US3002564A

US3002564A - Tubing anchor and catcher

Info

Publication number: US3002564A
Application number: US672768A
Authority: US
Inventors: Reuben C Baker
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1957-07-18
Filing date: 1957-07-18
Publication date: 1961-10-03
Anticipated expiration: 1978-10-03

Description

0a. 3, 1961 R. c. BAKER 3,002,564

TUBING ANCHOR AND CATCHER Filed July 18, 1957 2 Sheets-Sheet 1 INVENTOR. 195055 6 BAKE/9 Afro/614516 Oct. 3, 1961 R. C. BAKER TUBING ANCHOR AND CATCHER Filed July 18, 1957 2 Sheets-Sheet 2 INVENTOR.

fizz/552v C BAKE? United States Patent 9 i 3,002,564 V TUBING ANCHOR AND CATCHER Reuben C. Baker, Coalinga, Califi, assiguor to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Filed July 18, 1957, Ser. No. 672,768 17 Claims. (Cl. 166-212) The present invention relates to subsurface well bore equipment, and more particularly to apparatus for securing a tubing string, and the like, to a well casing, or similar conduit, disposed in a well bore.

An object of the invention is to provide an improved apparatus for releasably securing a string of tubing to a well casing against both upward and downward movement therewithin.

Another object of the invention is to provide an apparatus, such as a tubing anchor and catcher, for securing a string of tubing in a well casing, in which the apparatus is set automatically hydraulically by the hydrostatic head of fluid in the tubing string, and which is released automatically from the well casing upon appropriate reduction of such hydrostatic head or of the pressure differential within the apparatus.

A further object of the invention is to provide an apparatus for releasably securing a string of tubing in a well casing against both upward and downward movement therewithin, the apparatus being set in the casing hydraulically and released automatically from the well casing upon sufiicient reduction of the pressure differential in the apparatus and tubing string to which the apparatus is secured, the apparatus being automatically opened to the passage of fluid between the interior and exterior in response to manipulation of the tubing string to equalize the internal and external pressures in the event the internal pressure differential cannot otherwise be reduced sufliciently to effect release of the apparatus from the well casing.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating 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 inven- :tion is best defined by the appended claims.

Referring to the drawings: 'FIGURE 1 is a longitudinal section through a form of -well apparatus, with its slips in retracted position;

FIG. 2 is similar to FIG. 1, on an enlarged scale, with the slips anchored against the well casing;

FIG. 3 is a view similar to FIG. 2, disclosing the apparatus partially released from the well casing;

FIG. 4 is a cross-section taken along the line 44 on FIG. 1;

FIG. 5 is a cross-section taken along the line 55 on FIG. 1;

FIG. 6 is an enlarged fragmentary section through the stop ring portion of the apparatus.

The apparatus A is illustrated in the drawings and will be described herein with particular reference to functioning as a tubing anchor and catcher for securing a string of tubing B in a pumping well to a well casing, liner, or similar conduit string C, disposed in a well bore. It is to be understood, however, that the apparatus A can function to anchor running-in strings, such as tubular strings, of other characters in the well casing C.

The apparatus includes a tubular body 10 having a passage 11 therethrough which is preferably at least equal in diameter to the diameter through the tubing string B,

Patented Oct. 3, 1961 lCC of which the body actually forms a part, the tubing string extending to the top of the Well bore. There may be a portion D of the tubing string below the body of the tool, in which a pump (not shown) is secured, the pump being operated through the usual sucker rods (not shown), which will extend through the tubing string and the body 10 to the top of the hole for appropriate reciprocation. The tubular body 10 has an upper threaded pin 12 for attachment to a coupling 13 which, in turn, is threadedly secured to an adjacent upper section of the tubing string B. The lower end of the body may also be provided with a threaded pin 14 for threadedly securing the body to a coupling 15 which is, in turn, attached to a section of the tubing string D disposed therebelow.

