Abstract:
In a PBR system in well bores, a retrievable landing assembly which can be set either mechanically or hydraulically has a telescopic setting sleeve and setting collar where the setting collar is interconnected to a setting tool by a first threaded nut member and a second threaded nut member. The setting tool is threadedly attached by one of the threaded nut members to the setting collar and the one threaded nut member is splined for longitudinal movement with respect to a mandrel of the setting tool while the other nut member is longitudinally and releasably splined to the setting collar and threadedly attached to the mandrel of the setting tool. The setting tool has a shiftable sleeve member which can be shifted by a pressure ball and applied pressure to shift the setting sleeve of the landing assembly into a locking position in the setting collar. Alternatively, one of the nut members can be operated to release the mandrel of the setting tool relative to the setting collar of the land assembly so that weight can be applied through the tubing string to the mandrel and the shiftable sleeve member to the setting sleeve of the landing assembly.

Description:
FIELD OF THE INVENTION 
     This invention relates to oilwell production tools, and more particularly, to a retrievable landing assembly for use in a packer bore receptacle system which can be set in a packer bore receptacle either hydraulically or mechanically. 
     DESCRIPTION OF THE PRIOR ART 
     Packer bore receptacle systems or &#34;PBR&#34; Systems are typically employed on top of a production liner in conjunction with a liner hanger disposed in a well bore. A PBR typically has a long polished bore which slidably and sealingly receives a sealing assembly on the end of a tubing string or string of tubing. Thus, a tubing end is slidably and sealingly free to move in the polished bore in response to expansion or contraction of the tubing string without affecting the sealing relationship between the tubing string and the PBR. 
     A retrievable landing assembly is intended for use within a PBR and when installed; permits use of a smaller diameter tubing string or closure plugs for remedial work. The retrievable landing assembly typically is received within a PBR and uses a multiple latching lug system to releasably latch the retrievable landing assembly in a precut latching groove in the PBR. 
     In the prior art a latching lug system of a retrievable landing assembly can be mechanically set by first landing the landing assembly by engagement of the landing assembly with a no-go internal landing shoulder in the PBR. The setting of the latching lug system is accomplished by setting down weight through the tubing string to the landing assembly to force a setting sleeve to shear a shear pin and release to set the latching lug system in the precut latching groove in a PBR. The energy for setting the latching lug system in the latching groove comes from a compressed spring in the tool which drives the setting sleeve. A system of this type is illustrated in 1980, 1981 composite catalogue of oilfield equipment, 34th revision on page 6883. 
     Retrievable landing devices have also been hydraulically set in a PBR as illustrated in U.S. Pat. No. 4,497,371 or U.S. Pat. No. 4,399,873. In a hydraulically set landing assembly; a ball is dropped through the tubing string to close off the bore of a setting sleeve in the landing assembly or in a setting tool and then applied hydraulic pressure in the tubing string shifts a setting sleeve in the landing assembly or setting tool to set or actuate the latching lug system in the landing assembly into engagement with the latching groove of the PBR. 
     In some instances, a hydraulically actuated system in a retrievable landing assembly can plug up or fail to operate properly in a well bore. When the landing assembly fails to operate, another trip of the landing assembly is required to get another landing assembly in the well bore. Thus, it is desirable to provide an alternative positive setting operation of a landing assembly in a PBR in a well bore; either mechanically or hydraulically. 
     Accordingly it is object present invention to provide a system for setting a landing assembly which includes a retrievable insert landing assembly in a PBR which can be operated selectively either hydraulically or mechanically. 
