US2851108A - Well packer - Google Patents

Description

Sept. 9, 1958 J. A. REED 2,851,108

` WELL'PACKER Filed Nov. 25., 195e ATTORNEYS United States Patent O WELL PACKER John A. Reed, Corpus Christi, Tex., assgnor to Texas Iron Works, lne., Houston, Tex., a corporation of Texas Application November 23, 1956, Serial No. 624,102

9 Claims. (Cl. 166-139) This invention relates to new and useful improvements in oil well tools and more particularly to well packers which may be retracted and retrieved in their entirety.

Difficulties have heretofore been encountered in satisfactorily retracting the anchoring slips and expansion sleeves of well packers in order to permit removal of the packers from the well. This is particularly true of thosel danger that, not only the well packer, but a portion of thel tubing string itself will be left lodged in the hole. There have been previous attempts to solve this problem by providing for release of the packer in response to a sudden raising or lowering of the string but such method has not proved satisfactory because of the extreme stress caused by a sudden shift of the tremendous weight of the string, particularly when it is caused to fall against the well packer.

It is, therefore, an object of my invention to provide a well packer mechanism which provides for both expansion and retraction of the packing elements in response to rotation of the tool in one and the same direction to preclude uncoupling of the threaded joints along the tubing string.

` It is a further object of my invention to provide a well packer which may be set without the necessity of applying tubing weight or lowering the tubing on to the packer.

It is a further object of my invention to provide a well packer capable of resisting extreme pressures in both directions along the well casing.

It is a further object of my invention to provide a well packer which is simple and economical in construction and which is reliable in operation.

My invention includes a cylindrical body adapted to be' threaded or otherwise secured to the lower end of a string.` of tubing. Carried on the body isa sleeve member which.r moves downwardly relative to the body along one series of threads to move gripping slips into engagement, with the well casing and then to expand the packing elements# and moves upwardly along a second series of threads of opposite hand to release the slips and retract the packing: elements. Thus, both to set the well packer and to release it, the string of drill tubing is rotated in a single direction which logically is the direction of rotation necessary to insure tightness of the joints. I also provide means` to limit threading movement to the downwardly directed threads during the setting operation, which means are inactivated when further downward threading is prevented.

While my invention may differ in specific forms, I 'have shown in the accompanying drawings a typical embodiment in which the details of my invention will belbetter ICC understood when viewed in connection with the following description.

In the drawing, Fig. 1 is a view partially in section of my well packer as it is lowered into a well casing;

Fig. 2 is a view in partial section showing the packer anchored in packed-off condition against the well casing; and,

Fig. 3 is a view in partial section showing the packer after the packing elements have been released.

Referring now to the drawings in detail, my well packer 1 is shown within well bore or casing 2. The packer is lowered, and subsequently operated, by means of a string of tubing 3 which is connected by a threading coupling 4 to the upper end of a tubular body portion or mandrel 5 of the packer 1.

Near the lower end of mandrel 5 there is a radial flange or shoulder 6. For ease of assembly, the shoulder 6 may simply comprise one end of a sleeve or coupling 7 threaded or otherwise secured at the lower extremity of mandrel 5. Preferably a coupling is used to facilitate the attachment of additional pipe or another tool below the well packer 1. By means of such structure I can arrange a series of well packers in tandem, if desired.

Surrounding the lower portion of mandrel 5 is a slip housing or cage 8 bored to tit rotatably about the mandrel 5. The bore of the housing S is enlarged at 9 along the lower portion thereof in order to accommodate the sleeve or coupling 7. An annular anti-friction bearing race 10 is disposed between the shoulder 6 and the internal shoulder formed by the enlarged bore to facilitate relative rotation between mandrel 5 and slip cage 8 while preventing relative longitudinal movement therebetween. Preferably, O-rings 12 are provided to seal oil the space be-` tween carrier 8 and mandrel 5. A plurality of bowed friction springs 13 are secured to the slip cage 8 in order to resist rotation of the slip cage relative to the casing 2. A plurality of gripping slips 14 are mounted to slide radially within slots 15 in the slip cage 8, complete outward displacement of each slip being prevented by engagement of stop shoulders 16 on the slips with retainers 17 extending inwardly over the edge of slots 15.