Surrounding the body is a plurality of circumferentially spaced upper slips 16 which coact with an upward expander 17 for securing the body to the well casing C against upward movement therewithin. Also surrounding the body 10 is a plurality of circumferentially spaced lower slips 18 which coact with a lower expander 19 for anchoring the body to the well casing C against downward movement therewithin. The upper slips 16 are coupled together against relative longitudinal movement by an upper slip ring 20, which is slidably mounted on the body and which is adapted to abut an upper washer or shoulder 21 hearing against the lower end of the upper coupling or collar 13. This slip ring is slidable along a reduced external diameter portion 22 of the body, the remainder of the body therebelow having a larger diameter and providing a shoulder 23 with the upper portion which is adapted to engage the lower end 24 of the slip ring, for a purpose that will be described hereinbelow.

The circumterentially spaced slips 16 are coupled to the slip ring for longitudinal movement therewith, but may move radially inward and outward with respect thereto and with respect to the body 10. As specifically disclosed, the coupling occurs as a result of disposing the upper portion 26 of each slip in a slot 27 extending through the lower portion of the ring 20, the upper part of the slot opening into oppositely facing side grooves 28 which receive companion oppositely directed tongues 29 of the slip. The tongue and groove arrangement permits each slip 16 to slide radially inwardly and outwardly of the slip ring 26 and the body 10 of the tool, but in view of the engagement of the tongues 29 with upper and lower sides of the grooves 28, the slips 16 will move longitudinally with the slip ring 20, or will be prevented from moving longitudinally relative thereto.

The upper slips 16 have inner upwardly and inwardly tapering surfaces 30 adapted to coact with companion tapered surfaces 3 1 provided on the upper expander 17, which is slidably mounted on the larger diameter portion of the body 10 of the tool. Relative upward movement of the upper expander 17 along the body 10 and slips 16 will shift the latter outwardly into anchoring engagernent with the wall of the well casing C. The slips 16 are provided with upwardly facing external wickers or teeth 32 adapted to dig into the casing, and thereby secure the upper expander 17 and body 10 against upward movement. Relative downward movement of the upper expander 17 with respect to the slips 16 will effect retraction of the slips from the casing, in view of the dovetailed connection between each slip and the expander. As disclosed, each slip has a dove-tailed tongue 33 sliding within a companion dove-tailed groove 34 in the tapered portion 31 of the expander, so that downward movement of the expander 17 with respect to the slip will cause the sides of the dove-tailed groove 34 to engage the companion tapered portions of the tongue 33 and pull the slips radially inward toward the body 10, and away from the well casing C.

As stated above, the lower expander 19 and lower circumferentially spaced slips 18 serve to anchor the apparatus A and the tubing string B to the well casing against downward movement therewithin. The lower slips 18 are coupled to a lower slip ring 40, which is prevented from moving downward relative to the body by a split shear ring 41 disposed within a counterbore 42 in the lower portion of the slip ring and within a peripheral groove 43 in the body 10. Such shear ring 41 will prevent relative downward movement of the slip ring 40 along the body 10, or conversely, upward movement of the body with respect to the lower slip ring 40, but it will not prevent upward movement of the slip ring 40 and the slips 18 relative to the body.

The lower slips 18 also fit in circumferentially spaced slots 45 in the lower slip ring, projecting upwardly through the upper end of the latter and being provided with opposed tongues 46 received within companion grooves 47 in the sides of each slot to permit the slips 18 to move radially into and out of engagement with the well casing C. The lower slips 18 have downward and inwardly tapered surfaces 48 engaging companion tapering surfaces 49 on the lower expander 19, which is slidably mounted on the body 10 of the tool. Here again, a positive slidable interconnection is provided between the lower expander 19 and the slips 18 by having a dove-tailed rib or tongue 56 on the tapered portion of each slip 18 slidable within a companion dove-tailed groove 51 in the tapered portion of the lower expander 19. It is evident that downward movement of the lower expander 19 with respect to the lower slips 18 will eflect outward expansion of the latter to anchor them to the well casing against downward movement. The slips 18 are provided with external wickets or teeth 52 facing in a downward direction.