     DESCRIPTION OF THE INVENTION 
     The present invention includes a retrievable landing tool or assembly for a PBR which is insertable together with a retrievable setting tool through a string of pipe or tubing in a well bore and which seats on a landing shoulder in the bore of a polished bore receptacle (PBR). When seated on the landing shoulder, a pressure sealing ball is dropped through the tubing string to seat in the bore of an actuator sleeve in the setting tool to provide a hydraulic actuator. Hydraulic pressure is applied through the tubing string and the effect of the hydraulic pressure produces a force in the hydraulic actuator which shifts to break a shear pin. When the shear pin is severed, the tubular actuator sleeve shifts a tubular setting sleeve to project movable latching lugs in a setting collar into locking engagement with a latching groove in the production bore receptacle. The setting collar and setting sleeve are telescopically and releasably locked relatively to one another while the latching lug elements are in an extended position in the latching groove. 
     The setting tool is released by right hand rotation so that an interconnecting traveling nut on the setting tool disconnects from an internal thread in the setting collar and the tubing string and setting tool then can moved upwardly relative to the PBR and can be retrieved without affecting the PBR or the latched landing assembly. 
     If it is desired to retrieve the landing assembly from the PBR, a tubing string is run in the well bore with a spear which can be coupled to the setting sleeve to exert an upward pull on the setting sleeve. When the spear engages the setting sleeve and is pulled upwardly, shear releasable locking means between the setting collar body and setting sleeve are released. Once the locking means are released, the lugs are retracted and the landing assembly can be retrieved. 
     As an alternative to hydraulic setting of the setting sleeve, the setting tool has a mechanical setting system. The mechanical setting system is incorporated in a second releasable nut which is threadedly attached to the tubing string and has a longitudinally extending spline coupling to the setting collar. To set the setting sleeve mechanically, rotation of the tubing string releases the tubing string relative to the setting collar so that the tubing string can be moved downwardly to apply weight to the setting sleeve and shift the setting sleeve relative to the setting collar. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 schematically illustrates a well bore and liner hanger for background purposes; 
     FIGS. 2A and 2B are in partial longitudinal cross-section to illustrate the features of the present invention; 
     FIG. 3 is a view in cross-section taken along line 3--3 of FIG. 2A; 
     FIG. 4 is a view in cross-section taken along line 4--4 of FIG. 2A; and 
     FIG. 5 is a view in cross-section taken along line 5--5 of FIG. 2B. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, a well bore is illustrated to show use of the present invention. A surface string of casing 10 is shown in a cemented position in a well bore. At the lower end of the casing 10, a liner 11 overlaps the lower end of the casing 10 and extends downwardly from the end of casing 10 through a smaller diameter borehole and is in position for cementing. The liner 11 at its upper end is attached to a liner hanger which has a slip assembly 12, a packer bore receptacle 13 and a tie back sleeve 14. A setting tool (not shown) on a tubing string is utilized to set the liner slips of the slip assembly 12 in the casing 10. Thereafter, the liner 11 can be cemented in place in the borehole and the setting tool removed. 
     The tie back sleeve 14 has a polished bore which cooperates with an outer seal assembly 16 on a casing string 15. The seal assembly 16 is slidably and sealingly received in the tie back sleeve 14 where the bore of the casing string 15 is larger than the bore of the PBR 13. The PBR 13 has an a upwardly facing landing shoulder 17 and a retrievable landing assembly 18 is adapted to seat on the shoulder 17 and is provided with latching lugs 19 which are received in an annular latching groove 20 in the PBR 13. Annular seals are provided above and below the latching lugs 19 to seal off the landing assembly 18 with respect to the bore of the PBR 13. 
     The retrievable landing assembly 18 normally has a tail pipe or tubular member 22 with landing profiles or internal shoulders 23 for receiving plugs or the like. The retrievable landing assembly 18 is set in the PBR 13 by a setting tool (not shown) which actuates the latching lugs 19 into locking engagement with the locking groove in the PBR. 
     After the retrievable landing assembly 18 is positioned in place, a tubing string 25 with a sealing assembly 26 can be provided where the sealing assembly 26 is slidably and sealingly received in a polished bore of the PBR 13 and the tubing string 25 is in communication with earth&#39;s surface. Thus, the retrievable landing assembly permits the bore of the tail pipe 22 to receive sealing plugs so that the tubing string 25 can be pulled or replaced while not affecting the well bore below the landing assembly 18. 