Outward movement of the slips 14 is achieved by downward movement of expander cones 18 at the lower end of sleeve 19. Sleeve 19 is keyed at 19a to the slip cage v8.

but is slidable and rotatable on mandrel 5. Consequently, friction springs 13 will resist rotation of both slip cage 8 and sleeve 19 relative to the casing 2. A cantilever leaf spring 20 engages a recessed cam surface 21 on each slip to urge the slip inwardly when the expander cone 18 is fully raised along the mandrel 5 to its inactive position shown in Fig. 1. Threaded or otherwise secured to the upper end-of sleeve 19 is a lower wedge compressor ring 22. The sleeve 19 has an enlarged bore 23 at the upper end thereof to receive a radial iiange 24 at the lower extremity of la packer barrel 25 which is freely slidable along mandrel 5. Threaded or otherwise secured to the upper end of the packer barrel 25 is the upper wedge compressor ring 26. Carried on the packer barrel 25 is the resilient packer element 27 which is expanded outwardly by the compressor rings when they are moved toward each other. While the packer'element is shown as a simple sleeve it may, of course, be formed of several sleeves working in unison though separately expandable. This is not a material element-of my invention. Extending along packer barrel 25 is akey 25a longitudinally slidable in aligned keyways in expansible sleeve 27 and lower wedge ring 22. Thus, the upper and lower wedge rings, expander sleeve, slips and slip housing all rotate together as a unit relative to; mandrel 5. The packer barrel 25 is slidable within and.

relative to expander cone sleeve 19 in either direction to V the extent permitted by the bottom 28 of the enlarged assidua bore 23 and the radial shoulder 29 depending from lower compressor ring 22. Movement of the packer barrel in either direction after engagement with one of these elements produces; concomitant movement of thet expander t cone sleeve 19. The movement of packer barrelandf-` sleeve 19. is limitedby other means hereinafter-described.

Thus, asp-asker barrel 25 is causedto movefdown.-A wardlyfriomthe position shown in ,Fig Lthejnherent resistance. of` the packing element 27'.` to oompressiolb` transmits this motion to lower wedge compressor ring 10 27 to sealagainst the well casingZ, as showntintFiggVZ.. 20

An important feature of my invention resides inthe novel meansfor producing longitudinal` movement of upper compressor ring 26 along mandrel 5 to inuence the wellpacking operation just described. Adjacent the` upper end of mandrel 5 I provide `coarse `external screw threads 30 which` are engaged by similar coarsescrew threadsl formed internally of an` intermediate sleeve 32. Around the outside of the intermediate` sleeve 32;; isa series of coarse external screw threads, 33 engaging; with coarse internal screw threads 34 in anouterqactu-f` ating sleeve35.

It is important tonoteatthe outset thatthe=threadsf 34 on the actuating sleeve and theexternal threads 33?y on'the intermediate sleeve'must be of the handl opposite. to that of the threads 30 on the mandrel and internal of the intermediate sleeve. Thus, if the two pairs ofengag; ing'tthreads were active, in sequence and not at the same` time, rotation of the tubing string in one and the4 sameA directionwould produce downward movement ofactua-` tory sleeve 35 along mandrel 5 on one p air ofl engaging j threads and upward movement onl theA other.

Itis equally important that the threads beso disposedthat the rotation necessary to produce movement ofthe` actuator sleeve35, first to set the packerandthen: to

retract and, releaseA it,.be A only in the; directionwhich 4 tendsitotightenl the threadedcouplings alongy `the/tubingstring.

Preferably the thread connection between theinterl'ne-4 diate sleeve andthe mandrel is of the hand oppositeto the. threads at the tubing string couplings: That is,l the tubing 3 and couplings 4 haveright hand threadsy the threads 30 and 31 should be left-handed. Thus, with right-handedrotation the mandrel will tend to thread into"A the coupling 4 and out of the intermediate sleeve .32. In other words, right-hand rotation of the mandrel produces downward movement at the intermediate sleeve relative, to the mandrel. Such downward movement is` limited by a' thread stop 36 on the mandrel which defines thev fullyl expanded state at the expansion sleeve 27.-

