US3429375A

US3429375A - Well tool with selectively engaged anchoring means

Info

Publication number: US3429375A
Application number: US598846A
Authority: US
Inventors: Gene C Craig
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 1966-12-02
Filing date: 1966-12-02
Publication date: 1969-02-25
Anticipated expiration: 1986-02-25

Description

Feb. 25, 1969 G. c. CRAIG 3,429,375

WELL TOOL WITH SELECTIVELY ENGAGED ANCHORING MEANS Filed Dec. 2. 1966 Z 23 I 43 23 /2 a 42 if; I w

Gene 6. C/a/g 50 1 hWEN'I'OR.

ATTOPA EV 5 BY q r A United States Patent 13 Claims ABSTRACT OF THE DISCLOSURE This application discloses a well tool adapted to be anchored in a well bore. More particularly, upper and lower slips and expanders are arranged on a movable body telescopically disposed in a housing in such -a manner that longitudinal movement of the body relative to the housing will anchoringly engage one set of .slips and position the other set of slips in readiness for anchoring engagement. This anchors the tool against movement in one longitudinal direction. Then, should the housing be moved in the opposite longitudinal direction, this other set of slips will immediately engage the casing to secure the tool against longitudinal movement in this opposite direction.

Accordingly, as will become apparent, this invention relates to well tools; and, more particularly, this invention pertains to new and improved well tools that are adapted for setting in a well bore for service either as a production packer, a tubing anchor, or a retrievable bridge plug.

It is always desirable that any well tool be as economically constructed and as trouble-free in its operation as is possible. Certain basic requirements must still be met,

of course, where a tool is, for example, a so-called production packer, a retrievable bridge plug, or a tubing anchor. For instance, it is essential that none of these well tools are accidentially set as they are being positioned in a well bore. Similarly, it is preferable that the setting as well as the release of these tools be accomplished as simply as possible. On the other hand, once such a tool is set, it must be capable of remaining in position and, where it is a packer, maintaining a tight seal against high pressure differentials acting on it from either direction. Moreover, when the tool is being used as either a production packer or a tubing anchor, it must remain firmly set even when the tubing string connected thereto is in tension.

Accordingly, it is an object of the present invention to provide new and improved well tools that meet all of these requirements. This and other objects of the present invention are accomplished by providing a well tool with a first set of slips for anchoring the tool against movement in one direction and a second set of slips for anchoring the tool against movement in the Opposite direction. By interposing biasing means, such as a compression spring between the second slips and a movable body, these second slips are moved outwardly into engagement with a casing wall as the tool is being set but do not effectively anchor the tool until an oppositely directed force is applied thereto.

The novel features of the present invention are set forth with particularity in the appended claims. The operation together with further objects and advantages thereof, may best be understood by way of illustration and ex- 3,429,375 Patented Feb. 25, 1969 ample of a certain embodiment when taken in conjunction with the accompany drawings, in which:

FIG. 1 is an elevational view, partially in cross-section, of a well tool arranged in accordance with the present invention as it appears before being set in a well bore; and

FIG. 2 is a view similar to FIG. 1 but showing the tool depicted there after it has been set in a well bore.

Turning now to FIG. 1, a well tool 10 arranged in accordance with the present invention is shown as it will appear before being set in a well bore. Although the particular well tool 10 depicted and described with reference to the drawings is arranged as a production packer, it will subsequently become apparent that this same tool can also be quite easily adapted for service as either a retrievable bridge plug or a tubing anchor and still employ the principles of the present invention.

The production packer 10 is comprised of a tubular housing 11 of an intermediate length in which is telescopically arranged an elongated, rotatable body member or tubular mandrel 12 that is longitudinally movable therein between an extended position as seen in FIG. 1 and a telescoped position as seen in FIG. 2. As best seen in FIG. 1, the upper portion of the mandrel 12 is extended a substantial distance above the upper end of the housing 11 and supports packing means 13. In one manner of arranging the packing means 13 on the mandrel 12, two or more elastomeric annular packing elements 14 are mounted around a short tubular member 15 and confined thereon between the lower face of an enlarged-diameter upper end portion 16 thereof and an upwardly facing shoulder 17 provided by the upper end of another but larger tubular member 18 that has a diameter about that of the packing elements and is telescoped around the mandrel and short tubular member. To secure the smaller tubular member 15, its lower end is extended around the mandrel 12 and into the larger tubular member 18 where it is co-rotatively secured thereto by means such as one or more lateral pins 19 in the outer member that are received in longitudinal slots 20 in the inner tubular member.