The upper slips 16 are normally retained in a retracted position by spring means acting between the upper slip ring and the upper expander 17. As disclosed, a plurality of circumferentially spaced compression springs 55 are disposed in longitudinal sockets 56 in the upper slip ring and the upper expander, such springs tend to urge the upper slip ring 20 in an upward direction and the upper expander 17 in a downward direction, which will result in the upper set of slips 16 being disposed in a retracted position. When the slips 16 are retracted, it is apparent that there is a substantial longitudinal space existing between the upper end of the upper expander 17 and the lower end 24 of the upper slip ring.

Similarly, spring means tends to maintain the lower slips 18 in a retracted position and tends to urge such slips toward the retracted position after they have been expanded into engagement with the wall of the well casing. Such spring means may be the same as described above in connection with the upper slip ring 20, upper expander 17 and upper slips 16, including helical compression spring 55 disposed within longitudinal aligned sockets 56 in the lower portion of the lower expander 19 and the upper portion of the lower slip ring 40. These springs 55 normally retain the lower expander 19 and lower slip ring 40, separated from one another with the lower slips 18 disposed in a retracted position, such as illustrated in FIG. 1.

The upper and

lower slips

16, 18 are shifted to expanded positions in anchoring engagement with the wall of the well casing C by fluid pressure differential existing within the tubing string B and the body 10 of the tool. Such fluid pressure diiferential may be provided by a hydrostatic head in the tubing string, as a result of operation of the pump, which exceeds the hydrostatic head in the tubing-casing annulus E by the requisite amount to overcome the force of the various springs 55. The fluid under pressure is directed through a plurality of circumferentially spaced ports 60 in the body 10 of the tool into a cylinder space '61 provided by an annular cylinder 62, whlch is integral with, or otherwise suitably secured to, one -of the expander's, such as the lower expander 19. The upper portion 63 of this lower expander may be cons'idered as constituting a cylinder head slidable along the periphery of the tool body 10, the skirt 64 of the cylinder being displaced laterally from the body 10 of the tool to define the annular cylinder space 61 in which an annular piston 65 is slidable. This piston is integral with, or otherwise suitably secured to, the upper expander 17, its external diameter being substantially less than the maximum diameter of the upper expander 17, in order that the cylinder skirt 64 may have an external diameter substantially equal to the maximum diameter of the upper expander 17.

The piston 65 is slidable along the body 10 of the tool and also along the inner cylindrical wall of the cylinder skirt 64. Leakage of fluid from the cylinder space 61 in an upward direction and around the piston 65 is prevented by an inner side seal 66, such as a rubber or rubber-like 0 ring, disposed within an internal circumferential groove 67 in the piston head and slidably and sealingly engaging the periphery of the body 10, an external side seal ring 68, such as a rubber or rubber-like O ring, being disposed in a peripheral groove 69 in the piston head which sealingly and slidably engages the cylinder wall. Leakage of fluid past this cylinder head 63 is also prevented by a seal ring 66a in a head groove 67a and slidably and sealingly engaging the periphery of the body 10. The piston skirt 70 integral with the head extends upwardly from the latter and, as disclosed, is integral with the upper expander 17. The internal diameter of this skirt 70 may be substantially greater than the external diameter of the body 10, to provide an annular by-pass passage 71 which communicates with one or more ports 72 extending through the upper portion of the piston skirt and above the upper end of the cylinder 62 for a purpose that will be described hereinbelow.