     Referring now to FIGS. 2A and 2B, a tie back sleeve 14 and PBR 13 are partially illustrated wherein the PBR 13 has a landing shoulder 17 (FIG. 2B) formed between stepped diametrical portions of the bore in the PBR 13. Above the landing shoulder 17 is annular latching groove 20 cut into the bore 30 of the PBR 13. The annular latching groove 20 is adapted to receive latching lugs 19 which are incorporated into the retrievable landing assembly 18. 
     The retrievably landing assembly 18 includes a tubular setting collar 34 having upper and lower external and annular seal members 35 and 36 located above and below a slotted window 37, where the latching lugs 19 are located in the slotted window 37. At least three (3) latching lugs 19 are circumferentially disposed about the circumference of the setting collar 34 at an equal, angular relationship. 
     Telescopically received within the bore of the setting collar 34 is a tubular setting sleeve 40 which has a uniformly sized internal bore 41 (FIG. 2B). The bore 41 of the setting sleeve 40 is similar in diameter to an upper and lower bore portion 42 in the setting collar. The setting sleeve 40 is telescopically received in an enlarged bore section 45 of the setting collar 34 which is located intermediate of the upper and lower bore portions 42. 
     The setting sleeve 40 is shown in upper first position where the latching lugs 19 are retracted. The setting sleeve 40 is movable to a lower second position where the latching lugs 19 are extended into the annular latching groove 20 in the PBR and is movable to an upper third position where the latching lugs 19 are retracted and the sleeve 40 is locked to the setting collar 40 against substantial longitudinal movement. 
     The enlarged intermediate bore section 45 has a first bore section 45a which receives an upper tubular portion 40a of the setting sleeve 40. The cross-sectional area of the tubular portion 40a is sized to extend into and overlap the bore 42 so that an actuator sleeve 52 on a setting tool 55 can engage the facing upper end surface 40b of the tubular portion 40a. The tubular portion 40a has an outer inclined ramp surface 46 and recess 47 at its lower end. In the upper first position of the setting sleeve 40, the ramp 46 and recess 47 are disposed below an annular resilient snap ring 48 disposed in an annular groove 49 in the setting collar 34. When the setting sleeve 40 is moved to the third upper position, the snap ring 48 moves over the ramp 46 and into the recess 47 where engagement of the snap ring with a recess shoulder prevents downward movement of the setting sleeve 40 relative to the setting collar 34. 
     Below the recess 47 the setting sleeve 40 has an enlarged diametrical portion 40c which has an annular groove 50 adapted to receive a shear pin 51 to releasably maintain the setting sleeve 40 in the first upper position relative to the setting collar 34 until sufficient relative force is applied to shear the end of the shear pin 51 in the groove 50. Below the diametrical portion 40c is an conically shaped surface 40h which is inclined downwardly and inwardly to define an expander surface. At the lower end of the expander surface 40h is a reduced diameter portion 40d. In the first upper position of the setting sleeve 40, the latching lugs 19 are disposed adjacent to the diameter portion 40d. The latching lugs 19 are generally rectangularly shaped and respectively sized to slide radially between the end and side walls of a window or slot 37. The facing surface of a lug to the expander surface 40h can have a complementary inclination. While not shown, annular resilient retaining means can be received in an outer groove on the lugs to resiliently retain the lugs in a retracted position. When the setting sleeve 40 is moved from a first upper position to a second lower position, the expander surface 40h moves the latching lugs 19 outwardly into latching engagement with the latching groove 20. 
     Below the sleeve diameter portion 40d is a breakable thin wall section 40e constructed of brass which is adapted to part or sever upon application of a predetermined pulling force on the setting sleeve 40. 