Oppositely directed, upper and lower anchoring means 21 and 22 are provided on the housing 11 for anchoring the packer 10 against longitudinal movement in either direction once it is set in a well bore. More particularly, the upper anchoring means 21 are arranged to anchor the tool 10 against downward movement and include the cumferentially spaced around the upper end of the housing 11 and provided with upwardly and outwardly tapered larger tubular member 18 that slidably receives the lower portion of the short tubular member 15 and serves as the upper expander. A plurality of slip members 23 are cirflat inner surfaces 24 that are operatively engaged with complementary downwardly and inwardly directed inclined fiat surfaces 25 formed around the lower end of the expander member 18. To maintain the slips 23 uniformly spaced around the housing 11, their lower ends are keyed or T-shaped, as at 26, into slightly inclined, complementary slots 27 formed in the upper end of the housing. Similarly, to prevent the slips 23 from tilting relative to the expander member 18, the inclined surfaces 25 are cut only at intervals around the expander so as to form circumferentially spaced recesses, as at 28, therein. Outwardly projecting tongues 29 along the edges of each of the slips 23 are received in complementary slots 30 in the sides of the recesses 28 that are parallel to the inclined surfaces 25 to confine the slips in the recesses but still permit them to move relatively radially outwardly and slightly downwardly therefrom. Thus, as will subsequently become more apparent, downward movement of the expander 18 relative to the upper slips 23 will carry them outwardly to engage their external wickers or teeth 31 against a casing wall as the inclined expander surfaces are moved downwardly with respect to the Slip surfaces 24.

The lower anchoring means 22 are arranged to anchor the tool 10 against upward movement and include a plurality of slip members 32 respectively received in circumferentially spaced elongated openings 33 formed around the intermediate portion of the housing 11. These lower slips 32 are similar to the upper slips 23 but are reversely directed to cooperatively engage their tapered flat inner surfaces 34 on expander means such as complementary upwardly and inwardly directed fiat inclined surfaces 35 formed on the bottom of each opening 33 in the housing 11. In the same manner as already described, outwardly projecting tongues, as at 36, along the lower slips are similarly received in inclined mating slots (not seen) formed on each side of the openings 33 and parallel to the inclined surfaces 35 to secure the slips 32 against tilting relative to the housing 11 without impeding their movement into and out of the openings.

Of particular significance, however, it will be noted that aside from the incidental guiding afforded by their respective tongues 36 and mating slots, the lower slips 32 are not otherwise coupled to the housing 11. Instead, a ring 37 that is loosely disposed in the annular space 38 between the housing 11 and mandrel 12 has connected thereto separate circumferentially spaced retainer blocks 39 that are respectively received in the upper end of each housing opening 33. Each of these retainer blocks 39 has a complementary T-shaped slot 40 that loosely receives the T-shaped upper end 41 of the lower slip 32 within that particular housing openin 33. In a preferred manner of selectively biasing the lower slips 32, a compression spring 42 is disposed in the annular space 38 and slightly compressed between the upper face of the ring 37 and stop means such as the bottom face of another ring 43 that is in the annular space therea'bove and normally restrained against upward movement by an inwardly directed housing shoulder 44 just above this upper ring. Stop means, such as an outwardly directed mandrel shoulder 45 engaging the retainer blocks 39, are similarly provided to prevent the spring 42 from shifting the lower slips 32 downwardly so long as the mandrel 12 is in its elevated position shown in FIG. 1.

The mandrel 12 is normally secured in its elevated position as shown in FIG. 1 by selectively releasable means such as an expansible segmented nut 46 that is confined in an inwardly directed recess 47 near the bottom of the housing 11 and threadedly engaged with downwardly directed buttress threads 48 formed around the lower portion of the mandrel. In this manner, it will be appreciated that so long as these mandrel threads 48 are threadedly engaged with the split-nut 46, the mandrel 12 can not be moved downwardly in relation to the housing 11 unless it is first rotated in the appropriate direction for unthreading the mandrel threads from the split-nut. As is customary, it is preferred to arrange the threads 48 and nut 46 for disengagement upon so-called right-hand rotation.