A split stop ring 73 is mounted in a circumferential groove 74 in the body 10, surrounding its ported region to function as a stop for limiting downward movement of the upper expander 17 along the body by virtue of engagement with the lower end of the piston 65. This ring 73 inherently tends to contract into engagement with the base 75 of the peripheral groove 74. The lower inner corner 76 of the ring is beveled or tapered in an upward and inward direction, engaging a companion tapered lower side wall 77 of the groove, so that upward movement of the body 10 relative to the ring 73 can cam the ring out of the groove 74, as described hereinbelow. In order that the ring 73 will not preclude passage of fluid under pressure through the ports 6!) into the cylinder space 61, it is provided with an internal circumferential groove 78 which communicates with the body ports 6* and also with the ring split 7341 (FIG. 5), the iluid then being enabled to pass through the ports 60 and through the groove 78 to the split 73a of the ring, and then into the cylinder space 61. As assurance against passage of solid particles and other harmful materials into the cylinder space 61, the ports 69 may be covered by a fine mesh screen 80, in the form of a relatively short sleeve surrounding the ported regions of the body and engaging the base 75 of the groove. If such screen is used, the inherently contractible stop ring 73 will then bear against it.

The stop ring 73 can also preclude upward movement of the lower expander 19 along the body 10 when the lower slips 18 are in their retracted position. It is evident that the upper portion of the cylinder head 63 will engage the ring 73 and thereby prevent the lower expander 19 and the lower slips 18 from moving upwardly along the body 10.

In the absence of the stop ring 73, and with the upper and lower slips 16. 18 in their retracted positions, such as disclosed in FIG. 1, the upper slip ring 20, upper slips 16 and upper expander 17 might shift downwardly, engaging the lower expander 19 and overcoming the force of the lower springs 55 to shift the lower expander within the lower slips 18, urging the latter into anchoring engagement with the wall of the well casing C. Similarly, under some conditions, the lower slip ring 40, lower slips 18 and lower expander 19 could shift upwardly, engagingthe piston 65 and sliding the upward expander 17 longitudinally within the upper slips 16 to urge the latter into anchoring engagement with the wall of the well casing C. The inherent contractability of the stop ring 73 and the force required to earn it out of its groove 74 is such that a substantial force is necessary, which may be of the order of several thousand pounds, to shift it out of its companion body groove. conditions encountered in a well bore during the lowering of the tool A in the well casing C, and elevating it therewithin, the stop ring 73 will remain within the groove 74. It can engage the piston 65 and the cylinder head 63 to prevent inadvertent sliding movement of the several parts along the exterior of the body 10, which could inadvertently cause expansion of either the lower slips 18 or the upper slips 16 into engagement with the wall of the well casing.

In the use of the apparatus, such as in functioning as a tubing anchor and catcher in connection with the tubing string B disposed in a producing oil well, and through which the production is to be lifted by means of a pump, the tubing string B with the apparatus A attached thereto is lowered in the well casing C, the upper and lower sets of springs 55 insuring the retention of the upper and

lower slips

16, 18 in their retracted position, such as illustrated in FIG. 1.

At this time, the standing valve of the pump is already present in the tubing, preferably immediately below the apparatus A. When the location in the casing is reached at which the anchor and catcher is to be set, the tubing string B may be filled with fluid from the top of the hole, the standing valve (not shown) below the apparatus retaining the fluid in the tubing string. The hydrostatic head of fluid in the tubing string B will be exerted through the fluid in the ports 60 and the cylinder 61, exerting an upward force on the piston 65 and a downward force on the cylinder head 63. When the hydrostatic head in the tubing string becomes sufficient to overcome the force of the spring 55 and the hydrostatic head of fluid in the annulus E between the tubing and the casing, the piston 65 is shifted in an upward direction and the cylinder 62 in a downward direction against the force of the respective upper and lower springs 55, to shift the upper expander 17 upwardly along the body and with respect to the slips 16, urgingthe slips outwardly into anchoring engagement with the well casing. During such upward movement of the upper expander 17, the slips 16 cannot move upwardly since the slip ring 20 is engaging the washer or shoulder 21, which is in turn engaging the lower end of the body coupling 13.

