US3433304A

US3433304A - Coupling device for use in well tools

Info

Publication number: US3433304A
Application number: US639439A
Authority: US
Inventors: Garnet L Pavlas
Original assignee: Schlumberger Technology Corp
Current assignee: Schlumberger Technology Corp
Priority date: 1967-05-18
Filing date: 1967-05-18
Publication date: 1969-03-18
Anticipated expiration: 1986-03-18

Description

March 18, 1969 Filed May 18, 1967 G. L. PAVLAS COUPLING DEVICE FOR USE IN WELL TOOLS klim. A

r11-ac@ Y @Lyn t mg Sheetl 0f 5 l N VEN TOR.

MMM/MWA? ATTORNEY March 18, 1969 Q L PAVLAS 3,433,304

COUPLING DEVICE FOR USE IN WELL TOOLS Filed May 18, 1967 Sheet g of 5 ATTORNEY March 18, 1969 Filed May 18, 1967 G. L. PAvLAs 3,433,304

COUPLING DEVICE FOR USE IN WELL TOOLS Sheet 3 of 5 @df/iwf l. Pay/0J INVENTOR.

United States Patent Olce 3,433,304 Patented Mar. 18, 1969 16 Claims ABSTRACT F THE DISCLOSURE A coupling apparatus for use with well tools in well bores to releasably couple elongate members to one another includes a coupling device on one of the members which can engage the other member in one position to prevent longitudinal relative movement of the members. In response to rotation of one of the members, the coupling device is movable along at least one of the members to another position of engagement with the other member wherein limited reciprocation is permitted of one member relative to the other. In further response to a predetermined force applied to one of the members without rotation, the `coupling device can be released from engagement with the other member to uncouple the members from one another, and the members can be recoupled as desired with the coupling device in the second position.

This invention relates generally to well tools used in a well bore, and more specifically to a well tool apparatus having a new and improved coupling structure for permitting selective relative movement between parts of the well tool.

Well tools which are lowered into a well on a runningin string of tubing or drill pipe can include elongate members and a coupling mechanism which releasably `couples the members together and which can be operated by the running-in string to permit relative movement of the members for operating various parts of the tool in the well. The well tool may be, for example, a packer having slips and packing which are expanded in response to upward strain on the running-in string, and a valve which is operated by upward and downward movement of one of the elongate members by the running-in string.

It will be appreciated that the types of motion which can be imparted to the running-in string are somewhat limited to either vertical or rotational movement along or about the axis of the string. Accordingly, the types of coupling mechanisms which can be used are somewhat limited.

Moreover, such well tools are ordinarily disposed many thousands of feet down in a well so that the problem of remote operation of a coupling mechanism becomes more critical, necessitating simplicity in design and operation to provide a reliable well tool.

An object of the present invention is to provide a new and improved structural arrangement for releasably coupling elongate 'well tool parts to one another, and which is remotely operable to permit selective relative movement between parts.

Another object of the present invention is to provide a new and improved well tool structure which can be disposed in a well bore on a running-in string extending to the top of the well, and which includes relatively movable parts which can be releasably coupled to one another, and which can be operated #by surface manipulation of the running-in string to cause relative movement between parts as desired.

Another object of the present invention is to provide a new and improved apparatus for releasably coupling telescoping members of a well tool to one another and which can be operated by simple rotational and vertical motion.

Yet another object of the present invention is to provide a new and improved apparatus of the type described which is simple and reliable in design and operation.

These and other objects are attained in accordance with the present invention by the inclusion in an apparatus having inner and outer elongate members of a coupling device on one of the members which is engageable in one position with the other member to prevent relative movement between the members in longitudinal directions. Responsive to rotation of one of the members, the coupling device can be moved to another position of engagement with said other member wherein limited telescoping movement between said members is permitted in both longitudinal directions of operating, for example, a valve. Then, responsive to further rotation of one of the members, or responsive to a predetermined force applied to one of the members without rotation, the coupling device can be removed from engagement with said other member so that said members can be removed from telescoping relation to each other and one of said members can ybe withdrawn from the well. Moreover, said members can be selectively recoupled to one another for the aforementioned limited telescoping motion and then uncoupled from one another as often as desired.