It follows that both the threads 34 in the actuator. 60

sleeve and those external of the intermediate sleeve'l are right-handed so that actuator sleeve will tend to: moveY upwardly relative to the mandrel upon rotation'thereof.' These oppositely directed threads are; normally inacti=- vated by securing the intermediatesleeve andthe-actuating sleeve together with a shear -pin 37" so thatboth sleeves move downwardly in unison alongV mandrelA threads 30 when the tubing 3 is rotated in a direction to tighten threaded couplings along its length. Since the upper compressor ring 26 is secured to orisintegral with 70 actuatingV sleeve ring 35, it will also move'tdownwardlyH upon such rotation to.initiate the well packingoperation liereinbefore described. p

When `the intermediate sleeve 32 is moved downwardly,A

to the extent permitted by the thread stop 36, the-slipsr` 14 will have gripped the casing 2 and the packer element 27 will be fully expanded. Further rotation of the tubing string in the same direction will be resisted since the intermediate sleeve can thread no further along the mandrel and, of course, the shear pin 37 resists the tendency of the actuating sleeve 35 to thread upwardly along the opposite hand threads 33 on the intermediate sleeve. This relationship of the elements determines the fully set or packed-off condition of the well packer 1. Both, the slips14VY and the packer element 27 are fully extended andremain in such` condition until it is desired to removethepacker from the hole.

Of course, it is'possible to remove the packer from the hole by reversing the direction of rotation of the tubing string, but such reverse rotation could just as easily result in the loosening, and perhaps uncoupling of the threaded joints along the tubing string. However, my wellpacker,v may, be; removed simply by continued rotation-.fin the;samefjoint-tightening direction. pin 3.7.-is,ofv suicientstrength to retain the intermediate sleeve 32;and ,the'aetuatingpsleeve 35 in unison during ordinaryunresisted .movement of the intermediate sleeve along` the, mandrell threads 30. However, when the thread'stop-is reached the resistance maybe felt at the` conventional turn-table at ground level. Thereafter, a furtherV twist of! increased torque will shear the pin 37 and thereby actuate the` reverse threads33 and 34 toY causethe actuatingsleeve to move upwardly along the threads of-.the intermediate sleeve.

D11/operation, my well packer is lowered into the casingpasshowninFig. 1 until thel desired depth is reached.. T hen', the string of tubing is rotated in a right t hand'direction` to preclude loosening of the stringjoints through the packing element 27 and the lower compressor ring;.22:to .thet,slip, expander 18 to move the slips 14 radially to grip..thefwell,casing 2. Thereafter, further; downward movement of lower compressor ring 22.will,

beeresisted'` and :the continuedv downward movement of the upper compressor ring.26 will compress the expander element 27 outwardly to seal od any ow through the well` casing. Such compression continues until the intermediatesleeve .threads 31 engage the thread stop 36.

In this `condition the well packer can resist extremepressuresA in either direction and functionsas an ecient packingtool.

When it is desired to removemy well' packer from the holeetheoperator-need only apply additional torque in thelsame` direction in whichvthe tubing string was rotated toset the tool.

a.1suticient;.rotational twist of `the. drill string vwill shear the'pin 37 topermit relative movement between the intermediate sleeve and outer actuating sleeve 35. The

engaging threads on these two members being of the j opposite hand, further rotation in the same direction willcause the louter sleeve to move upwardly along the intermediate sleeve as shown in Fig. 3. This movement, of.course, releases compression on the expanding element and, by engagement of shoulders 29 and 24 raises the slipexpanders 18'to permit the cantilever leaf springs 20 to retract the slips 14 and permit` removal ofthe well packer.

The `foregoing disclosure and description of the invention is illustrative and explanatory thereofland various changes'in the size, shape and-materials, as well as in the details Vof vthe illustrated construction may be made,

The shear Since the internal threads of inter- Y mediate sleeve have reached the limit of theirmovement` within the scope of the claims, without departing from the spirit of the invention.

Having described my invention I claim:

l. In a well tool comprising a mandrel, a slip cage carried by said mandrel, anchoring slips normally retracted but radially extensible in said cage, cam means adapted when displaced to extend said slips to anchor said cage within a well casing, a pack-ott sleeve normally retracted but expansible about said mandrel, expansion means adapted when displaced to expand said sleeve into sealing engagement with said well casing, and an actuator axially movable along said mandrel in a setting direction to `displace said cam means and said sleeve expansion means, and in a releasing direction to release said sleeve expansion means and said cam means, the combination with said Well tool of mechanism for moving said actuator sequentially in said setting and releasing direction comprising a rst means operably connecting said mandrel and said actuator to produce movement of said actuator in said setting direction in response to rotation of said mandrel in a predetermined circumferential direction, a second means operably connecting said mandrel and said actuator to produce movement of said actuator in said releasing direction in response to rotation of said mandrel in said predetermined circumferential direction, lock means associated with said second means to prevent operation thereof, said lock means being released when movement of said actuator in said setting direction is prevented, and a tixed stop member to prevent movement of said actuator in said setting direction after said pack-o sleeve is fully expanded.