Similarly, the hydraulic force is shifting the lower expander 19 downwardly along the body 10 and with re spect to the slips 18, the shear ring 41 preventing the lower slip ring 40 from moving downward. As a result, the slips 18 are shifted radially outward by the lower expander 19 into anchoring engagement with the well casing C and are wedged in such anchored position by the lower expander.

The parts now occupy the position illustrated in FIG. 2, in which the fluid under pressure is acting in a downward direction on the cylinder head 63 to maintain the expander 19 wedged within the lower slips 18. It is also acting in an upward direction on the piston 65 and upper expander 17 to maintain the latter wedged behind the upper slips 16. At this time, the upper slip ring 20 is engaging the thrust washer, so that it cannot move in an upward direction, and the lower slip ring 40 is engaging the shear ring 41, which is secured to the body of the tool. Since it is usually desirable to maintain the tubing string B in tension in a pumping well, an upward force can now be taken on the tubing string. This upward force is incapable of shifting the anchor A with respect to the casing since it is transmitted through the shear ring 41 to the lower slip ring 40, and through the lower slips 18 to the lower expander 19, then passing through the fluid in the-cylinder space 61 to the upper piston 65 and the Accordingly, under the 6 upper expander 17, which is wedged within the upper slips 16. The force is then transferred through the upper wickers 32 of the slips 16 to the casing C.

If, for some reason, a downward force is imposed on the tubing string B, such downward force will be transferred through the coupling 13 and thrust washer 21 to the upper slip ring 20, then passing through the upper slips 16 and expander 17 to the piston 65, and through the fluid in the cylinder space 61 to the lower expander 19, the lower expander being urged downwardly within the lower slips 18, which are anchored to the well casing. Thus, the downward force is transmitted through the lower slips 18 to the well casing C to preclude downward displacement of the body 10 of the tool and of the tubing stn'ng B attached thereto with respect to the well casing.

When it is desired to retrieve the apparatus A from the well casing C, the lower pump valve (not shown) need merely be opened, so that the hydrostatic head of fluid in the tubing string C is lowered with respect to the level of fluid in the tubing-casing annulus B. When the pressure differential due to the hydrostatic head reduces sufliciently, the upper springs 55 will shift the upper expander 17 downwardly to retract the upper slips 16 from the well casing, and the lower springs 55 will shift the lower expander 19 upwardly to retract the lower slips 18 from the well casing, the parts then being shifted back to the position illustrated in FIG. 1. The apparatus can now be elevated in the well casing and withdrawn entirely therefrom, if desired.

If diflficulty is encountered in releasing the upper or lower slips from the well casing, or both of such sets of slips from the well casing, as, for example, in the event the column of liquid within the tubing string B cannot be dumped into the tubing-casing annulus E, an upward pull is taken on the tubing string B and the body 10 of the tool. When the force of such pull exceeds the shear strength of the shear ring 41, the latter will be disrupted. During such upward pull the upper expander 17 will remain wedged within the upper set of slips 16, inasmuch as the upper force is being transmitted through the lower slip ring 41 lower slips 18, lower expander 19 and fluid in the cylinder space 61 to the upper expander. Following disruption of the shear ring 41, the body 10 of the tool is free from the lower slip ring 40, which will allow the body to move upwardly until the split stop ring 73 engages the lower end of the piston 65. A suflicient upward. force can be exerted so that the lower cam side 77 of the peripheral groove 74 cams the stop ring 73 out of the groove 74, permitting the body 10 to continue sliding upwardly relative to the parts surrounding it. When the body has been moved upwardly to a position in which the ports 60 are disposed above the piston65, the ports are then in communication with the by-pass passage 71 between the piston skirt 70 and the body 10 (FIG. 3). Fluid within the tubing string B can then flow out through the ports 60 and the by-pass passage 71 and through the unloading port or ports '72 in the piston skirt into the tubing-casing annulus E, until the hydrostatic heads of fluid internally and externally of the tubing string have been equalized, or at least the differential is less than the equivalent force of the springs 55. The latter can then shift the

expanders

17, 19 and the

slips

16, 18 in directions away from each other, so that the slips are returned to their retracted positions.

