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Publication numberUS3456723 A
Publication typeGrant
Publication dateJul 22, 1969
Filing dateJun 30, 1967
Priority dateJun 30, 1967
Publication numberUS 3456723 A, US 3456723A, US-A-3456723, US3456723 A, US3456723A
InventorsCurrent James H, Ehlert Harry C
Original AssigneeCamco Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hydraulically set well packer
US 3456723 A
Images(8)
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Description  (OCR text may contain errors)

July 22, 1969 J. H. CURRENT ETAL 3,456,723

HYDRAULICALLY SET WELL PACKER 8 Sheets-Sheet 1 Filed June 30, 1967 BY 1 56 r ,f

,mfom/E Ys July 22, 1969 J. H. CURRENT ET AL 3,456,723

HYDRAULICALLY SET WELL PACKER Filed June 30, 1967 8 Sheets-Sheet. 2

BY 56 Aid-7 TIOR NE YS July 22, 1969 J. H. CURRENT ET AL 3,456,723

HYDRAULICALLY SET WELL PACKER Filed June 30, 1967 8 Sheets-Sheet 3 TI'ORNE Y6 July 22, 1969 J. H. CURRENT ETAL 3,456.723

HYDRAULICALLY SET WELL PACKER Filed June 30, 196'? 8 Sheets-Sheet 4 f/77cm Carr ef? z" J. H. CURRENT ET AL HYDRAULICALLY SET WELL PACKER Filed June 30, 1967 8 Sheets-Sheet 5 cfa/27e; H Caf/enf J. H. CURRENT ET AL 3,455,723

HYDRAULICALLY SET WELL PACKER July 22, 1969 8 Sheets-Sheet 7 Filed June 30, 1967 INVENTORS July 22, 1969 Filed Jima so, 1967 J. H. CURRENT ET AL 3,456,723

HYDRAULICALLY SET WELL PACKER 8 Sheets-Sheet 8 I T of w ORS ATT ORNE Y United States Patent O U.S. Cl. 166-120 20 Claims ABSTRACT F THE DISCLOSURE A well `packer hydraulically set by the sequential operation of opposed pistons and provided with one-way clutches whereby the well packer may be set hydraulically without moving the tubing string. A centering sleeve for maintaining the slip segments parallel to the sleeve..A spring recessed in each slip segment to retract the slip segments from the well conduit. A one-way clutch with an external helical thread having a plurality of mating ratchet segments which are positioned about the external helical thread in reverse consecutive rotational position. An equalizing port and sealed thread in a packer releasing sub for easily releasing the packer.

BACKGROUND OF THE INVENTION The present invention relates to a well packer that is to be set in a conduit disposed in a well bore having a hydraulically set packer seal and slips, and which is retrievable therefrom.

While packers in the prior art are available in which the packer seal and 'the slips are hydraulically set, the present packer is an improvement in that the tubing string neither moves upwardly or downwardly due to the setting forces created by the hydraulic setting pressure, neither compressive or tensional forces in the tubing string will cause the packer seal to move after it has been set, the seal will remain in its fully set position regardless of differential pressures above and below the set packer and the packer seal is maintained in a set position regardless of any movement of the slips. The present invention is also directed to various other improvements such as a slip guide insuring that the slips are moved in unison while they are being expanded and retracted, improved one-Way ratchet clutches which will reduce breaking of the clutch teeth and which reduce the distance of ratching, an improved releasing sub in which is provided an equalizing port for balancing the internal and external pressure in the packer seal at the time of release and which is provided with release threads which are sealed off from contamination so that they will readily release when it is desired to retrieve the packer and slip segment springs which are positioned to prevent undesired wear when the packer is being moved downhole.

SUMMARY OF THE INVENTION The present invention relates to a well packer adapted to be set in a conduit disposed in a well bore and which is provided with a mandrel and initially retracted packing seal means and slips surrounding the mandrel in which hydraulic means are provided for setting the seal and the slips in which a one-way clutch is provided between the mandrel and a packer seal expanding sleeve and a one-Way clutch is provided between the slip expanding sleeve and a seal expanding sleeve in which the hydraulic pistons are actuated without moving the mandrel, and in which the packer seal will remain in its expanded and sealed position in spite of compressive or tensional forces in the tubing string acting on the mandrel in spite of differential pressures about the packer and independently from the packer slips.

Another object of the present invention is the pro- 3,456,723 Patented July 22, 1969 vision of a releasing sub in a well packer having an equalizing port for equalizing the pressure inside and outside the mandrel when the releasing sub is longitudinally moved upwardly from the mandrel and providing seal means between the releasing sub and the mandrel initially blocking oit the equalizing port.

Still a further object of the present invention is the provision of an improvement in a releasing sub in a well packer which threadably engages the mandrel for release therefrom by right hand rotation to release the packer in which seal means seal off the threaded connection between the sleeve and the mandrel to prevent entry of well fluid to the connection so that the connection will remain free and easily operable after an extended period of time.

Still a further object of the present invention is the provision of an improvement in a slip assembly in which a plurality of slip segments are connected at each end by dovetail shaped coacting engaging surfaces, and in which a centering sleeve is slidably positioned between the mandrel and the segments and slidable coacting engaging elements are provided on the sleeve and each segment and positioned transversely of the sleeve for maintaining the segments parallel to the sleeve so that slip segments are expanded outwardly and retracted inwardly in unison.

Still a further object of the present invention is the improvement in a slip assembly in a well packer in which a spring is `provided recessed in a slot in the face of each Slip element with the spring extending outwardly on the segment further than the outer surface of the segment so as to engage the conduit in which the packer is set and act to provide a torsional restraint to retract the segments from their conduit engaging position on release of the packer, but in which the springs extend outwardly less than the internal diameter of the conduit so as not to engage the conduit when lthe packer is initially moved into position and thereby avoid becoming worn and weakened.

Another object of the present invention is the provision of an improved one-way ratchet clutch for use between two members in a well packer and having an external helical thread on one member and a plurality of ratchet segments connected to the other member which have, when positioned in one consecutive rotational position to each other an internal helical thread on said segments adapted to fully mate with the external helica-l thread, but which are positioned about the external helical thread in the reverse consecutive rotational position thereby insuring that at least some of the ratchet segments will be in substantial gripping position with the external helical threads at all times.

Other and further objects, features and advantages will be apparent from the following description of a presently preferred embodiment of the invention given for the purpose of disclosure and taken in conjuction with the accompanying drawings.

