US2751018A - Aligned slip well tool - Google Patents

Description

June' 19, 1956 R. c. BAKER 2,751,018

Filed Feb. 5, 1953 J2 v 17 3; INVENTOR.

'' EEUEEN C. BAKER,

BY a? 1% MJMW A TTOQNE'YJ United States Patent ALIGNED SLIP WELL TOOL Reuben C. Baker, Coalinga, Calif., assignor to Baker Oil gools, Inc., Los Angeles, Calil., a corporation of Caliornia Application February 3, 1953, Serial No. 334,783 Claims. (Cl. 166-217) The present invention relates to subsurface well tools, and more particularly to well tools embodying segmental slips that are expanded outwardly against the walls of well conduits, such as well casing disposed in well bores.

Certain kinds of subsurface well tools utilize segmental slips for anchoring them in a well conduit, such as a well casing. The slips occupy a normal or initial retracted position, from which they are expanded outwardly into engagement with the wall of the well conduit. During their outward expansion, the slip segments may not remain in transverse alignment, and, if they become dis aligned, they will engage a companion expander in such manner as to force the tool 011 center within the well conduit, or tilted out of a desirable coaxial position with the well conduit.

Accordingly, an object of the invention is to provide an improved device for maintaining segmental slips transversely aligned, all in a positive manner. Another object of the invention is to provide a transverse aligning device for segmental slips which are initially retained in retracted position, in which the aligning device a well packer A of the general type illustrated in United States Patent No. 2,121,051. This well packer is designed to be lowered through a well casing B on the lower end of a tubular string C, with the packer parts initially or normally held in retracted position. The packer includes a main body 10 that can be secured to the lower end of the tubular string C by means of a suitable lefthand threaded connection 11. This body carries a set of upper annular segmental tapered slips 12 adapted to be moved into engagement with the casing B by an upper conical expander 13 initially secured to the body 10 by one or more shear screws 14. The upper slips 12 are retained initially in retracted or ineifective position by shear screws 15 securing them to the conical expander, the upper ends of the slips 12 engaging the lower surface of an abutment member or ring 16 threaded on the main body 10. Suitable guide means are provided between the abutment member 16 and the slip segments 12, to insure the proper arcuate disposition of the slip segments with respect to each other during their outward expansion into engagement with the well casing B. As shown, longiresists the longitudinal movement of the slips upon their release for outward expansion.

A further object of the invention is to provide a transverse aligning arrangement for segmental slips, which not only maintains the slips in transverse alignment during their outward expansion into engagement with the well will now be described in detail, for the purpose of illushitting the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention isbest defined by the appended claims.

Referring to the drawings:

view of a well tool, with its parts disposed in their initial or normally retracted position;

Fig. 2 is a view similar to Fig. l, disclosing the well the casing;

Fig. 3 is a view similar to Fig. 2, showing the well tool fully set in the well casing;

Fig. 4 is an enlarged fragmentary, longitudinal section,

disclosing a relative condition that some of the parts may out of the housing 24 permits the ball 35 to engage its assume; Fig. 5 is a cross-section, taken along the line 5-5 on Fig. l; 1

Fig. 6 is a cross-section, taken along the line 6-6.on F g: I

tudinally extending pins 17 are secured in the lower portion of the abutment ring 16, which project into generally radial, transverse slots 18 formed in the upper portions of the segments 12.

A lower set of annular segmental slips 19 is initially held in retracted position by attaching them to a lower conical expander 20 through the agency of shear screws 21. This lower expander is initially held in inefiective position by shear screws 22 threaded into the body 10. The lower ends of the lower slips 19 engage an abutment consisting of a flanged portion 23 at the lower end of the body 10 and a valve housing 24 threaded on the flange.