In the event that the springs 55 cannot retract the

slips

16, 18 following the shearing of the shear ring 41 and the equalizing of the pressure in the manner described, a continuation of the upward movement of the body 10 will cause its upper shoulder 23 to engage the lower end 24 of the upper slip ring 20, which will then forcibly pull the upper slips 16 in an upward direction relative to the upper expander 17, thereby effecting retraction of the upper slips 16 by virtue of their dove-tailed

interconnections

33, 34 with the expander. In the event that the lower slips 18 are not retracted, the upward movement of the body 10 will cause a lower body shoulder 90 to engage the lower end of the lower expander 19 and shift the latter upwardly relative to the lower slips, thereby shifting the latter to their retracted position.

To insure against the trapping of any fluid in the cylinder space 61 between the piston 65 and the cylinder head 63 as a result of elevation of the body with respect to the external parts, following disruption of the lower shear ring 41, a by-pass passage or longitudinal groove 91 is provided in the lower portion of the body 10. The upper end of this by-pass passage 91 is normally below the lowermost position of the groove 67a and seal ring 6611 in the lower cylinder head 63, but elevation of the body 10 will bring the upper end of the by-pass passage 91 into communication with the cylinder space 61 (FIG. 3), the lower end of the by-pass passage 91 opening in an outward direction below the lower end of the expander 19. As a matter of fact, the upper end of the bypass body passage 91 preferably communicates with the cylinder space 61 before the ports 60 move upwardly past the piston head 65, so that the fluid in the cylinder space 61, and, for that matter, in the body 10 of the tool and the tubing string B commences dumping out through the by-pass passage 91. However, the main body of the fluid will flow out through the ports 60 and annular by-pass passage 71 between the piston skirt 70 and body 10, and through the unloading ports 72 in the piston skirt to the exterior of the apparatus, as described above.

After the shear ring 41 has been disrupted and the fluid pressures externally and internally of the apparatus have been substantially balanced, the upper and lower sets of

slips

16, 18 are returned to their retracted position, either under the influence of the springs 55, or forcibly as a result of the operation of the body shoulders 23, 90, enabling the tubing string B and the apparatus A to be elevated in the well casing C and withdrawn completely therefrom.

The inventor claims:

1. In apparatus of the character described to be disposed in a well conduit: a tubular body; first slip means disposed about said body; a first expander disposed about said body coacting with said first slip means and movable longitudinally relative thereto to expand said first slip means into anchoring engagement with the conduit against upward movement therewithin; a second slip means disposed about said body; a second expander disposed about said body coacting with said second slip means and movable longitudinally relative thereto to expand said second slip means into anchoring engagement with said conduit against downward movement therewithin; and hydraulically operable means on said body between said expanders and responsive to the pressure fluid within said body for relatively shifting said first slip means and first expander with respect to each other and said second slip means and second expander with respect to each other to engage both slip means with the well conduit.

2. In apparatus of the character described to be disposed in a Well conduit: a tubular body; first slip means disposed about said body; a first expander shiftable along said body and coacting with said first slip means to expand said first slip means into anchoring engagement with the conduit against upward movement therewithin; a second slip means disposed about said body; a second expander shiftable along said body and coacting with said second slip means to expand said second slip means into anchoring engagement with said conduit against downward movement therewithin; and hydraulically operable means between said expanders responsive to the pressure of fluid within said body for shifting said first and second expanders along said body and first and second slip means, respectively, to expand said first and second slip means into engagement with the well conduit.