This invention has other objects and advantages which will become more apparent in connection with the following detailed description. A preferred embodiment of the present invention is shown in the accompanying drawings in which:

FIGURES 1A and 1B are longitudinal sectional views, with portions in side elevation, of the present invention in connection with a well tool having parts in retracted positions for lowering into a well, FIGURE 1B forming a lower continuation of FIGURE 1A;

FIGURES 2A and 2B are views similar to FIGURE 1 except with the well tool illustrated in packed-olf condition in a well conduit;

FIGURE 3 is a cross section on line 3 3 in FIGURE 1B;

FIGURE 4 is an enlarged fragmentary sectional view illustrating in detail the structure and operating modes of the well tool valve structure; and

FIGURES 5 and 6 are enlarged, fragmentary sectional views to more clearly illustrate the structural details of a coupling mechanism in accordance with the present invention.

Referring to FIGURES 1A and lfB, the apparatus of the present invention is shown in connection with a well tool having a setting tool assembly A, a packer assembly B and a valve assembly C. Although the particular well tool shown is a cement retainer packer, it will be appreciated that the present invention has application to other well tools. The entire apparatus is arranged to be lowered into a well bore on a running-in string 10 of tubing or drill pipe. When set in the well bore, the packer assembly B packs off the annulus between the well casing and the running-in string 10. The running-in string 10 provides a conductor through which fluid under pressure can be supplied to the well bore below the packer assembly B, as well as an operating member which can be manipulated at the earths surface for setting the packer assembly B and for opening and closing the valve assembly C.

The setting tool assembly A includes a central mandrel 11 which is coupled at its upper end by a collar 12 to the running-in string 10, and coupled at its lower end by a mounting sub 13 to an elongated mandrel extension or Stringer 14. The mandrel 11 and extension 14 have a iluid passage 15 therethrough in communication with the bore of the running-in string 10. A control sleeve 17 is co-rotatively secured to the mandrel 11 by splines 18 or the like, the control sleeve being threadedly coupled by a sub 19 to a downwardly depending setting sleeve 20. A friction drag mechanism 21 is mounted on the control sleve 17 and includes a tubular cage 22 having a plurality of circumferentially spaced, radially directed recesses 23, each of which receives a typical drag block 25 which is urged outwardly by coil springs 26. The drag blocks 25 are ararnged to frictionally engage the inner surface of a well casing to resist both longitudinal and turning motion of the cage 22 within the well casing in a conventional manner.

The cage 22 is connected at its lower end to a retainer sleeve 27 which initially extends downwardly below the lower end of the setting sleeve for purposes which will be hereinafter described. Moreover, the cage 22 is coupled to the control sleeve 17 by internal right-hand threads 28 which engage companion external threads 29 on the control sleeve. It will be appreciated that the cage 22 is vertically :xed in a lower position relative to the control sleeve during lowering into a well bore. At setting depth, right-hand rotation of the mandrel 11 and control sleeve 17 will cause upward feeding of the cage 22 and retainer sleeve 27 along the control sleeve due to the interengagement of the

threads

28 and 29, the cage 22 being held against rotation by frictional engagement of the drag blocks within the well casing.

The control sleeve 17 will rotate with the mandrel 11 due to the interengagement of the splines 18. The control sleve 17 is initially locked against longitudinal movement relative to the mandrel 11 by a suitable latch device which can include a ball 30 which is engaged in an aperture 31 in the control sleve and in a mandrel detent 32, the ball being held inwardly in engaged condition by an inner surface 33 on the cage 22. However, upward feeding of the cage 22 along the control sleeve 17, as previously described, will eventually position an internal cage recess 34 opposite the ball 30 and permit the ball to shift outwardly and disengage from the mandrel detent 32 to free the mandrel 11 for upward movement relative to the control sleeve 17 and the cage 22.