BR'IEF DESCRIPTION OF THE DRAWINGS In the attached drawings, like character references refer to like parts throughout the several views which are las follows:

FIGURE 1 is an elevational view of the well packer of the present invention in position being lowered in a conduit in a well bore,

FIGURE 2A is an enlarged cross-sectional view of the upper portion of the present invention with the parts in position as the packer is being lowered into the well bore,

FIGURE 2B is a continuation of FIGURE 2A, showing the lower portion of the packer,

FIGURE 3A is an elevational view, partly in crosssection, of the top portion of the packer of the present invention shown in position in a well conduit with the slips in a set position,

FIGURE 3B is a continuation of FIGURE 3A showing the lower portion of the packer,

FIGURE 4A is an elevational view, partly in crosssection, of the top portion of the packer of the present invention shown in position in which the slips and the packer seal are set in position,

FIGURE 4B is a continuation of FIGURE 4A showing the lower portion of the packer,

FIGURE 5A is an elevational View, partly in crosssection, illustrating the top portion of the packer of the present invention in position in which the releasing sub has been rotated to equalize the pressure inside and outside of the packer,

FIGURE 5B is a continu-ation of FIGURE 5A showing the lower portion of the packer,

FIGURE 6A is an elevational view, partly in crosssection, illustrating the top portion of the packer of the present invention in which the releasing assembly has been backed oit" from the packer so that the packer seal may retract,

FIGURE 6B is a continuation of FIGURE 6A showing the lower portion of the packer,

FIGURE 7A is an elevational view, partly in crosssection, illustrating the top portion of the packer of the present invention in a fully retracted position,

FIGURE 7B is a continuation of FIGURE 7A illustrating the middle portion of the packer,

FIGURE 7C is a continuation of FIGURES 7A and 7B showing the lower portion of the packer,

FIGURE 8 is a cross-sectional View taken along the line 8 8 of FIGURE 2A,

FIGURE 9 is an enlarged perspective view showing the conventional positioning of the clutch elements of FIGURE 8,

FIGURE 10 is an enlarged cross-sectional View taken along line 10-10 of FIGURE 2B,

FIGURE 11 is an enlarged perspective view of the slip centering guide of the present invention, and

FIGURE 12 is a schematic elevational cross-sectional view of the clutch elements of FIGURE 8.

Referring now to the drawings, and particularly to FIGURE 1, the packer of the present invention is generally indicated by the numeral 10, and is shown being lowered into position on a pipe or running in string 12 in a conduit 14 such as a casing in a well bore. In order to actuate the packer 10 by hydraulic iluid, a suitable plugging tool 16 is connected to the lower end of the packer 10 to block the bottom of the running in string 12 and the packer 10 so that hydraulic pressure may be applied therein. The tool 16 may be, by way of example, a Camco PE-SOO pump out plug which is conventional and no further description is believed necessary.

The packer 10 includes the usual packing sealing means or packer seal generally indicated by the numeral 18 and a slip assembly generally indicated by the numeral 20, both of which are shown in their retracted position in FIGURES 1, 2A and 2B as the packer 10 is being lowered to the desired location in the casing 14.

Referring now to FIGURES 2A and 2B, the packer 10 includes a mandrel 22 which for convenience includes an upper portion 24 and a lower portion 26 secured together to provide an internal passageway 28 in communication with the pipe or running in string 12 for receiving hydraulic iluid to set the packer and includes at least one port 30 for passage of the hydraulic pressure for setting the slip assembly and the packer seal means 18.

The packing seal means 18 may include a suitable and conventional packer seal element 38, back up seal rings 40, and expander rings 42 all of which are conventional and no further description is believed to be necessary.

A top releasing assembly is generally indicated by the numeral 32 and is threadably secured to the upper mandrel 24 by a left-handed thread connection 33- and includes an upper abutment 34 for engaging the top of the packer seal means 18 and a releasing sleeve 36 slidsbly msunted be- 4 tween the mandrel 24 and the packing seal means 18, and will be more fully described hereinafter.

A lower slip cone 54 is provided secured to the mandrel 26 and positioned against the lower end of the slip assembly Z0. A hydraulically actuated slip expanding means which includes slip setting sleeve 56 is provided above the slip assembly 20 and includes an upper movable slip cone 58 and a piston 60 detined by seals 62 and 64 and is exposed to hydraulic pressure in a chamber 31 which communicates with port 30 for actuation of the piston 60 for expanding the slip assembly 20 outwardly and into engagement with the casing 14.

-A hydraulically actuated packer seal expanding means which includes packing seal setting sleeve 44 the upper end 46 of which is positioned adjacent the bottom of the seal means 18, and the lower end of which is provided with a piston 4S formed between seals 5G and 52. The piston 48 is exposed to hydraulic pressure in the chamber 31 for movement upwardly against the packer seal means 18 for setting the seal.

A one-way clutch 66, which will be more fully described hereinafter, is provided between the sleeve 56 and the sleeve 44 allowing downward movement of the sleeve 56 when hydraulic pressure is applied to the piston 60 to allow the slip assembly 20 to Vbe expanded outwardly and to allow the sleeve 44 to move upwardly relative to the sleeve 56 for preventing upward movement of the sleeve 56 relative to the sleeve 44 thereby locking the slip assembly 20 in its expanded position.

A one-way clutch S3, which would be more fully de scribed hereinafter, is provided between the sleeve 44 and the mandrel 24 allowing movement upwardly of the sleeve 44 to expand the packer seal 18, but preventing downward movement of the sleeve 44 thereby locking the packer seal 18 into an expanded position when actuated.