Y A packing sleeve 25 of synthetic or natural rubber is positioned on the body 10 between and suitably secured to the ends of the expanders 13, 20. This sleeve is retained initially in retracted position free from contact with the casing wall, but is capable of being expanded into engagement therein. As described hereinafter, the upper segmental slips 12 are released from their normally retracted position and expanded outwardly by pumping fluid under pressure into the packing sleeve 25 through the body ports 26 to inflate the sleeve. For the purpose of preventing leakage from the pocking sleeve 25 during this inflating operation, its end portions are provided with E opposed annular lip seals 27 which engage the periphery of the body 10 in leakproof fashion.

It is to be noted that the coengaging surfaces 28, 29 on the upper conical expander 13 and upper slips 12 taper in an upward and inward direction, so that relative longitudinal movement of the upper expander 13 within the slips 12 will move the latter outwardly against the casing B. In like manner, the lower expander 20 and lower slips 19 have their coengaging surfaces 30, 31 tapering in a downward and inward direction, in order that relative longitudinal movement of the lower expander within the Figure 1 is a longitudinal sectional and'side elevational k Slips 19 will Shift the latter radially Outward into engagement with the casing B.

The valve housing 24 contains a tripping ball seat 32 that is held initially therewithin by a shear screw 33.

tool in a well casing, and parts thereof expanded against This seat has an upstanding arm 34 for holding a buoyant back pressure ball valve 35 in ineflective position against the interior of the housing 24 to prevent its upward movement and seating against a valve seat 36 at the lower end of the main packer body 10. Removal of this arm 34 by pumping the tripping ball seat unit 32 cooperable seat 36 whenever upward or reverse flow of fluid through the body 10 tends to occur. I The packer vA is run in the casing B to the desired setting point, after which a tripping ball 37 may be low- The invention is disclosed in the' drawings as ap plie'dto 'ered or pumped down through the tubular 'string' C into Patented June 19, 1956 seating engagement with the tripping ball seat 32. Such engagement prevents any further downward passage of fluid through the well packer A and allows the pressure of the fluid within the tubular string C and packer body to be increased. This fluid under pressure passes outwardly through the ports 26 that open through the body 1% into the interior of the packing 25 between its lip seals 27. Fluid under pressure inflates and elongates the packing sleeve 25 and urges the upper expander 13 upwardly, disrupting the shear screws 14, and shifting the upper expander 13 within the slips. This action slides the latter radially outward along the abutment ring 16, as guided by the slidable pins 17 and slots 18, and into engagement with the wall of the well casing B (see Fig. 2). The lower shear screws 21, 22 have a substantially greater shear value than the upper shear screws 14, 15, which insures disruption of the latter under the action of the fluid pressure, as described above, while the lower shear screws 21, 22 remain intact.

After the upper slips 12 have been expanded against the casing 13, an upward strain may be taken on the tubing string C, which shifts the packer body 10 upwardly within the upper conical expander 13 and carries the lower expander 21) and slips 19 upwardly with the body. This action foreshortens and compresses the packing sleeve 25 and expands it outwardly into sealing engagement with the wall of the well casing B. A continuation of the upward strain then disrupts the lower shear screws 21, 22, which allows the lower abutment 23, 24 to shift the lower slips 19 upwardly along the lower expander and radially outward into anchoring engagement with the well casing B (Fig. 3). All of the parts are held in the position to which they have been expanded, and are prevented from moving to retracted position, by a suitable lock ring which maybe in the form of a split, contractile element 38 retained within a groove 39 in the upper expander 13 and adapted to engage the downwardly facing ratchet teeth 40 formed on the exterior of the packer body 11).

After the packer A has been anchored in packed-off condition against the wall of the well casing B, the pressure can be increased to shear the screw 33 holding the trip ball seat 32 to the valve housing 24, which enables the seat to be blown out of the valve housing and removes the arm 34 from its holding position against the ball valve element 35, allowing the latter to shift upwardly into engagement with the valve seat 36, in the event that reverse flow through the well packer tends to occur.