The mounting sub 13 located between the mandrel 11 and the mandrel extension 14 is arranged to carry the upper slips 35 for the packer assembly B. The upper slips can be formed in segments 36 with each segment having external wickers or teeth 37 which face upwardly and are adapted to grip a well conduit wall and prevent upward movement. Each segment 36 further has an inner surface 38 which inclines downwardly and outwardly, and has an internal annular recess 39 which receives an external ange 40 on the mounting sub 13. Each segment 36 also has an upwardly extending section 42 over which the lower end portion of the retainer sleeve 27 extends to hold the segments in engagement with the sub flange 40, thereby preventing any vertical motion of the slip segments relative to the mounting sub 13 as long as the retainer sleeve 27 encompasses the upper sections 42 of the segments as shown in FIGURE 11B. Each slip segment 36 is further retained on the mounting sub 13 by a leaf spring 43 having its free end engaging in an external notch 44 formed in each segment, the other end of each leaf spring being connected to the mounting sub by a screw 45 or other suitable fastening device. It will be appreciated that the engagement of the retainer sleeve 27 over the upper sections 42 of the slip segments 36 provides a strong and rigid coupling to prevent any longitudinal motion which might result in prematurely setting the slips. Even when the retainer sleeve 27 is removed by upward feeding of the cage 22, as previously described, the slip segments are still retained on the mounting sub 13 by the inward bias of the leaf springs 43. However, upward feeding of the retainer sleeve 27 clears the lower end surface 46 of the setting sleeve 20 for engagement with the upper end surfaces of the slip segments -36 so that the setting sleeve can exert a holding force on the segments. Accordingly, when the mandrel 11 is freed from the control sleeve 17 by rotation, as previously described, the mandrel can then be elevated by upward movement of the running-in string 10 to engage the slips with the setting sleeve 20. Inasmuch as the control sleeve 17 is still coupled to the drag cage 22 by the

threads

28 and 29, the drag cage 22, control sleeve 17 and setting sleeve 20 will transmit the holding force of the drag blocks 25 to the slip segments 36 to hold the segments against upward movement as the mandrel 11 is moved upwardly for shifting the slips outward into gripping engagement with the wellcasing.

As shown in FIGURE 1B, the packer assembly B includes a body 50 having a central bore 51 which is sized to receive the mandrel extension 14, the lower end of the tbody being constituted as a valve housing by a guide and valve body 52 threadedly coupled at its lower end. Mounted at the lower portion of the packer body 50 are slips 53 of any typical construction having wickers or teeth 54 facing in a downward direction and capable of anchoring, when expanded, against downward movement in the well casing. The slips 53 rest on the guide 52 and have inner surfaces 55 inclined downward and inwardly and arranged to engage companion external surfaces 56 on a lower expander 5'7 mounted on the body 50. The expander 57 can be releasably secured to the body 50 by one or more shear pins 62 and can also be corotatively coupled to the body 50 by a lock pin 62a.

The upper end of the lower expander 57 engages the lower portion of a packing 4structure 58, such as a plurality of elastomeric rings, surrounding the body, the ulpper end of which engage-s an upper expander S9 initially releasably secured to the body 50 by one or more shear pins 60. The ends of the packing structure 58 can be conned by typical anti-extrusion rings 58a and 58h. The upper expander 59 has an outer surface 61 which inclines upwardly and inwardly and which is companion to the inner inclined surfaces 38 on the upper slips 36.

For the purpose of locking the compression force in the packing structure 53 during setting as well as locking the slips 35 and S3 in set condition, a split lock ring 63 is provided which has internal ratchet teeth 64 facing in an upward direction and arranged to mesh with like downwardly facing ratchet teeth 65 on the outer periphery of the -body 50. The lock ring 63 also has external tapered cam teeth 66 arranged to engage companion cam surfaces 67 in the expander 59, the cam surfaces tending to urge the

ratchet teeth

64 and 65 into mesh with one another. However, ulpward movement of the body 50y relative to the lock ring 63 can expand the lock ring outwardly, due to the lateral play between the cam surfaces 66 and 67 when the lock ring is moved upwardly relative to the expander 59. The lock ring 63 functions as a one-way clutch to permit upward movement of the body 50 relative to the expander 59 but prevent converse relative movement in a conventional manner.

