anchor means to separate said upper and lower sections and permit relaxation of the compressive forces in said packing means, and

means on said upper and lower sections for moving said slips to an inactive position in response to longitudinal movement of said separated body sections relative to said anchor means.

Claims

1. A well packer apparatus comprising: a body member including upper and lower sections having abutting end portions; an upper expander means and a lower expander means on said body member; packing means on said body member and surrounding said abutting end portions and adapted to be compressed and expanded into sealing contact with a well casing by advancement of one of said expander means toward the other of said expander means; upper and lower slip means cooperable respectively with said upper and lower expander means and adapted to be shifted outwardly thereby into gripping contact with the well casing; and releasable means for attaching the other of said expander means to one of said sections, release of said releasable means enabling separation of said sections and release of the compression in said packing means.

6. A well packer apparatus comprising an upper mandrel section adapted to be longitudinally disposed in a well casing or the like, a lower mandrel section also adapted to be longitudinally disposed in said well casing and disposed in abutting end-to-end relationship with said upper mandrel section, a resilient annular packing body disposed about said abutting ends of said mandrel sections and compressible into fluidtight engagement with said well casing, upper expander means slidably mounted on and releasably secured to said upper mandrel section, upper slip means slidably mounted on said upper mandrel section for downward wedged engagement between said upper expander means and said well casing, lower expander means slidably mounted on said lower mandrel section, and lower slip means slidably mounted on said lower mandrel section for urging said lower expander upwardly against said packing body to compress said packing body between said upper and lower expander means and further adapted for upward wedged engagement between said lower expander means and said well casing, shear means for releasably coupling said upper expander means to said upper mandrel section, said shear means being releasable upon the application of sufficient force to said upper mandrel section for moving said upper mandrel section relative to said lower mandrel section.

10. A well packer for use in a well bore comprising longitudinally extending body means which are normally functionally integral for setting of a well packer and are selectively separable for release of a well packer, packing means on said body means for sealing with respect to the wall of a well bore, said body means providing internal support for said packing means and being separable into spaced-apart sections to release such support, anchor means on said body means above and below said packing means, said anchor means being movable relative to one another for compressing said packing means therebetween and for gripping engagement with the wall of a well bore to prevent release of compressive forces in a compressed packing means, and means for selectively effecting a separation of said body means supporting said packing means to release compressive forces in said packing means subsequent to compression of said packing means and gripping of the wall of a well bore by said anchor means.

11. A well packer for use in a well bore and including longitudinally extending body means which are functionally integral during setting and sealing of said well packer and longitudinally separable for release of said well packer, packing means on said body means for sealing with respect to a well bore, anchor means on said body means above and below said packing means, said anchor means having expanders and slips and being movably mounted for relative movement toward one another to compress said packing means to seal with respect to a well bore and for anchoring to a well bore against movement in either direction in response to the compression forces in an expanded packing means, and means for selectively effecting a separation of said body means after said packing means are compressed, said body means being separable in a location permitting release of the compression forces in a compressed packing means.

12. A well packer for use in a well bore comprising longitudinally extending body means which are functionally integral during setting and sealing of a well packer and are longitudinally separable into upper and lower sections for release of such well packer, packing means on said body means for sealing with respect to a well bore, said packing means extending over said upper and lower sections, anchor means on said body means above and below said packing means, said anchor means being relatively movable between an inactive position and an active position compressing the packing means into sealing engagement with the wall of a well bore, said anchor means including slips movable between an inactive position and an active position engaging the wall of a bore well bore, first means releasably retaining said anchor means and slips in an inactive position, said first means being releasable in response to opposing forces applied to said anchor means to permit compression of said packing means into sealing engagement with the wall of a well bore and engagement of said slips with the wall of a well bore, second means releasably retaining one of said anchor means fixed relative to said body means during sealing of a well packer and engagement of said slips, said second means being independently releasable to permit movement of one of said body sections relative to said one anchor means to separate said upper and lower sections and permit relaxation of the compressive forces in said packing means, and means on said upper and lower sections for moving said slips to an inactive position in response to longitudinal movement of said separated body sections relative to said anchor means.