It is to be noted that the shear screws 15 normally or initially retain the upper slip segments 12 in their retracted position, and also in transverse alignment with respect to one another. In addition, the guide pins 17 in the abutment 16 are then properly disposed within the transverse slip slots 18. However, upon the shearing of the screws 15 attaching the slips 12 to the upper conical expander 13, assurance is not had that this transverse alignment of the slip segments 12 with respect to each other, and the engagement of the slips 12 with the lower surface of the abutment ring 16 will be maintained. Disruption of the shear screws 15 might allow one or more of the slip segments 12 to drop downwardly along the packer body 10 and also along the conical expander 13, to shift one or more of the slip segments out of engagement with the abutment ring 16. The extent of downward dropping of one or more of the slip segments 12 may be sufficient to remove the slip slot or slots 18 from a position receiving the associated guide pin or pins 17 secured to the abutment ring 16.

As a result of the disalignment between the slip segments 12, they do not engage the tapered expander sur face 28 along the same relative portion. A slip segment 12 that may have dropped downwardly along the expander 13 a greater distance than another slip segment will ob: viously engage the well casing and will cock or shift the expander 13and the packer body 19 (and for that matter the entire well packer) into a position that is no longer coaxial with the well casing B in which the well packer A is located. This action not only will result in the lack of coaxiality, but it will subject the well packer to bending strains that may produce its failure, particularly since it is common practice to make the packer body 10 of cast magnesium or cast aluminum, particularly in the event it is desired to disintegrate or otherwise drill out the well packer at a later date.

The present invention seeks to overcome the aforenoted difliculties. The upper segmental slips 12 are pro,- vided collectively with an internal circumferential groove 50, the groove portions of the slips lying in a common transverse plane that is normal to the axis of the well packer. Disposed within the circumferential groove 50, that is common to all of the slip segments 12, is a ring 51 which bridges the spaces or gaps 52 between the slip segments 12. This ring 51 is split and tends to contract into frictional engagement with the periphery of the packer body 10. By virtue of this frictional engagement, the ring holds the slip segments 12 in an upward position, with their upper surfaces in engagement with the lower surface of the abutment ring 16. Accordingly, when the packing sleeve 25 is inflated, for the purpose of expanding the upper slip segments 12 outwardly against the well casing B, such action shears the screws 14, 15 and releases the slip segments 12 from the upper expander 13 (Fig. 2). However, upon disruption of the slip screws 15, the slips 12 cannot drop downwardly along the expander 13 and the body 10, in view of. the frictional engagement of the aligning ring 51 with the periphery of the packer body 10. Accordingly, the expander 13 moves upwardly within the slips 12 and slides the latter along the undersurface of the abutment ring 16 and radially outward into firm anchoring engagement with the wall of the well casing B.

The pressure normally imposed within the packing sleeve 25 for shifting the upper expander 13 upwardly within the slips 12 is sufiiciently great as to firmly wedge the expander within the slips and dig the slip wickers 53 into anchoring engagement with the well casing, in which position the slips will remain.

It is, accordingly, apparent that the aligning ring 51 not only maintains the slip segments 12 in transverse alignment with respect to one another while they are being expanded outwardly into engagement with the wall of the well casing B, but it also holds the slip segments 12 in an upward position against the abutment ring 16, which is highly desirable. This upward maintenance of the slip segments against the abutment ring also insures that the guide slots 18 in the slip segments will remain in a position to fully receive the guide pins 17. The retention of the guide pins 17 in these slots 18 will cause the slip segments to be shifted radially outward, to maintain the angular disposition between the slip segments 12 uniformly around the body 10 of the well packer (Fig. 6). As a resuit, assurance is had that the slip segments will engage the well casing B and the expander wedged therewithiu in such position as to center and maintain the packer bodyll) coaxially of the well conduit B. During the outward expansion of the slip segments 12, the split ring bridges the gaps 52 between the segments themselves, and maintains the latter in the desired transversely aligned relationship.