The mandrel extension 14 is arranged to reciprocate upwardly and downwardly within the body bore 51 in response to manipulation of the running-in string 10 to operate the valve assembly C. An external seal device 69, of any suitable construction, is provided to seal between the mandrel extension 14 and the body 50 so that uid under pressure can be displaced through the valve assembly C without leakage back into the well annulus above the packing assembly B. The mandrel extension 14 is releasably coupled to the upper end of the body 50 by a coupling arrangement 70 in accordance with the lpresent invention which permits rigid connection lbetween the running-in string 10 and the body 50 during setting, partial release to enable positive valve assembly operation, selective disengagement by upward strain on the running-in string 10 to permit circulation of well fluids if desired, and selective engagement by downward motion of the runningin string for further operations.

As shown in FIGURES 1B and 5, this coupling structure 70 includes a split ratchet nut 71 having external, ups

wardly facing ratchet teeth 72 formed on a left-hand helix. Due to the fact that the nut 71 is split, it is capable of assuming an unstressed expanded size where the teeth 72 are engageable with upper, larger diameter threads 73 on the body 50, and a contracted size where the teeth are engageable with lower, smaller diameter companion threads 74 on the body. The

body threads

73 and 74 are formed on the same lead so that the ratchet nut 71 can readily mesh with both threads. The ratchet nut 71 is seated in an annular recess 75 in the upper portion of the mandrel extension 14, the recess being terminated at its upper end by the lower face of the mounting sub 13 and at its lower end by an annular ange 76. As shown in FIGURE 3, a longitudinal spline or key 77 extends radially outwardly in the recess 75 to engage in the slot or cut 78 formed in the split ratchet nut 71 so that the nut is co-rotatively secured to the mandrel extension 14.

In the running-in position of parts shown in FIGURES 1A and 1B, the ratchet nut 71 occulpies a lower position within the recess 75 and is contracted and threaded into the lower body threads 74. Inadvertent unthreading of the ratchet nut is precluded by a shear screw 80 engaging in the tbody 50 and in the mounting sub 13. Since the mounting sub 13 engages the upper end of the mandrel 50 and the extension flange 76 engages the lower surface of the ratchet nut 71, the extension 14 and body 50 are rigidly coupled to one another. After setting, right-hand rotation of the mandrel extension l14 relative to the body 50 will shear the screw 80 and cause the ratchet nut 71 to feed upwardly and out of engagement with the lower body threads 74. When the nut clears the lower threads 74, it will expand into mesh with the upper threads 73 and continued rotation of the nut can eventually cause it tt unthread out of the upper threads also. It will be noted that both the upper and lower faces of the ratchet nut threads 72 are inclined to some extent. This construction permits the threads 72 to be ratcheted through the uptper body threads 74 in either longitudinal direction without rotation. That is to say, the nut can repeatedly expand and contract and ratchet through the upper body threads 74, there being suicient lateral play between the inside surface of the nut and the bottom of the recess 75 when the nut 71 is adjacent to the upper body threads to permit this to occur. Due to the inclination of the upper faces of the teeth 72, the nut 71 can be released from the upper body threads 74 in response to a predetermined upward strain on the mandrel extension. In like manner, the ratchet nut 71 can be re-engaged with the upper body threads 74 by lowering the mandrel extension until the weight of the running-in string causes the nut to ratchet iback into engagement with the body threads. This arrangement permits a positive yet releasable coupling between the mandrel extension 14 and the body 50 which is highly advantageous in that, initially, a rigid connection between the extension and body is effected for transmitting high setting loads to expand the packing structure 58 and to iirmly set the slips `35 and 53. Then, with the ratchet nut 71 engaging the upper body threads 73, a coupling is effected which permits a limited amount of reciprocating motion between the extension and the body for operating the valve assembly C without disconnecting the extension from the body. When desired, a predetermined upward strain on the running-in string 10 will completely release same from the body 50 without rotation should a quick disconnection be advisable, and the extension 14 can later be merely lowered into the body Ibore 51 to re-engage the ratchet nut 71 within the upper body threads 73 for further operations.