Thus, with the temporary plugging tool 16 in place at the bottom end of the packer 10 (FIGURE l), and with hydraulic pressure applied through the pipe 12 to the passageway 28, hydraulic fluid will ow through the port 30 and be applied against both of the opposing pistons 48 and 60. A rst releasable holding means such as a shear pin 68 is provided connected between the slip setting sleeve 56 and the seal setting sleeve 44 to prevent actuation. of the slip setting sleeve 56 until a predetermined hydraulic setting pressure has been applied after the packer has been desirably positioned in the well conduit 14. A second releasable holding means or shear pin 70 is provided between the seal setting sleeve 44 and the releasing sleeve 36 to prevent actuation of the sleeve 44 until a predetermined hydraulic pressure has been applied in the chamber 31. The shear pin 68 shears irst allowing the slip setting sleeve 56 to move downwardly carrying the upper slip cone 58 to expand the slip assembly 20 into setting engagement with the conduit 14 after which the shear pin 70 is sheared, allowing the upward movement of the seal setting sleeve 44 to compress and/ or displace the seal means 18 by the end 46 against the abutment 34 and sleeve 36 and expand the packer seal means outwardly into a sealing relationship with the conduit 14. It is noted that the one-Way ratchet clutch 66 allows the slip setting sleeve 56 to move downwardly relative to the seal setting sleeve 44, and it is noted that both the one-way clutches 53 and 66 allow the packer seal setting sleeve 44 to move upwardly relative to both the mandrel 24 and the slip setting sleeve 56, and that upon a stoppage of hydraulic pressure to the chamber 31, the packer seal 18 and the slip assembly 20 will remain in a set position by the action of the clutches 53 and 66.

The setting of the slip assembly 20 is best seen in FIG- URES 3A and 3B wherein liuid pressure is applied to the internal passageway 28, through the port 30 and against the packer seal setting piston 48 and the slip setting piston 60. Upon predetermined hydraulic pressure shear pin 68 will be sheared, and the slip setting piston 60 and sleeve 56 and will move downwardly actuating slip cone 58 toward the lower cone 54 tp move the slip assembly 20 out` wardly and downwardly into engagement with the conduit wall 14.

As best seen in FIGURES 4A and 4B, the pressure in chamber 31 continues to build up, and since piston 60 is now in a fixed position, the pressure acts against the packer seal setting piston 48 until shear pin 70 shears thereby moving the packer seal setting sleeve 44 upwardly pushing end 46 against the seal means 18 compressing and/or displacing it against the abutment 34 and sleeve 36 and outwardly into engagement with the well conduit 14 to provide a seal.

The one-way clutches 66 and 53 allow relative movement between the seal setting sleeve 44 and the slip setting sleeve 56 and between the packer seal setting sleeve 44 and the mandrel 24, respectively, and act to hold the setting sleeves 44 and 56 and thus the packer means 18 and the slip assembly 20 in an expanded set position. Thus in FIGURES 4A and 4B, the packer 10 is in a fully set position.

It is to be noted that the running in pipe 12, as the packer is hydraulically set, neither moves upwardly or downwardly due to setting forces created by hydraulic pressure and thus does not cause undesired buckling of the pipe 12. Once the packer 10 has been set, it is also noted that pressure differentials either above or below the packing means '18 will not cause any relaxation of the seal 18. Furthermore, weight may be imposed upon the pipe 12 or it may be pulled in tension after the packer is set and the compressive or tensional forces will not cause the seal 18 to relax or leak. That is, the packer means 18 and the slip assembly 20 are held in a fully set position and locked therein by the interlocking relationships between the mandrel 22, the lower cone 54, the slip assembly 20, the upper cone 58, the slip setting sleeve S6, clutch 66, clutch 53, seal setting sleeve 44, packing means 18, the upper abutment 34 and the top sub 32. The packing seal means 18 is capable of storing a great amount of energy to maintain a high sealing relationship with the conduit 14 and the packer will maintain this seal in a compressed condition. That is, the seal means 18 is maintained in a compressed position independently of the slip assembly 20 and forces acting against the packer will not release the seal means.

After the packer l10 is set the hydraulic pressure in the passageway 28 is removed. This may be done by increasing the hydraulic pressure to blow out the temporary plugging tool 16 (FIGURE 1) or other conventional methods. In any case, it is important that the one-way clutches 53 and 66 maintain the packer 10 in a fully set position independently of other moving parts so as to maintain the sealing relationship of the packer to the conduit 14. Another of the features of the present invention is the provision of an improved ratchet one-way clutch such as the one-way clutches 53 and 66. Referring now to FIGURE 9, a conventional ratchet clutch is provided by providing a plurality of ratchet segments 72 having an internal helical thread 73 which coacts with an external helical thread to provide uni-directional ratchet movement. Thus referring to FIGURES 4A and 4B the ratchet segments of clutch S3 would coact with the helical thread 55 on the mandrel 24, and the ratchet segments of oneway clutch 66 would coact with the helical thread 67 on the packer seal setting sleeve 44. The rachet segments are urged into engagement with the coacting external helical threads by yieldable retaining means or springs. Thus ratchet segments of clutch 53 are urged into engagement with thread 55 by garter springs 120, and the rachet segments of clutch 66 are urged into engagement with thread 67 by garter springs 122. Such a one-way clutch is conventional. That is, again referring to FIGURE 9, the ratchet segments 72 are conventionally manufactured with a helical thread 73 and are conventionally mounted about an external helical thread in the same consecutive rotational position as numbered 1, 2, 3, 4 in a clockwise position as shown such that the helical threaded segments 72 are in continuous alignment. However, such conventional ratchets when actuated may stop with the crest of the external helical threads with which they coact and then when the hydraulic pressure is released the coacting helical interior and exterior threads may skip several threads or may Vbreak several threads before gripping thereby providing a release in the setting force of either the seal means 18 or the slip assembly 20 where it would be undesirable and could result in the packer failing to function. Even if `the mating internal and external helical threads were not set in a crest to crest position, they would likely be set in an intermediate or non-mating position which would allow some relaxing of the setting mechanism on release of hydraulic pressure which is undesirable.

The improved ratchet clutch of the present invention is provided by positioning the segments 72 as manufactured and numbered 1, 2, 3, 4 in FIGURE 9, in a counterclockwise numbered direction in position as shown in FIG- URE 8 in a counterclockwise numbered position 1, 2, 3 4. Such positioning of the ratchet segments 72 will insure that at least one or more of the segments 72 will 'be in a closely engaging position with the mating external helical thread with which they coact thereby overcoming the disadvantages mentioned. That is, reversal of the direction of positioning the segments 72 will not prevent mating with the external helical thread, but will merely cause some of the segments to be shifted vertically so that one or more will always be in a near clutch holding position.

Thus, referring to FIGURE 12, even though ratchet segments 72 which are in numbered position 2 and 4 are in a crest position in relationship to helical threads 55, it is noted that segments 72 at positions 1 and 3 are in a fully engaged position and thus the one-way ratchet is engaged. From FIGURE 12 it is noted that at no time would all of the segments 72 be in a crest to crest relationship with the thread 5S and thus could not skip. Furthermore, even if all of the threads of the segments 72 were in intermediate positions relative to the thread 55, `the clutch would relax or release no more than one-half of the threads width thereby minimizing release.