Once the mandrel threads 48 are free of their associated nut 46, the mandrel 12 can be moved on downwardly relative to the housing 11 to its telescoped position, which movement carries a plurality of upwardly directed buttress threads 49 around the mandrel and above the lower mandrel threads 48 into threaded engagement with another split-nut 50 confined in the recess 47 above the lower split-nut. It will be understood, of course, that by directing the upper mandrel threads 49 upwardly as shown, they will move freely downwardly through the upper split-nut 50 as it is alternately expanded and contracted by the passage of these threads. Once the mandrel 12 is halted, however, the upper split-nut 50 will contract and threadedly engage the threads 49 firmly to secure the mandrel in its telescoped position (FIG. 2) until it is rotated sufiiciently to unthread the upper threads from the upper nut. Similarly, although the mandrel 12 must be rotated to release the lower threads 48 from the lower split-nut 46, these threads are directed downwardly as shown to permit them to ratchet freely back into the lower split-nut whenever the mandrel is being returned to its elevated position as shown in FIG. 1.

To secure the housing 11 against rotation whenever the mandrel 12 is rotated to disengage the lower mandrel threads 48 from the lower split-nut 46, restraining means, such as a plurality of typical drag blocks 51 are provided on'the housing. As is customary, these drag blocks 51 are confined in an outwardly directed housing recess 52 and normally urged outwardly therefrom by springs 53. Thus, by suitably arranging the drag blocks 51, they will frictionally engage an adjacent wall of the casing in a well bore with at least sufficient force to permit the mandrel 12 to be rotated relative to the housing 11 so as to disengage the lower mandrel threads 48 from the lower split-nut 46.

As is typical, bypass means are provided around the packing elements 14 so the packer 10 can be freely moved through a fluid-filled well bore as the tool is being positioned therein. Accordingly, in one manner of providing such bypass means, an annular sealing member 54 is arranged in the upper end of the short tubular member 15 and adapted to sealingly engage an enlarged-diameter portion 55 at the upper end of the mandrel l2 whenever themandrel is in its telescoped position (FIG. 2). A plurality of lateral ports 56 through the upper expander member 18 are in communication with the annular space 57 between the tubular member 15 and the mandrel 12 by. way of the longitudinal slots 20. Thus, whenever the mandrel 12 is in its elevated position as shown in FIG. 1, a {bypass passage is rovided around the packing elements 14'. by the ports 56, slots 20 and the annular space 57. On the other hand, as the mandrel 12 is moved into its telescoped position as seen in FIG. 2, the enlarged mandrel portion 55 will enter the upper end of the short tubular member 15 and be sealingly received therein by the sealing member 54 to close this fluid communication.

It will be appreciated that so long as the mandrel 12 issecured in its elevated position shown in FIG. 1, neither the upper nor the lower slips 23 and 32 can be inadvertently set as, for example, might otherwise occur should they strike an obstruction in the well bore. For example, the lower slips 32 are secured against premature setting as might be caused by striking an obstruction as the tool 10 is being raised in the well bore. Should the lower slips 32 strike such an obstruction, their downward movement relative to the housing surfaces 35 will be prevented, however, by the co-engagement of the retainer members 39 against the upwardly directed shoulder 45 on the mandrel 12 that is adjacent thereto so long as the mandrel is secured in its elevated position. Similarly, should the housing 11 strike an obstruction in a well bore as the tool 10 is being lowered, the expander surfaces 35 would tend to move upwardly in relation to the lower slips 32 were it not for the co-engagement of the lower split-nut 46 with the lower mandrel threads 48.