Fluid flow through the body bore 51 is controlled by the valve assembly C which includes the valve housing 52 as previously described. The valve housing 52 has side ports 85 through the wall thereof, and the lower portion 86 of the valve housing is closed. A valve sleeve 87 is positioned within the bore of the valve housing 52 and arranged for upward and downward motion therein between an upper position shown in FIGURE 1B where upper and lower seal rings 88 and 89 seal above and below the side ports to block flow therethrough, and a lower position shown in FIGURE 2B where the side ports 85 are open for uid flow. The valve sleeve bore 90 provides a -iluid communication path through the valve sleeve 87 so that uid pressure will act on the sleeve in equal but op posite directions and will not tend to move the valve sleeve. An annular flange 91 is provided in the bore of the valve sleeve 87, and a coil spring 92 of any suitalbie construction presses upwardly against the ange 91 tending to move the valve sleeve upwardly.

The upper portion of the valve sleeve 87 is constituted as a latch `device 93 comprising a plurality of circumferentially spaced, upwardly extending latch tingers 94 having enlarged head portions 95 at their upper ends. The latch fingers 94 are spring-like or resilient and inherently tend to resile outwardly to the extent shown in detail in FIGURE 1B. As shown more clearly in FIGURE 5, each head portion 95 has an inner projection 96 and an outer projection 97, each inner projection having an upwardly facing shoulder 98 and a lower upwardly and inwardly inclined surface 99, each outer projection 97 having upper and lower oppositely

inclined surfaces

100 and 101. Moreover, the outer portion of each head is formed to extend upwardy beyond the shoulder 98 to provide a tang having an inner surface 103 which inclines downwardly and inwardly.

The lower end portion 105 of the mandrel extension 14 is formed for coupling with the latch device 93 and has spaced

annular recesses

106 and 107 thereon in which the inner projections 96 of the finger heads 95 can engage. The lower recess 107 is formed to extend to a greater depth in the coupling portion 105 than is the upper recess 106. The valve body 52 is provided with spaced

annular grooves

108 and 109 in which the outer projections 97 on the nger heads 95 can extend, the upper groove 108 extedning more deeply into the valve body than the lower groove 109 and having a lower downwardly and inwardly inclined cam surface 110.

Assuming that it is desirable to lower the tool into the well with the valve sleeve 87 in its upper closed position, the valve assembly parts are positioned as shown in FIGURE 1B with the nger heads 95 opposite the upper groove 108 and with the outer projections 97 extending into the uplper groove and with the inner projections 96 engaging within the upper extension recess 106. The upper extension recess 106 is not suiciently deep to allow the linger heads 95 to disengage from the upper body groove 108 and the valve sleeve 87 is locked in closed condition and cannot be moved downwardly. However, after the packing assembly B is set and the ratchet nut 71 disengaged by mandrel rotation as previously described, the mandrel extension 14 can be elevated until the lower recess 107 is either somewhere above, or opposite to, the nger heads 95. The extension flange 112 can readily force or cam the heads 95 outwardly and pass upwardly past the heads. Then, lowering the extension 14 will engage the extension flange 112 with the head shoulders 98 and, due to the interengagement of the inclined surfaces 101 and 110, cam the heads 95 inwardly. The lower extension recess 107 is sufciently `deep to allow the heads 95 to shift inwardly and disengage from the groove 108. Accordingly, the valve sleeve 87 can be pushed downwardly to open position as shown in FIGURE 4 by downward movement of the extension 14. Also the valve sleeve 87 can be moved upwardly to closed position lby merely elevating the extension 14 because the heads 95 are held inwardly in locked position within the lower recess 107 by the inner surface 113 of the valve body. When the heads 95 move upwardly and opposite the upper groove 108, they will resile outwardly into the groove and the end flange 114 on the lextension 14 can bypass the heads to free the coupling portion 105 from the latch device 93.