The internal circumferential groove 50 in the slip segments 12 and the ring 51 therewithin that frictionally engages the periphery of the packer body 10 are disposed initially a substantial distance longitudinally away from the near or small end 13a of the expander 13. In the specific exemplification of the invention shown in the drawings, the ring 51 and slip groove 50 are disposed a substantial distance above the smaller end 13a of the upper expander. This distance is provided to insure the movement of the expander 13 within the slip segments 12 while the latter are being expanded outwardly, with free: 10m. nl intsri rens r m the n 5 itself- In s casing sizes having a relatively large inside diameter, such as lightweight casing, a situation might develop in which the smaller end 13a of the expander may engage the split aligning ring 51. However, the parts are so related to one another that just before such engagement can occur, the slips 12 will have moved laterally outwardly to an extent sufilcient to completely shift the segments 12 off thealigning ring 51. Accordingly, the end of the expander 13a will then engage the ring 51 and shift the ring with it longitudinally of the body 10, this shifting action being without interference from the slips (see Fig. 4).

The operation just described may only occur in comparatively. rare instances, and when it does occur the slips 12 only have a comparatively small lateral distance left ,to travel before their wickers 53 are engaged with the wall ofthe well casing B. Accordingly, under those extreme conditions, the slips 12 could only move relatively downward along the body after having become disengaged from the alignment ring a very small distance, which, as a practical matter, is insufiicient to produce any substantial transverse disalignment between the segments 12 before they are-wedged into anchoring engagement with the wall of the well casing. In addition, the distance that these segments have to move transversely outward into engagement with the well casing is insuflicient to permit the segments to drop downwardly with respect to the abutment ring 16, so as to bring the slotted slip portions out of enclosing engagement with respect to the guide pins 17.

From the foregoing description, it is apparent that an aligning ring arrangement has been provided which does not interfere with outward expansion of the slip segments 12 into engagement with the well casing B after the retaining screws 15 have been disrupted. The aligning device keeps the segments in transverse alignment with respect to each other while maintaining them in upward position against the abutment ring 16, in which position the slips are properly coordinated with respect to the guide pin 17. so as to insure their arcuatedisplacement with respect to each other when they are in firm anchoring engagement with the wall of the well casing B.

The inventor claims:

l. A well too], including a body adapted to be lowered in a well conduit on a running-in string, means for anchoring said body to the well conduit comprising a set of initially retracted segmental slips having an internal circumferential groove therein, an expander slidable on said body and along and within said slips to. expand said slips outwardly into engagement with the well conduit, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward expansion of said slips to maintain said segmental slips in transverse alignment with respect to each other.

2. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, means for anchoring said body to the well conduit comprising a set of initially retracted segmental slips having an internal circumferential groove therein and expandible outwardly into engagement with the well conduit, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward expansion of said slips and frictionally engaging said body to maintain said segmental slips in transverse alignment with respect to each other and to resist movement of said slips longitudinally of said body, while permitting said body to move longitudinally of said slips after said slips have engaged the well conduit.

3. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an abutment on said body, means for anchoring said body to the well conduit comprising an expander on said body and a set of segmental slips engaging said expander, means for shifting said expander along said body and slips to shift said slips along said abutment outwardly into engagement with the well conduit, said set of slips having an internal circumferential groove therein, and an annular and disposed in said groove'during outward movement of said slips into engagement with the well conduit to maintain said slips in transverse alignment with respect to each other during their outward movement into engagement with the well conduit.

4. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an. abutment on said body, means for anchoring said body to the well conduit comprising an expander on said body and a set of segmental slips engaging said expander, means for shifting said expander and slips longitudinally with respect to each other to shift said slips transversely along said abutment outwardly into engagement with the well conduit, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward movement of said slips into engagement with the well conduit to maintain said slips in transverse alignment with respect to each other during their outward movement into engagement with the well conduit.

5. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an abutment on said body, means for anchoring said body to the well conduit comprising an expander on said body and a set of segmental slips engaging said expander, means for shifting said expander and slips longitudinally with respect to each other to shift said slips transversely along said abutment outwardly into engagement with the well conduit, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward movement of said slips into engagement with the Well conduit and frictionally engaging said body to maintain said segmental slips in transverse alignment with respect to each other and to resist movement of said slips longitudinally of said body, while permitting said body to move longitudinally of said slips after said slips have engaged the well conduit.