The upper slips 23 are similarly restrained against premature setting. For example, the interlocking relationship of the T-shaped portion 26 of the upper slips 23 in the complementary T-shaped housing slots 27 will prevent theupper slips from moving upwardly in relation to the upper expander 18. On the other hand, should either the short tubular member or the upper expander 18 strike an obstruction in a well bore as the tool 10 is being pulled upwardly therethrough, the tubular member 15 cannot be moved downwardly by virtue of its engagement with stop means, such as a mandrel shoulder 58 located at an intermediate position thereon. Similarly, the upper expander 18 cannot be moved downwardly since it is restrained from downward movement in relation to the short, tubular member 15 by the engagement of the inwardly directed lugs 19 with the bottom of the longitudinal slots 20 in the tubular member. Accordingly, it will be appreciated that all relatively movable elements of the well tool are securely but releasably interlocked so long as the mandrel 12 remains in its elevated position as shown in FIG. 1.

To operate the production packer 10 shown in FIG. 1, the upper end of the mandrel 12 is threadedly connected as by a coupling 59 to the lower end of a tubing string (not shown) and the tool is lowered into a well bore. With the mandrel 12 being secured in the elevated position shown in FIG. 1, fluids in the well bore can readily bypass the packing elements 14 by entering the lateral ports 56 and passing through the slots into the annular space 57 and on out of the open upper end of this space.

Upon reaching a desired position in the well bore, the tubing string (not shown) is halted in preparation for setting the packer 10. By rotating the tubing string a suflicient number of revolutions to unthread the lower mandrel threads 48 from the lower split-nut 46, the mandrel 12 will be freed and can be shifted downwardly with respect to the housing 11. It Will be recalled that the frictional restraint provided by the engagement of the drag blocks 51 with the casing 60 is suificient to secure the housing 11 relative thereto as the tubing string is first rotated and then shifted to carry the mandrel 12 on downwardly.

As the mandrel 12 moves downwardly, the upper mandrel threads 49 will ratchet freely through the upper split-nut 50 until the coupling 59 at the upper end of the mandrel engages the upper end of the short, tubular memer 15. Then, as best seen in FIG. 2, further downward movement of the mandrel 12 Will carry the tubular member 15 on downwardly to begin compressing the packing elements 14. As the packing elements 14 begin to compress, they will in turn urge the upper expander 18 downwardly with respect to the stationary upper slips 23 and move them radially outwardly and against the adjacent wall of the casing 6@.

Once the teeth 31 on the upper slips 23 have engaged the casing wall, the increased load on the tool 10 will be supported thereby so as to permit sufficient weight to be applied through the tubing string to the upper end of the tubular member 15 for fully expanding the packing elements 14 outwardly and into complete sealing engagement with the casing 60. It will be noted by comparison of FIGS. 1 and 2 that at about the time that the coupling 59 engages the upper end of the tubular member 15, the mandrel shoulder 58 will contact the upper face of the ring 43 above the spring 42. Thus, as the mandrel 12 continues to move downwardly to expand the packing elements 14, its continued downward movement will be transmitted through the spring 42 to now move the lower slips 32 downwardly and radially outwardly into engagement with the casing 60. It will be appreciated, however, that the downward force on the lower slips 32 will be strictly governed by the spring rate of the compression spring 42 so long as this spring has not been fully compressed. Thus, by selecting an appropriate spring rate for the compression spring 42, the spring will urge the lower slips 32 against the casing 60 with only suflficient force to merely engage the slip teeth 61 therewith but Without causing them to be imbedded.

Once the abov -described movements have ceased, the tubing string is halted without further ado. The upper split-nut 50 will now secure the mandrel 12 (through its threads 49) in the position shown in FIG. 2 so that the lower end of the tu ing string is securely anchor d in the well bore. It will be appreciated, of course, that any pressure differential acting downwardly on the production packer 10 will be fully supported by the upper slips 23 and will tend only to furth r compress the packing elements 14. On the other hand, should there be a pressure differential acting upwardly on the production packer 10 or should the tubing string subsequently be tensioned, the co-engagement of the mandrel thr ads 49 with the upper split-nut 50 will shoulder the upper split-nut at the top of the recess 47 and tend to shift the housing l1]. upwardly. Such upward movement of the housing 11 will, however, be fully restrained inasmuch as the slightest upward movement thereof can only tend to imbed the teeth 61 of the lower slips 32 firmly into the casing 60. Thus, any upwardly acting forces on the packer 10 will be fully supported by the lower slips 32.