Assuming that it is desired to run the tool into the well with the valve sleeve 87 in open position, the parts can be assembled with the valve sleeve in the lower position and with the head portions 95 locked in engagement within the lower extension recess 107. To move the valve sleeve 87 to closed position, the extension 14 is elevated and the latch fingers 94 will pull the valve sleeve upwardly. When the upper groove 108 is reached, the head portions 95 will resile into the groove 108 to release the valve sleeve from the extension as previously described.

The valve assembly C is also provided with a structural arrangement to permit positive recoupling of the mandrel extension 14 and valve sleeve 87 even though the valve sleeve may be intermediate its open and closed positions. Should this occur, the head portions 95 will be located at some point below the upper groove 108. As the mandrel extension 14 moves downwardly, the end flange 114 will engage and push the head portions 9S downwardly until they are opposite the lower body groove 109, at which point they will resile outwardly and into the lower groove, `thereby permitting the flange 114 to bypass the head portions. Then, the valve spring 92, being compressed by downward movement of the valve sleeve 87, will function to force the Valve sleeve 87 and fingers 94 upwardly, camming the head portions 95 inwardly into locked engagement within the lower extension recess 107. This coaction positively couples the valve sleeve 87 to the extension 14 for further and repeated movements between open and closed positions.

Operation In operation, the various parts of the present invention can be assembled as shown in FIGURE l with the mandrel 11 connected to the lower end of the running-in string 10, and then lowered into a well bore to a desired setting point. The

slips

35 and 53 and the packing structure 58 are retracted, the upper slips 35 being encompassed by the retainer sleeve 27. The drag blocks 25 can slide along in frictional engagement with the well casing P and the cage 22, and the control sleeve 17 cannot move upwardly on the mandrel 11 due to the engagement of the

threads

28 and 29 and the locking condition of the latch ball 30. The ratchet nut 71 is in full mesh with the lower body threads 74 and engages the extension stop flange 76. The lower surface of the mounting sub 13 abuts against the upper end of the mandrel 50 so that the mandrel 11 and the mandrel extension 14 are, in net effect, integrally connected to the packer body 50.

The valve sleeve 87 can initially occupy its upper port closing position by positioning the finger heads 95 within the upper body groove 108. This can be conveniently accomplished during assembly by exerting an upward force on the lower end of the valve sleeve 87 so that the engagement of the upper head surfaces 103l with the inclined top surface of the upper groove 108 will cause the heads 95 to extend to their fullest extent into the upper groove. Thus, extended, the extension flange 112 can readily bypass downwardly beyond the heads to position upper extension recess 106 opposite the heads. On the other hand, the valve sleeve 87 can initially occupy its lower open position by making up the valve assembly C such that the iinger heads 95 are engaged in the lower extension recess 107.

At setting depth, the running-in string is rotated a suicient number of turns to the right to feed the cage 22 and the retainer sleeve 27 upwardly as previously described, the entire packer assembly B turning a corresponding amount. Upward movement of the retainer sleeve 27 disengages the sleeve from the upper sections 42 of the slip segments 36 so that the segments can be shifted outwardly. At this point, the segments 36 are still retained on the mounting sub 13 by the leaf springs 43. Upward movement of the cage 22 positions the cage recess 34 opposite the ball 30 so that the ball can move out of the mandrel detent 32 to release the mandrel 11 for upward movement relative to the control sleeve 17 and the `cage 22.

The mandrel 11 is then elevated by upward strain on the running-in string 10 to set the packer assembly B. The

engagement of the drag blocks 25 against the well casing P produces a holding force which is transmitted through the

threads

28 and 29 to the control sleeve 17, thereby resisting upward movement of the setting sleeve 20. Accordingly, as the mandrel 11 is elevated, the upper end surfaces of the slip segments 36 are brought into engagement with the lower end surface of the setting sleeve 20 and continued upward movement of the mandrel 11 causes the setting sleeve 20 to push the slip segments 36 out of retained relationship with the leaf springs 43 and out of engagement with the mounting sub flange 40. The setting sleeve 20 then functions to hold the segments against upward movement as the upper expander 59 is moved underneath the segments 36 to expand them outwardly as shown in FIGURE 2B. As the expander 59 moves upwardly, its outer inclined surfaces 61 wedge the slip segments 36 outwardly luntil the teeth 37 grip the well casing wall. Now, the upper expander 59 cannot move any further upwardly relative to Ithe well casing and continued upward move- -ment of the mandrel 11 and packer body 50, after shearing the