     Below the breakable portion 40e is an outer serrated locking section 40f and at the lower end of the locking section 40f is an annular locking ring 53 having internal serrated teeth 54 and an outer conically shaped inclined surface 56 which is upwardly and inwardly inclined. The locking ring 53 is located within an annular recess in the setting collar 34 which has a complementary inclined surface. The locking ring 53 is split and of resilient material so that upon downward relative movement of the setting sleeve 40 relative to the setting collar 34, the ring 53 ratchets relative to the serrations on the locking section 40f and permits the relative movement. The ring 53 is a one-way locking mechanism in that the interengagement of the ring 53 with the serrations on the locking section 40f and the interengagement of the inclined surface 56 with the inclined surface in the setting collar 34 prevents upward movement of the locking section 40f relative to the setting collar. Thus, when the setting sleeve 40 is moved from the first position to the second position, the latching lugs 19 are brought in locking relationship to the latching groove 20 and the setting sleeve 40 is locked in the second position by the one way locking mechanism. 
     The setting sleeve 40 subsequently can be released from the second position by connecting a spear on a tubing string and exerting an upward pull which is sufficient to part the breakable portion 40e. When the portion 40e severs or breaks, the upper part of the setting sleeve 40 above the portion 40e moves upwardly and releases and retracts the latching lugs 19 from the latching groove 20 and ultimately the snap ring 48 locks the recess 47 of setting sleeve 40 in a upper third position. 
     Referring now to FIG. 2A, at the upper end of the setting collar 34, the upper bore portion 42 has (in ascending order of dimensions) a first enlarged diameter portion 42a, a second enlarged and internally threaded portion 42b, a third enlarged bore portion 42c and a fourth terminal locking portion 42d. 
     The setting tool 55 includes a tubular setting tool mandrel 54 which is adapted for coupling at its upper end 55a to a string of tubing and has a telescopically arranged tubular actuator sleeve 52 at its lower end. The setting tool mandrel 54 is adapted to be received within the bore 42 of the setting collar 43. 
     The actuator sleeve 52 has an outer upper flange portion 52a which is slidably and sealingly received in an enlarged internal recessed bore portion 54a of the mandrel 54. Thus, the flange portion 52a is slidably and sealingly received within the longitudinal confines of the recessed bore portion 54a of the mandrel 54 for movement between the upper position shown and a lower position where the end 52b of the sleeve 52 engages and moves the setting sleeve 40 from a first upper position to a second lower position. The recess 54a is defined between upper and lower shoulders 56 and 57 and a bypass port 58 is provided in the wall of the mandrel 54 for a fluid bypass upon retrieval. The lower end 52b of the actuator sleeve is engagable with the upper end 40b of the sleeve 40. 
     The bore 52c of the actuator sleeve 52 at its upper end is provided with an inwardly extending flange 59 relative to the bore 60 of the mandrel 54 to form a pressure ball seat. Thus, a pressure ball when dropped through a tubing string can be sealingly seated on the flange 59 so that application of fluid pressure in the tubing string will shift the actuator sleeve 52 from a first upper position to a second lower position. In the upper position of the actuator sleeve, the flange 52a engages the downwardly facing surface 56. 
     The setting tool mandrel 54 at its lower end has an internal flange 54c which is slidably in an outer recess of the actuator sleeve 52 where the recess is between the flange 52a and the end 52b of the sleeve 52. The outer surface of the mandrel 54 which is located above the internal recess shoulder 56 is reduced in diameter successively at portions 54d, 54e and 54f. An annular traveling nut 70 is disposed in the annular space between the setting tool mandrel 54 and the setting collar 34. The traveling nut 70 has a pressure relief bore 70a and a lower annular ring section 70b which is slidably and sealing received between the bore portion 42a and mandrel portion 54d. In the bore of the traveling nut 70 is a longitudinal spline groove or surface which cooperates with a longitudinal spline surface on the mandrel 54 so that the nut 70 is longitudinally but non-rotatively coupled to the mandrel 54. The external threads on the nut 70 are left hand threads and threadedly attach the nut 70 to the setting collar 34. The upwardly facing shoulder 54g between the surfaces 54d and 54e supports the nut 70 on the mandrel 54. The annulus between the mandrel 54 and setting collar 18 are pressure sealed by o-rings. 