6. A well tool, including a body adapted to be lowered in a well-conduit on a running-in string, an abutment on said body, means for anchoring said body to the well conduit comprising an expander on said body and a set of segmental slips engaging said expander, means for shifting said expander and slips longitudinally with respect to each other to shift said slips transversely along said abutment outwardly into engagement with the well conduit, interengageable means on said abutment and slips for guiding said slips generally radially outwardly along said abutment, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward movement of said slips into engagement with the well conduit and fric tionally engaging said body.

7. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an abutment on said body, means for anchoring said body to the well conduit comprising an expander on said body and a set of segmental slips engaging said expander, means for shifting said expander along said body and slips toward said abutment to shift said slips along said abutment outwardly into engagement with the well conduit, interengageable means on said abutment and slips for guiding said slips generally radially outward along said abutment, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward movement of said slips into engagement with the well conduit and frictionally engaging said body.

8. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an abutment fixed to said body, means for anchoring said body to the well conduit, comprising an expander slidable on said body and a set of segmental slips engaging said expander and'the lower surface of said abutment, means for shifting said expander upwardly along said body and slips and towards said abutment to shift said slips along said abutment outwardly into engagement with the Well conduit, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward movement of said slips into engagement with the well conduit and frictionally engaging said body.

9. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an abutment fixed to said body, means for anchoring said body to the well conduit, comprising an expander slidable on said body and a set of segmental slips engaging said expander and the lower surface of said abutment, means for shift ing said expander upwardly along said body and slips toward said abutment to shift said slips along said abutment outwardly into engagement with the well conduit, interengageable means on said abutment and slips for guiding said slips generally radially outward along said abutment, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect to said body and disposed in said groove during outward movement of said slips into engagement with the well conduit and frictionally engaging said body.

10. A well tool, including a body adapted to be lowered in a well conduit on a running-in string, an expander on said body having a circumferentially continuous ex; ternal expander surface; a set of segmental slips -engage able with said expander surface for anchoring said body in a well bore, frangible means initially securing said slips in retracted position with respect to said body and expander, means for relatively moving said slips and expander to disrupt said frangible means and shift said slips outwardly into engagement with the well conduit, said set of slips having an internal circumferential groove therein, and an annular member movable longitudinally with respect tosaid body and disposed in said groove during outward movement of said slips to maintain said slips in transverse alignment with respect to each other following disruption of said frangible means and during outward movement of said slips into engagement with the well conduit.

References Cited in the file of this patent UNITED STATES PATENTS 909,609 Kesselman Jan. 12, 1909 1,118,538 Driscoll Nov. 24, 1914 1,815,376 Jones July 21, 1931 2,187,482 Baker et al. Jan. 16, 1940 2,241,532 Barnes May 13, 1941 2,248,211 Young July 8,.1941 2,368,409 Burt Jan. 30, 1945 2,383,453 Crickmer Aug. 28, 1945

Claims (1)

1. A WELL TOOL, INCLUDING A BODY ADAPTED TO BE LOWERED IN A WELL CONDUIT ON A RUNNING-IN STRING, MEANS FOR ANCHORING SAID BODY TO THE WELL CONDUIT COMPRISING A SET OF INITIALLY RETRACTED SEGMENTAL SLIPS HAVING AN INTERNAL CIRCUMFERENTIAL GROOVE THEREIN, AN EXPANDER SLIDABLE ON SAID BODY AND ALONG AND WITHIN SAID SLIPS TO EXPAND SAID SLIPS OUTWARDLY INTO ENGAGEMENT WITH THE WELL CONDUIT, AND AN ANNULAR MEMBER MOVABLE LONGITUDINALLY WITH RESPECT TO SAID BODY AND DISPOSED IN SAID GROOVE DURING OUTWARD EXPANSION OF SAID SLIPS TO MAINTAIN SAID SEGMENTAL SLIPS IN TRANSVERSE ALIGNMENT WITH RESPECT TO EACH OTHER.

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