Referring now to FIGURES 2B, 3B, 6B, 7C, 10 and 11, various improvements in the slip assembly 20 are provided. A plurality of slips 74, here shown as four, which are held in place by coacting angled dove-tail shaped engaging surfaces 76 on the end of each slip 74 and the lower slip cone 54 and the upper movable slip cone 58 whereby the slips 74 may be moved radially outwardly into engagement with the wall of the conduit 14. Thus as the upper movable slip cone 58 is moved downwardly toward the lower slip cone 54 by the action of the hydraulic piston 60 the slips 74 will be moved downwardly and outwardly so that the slip teeth 88 grippingly engage pipe 14.

However, it is important that the slips 74 move downwardly and outwardly in unison and on release transverse both upwardly and inwardly in unison and parallel to each other and the mandrel 26. Without this uniformity of movement, one slip 74 may transverse ahead of another slip and cause frictional binding in the dove-tailed coacting engaging surfaces 76 which will bind and prevent the entire slip assembly 20 from functioning. A centering Sleeve 78 is provided which is slidably mounted between the mandrel 26 and the slips 74. Slidably coacting engaging means are provided on the sleeve 78 and the slips 74 such as ears 80 on the sleeve 78 and the coacting slots 82 on the slips 74. Thus, as the slips 74 move outwardly, inwardly, downwardly, or upwardly, the centering sleeve 78 is slidably moved along the mandrel 26 and the slip segments 74 are Iable to move inwardly and outwardly on the ears 80 to maintain the slips parallel to each other and thus move in unison without cocking or binding in the dove-tail slots. In addition, the centering sleeve insures centering. of the packer in the conduit when the slips are set.

Another feature of the slip assembly 20 is the provision of energy storing means such as springs 84 provided in recess slots 86 in the face of each of the slip segments 74. The springs 84 extend outwardly in their extended or uncompressed position -a radial distance from the packer further than the outward surface or teeth 88 on the slips 74. However, the springs 84 extend outwardly less than the internal diameter of the conduit 14 and thus do not engage the cond-uit when the packer is initially moved into setting position, and thus the springs are not weakened by frictional contact and wear upon running the packer 10 to its setting location. The springs 84 serve no function during the setting operation and as shown in FIG- URE 3B are compressed into the recessed slots 86 when the slip assembly 20 is set. However, when the packer is released as will be more fully described hereinafter, the energy storing means or springs 84 act as torsional restraints against which the releasing sub 32 operates to fully retract the slip assembly 20 out of engagement with the interior wall of the conduit 14.

Referring now to FIGURES l, 2A and 2B, the top releasing assembly 32, which is connected to the upper mandrel portion 24 includes a top sub 90 connected to an unloader sleeve 92 by a left handed thread connection 94 which is in turn connected to the left hand threaded connection 33, a bearing housing 96, bearings 98, the housing 96 being connected to the abutment 34 vand the releasing sleeve 36. The top sub 90 is connected to the pipe or running in string 12 by any suitable connection (not shown) such as a conventional box and pin connection. A shear pin 100' is provided between top sub 90 and the unloader sleeve 92. An equalizing port 91 is provided in the top sub 90 and as shown in the running in position in FIGURE 2A, is sealed by seal 93 preventing commmunication at this time between the well fluids and/or gases inside and outside of the packer 10.

It is also noted that in the running in position the seals 95, 97 and 99 seal oi the threaded connection 33 and the bearings 98 from contamination with well iluids inside or outside of the packer so that the threaded connection 33 may be packed with grease and thus even though the packer remains in -a set position in the well bore for an extended period of time, the threaded connection 33 will not become frozen but will remain operable for release of the packer.

As previously mentioned, the packer is shown in its set position in FIGURES 4A and 4B. When it is desired to release the packer 10, the pipe or running in string 12 is rotated in a right-hand direction shearing the shear pin 100 allowing rotation of the top sub 90 relative to the unloader sleeve 92 through the left-handed thread connection 94 moving the equalizing port 91 upwardly past the top end of the mandrel 24 thereby providing a lluld communication between the inside and outside of the packer 10 and thus above and below the packer seal means 18, as best seen in FIGURES 5A, to equalize any differential pressure that may exist above and below the seal means 18. Further right-hand rotation of the top sub 90 will bring coacting engaging shoulders 104 and 102, which are on the top sub 90 and the unloader sleeve 92 respectively, into engagement whereby further right-hand rotation of the top sub 90 will unthread the threaded connection 33 by rotating unloader sleeve 92 which may be more easily rotated because of the bearings 98, even though the sealing energy stored in the packing means 18 presses against the abutment 34 and the unloader sleeve 92 through bearings 98.

As best seen in FIGURE 6A, as the unloader sleeve 92 moves upwardly it carries the housing 96 and the abutment 34 upwardly away from the seal means 18 t0 release the setting force on the seal means 18 allowing the seal 18 to resiliently retract away from the sealing relationship with, the interior of the wall 14.

Thus the right-handed rotation of the pipe 12 and the releasing assembly 32 has now retracted the packer seal 18 and is ready to release the slip assembly 20. As the right-hand rotation is continued carrying the abutment 34 upwardly, the releasing sleeve 36 is slidably carried upwardly until an engaging shoulder 106 on the releasing sleeve 36 engages a shoulder 108 on the seal setting sleeve 44. Continued right-hand rotation of the pipe 12 and releasing assembly 32, as best seen in FIGURES 6A, 6B, 7A, 7B, and 7C will continue with rotation of the releasing assembly 32 and movement upwardly relative to the mandrel 24 through the threaded connection 33 moving the releasing sleeve 36 upwardly which now carries the seal setting sleeve 44 upwardly as the one-way clutch 53 ratchets upwardly against the mandrel 24, and the seal setting sleeve 44 ratchets upwardly past the oneway clutch 66. Upward movement of the seal setting sleeve 44 continues until coacting mating shoulders 112 and (FIGURE 7B) on the packer setting sleeve 44 and on the slip setting sleeve S6, respectively, are engaged. Continued upward movement of the sleeve 44 and thus the sleeve 56 carries the upper movable slip cone 58 away from the lower slip cone 54 to allow the slips 74 to be retracted away from the interior wall of the conduit 14.