3. In apparatus of the character described to be disposed in a well conduit: a tubular body; first slip means disposed about said body; a first expander disposed about said body coacting with said first slip means and movable longitudinally relative thereto to expand said first slip means into anchoring engagement with the conduit against upward movement therewithin; a second slip means disposed about said body; a second expander disposed about said body coacting with said second slip means and movable longitudinally relative thereto to expand said second slip means into anchoring engagement with said conduit against downward movement therewithin; first spring means engaging said first expander and first slip means to urge said first slip means toward a retracted position; second spring means engaging said second expander and second slip means to urge said second slip means toward a retracted position; and hydraulically operable means responsive to the pressure of fluid within said body for relatively shifting said first slip means and first expander with respect to each other against the force of said first spring means and said second slip means and second expander with respect to each other against the force of said second spring means to engage both slip means with the well conduit.

4. In apparatus of the character described to be disposed in a well conduit: a tubular body; first slip means disposed about said body; a first expander disposed about said body coacting with said first slip means and movable longitudinally relative thereto to expand said first slip means into anchoring engagement with the conduit against upward movement therewithin; a second slip means disposed about said body; a second expander disposed about said body coacting with said second slip means and movable longitudinally relative thereto to expand said second slip means into anchoring engagement with said conduit against downward movement therewithin; first spring means engaging said first expander and first slip means to urge said first slip means toward a retracted position; second spring means engaging said second expander and second slip means to urge said second slip means toward a retracted position; and hydraulically operable means responsive to the pressure of fluid within said body for shifting said first and second expanders along said body and first and second slip means, respectively, to expand said first and second slip means against the force of said first and second spring means into engagement with the well conduit.

5. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; and hydraulically operable means between said expanders responsive to the pressure of the fluid within said body for relatively shifting said upper slip means and upper expander with respect to each other and said lower slip means and said lower expander with respect to each other to engage both slip means with the well conduit.

6. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander shiftable along said body and coacting with said upper slip means to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander shiftable along said body and coacting with said lower slip means to expand said lower slip means into anchoring engagement with the conduit against downward movement therewith; and bydraulically operable means operatively engaging said upper and lower expanders and actuatable by the pressure of the fluid within said body for shifting saidupper and lower expanders in directions awaylfrom each other and along said body and upper and lower sets of slip means, respectively, to expand said upper and lower slip means into engagement with the well conduit.

7. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; upper spring means engaging said upper expander and upper slip means to urge said upper slip means toward a retracted position; lower spring means engaging said lower expander and lower slip means to urge said lower slip means toward a retracted position; and hydraulically operable means responsive to the pressure of fluid within said body for relatively shifting said upper slip means and upper expander with respect to each other against the force of said upper spring means and said lower slip means and said lower expander with respect to each other against the force of said lower spring means to engage both sets of slip means with the well conduit. p

8. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander shiftable along said body and coacting with said upper slip means to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander shiftable along said body and coacting with said lower slip means to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; upper spring means engaging said upper expander and upper slip means to yieldably urge said upper slip means toward a retracted position; lower spring means engaging said lower expander and lower slip means to yieldably urge said lower slip means toward aretracted position; and hydraulically operable means responsive to the pressure of fluid within said body for shifting said upper and lower expanders along said body and upper and lower sets of slip means, respectively, to expand said upper and lower sets of slip means into engagement with the well conduit.

9. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; and means for feeding fluid underpressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in oppositeidirections along said body; to engage both sets of slip mea r1s"with"thewell "c'onduit.

10. In apparatus'of 'the' character described to be disposed ina'well conduit: a tubular body; an upper set of slip means disposed about-said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; upper spring means engaging said upper expander and upper slip means to urge said upper slip means toward a retracted position; lower spring means engaging said lower expander and lower slip means to urge said lower slip means toward a retracted position; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; and means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in opposite directions along said body to engage both sets of slip means with the well conduit against the force of said upper and lower spring means.

11. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to said lower expander; a piston secured to said upper expander and slidable in said cylinder; and means for feeding fiuid under pressure from the interior of said body into said cylinder to shift said cylinder downwardly and said piston upwardly along said body to correspondingly shift said lower and upper expanders to engage both sets of slip means with the well conduit.

12. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; upper spring means engaging said upper expander and upper slip means to urge said upper slip means toward a retracted position; lower spring means engaging said lower expander and lower slip means to urge said lower slip means toward a retracted position; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in opposite directions along said body to engage both sets of slip means with the well conduit against the force of said upper and lower spring means; and stop means on said body engageable with said cylinder and piston to limit movement of said cylinder and piston along said body.

13. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to ex pand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to said lower expander; a piston secured to said upper expander and slidable in said cylinder; means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder downwardly and said piston upwardly along said body to correspondingly shift said lower and upper expanders to engage both sets of slip means with the well conduit; and stop means on said body engageable with said cylinder and piston to limit movement of said cylinder and piston along said body.

14. In apparatus of the character described to be dis posed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lovi er slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in opposite directions along said body to engage both sets of slip means with the well conduit; means including releasable abutment instrumentalities for limiting downward movement of said lower slip means relative to said body, said instrumentalities being releasable upon being subjected to a predetermined upward pull by said body; passage means which when open provides a normally closed passage for fluid between the interior of said body and the annulus in the well conduit surrounding said apparatus; and means for opening said passage means upon release of said instrumentalities and upward movement of said body.

15. In apparatus of the character described to be dis-. posed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in opposite directions along said body to engage both sets of slip means with the well conduit; shear means engaging said body and lower slip means for limiting downward movement of said lower slip means relative to said body, said shear means being disruptable upon the taking of a predetermined upward pull on said body; normally closed passage means which when open provides a passage for fluid between the interior of said body and the annulus in the well conduit surrounding said apparatus; means for open ing said passage means following disruption of said shear means and upward movement of said body; and means on said body engageable with said upper slip means, after disruption of said shear means, tending to shift said upper slip means upwardly relative to said upper expander to retract said upper slip means.

16. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in opposite directions along said body to engage both sets of slip means with the well conduit; means including releasable abutment instrumentalities for limiting downward movement of said lower slip means relative to said body, said instrumentalities being releasable upon being subjected to a predetermined upward pull by said body; and normally closed passage means extending from the interior of said cylinder to the exterior of said cylinder; and means for opening said passage means following release of said instrumentalities and upward movement of said body, to permit fluid to pass between the interior of said body and the annulus in the well conduit surrounding said apparatus.

17. In apparatus of the character described to be disposed in a well conduit: a tubular body; an upper set of slip means disposed about said body; an upper expander disposed about said body coacting with said upper slip means and movable longitudinally relative thereto to expand said upper slip means into anchoring engagement with the conduit against upward movement therewithin; a lower set of slip means disposed about said body; a lower expander disposed about said body coacting with said lower slip means and movable longitudinally relative thereto to expand said lower slip means into anchoring engagement with the conduit against downward movement therewithin; a cylinder secured to one of said expanders; a piston secured to the other of said expanders and slidable in said cylinder; means for feeding fluid under pressure from the interior of said body into said cylinder to shift said cylinder and piston, and said upper and lower expanders secured thereto, in opposite directions along said body to engage both sets of slip means with the well conduit; means including releasable abutment instrumentalities for limiting downward movement of said lower slip means relative to said body, said instrumentalities being releasable upon being subjected to a predetermined upward pull by said body; and normally closed passage means extending from the interior of said body through said piston to the exterior of said cylinder; and means for opening said passage means following release of said instrumentalities and upward movement of said body, to permit fluid to pass between the interior of said body and the exterior of said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 2,121,002 Baker June 21, 1938 2,159,640 StrOrn May 23, 1939 2,189,697 Baker Feb. 6, 1940 2,435,899 Page Feb. 10, 1948