2. The combination delined in claim l wherein said first and second means comprise threaded connections of opposite hands interconnecting said mandrel and said actuator.

3. In a well tool comprisingr a mandrel adapted for connection by threads of a given hand to a tubular string, anchoring slips carried on said mandrel, said slips being normally retracted but radially extensible relative thereto, cam means adapted when displaced to extend said slips to grip a well casing, a pack-off sleeve knormally retracted but radially expansible about said mandrel, sleeve expansion means adapted when displaced to expand said sleeve into sealing engagement with said well casing,

and an actuator axially movable along said mandrel in a setting direction to displace said cam means and said sleeve expansion means, and in a releasing direction to release said sleeve expansion means and said cam means, the combination with said well tool of mechanism for moving said actuator rst in said setting direction and then in said releasing ldirection responsive to unidirectional rotation of said tubular string in the direction which tends to tighten threaded connections of said given hand, said mechanism comprising a rst threaded connection of the hand opposite to said given hand interconnecting said actuator and said mandrel for producing movement of said actuator in said setting direction, a second threaded connection of said given hand interconnecting said actuator and said mandrel to produce movement of Said actuator in said releasing direction, lock means to prevent operation of said second threaded connection, said lock means being released by rotation of said mandrel when movement of said actuator in a setting direction is prevented, and a tixed thread stop to limit positively movement of said actuator in said setting direction when said pack-off sleeve is fully expanded.

4. In a well tool comprising a mandrel adapted for threaded connection to a tubular string by unidirectional rotation thereof, a slip cage carried by said mandrel, anchoring slips normally retracted but radially extensible in said cage, cam means adapted when displaced to extend said slips to anchor said cage within a well casing, a pack-oil sleeve normally retracted but expansible about said mandrel, sleeve expansion means adapted when displaced to expand said sleeve into sealing engagement with said well casing, and an actuator ring axially movable along said mandrel in a setting direction sequentially todisplace said cam means and said sleeve expansion means,

and in a releasing direction sequentially to release said sleeve expansion means and said cam means, lthe combination with said Well tool of machanism for moving said actuator ring selectively rst in said setting direction and then in said releasing direction in response to said unidirectional rotation of said tubular string, said mechanism comprising an intermediate sleeve, threads of a given hand between said mandrel and said intermediate sleeve to produce movement of said sleeve in said setting direction, threads of the opposite hand between said intermediate sleeve and said actuator ring, a shear pin securing said actuator ring to said intermediate sleeve for movement therewith, and a rigid stop member to limit positively movement of said intermediate sleeve relative to saidv mandrel along said threads of said given hand.

connection by threads of a particular hand to a tubular string, a slip cage carried by said mandrel, anchoring slips normally retracted but radially extensible in said cage, cam means adapted' when displaced to extend said slips to anchor said cage to a Well casing, a pack-ott sleeve normally retracted but radially expansible about said mandrel, sleeve expansion means adapted when displaced to expand said sleeve into sealing engagement with said casing, and an actuator ring operative when moved in a setting direction to displace said cam means and said sleeve expansion means and when moved in the opposite vreleasing direction to release said sleeve expansion means and said cam means, the combination with said well tool of mechanism for moving said actuator ring sequentially in said setting and releasing direction in response to rotation of said tubular string in a single direction tending to tighten threaded connection of said particular hand, said mechanism comprising an intermediate sleeve, threads of said particular hand'between said intermediate sleeve and said actuator ring, threads of the hand opposite to said particular hand between said intermediate sleeve and said mandrel, releasable lock means to prevent movement of said actuator ring relative to said intermediate sleeve, said locl'` means being released by rotation of said tubular string after movement of said intermediate sleeve along said threads of said opposite hand is prevented, and a thread stop on said threads of the opposite hand to limit positively movement of said intermediate sleeve therealong.