It is to be noted that as the right-handed rotation continues carrying the slip setting sleeve 56 upwardly, the springs 84 act against the inside of conduit 14 to provide a torsional restraint so the slips may be mounted to a retracted position. Since the right-hand rotation for re leasing the packer acts against the engagement of the slip assembly 20 with the conduit 14 further releasing of the slip setting sleeve 56 and retraction of the slip segments 74 would not occur once the slip segments have backed away from the interior wall of the conduit 14 in the absence of the springs 84. Also, it is obvious that the internal diameter of the conduit 14 is not sized exactly the same throughout its entire length. Therefore, in the absence of the springs 84, the slips 74 would retract only a small distance, and when the packer was being longitudinally withdrawn upwardly throughout the conduit 14, the slips 74 would encounter other sections of a smaller diameter and would lock into position causing possible damage and would again require that the packer be released from its set location by further righthand rotation. However, the springs 84 act as bow strings aganist which the right-hand rotation of the releasing sub 32 may continue for carrying the releasing sub assembly 32, the slip setting sleeve 56, and the upper cone 58 upwardly, in order that the slips 74 may be retracted a sufficient distance to clear any variations in the internal diameter of the conduit 14 and thus the packer may be lifted to the surface of the well bore clear of the conduit.

In operation, the packer 10 is connected to a pipe running in string 12 and includes provision of a suitable plugging tool 16 (FIGURE 1) connected to and closing the bottom thereof to allow a hydraulic pressure to be built up internally of the running in string 12 and in the internal passageway 28 of the packer 10. The packer 10 is lowered to the desired setting location in the conduit 14, a plug is provided and pressure is applied down the tubing string 12 from the surface which pressure passes through port 30 into the chamber 31 and applies a hydraulic force against the opposing packer seal setting piston 48 and slip setting piston 60'. Initially, shear pins 68 and 70 prevent movement of the piston 48 and 60. Upon a predetermined hydraulic pressure, the iirst shear pin and/ or pins 68 shear allowing the slip setting piston 60 to move downwardy moving the upper slip cone 58 and moving the upper slip cone 58 toward the lower slip cone 54 and moving the slips 74 out into a gripping relationship with the interior wall of the conduit 14. Because of the centering sleeve 78 the slips will move in unison without any cocking and inadvertent locking action and will centralize the packer. Once the slip assembly is set, further downward movement of the slip setting piston 60 is prevented and the second shear pin and/or pins 70 shear allowing the packer seal setting piston 48 to move upwardly and the seal setting sleeve 44 through end 46 pushes the packer seal means 18 against the upper abutment 34 which is xed to set the packer seal in a sealing relationship between the interior wall of the conduit 14 and the exterior surface of releasing sleeve 36. The sleeves 44 and 56 now hold the seal means 18 and the slip setting assembly 20 in a set position through the one-way clutches 53 and 66. And the setting pressure may be removed and the packer will remain in its set position.

When it is desired to release the packer the string 12 is rotated to the right shearing pin 100 and allowing the top sub 90 to rotate upwardly until the equalizing port 91 is above the upper end of mandrel 24 to equalize any diierential pressure above and below the packing means 18. Further right-hand rotational movement carries the unloading sleeve 92 upwardly along with the abutment 34 to release the setting pressure in the seal means 18 and the seal is able to retract from the wall of the conduit 14.

Further rotational movement of the releasing sub assembly 32 will also carry the releasing sleeve 36 upwardly which will engage the packer seal setting sleeve 44 which in turn will engage and carry the slip setting sleeve 56 upwardly to move the setting cone 58 away from the lower cones 54 allowing the slips 74 to be retracted from engagement with the interior wall of the conduit. The packer is then in a fully released position as best seen in FIGURES 7A, 7B, and 7C and may be longitudinally lifted and removed from the conduit 14.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While a presently preferred embodiment is given for the purpose of disclosure, numerous changes in the details of construction and arrangement of parts may be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention and the scope of the appended claims.

We claim:

1. In a well packer adapted to be set in a conduit disposed in a well bore having a mandrel, an initially retracted packing seal means surrounding the mandrel, an abutment above and adjacent the seal means, a slip means surrounding said mandrel and positioned below said packing seal means, means for expanding the slip means into engagement with the conduit, the improvement comprising,

packing seal expanding means surrounding said mandrel for moving away from the slip means and toward the packing seal means for expanding said packer seal means into engagement with the conduit, one-way clutch means lbetween the mandrel and said packer seal expanding means allowing one-way movement of the packer seal expanding means toward Vthe packer seal means whereby the seal means can be held in an expanded position independently of the slip means, means about the mandrel longitudinally -movable relative to the mandrel for relatively moving the abutment and the packer seal expanding means away from each other for releasing the packer seal means, and

means for retracting the slips from engagement with the conduit.

2. A well packer adapted to be set in a conduit disposed in a well bore comprising,

a mandrel,

an initially retracted packing seal means surrounding said mandrel,

abutment means connected to the mandrel on one side of the packer seal means preventing movement of the packer seal means in the direction of said abutment during and after expansion of said seal means but movable for releasing the packer,

slip means surrounding said mandrel,

hydraulic actuated slip expanding means surrounding the mandrel for moving away from said packing seal means and toward said slip means expanding said slip means into engagement with said conduit,

one-way clutch means connected to the slip expanding means for allowing one-way movement of the slip expanding means to move toward the slip means,

hydraulic actuated packing seal expanding means surrounding said mandrel for moving away from said slip means and toward said packing means for expanding said packer means into engagement with said conduit,

one-way clutch means connected to the packer expanding means for allowing one-way movement of the packer seal expanding means toward the packer seal means,

means about the mandrel longitudinally movable relative to the mandrel for relatively -moving the abutment and the packer seal expanding means away from each other for releasing the packer seal means, and

means for retracting the slips from engagement with the conduit.

