US3749166A

US3749166A - Well packer apparatus

Info

Publication number: US3749166A
Application number: US00257405A
Authority: US
Inventors: D Young
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 1972-05-26
Filing date: 1972-05-26
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31

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.

Description

[45] July 31, 1973 Young [54] WELL PACKER APPARATUS 3,678,998 7/1972 Cockrell et a1. 166/134 X H51 Inventor: David Young, Friendswood, 123323 1311333 1221 11:11:11.1: 166,134 X [73] Assignee: Schlumherger Technology Corporation, New York, N.Y. Primary Examiner-David H. Brown v V Attorney-Ernest R. Archambeau, Jr., David L. [22] Filed: May 26, 1972 Moseley e a].

211 App]. No.: 257,405

[51] Int. Cl.E2lb 23/06, E2lb 33/128, E2lb 33/129 [58] Field of Search 166/120, 123, 134, 166/135, 237, 238, 216, 217

[56] References Cited UNITED STATES PATENTS 3,361,209 l/1968 Edwards 166/120 3,398,795 8/1968 Elliston.... 166/120 3,631,924 1/1972 McGill 166/123 57] 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.

20 Claims, 8 Drawing Figures Patented July 31, 1973 4 Shuts-Shoot 2 Patented July 31, 1973 FIG. 4A

4 Sheets-Sheet 5 FIG. 4B

Patented July 31, 1973 3,749,166

4 Sheets-Sheet 4 37 38 FIG. 5A

WELL PACKER APPARATUS 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 ofi" 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. 18 forming a lower continuation of FIG. 1A;

FIGS. 2 and 3 are cross-sections taken on lines 22 and 3-3 of FIGS. 1A and 18, 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 I1 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 wickets 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 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 runningin 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 l0 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 l0, 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 dis posed 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 32in 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 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 l 14 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..ln 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 down wardly 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. 413 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 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 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 48, 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 l 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 grappletype 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 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 l0 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. 58. 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 pres ent invention.

1 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.

t I t t

Claims

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.