To release the packer 10, it is necessary only to rotate the tubing string in an appropriate direction to unthr ad the upper mandrel threads 49 from the upper split-nut 50. By making these threads 49 as well as those in the nut 50 so-called left-hand threads, it will be appreciated that right-hand rotation of the tubing string and the mandrel 12 will unthread the mandrel threads 49 from the upper split-nut and tend to elevate the mandrel with respect to the housing 111. Thus, it is never necessary to apply left-hand torque to the tubing string which might tend to loosen or disconnect couplings in the tubing string.

As the mandrel 12 is elevated, the restraint against the packing elements 14 is, of course, relieved to permit them to reassum their normal retracted positions. Similarly, as the mandrel 12 is returned upwardly, the lower shoulder 45 thereon will engage the lower nd of the retainer members 39 and pull the lower slips 32 upwardly with respect to the low r expander surfaces 35 so as to retract these slips. Moreover, as the mandrel 12 continues further upwardly, the upper mandrel shoulder 58 will engage the lower end of the tubular member 15 to move both it as Well as the upp r expander 18 upwardly so as to permit the upper slips 23 to also be retracted. Thus, by simply rotating the tubing string and picking up thereon, the packer 'will be quickly released and fully retracted to permit its ready retrieval from the well bore. It will be understood, of course, that once the mandrel 12 is returned to the position as shown in FIG. 1, the lower split-nut 46 will re-engage the lower mandrel threads 48 to res cure the mandrel in its elevated position.

It will be appreciated from the foregoing description that the tool 10 can also be employed as a retrievable bridge plug. In one manner of accomplishing this, the

central bore of th mandrel 12 is blocked in sOrne convenient manner as, for example, a threaded plug (not shown) on the lower end of the mandrel which would leave the previously described bypass passages through the tubular member 15 th only controlled flow path around the packing elements 14. On the other hand, it will be appreciated that this bypass passage could be either supplemented or replaced by a sliding sleeve valve (not shown) thr adedly connected to the upper end of the mandrel. Typical of such sliding sleeve bypass valves is that shown generally at 43 in Patent No. 3,305,022. It will be understood, of course, by viewing this patent that such a sliding sleeve bypass valve would be controlled as described fully there by the removal and re-engaging of an overshot (such as at 14 therein) off of and onto the sliding sl eve valve.

It will also be understood that the present tool can be employed as a tubing anchor merely by omission of the packing elements I14. This would, of course, mean that the space normally occupied by the packing lements 14 would be filled with a stout compression spring (not shown) between the shoulders 16 and 17 and around the short, tubular member 15. This stout spring would function as the elements 14 by allowing the mandrel 12 to move still further once the upper slips 23 are set and further compress the spring 42.

Accordingly, it will be appreciated that the present invention has provided new and improved well tools that are readily adaptabl for service as either a production packer, a retrievable bridge plug, or a tubing anchor.

As described, these tools are simply set with a minimum of effort as well as being fully protected against premature setting as th y are being positioned in the well bore. It will be appreciated, therefore, that the present invention has provided several versatile well tools that are quite capable of fulfilling all and more of the objects of the pr sent invention at a minimum of expense.

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects; and, th refore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A well tool comprising: first and second members telescopically arranged together for longitudinal movement r lative to one another; first normally-retracted anchoring means on one of said members and movable outwardly into anchoring engagement with an adjacent well ore wall in response to initial movement of the other of said members relative to said one m mber in one direction for anchoring said well tool in a well bore against longitudinal movement therein in a first dir ction; second normally-retracted anchoring means on said one member; means including spring means and means on said other member for subsequently moving said second anchoring means outwardly into non-anchoring contact with an adjacent well bore wall in response to continuation of said mov ment of said other member; locking means operative upon said continued movement of said other member for locking said members to one another to halt return movement of said other member in the opposite direction relative to said one member without limiting movement of said one member in said opposite direction; and means on said one member and responsive only to movement thereof in said opposite direction for moving said second anchoring means further outwardly and into anchoring engagement with an adjacent well bore wall for anchoring said well tool in a well bore against longitudinal movement therein in a second direction.