3. A well packer adapted to be set in a conduit disposed in a well Ibore comprising,

a mandrel,

an initially retracting packing seal means surrounding said mandrel,

abutment means connected to the mandrel on one side of the packer seal means preventing movement of the packer seal means in the direction of said abutment during and after expansion of said seal means but movable for releasing the packer,

slip means surrounding said mandrel and positioned below said packing seal means,

hydraulically actuated packer seal expanding means surrounding the mandrel for moving away from said slip means and toward said packing seal means for expanding said packer seal means into engagement with said conduit,

one-way clutch means between the mandrel and said packer seal expanding means allowing one-way movement of the packer seal expanding means toward the packer seal means,

hydraulically actuated slip expanding means surrounding said mandrel and a portion of the packer seal expanding means,

one-way clutch means between the slip expanding means and said packer expanding means allowing one-way movement of the slip expanding means toward said slip means,

means connected to the packer expanding means preventing setting of the packing means until the slip means have been set,

means about the mandrel longitudinally movable relative to the mandrel for relatively moving the abutment and the packer seal expanding means away from each other for releasing the packer seal means, and

means for retracting the slips from engagement with the conduit.

4. The apparatus of claim 3 including,

an abutment member surrounding the mandrel and positioned against the packing means,

a sleeve threadably engaging the mandrel for release therefrom fby right hand rotation, said sleeve engaging said abutment member whereby said abutment member may be moved away from the packing means for release thereof, and

seal means sealing oi the threaded connection between the sleeve and the mandrel for" preventing the entry of well fluid to the connection.

5. The apparatus of claim 3 wherein said slip means includes,

a plurality of slips surrounding the mandrel,

dove-tailed shaped coacting engaging surfaces on each end of the segments and the supporting means at each end of the segments,

a centering sleeve slidably positioned between the mandrel and the segments,

slidable coacting engaging lmeans on the sleeve and each slip positioned transversely of the sleeve for maintaining the slips parallel to the sleeve as the slips are expanded outwardly and retracted inwardly.

6. The apparatus of claim 3 wherein the slip means includes,

a plurality of slips surrounding the mandrel,

each of said slips having an' energy storing means extending outwardly from the slips further than the outer surface of said slips, but said energy storing means extending outwardly less than the internal diameter of the conduit so as not to engage the conduit when the packer is initially moved into the conduit.

7. The apparatus of claim 3 wherein the one-way clutch between the mandrel and said packer seal expanding means includes,

an external helical thread on the mandrel,

a plurality of ratchet segments having when positioned in one consecutive rotational position to each other an internal helical thread on said segment sized to mesh with said external helical thread, but which are positioned about the external helical thread in a reverse consecutive rotational position, and

yeldable retaining means afbout said segments yieldably urging said segments into engagement with the external helical thread.

8. The apparatus of claim 3 including,

a releasing sub movably connected to the mandrel for releasing the packing seal means, and

a releasing sleeve connected to the releasing sub and adapted to engage the packer expanding means and release the slip expanding means.

9. The apparatus of claim 8 including,

an equalizing port in the releasing sub for equalizing the pressure inside and outside said mandrel and thus on either side of the packing seal means when the releasing sub is longitudinally moved upwardly from the mandrel, and

seal means between the releasing sub and the mandrel initially blocking off the equalizing port.

10. A well packer adapted to be set in a conduit for closing a well bore comprising,

a mandrel,

an initially retracted packing seal means surrounding said mandrel,

slip means surrounding said mandrel and positioned below said packer seal means,

hydraulically actuated packer seal expanding means surrounding the mandrel for expanding said seal means into engagement with said conduit,

one-way clutch means between the mandrel and said seal expanding means allowing one-way movement of the seal expanding means in a direction to expand the seal means,

hydraulically actuated slip expanding means surrounding said mandrel and a portion of the seal expanding means,

one-way clutch means between the slip expanding means and said seal expanding means allowing one-way -movement of the seal expanding means in a direction to expand the slip means,

releasable holding means connected to the slip expanding means for preventing setting of the slip means until a predetermined hydraulic pressure has been applied against the slip expanding means,

means connected to the packer seal expanding means 12 preventing setting of the seal expanding means until the slip means have been set,

coacting shoulders between the seal expanding means and the slip expanding means positioned so that when the seal expanding means is lifted sufficiently the shoulders will contact and the slip expanding means will disengage the slip means, and

a releasing sub movable connected to the mandrel and engageable with the packer expanding means for releasing the packer seal means and the slip means when longitudinally moved relative to the mandrel.

11. A well packer adapted to be set in a conduit disposed in a well bore comprising,

a mandrel,

an initially retracted packing seal means surrounding said mandrel,

slip means surrounding said mandrel and positioned below said packing seal means,

an abutment member surrounding the mandrel against which the top of the packing seal means is engaged,

a seal expanding sleeve surrounding the mandrel for movement toward said packing means for expanding said packing seal means into engagement with the conduit,

one-way clutch means between the mandrel and said packer expanding sleeve allowing one-way movement of the packer expanding sleeve upwardly, a slip expanding sleeve surrounding said mandrel and a portion of the seal expanding sleeve,

one-way clutch means between the slip expanding sleeve and the seal expanding sleeve allowing one-way movement of the slip expanding sleeve downwardly,

opposing pistons inside of said slip expanding sleeve and surrounding said mandrel, one of which is connected to the slip expanding sleeve and one of which is connected to the seal expanding sleeve,

releasa'ble holding means connected to the slip expanding sleeve for preventing the setting of the slip means until a predetermined pressure is applied against the opposing pistons, and

means connected to the seal expanding sleeve preventing setting of the packer means until the slip means have been set, and

a releasable sub connected to said abutment and engageable with the seal expanding sleeve for releasing the packing seal means `and the slip means.

12. In a well packer having an initially retracted packing seal means and initially retracted slip means surrounding a mandrel and adapted to be set in a conduit in a well bore, the improvement in a releasing assembly comprismg,

an abutment member surrounding the mandrel against which the packing seal means is engaged,

an unloader sleeve threadably engaging the mandrel and engaging the abutment member,

a top sub threadably engaging the unloader sleeve,

coacting shoulders on the unloader sleeve and on the top sub whereby rotating the top sub will rotate the unloader sleeve after engagement of the coacting shoulders,

4an equalizing port in the top sub for equalizing the pressure inside and outside said mandrel when the top sub is longitudinally moved away from the mandrel before releasing the energy stored in the seal means,

seal means between the top sub and said mandrel initially blocking olf the equalizing port,

seal means sealing ol the threaded connection Ibetween the unloader sleeve and the mandrel.