     Above the mandrel portion 54e the mandrel portion 54f has an external threaded section 54h with right hand threads. The threaded section 54h is spaced by smooth diameter portion 54f from a downward facing shoulder 54i. A second tubular collar nut member 80 has an internal thread for threaded interconnection with the threaded section 54h on the mandrel 54. At the upper end of the nut member 80, the nut member has an internal o-ring seal to slidably and sealingly receive the diameter portion 54f of the mandrel 54. The threaded interconnection between the nut member 80 and mandrel 54 is a left hand thread. The nut member 80 at its lower outer end has outer downwardly extending spline fingers 80b. The spline fingers 80b interlock with spline grooves 80c in the bore section 42d to releasably interlock the nut member 80 to the setting collar 34. 
     In operation, the PBR 13 is previously located in the well bore. The setting tool 53 and retrievable assembly (collar 34 and sleeve 40) are lowered into the well bore on a tubing string until the setting collar 40 seats on the landing shoulder 17 of the PBR 13. A pressure sealing ball is dropped through the tubing string to seat on the seating flange 59 of the actuator sleeve 52 in the setting tool. The application of hydraulic pressure in the tubing string shifts the actuator sleeve 52 downwardly to apply force to the setting sleeve 40 and shear the interconnecting shear pin 51 between the setting sleeve 40 and setting collar 34 to move the setting sleeve 40 from an upper first position to a lower second position so that the latching lugs 19 are brought into latching engagement with the latching groove 20 in the PBR 13. The setting sleeve 40 is releasably locked in the second lower position by the one-way locking mechanism which includes the ring 53. 
     The setting tool is releasable from the setting collar 34 by right hand rotation which moves the traveling nut 70 upwardly and threadedly uncouples the traveling unit 70 from the setting collar 34. When the nut 70 is uncoupled from the setting collar 34, the tubing can retrieve the setting tool from the setting collar. The port 58 in the mandrel 55 bypasses fluid in the tubing string past the sealing ball on the flange 59. 
     To retrieve landing assembly, a tubing string with a spear is lowered into the upper end of the sleeve 40 and locks in the setting sleeve 40. Thereafter, a pull on the tubing string with sufficient force causes the breakable section 40e to part so that the setting sleeve 40 moves from a second lower position to a third upper position where a snap ring 48 locks the setting sleeve in the third position. With the latching lugs 19 released, setting sleeve and setting collar can be retrieved. 
     In the foregoing operation, with the landing assembly seated on the shoulder 17, the hydraulic setting need not be used or, in the event the hydraulic operation does not shift the actuator sleeve 52, then the operator can mechanically move the setting sleeve between the first upper position and the second lower position. The mechanical operation is accomplished by right-hand rotation which causes the setting collar 34 to unthread from the collar nut 80. The nut 80 is threaded to release with 5 turns or rotations while the nut 70 is threaded to release with 15 turns or rotations. Thus the nut 70 stays attached while the mandrel 54 is released from the collar nut 80 so that the mandrel 54 can be moved downwardly and the shoulder 52b on the mandrel 54 drives the actuator sleeve 52 downward and mechanically shifts the setting sleeve 40 from the first position to the second position. The threads 54 do not pass through the nut 70 as the downward stroke is sufficient to set the setting sleeve 40. In mechanically setting the setting sleeve 40, the setting sleeve 40 and setting collar 34 function as if they had been hydraulically set. The setting tool can then be rotated to release the nut 70 and the setting tool can be retrieved. 
     It will be apparent to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is enclosed in the drawings and specifications, but only as indicated in the appended claims.