2. A well tool comprising: a housing; a body telescopically disposed in said housing and adapted for movement relative thereto between longitudinally-spaced positions; first and second normally-retracted anchoring means on said housing and adapted for selective movement outwardly into anchoring engagement with an adjacent well bore Wall for respectively anchoring said well tool against longitudinal movement in opposite directions in a well bore; first means on said body and responsive to the initial movement thereof in one direction toward one of its said positions for moving said first anchoring means outwardly into anchoring engagement; spring means responsive to continuation of said body movement for moving said second anchoring means outwardly into a position next to an adjacent well bore wall; normally-released locking means operative upon said continued movement of said body for releasably securing said body to said housing and preventing return movement of said body relative thereto in the opposite direction without limiting movement of said housing in said opposite direction: and second means on said housing and responsive only to movement thereof in said opposite direction for moving said second anchoring means further outwardly and into anchoring engagement with an adjacent well bore wall.

3. The well tool of claim 2 further including normallyretracted packing means on said housing adapted for packing-off a well bore and said first means further include means responsive to said body movement for moving said packing means outwardly into sealing engagement around an adjacent well bore wall.

4. The well tool of claim 3 wherein said normallyreleased locking means are also operative for securing said packing means in their sealingly-engaged position.

5. The well tool of claim 4 wherein said packing means are between said body and said housing and said normallyreleased locking means are adapted to secure said body against movement in said opposite direction away from its said one position for maintaining said packing means in their said sealing-engaged positions.

6. The well tool of claim 5 further including second locking means normally releasably securing said body in the other of its said positions.

7. A well tool comprising: a housing; a body having a shoulder adjacent to its upper end and its lower portion telescopically disposed in said housing and adapted for movement relative thereto between an extended position and a telescoped position; first anchoring means on said well tool and adapted for anchoring said well tool against downward movement in a well bore, said first anchoring means including first slip means movably connected to said housing and first expander means loosely disposed around said body and adapted for movement relative to said first slip means to extend said first slip means into anchoring engagement with an adjacent well bore wall; normally-retracted expansible packing means around said body between said body shoulder and said first expander means and adapted for expansion into sealing engagement around an adjacent well bore wall upon movement of said body toward its said telescoped position; second anchoring means on said well tool and adapted for anchoring said well tool against upward movement in a well bore, said second anchoring means including second expander means on said housing and second slip means movably connected to said housing and adapted for movement relative to said second expander means into anchoring engagement with an adjacent well bore wall; spring means between said second slip means and said body for moving said second slip means outwardly into a position next to an adjacent well bore wall upon movement of said body toward its said telescoped position; and means on said housing for securing said body in its said telescoped position.

8. The well tool of claim 7 further including normallyopen bypass means between said packing means and said body; and valve means responsive to movement of said body toward its said telescoped position for closing said bypass means.

9. The well tool of claim 7 further including means on said housing for releasably securing said body in its said extended position.

10. The well tool of claim 9 wherein said first securing means are releasable upon rotation of said body relative to said housing.

11. The well tool of claim 10 wherein said second securing means are releasable upon rotation of said body relative to said housing.

12. A well tool comprising: a body; an anchoring assembly carried by said body and including upper and lower slip means cooperatively disposed between oppositely-directed upper and lower expander means; first means for releasably coupling said body to said anchoring assembly to prevent movement of said body relative thereto in one direction; means on said body cooperable with said anchoring assembly and, whenever said first coupling means are released, responsive to movement of said body in said one direction for extending said upper slip means into anchoring engagement with a wall of a well bore to prevent further movement of said anchoring assembly in said one direction; spring means on said lower slip means and adapted for engagement by said body upon movement thereof in said one direction for extending said lower slip means into non-anchoring engagement with a wall of a well bore; second means for releasably coupling said body to the other of said slip means whenever said slip means are extended to prevent return movement of said body in the other direction without limiting movement of said anchoring assembly in said other direction; and means on said anchoring assembly cooperable with said lower slip means and responsive to movement of said anchoring assembly in said other direction for moving said lower slip means into anchoring engagement with a wall of a well bore to prevent further movement of said anchoring assembly in said other direction.

13. The well tool of claim 12 further including: normally-retracted packing means carried on said anchoring assembly and arranged around said body for expansion into sealing engagement around a wall of a well bore; and means on said body and cooperable with said packing means for expanding said packing means upon said movement of said body in said one direction.

References Cited UNITED STATES PATENTS DAVID H. BROWN, Primary Examiner.

US. C1.X.R.