13. In a well packer having an initially retracted packing means and initially retracted slip means surrounding a mandrel and adapted to be set in a conduit in a well bore, the improvement in a slip assembly comprising,

a plurality of unitary slips surrounding the mandrel,

wedge shaped slip supporting means on each end of the segments which when moved relative to each other expand the slips outwardly into engagement with the conduit,

dove-tail shaped coacting engaging surfaces on each end of the slips and on the supporting means at the end of the slips,

a centering sleeve slidable at all times relative to and surrounding the `tmandrel,

engaging means on the sleeve and each slip for maintaining the longitudinal movement of all of the unitary slips in unison as the segments are moved outwardly and inwardly.

14. In a well packer having a packing means and a plurality of slip segments mounted on a mandrel and adapted to be set in a conduit in a well bore, the improvement in a slip assembly comprising,

wedge shaped slip supporting means on each end of the slips which when moved toward each other expand the slips outwardly into engagement With the conduit,

each of said segments having an energy storing means in the outer face thereof, said energy storing means in its expanded position extending outwardly from the segments further than the outer surface of said slips so as to engage the conduit so the supporting means can be moved away from each other, but said energy storage means extending outwardly less than the internal diameter of the conduit when the packer is initially moved into the conduit.

15. In a well packer having a packing means and a plurality of unitary slips surrounding a mandrel and adapted to be set in a conduit in a well bore, the improvement in a slip assembly comprising,

wedge shaped slip supporting means on each end of the slips which when moved toward each other will expand the slips in unison outwardly into engagement with the conduit,

dove-tailed shaped coacting engaging surfaces on each end of the slips and the supporting means at the end of the slips,

a centering sleeve slidably positioned between the mandrel and the slips,

slidable engaging means on the sleeve for maintaining the slips parallel to the sleeve as the slips are expanded outwardly and inwardly,

each of said slips having a spring which in their expanded position extending outwardly from the slips further than the outer surface of said slips but said springs extending outwardly less than the t internal diameter of the conduit when the packer is initially moved into the conduit.

16. In a well packer having seal means and a plurality of slip segments mounted on a mandrel and adapted to be set in a conduit in a well bore, the improvement in a one-way clutch for holding one member of the packer relative to another member while permitting one-Way movement in the second direction comprising,

an external helical thread on one of said members,

a plurality of ratchet segments connected to the other 1 member, having when positioned in one consecutive rotational position to each other an internal helical thread on said segments, but which are positioned about the external helical thread in a reverse consecutive rotational position, and

yieldable retaining means about said segments yieldably urging said segments into engagement with the external helical thread.

17. A well packer adapted to be set in a conduit exposed in a well bore comprising,

amandrel,

an initially retracted seal means surrounding said mandrel,

slip means surrounding said mandrel and positioned below said seal means,

said slip means including,

a plurality of slips surrounding the mandrel,

wedge shaped slip supporting means on each end of the slips which when moved toward each other move the slips outwardly into engagement with the conduit,

dove-tail shaped coacting engaging surfaces on each end of the slips and the supporting means at the end of the slips,

a centering sleeve slidably positioned between the mandrel and the slips,

slidable engaging means on the sleeve and the slips for maintaining the slips parallel to the sleeve as the slips are expanded outwardly and inwardly,

each of said slips having a spring receiving slot i in the space thereof,

a spring in each slot, said spring in its expanded position extending outwardly from the slips further than the outer surface of such slip, but said springs extending outwardly less than the packer is initially moved into the conduit,

a releasable sub including,

an abutment member surrounding said mandrel and positioned about the packing means,

an unloader sleeve threadably engaging the mandrel and engaging the abutment member,

a top sub threadably engaging the unloader sleeve,

coacting shoulders on the unloader sleeve and on the top sub whereby rotating the top sub will rotate the unloader sleeve after engagement of the coacting shoulders,

an equalizing port in the top sub which equalizes the pressure inside and outside said mandrel when the top sub is longitudinally moved away from the mandrel,

seal means between the top sub and said mandrel initially blocking off the equalizing ports,

seal means sealing olf the threaded connection between the unloader sleeve and the mandrel,

a seal expanding sleeve surrounding the mandrel for movement toward said packing means for expanding said packing means into engagement with the conduit,

one-way clutch means between the mandrel and said seal expanding sleeve allowing one-way movement of the seal expanding sleeve upwardly,

a slip expanding sleeve surrounding said mandrel and a portion of the seal expanding sleeve,

one-way clutch means between the slip expanding sleeve and the seal expanding sleeve allowing one-way movement of the slip expanding sleeve downwardly,

each of said one-way clutch means including,

an external helical thread,

a plurality of ratchet `segments having when positioned in one consecutive rotational position to each other, an internal helical thread on said segment sized to match the said external helical thread, but which are positioned about the external helical threads in a reverse consecutive rotational position, and

yieldable retaining means about said segments yieldably urging said segments into engagement with the external helical thread,

hydraulic means connected to said slip expanding sleeve and said packer expanding sleeve for movement of said sleeve oppositely to each other,

means connected to the seal expanding sleeve preventing setting of the seal means until the slip means have been set.

18. A well packer adapted to be set in a conduit disposed in a well bore comprising,

amandrel, an initially retracted packing seal means surrounding said mandrel,

abutment means connected to the mandrel on one side of the packer seal means preventing movement of the packer seal means in the direction of said abutment `during and after expansion of said seal means but movable for releasing the packer,

slip means surrounding said mandrel and positioned below said packing seal means,

packer seal expanding means surrounding the mandrel for moving away from said slip means and toward said packing seal means for expanding said packer seal means into engagement with said conduit,

one-way clutch means between the mandrel and said packer seal expanding means allowing one-way movement of the packer seal expanding means toward the packer seal means,

slip expanding means surrounding said mandrel and a portion of the packer seal expanding means,

one-way clutch means between the slip expanding means and said packer expanding means allowing one-way movement of the slip expanding means toward said slip means,

means about the mandrel longitudinally movable relative to the mandrel for relatively moving the abutment and the packer seal expanding means away from each other for releasing the packer seal means, and

means for retracting the slips from engagement with the conduit.