6. In a Well tool comprising a mandrel including a right-hand threaded connection for coupling to a tubular string, a slip cage carried by said mandrel, anchorwell casing, and an actuator ring operative when moved downwardly along said mandrel .to displace said cam means and said sleeve expansion means, and when moved upwardly along said mandrel to release said sleeve expansion means and said cam means, the combination with said well tool of mechanism for moving said actuator ring sequentially in opposite directions in response to right-hand rotation of said tubular string, said mechanism comprising drag means for resisting rotation of said actuator ring relative to said well casing, separate right land left-hand threaded connections interconnecting said actuator and said mandrel, lock means to prevent operation of said right-hand threaded connection, said lock meansb'eing released in response to rotation of said tubular string when operation of said left-hand threaded connection is prevented, and a thread stop on said left-hand threaded connection to limit positively downward movement of said actuator ring.

7.D In a well toolcomprising'a mandreladapted forV right-hand threaded connection to-al tubular string,- aY

slip cagey carriedon-saidmandrel, anchoring-slips-nor mally retracted but radially extensible in saidcage, cam

saidwell'tool of 'mechanism for moving said` actuatorl downwardly andithen upwardly in'response -toright-'hand rotation of said tubular` string comprising dragmeans associated with said actuator ring to resist 'rotation thereof relative to said well casing, an intermediateV sleeve within said actuator ring, right-hand threads operably connecting said actuator ring to said intermediate sleeve,V

left-hand threads operably connecting saidintermediate sleeve to said mandrel, a shear pin securing said actuator ring and said intermediate sleevetogether, andarigid thread stop on said left-hand threads to dene the limit of downward movement of said intermediate sleeve therealong.l t

8l A well tool comprising amandreLf a.slpcag,e carried by, said'mandrel, anchoringslips normally retracted but radially` extensible in said cage, cam means adapted when displaced to extend said anchor slips to anchor said cage within a well casing, a pack-ot sleeve normally retracted but expansible about said mandrel, sleeve ex,- pansion means adapted when displaced to expand` said sleeve into sealing engagement with said well casing,; an actuator ring attached to said cam means and'saidsleeve expansion means, said actuator ring being movable along said mandrel inY a setting direction to displace saidfcam means and said sleeve expansion means, and in a releas` t ing direction to release said sleeve expansion means and Cil said cam' means,- separate threaded connections y ofop posite hands interconnecting said actuatorring and saidn mandrel, means to'permit operation' of Aonlyone of said threadedconnections at a time, andfriction meansassociatedwith said actuator ring to resist rotation thereof relative to-said well casing.

9. A well tool'comprising `a mandrel having anexternalright-hand thread at its upper extremity for-con'- nection toatubular-string adapted for right-hand rotation a slip cage rotatable on said mandrel,` drag means on said slip cage to engage frictionally a well casing tofresist rotation therebetween, anchoring slips mounted in'said cage for radialv sliding movement relative thereto, a' tapered slip expander Aslidable on saidmandrel, saidslip expander sleeve being operative when moved downwardly7` to force saidslips outwardly and anchor saidv cagewithin said well casing, apack-oif'sleeveslidable on said mandrel, the-lower circumferential edge of saidpackoff sleeve being in `abutment withA said slip expander, said pack-off sleeve being radiallyexpandable under axial compression into sealing engagement with'said well casing, an upper compressor ring engaging the upper circumferential edge of saidpack-ot sleeve, an actuator sleeve, said compressor ring being carried on saidA actu` ator sleeve, said slip,expander, pack-olf sleeve, compressor ring and actuator sleeve being rotatable on said mandrel' with said slip cage, an intermediate. sleeve, left-hand'- threads between said intermediate sleeve and said mandrel, right-hand threads between said intermediate sleeve and said actuator sleeve, a shear pin intercon` necting said actuatorsleeve and said intermediate sleeveto prevent relative movement therebetween, and a rigid` fixed thread stop to dene the lower limit of movement `of said intermediate sleeve along said left-hand threads.

References Cited in the tile of this patent UNITED STATES PATENTS 2,633,201 Clark Mar. 31, 1953 2,704,126 Davidson Mar. 13, 1955 2,715,442 Brown Aug.,l6, l955` 2,755,864 Vaughn July 24, 1956

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