19. A well packer adapted to be set in a conduit disposed in a well bore comprising,

a mandrel,

an initially retracted packing seal means surrounding said mandrel,

abutment means connected to the mandrel on one side of the packer seal means preventing movement of said packer seal means in the direction of said abutment during and after expansion of said seal means, but movable for releasing the packer,

slip means surrounding said mandrel and positioned on the second side of said packing seal means preventing either upward or downward movement when engaged with the conduit,

packer seal expanding means surrounding the mandrel and moving away from said slip means and toward said packing seal means for expanding said packer seal means into engagement with said conduit,

one-way clutch means between the mandrel and said packer seal expanding means allowing one-way movement of the packer seal expanding means toward the packer seal means,

slip expanding means surrounding said mandrel and a portion of the packer seal expanding means,

one-way clutch means between the slip expanding means and said packer expanding means allowing one-way movement of the slip expanding means toward said slip means,

means about the mandrel longitudinally movable relative to the mandrel for relatively moving the abutment and the packer seal expanding means away from each other for releasing the packer seal means, and

means for retracting the slips from engagement with the conduit.

20. The apparatus of claim 19 wherein the slip means are positioned below the packing seal means.

References Cited UNITED STATES PATENTS 2,715,441 8/1955 Bouvier 166-217 X 2,982,358 5/1961 Brown 166-120 3,142,338 7/1964 Brown 166-12() 3,142,339 7/1964 Brown et al. 166-122 3,211,227 lll/1965 Mott 166-120 3,215,207 1l/l'965 Sizer 166--134 X 3,236,309 2/ 1966 Conrad 166-120 3,244,233 4/ 1966 VillalOn 166-134 X 3,344,861 10/1967 Claycomb 166-120 DAVID H. BROWN, Primary Examiner U.S. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2715441 *May 24, 1951Aug 16, 1955Dresser IndBridging plug
US2982358 *Sep 21, 1956May 2, 1961Cicero C BrownHydraulic set packer
US3142338 *Nov 14, 1960Jul 28, 1964Brown Cicero CWell tools
US3142339 *Jun 30, 1958Jul 28, 1964Brown Oil ToolsHydraulically-actuated well packers
US3211227 *Jun 27, 1962Oct 12, 1965Cicero C BrownRelease mechanism for well equipment
US3215207 *Sep 20, 1962Nov 2, 1965Otis Eng CoWell tools
US3236309 *Jul 9, 1962Feb 22, 1966Martin B ConradRetrievable packer holddown device
US3244233 *Apr 4, 1963Apr 5, 1966Halliburton CoRetrievable bridge plug
US3344861 *May 13, 1965Oct 3, 1967Baker Oil Tools IncStage set well packers
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3520361 *Jan 22, 1969Jul 14, 1970Kiva CorpWell packer with slip and drag block assembly
US3603388 *Feb 4, 1970Sep 7, 1971Camco IncRetrievable well packer
US3625281 *Apr 23, 1969Dec 7, 1971Rockwell Mfg CoWell completion method and apparatus
US3643737 *Nov 27, 1970Feb 22, 1972Camco IncSlip assembly for a well tool
US3746093 *May 26, 1972Jul 17, 1973Schlumberger Technology CorpReleasable locking system for a well tool
US3783941 *Nov 22, 1971Jan 8, 1974Schlumberger Technology CorpAnchoring mechanism for a well tool
US3850250 *Sep 11, 1972Nov 26, 1974Halliburton CoWellbore circulating valve
US3930540 *Oct 10, 1974Jan 6, 1976Halliburton CompanyWellbore circulating valve
US4044826 *May 17, 1976Aug 30, 1977Baker International CorporationRetrievable well packers
US4156460 *Nov 3, 1977May 29, 1979Baker International CorporationRetrievable double grip well packer
US4263968 *Mar 11, 1980Apr 28, 1981Camco, IncorporatedHydraulic set and straight pull release well packer
US4352394 *Aug 1, 1980Oct 5, 1982Trw Inc.Cable-suspended well pumping systems
US4393929 *Feb 17, 1981Jul 19, 1983Ava InternationalWell packers and slip assemblies for use therewith
US4637469 *Aug 6, 1984Jan 20, 1987Dresser Industries, Inc.Apparatus and method of well preparation for chemical treatment of produced fluids
US4681160 *Nov 12, 1985Jul 21, 1987Dresser Industries, Inc.Apparatus for securing a measurement-while-drilling (MWD) instrument within a pipe
US4921045 *Dec 6, 1985May 1, 1990Baker Oil Tools, Inc.Slip retention mechanism for subterranean well packer
US5000265 *Jan 23, 1990Mar 19, 1991Otis Engineering CorporationPacking assembly for use with reeled tubing and method of operating and removing same
US5146994 *Dec 27, 1990Sep 15, 1992Otis Engineering CorporationPacking assembly for use with reeled tubing and method of operating and removing same
US5181570 *May 10, 1984Jan 26, 1993Mwl Tool CompanyLiner hanger assembly
US5207272 *Sep 29, 1992May 4, 1993Camco International Inc.Electrically actuated well packer
US5226491 *Sep 29, 1992Jul 13, 1993Camco International Inc.Solenoid operated blanking block valve
US5230383 *Sep 29, 1992Jul 27, 1993Camco International Inc.Electrically actuated well annulus safety valve
US5236047 *Oct 7, 1991Aug 17, 1993Camco International Inc.Electrically operated well completion apparatus and method
US5257663 *Sep 29, 1992Nov 2, 1993Camco Internationa Inc.For use in a well
US6202747Aug 31, 1999Mar 20, 2001Schlumberger Technology CorporationHydraulic well packer and method
US6349772 *Nov 2, 1998Feb 26, 2002Halliburton Energy Services, Inc.Apparatus and method for hydraulically actuating a downhole device from a remote location
US7082991 *Apr 18, 2003Aug 1, 2006Team Oil ToolsSlip spring with heel notch
US7735562Apr 12, 2007Jun 15, 2010Baker Hughes IncorporatedTieback seal system and method
US8336615 *Nov 27, 2006Dec 25, 2012Bj Tool Services Ltd.Low pressure-set packer
US8561709Apr 12, 2007Oct 22, 2013Baker Hughes IncorporatedLiner top packer seal assembly and method
CN102561991BJan 18, 2012Aug 6, 2014中国石油天然气股份有限公司小直径静液压坐封堵塞器
DE3235719A1 *Sep 27, 1982Apr 7, 1983Otis Eng CoBridge-plug
WO2000012862A1Aug 31, 1999Mar 9, 2000Camco IntHydraulic well packer
Classifications
U.S. Classification166/120, 166/131, 166/217, 166/134
International ClassificationE21B33/12, E21B33/1295, E21B33/129
Cooperative ClassificationE21B33/1292, E21B33/1295
European ClassificationE21B33/1295, E21B33/129F2