pins

60 and 62, serves to the expand the lower slips 53 over the lower expander S7 and to compress and expand the packing structure 58. When a predetermined upward strain has been taken on the running-in string 10, both the upper and

lower slips

35 and 53 are shifted outwardly to grip the well casing P and prevent movement in either longitudinal direction, and the packing structure 58 is expanded to pack oil the annulus between the well casing and the body 50. During upward movement of the body 50 relative to the upper expander 59, the lock ring 63 will pass over the external body teeth 65 and trap the mandrel in the highest relative position to which it is moved, thereby trapping the compression load in the packing structure 58 and locking the

slips

35 and 53 in set condition.

If it is desired to test the running-in string 10` for leakage, this can be accomplished. Should the valve sleeve 87 be initially positioned in closed condition as shown in FIGURE 1B and as previously described, the running-in string 10 will already be closed off at its lower end and can be pressure tested for leakage by applying pump pressure to the inside of the string at the earths surface. Should the valve sleeve 87 be initially positioned in open condition, the valve sleeve can be moved to closed position as will be subsequently described and the running-in string 10 leak tested in the same manner.

At any rate, the packer assembly B is now set and a pressure operation, such as squeeze cementing or hydraulic fracturing can be undertaken. To operate the valve assembly C, a relatively small upward strain, say 1000 pounds above the free point, is taken in the running-in string 10 and the string is torqued to the right. Since the packer body 50 is now fixed in the well bore due to the set condition of the packer assembly B, rotation of the mandrel extension 14 will shear the screw 80 and cause the ratchet nut 71 to feed upwardly and out of the lower body threads 74. When the nut 71 clears the lower threads 74, it will expand into mesh with the upper ratchet threads 73 and continued rotation to the right can feed the nut upwardly through the upper threads also. When the free point is indicated at the surface, the nut 71 is completely disengaged and the extension 14 is uncoupled from the packer body 50. Then the running-in string 10 can be lowered without rotation to ratchet the nut 71 back into the upper body threads 73 as shown in FIGURES 2B and 6. With this relative position of parts, it will be appreciated that the mandrel extension 14 can be reciprocated upwardly relative to the packer body 50 until the stop flange 76 pumps against the ratchet nut 71, and downwardly until the mounting sub 13 bumps against the upper end of the mandrel 50. The relative travel permitted is suiiicient to operate the valve assembly C while providing positive surface indications of the position of the valve sleeve 87 relative to the side ports in the valve body 52.

When the mandrel extension 14 is moved upwardly during complete release of the ratchet nut 71 from the

body threads

73 and 74 as previously described, the lower portion 105 of the extension is positioned at some point above the finger heads 95 which are located within the upper body groove 108. Accordingly, downward movement of the mandrel extension 14 will cause the extension ange 112 to engage the head shoulders 98 and push the valve sleeve 87 downwardly against the bias of the valve spring 92. As the heads 95 move downwardly, they are cammed inwardly out of the upper body groove 108 and into locked relationship within the lower extension recess 107 and held locked therein by the inner surface 113 on the valve body 52. as shown in FIGURE 5. Accordingly, the valve sleeve 87 is positively coupled to the mandrel extension 14 and downward movement of the mandrel extension will shift the valve sleeve to open position and upward movement will move the sleeve to closed position. During upward movement, when the heads 95 move opposite the upper body groove 108, they will reside into the groove and permit the end ange 114 on the extension 14 to bypass the inner projections 96 to release the extension 14 from the valve sleeve 87 and permit removal of the extension from the packer body 50. It will be appreciated that whenever the mandrel extension 14 is thus removed, the valve sleeve 87 should always be in its upper closed position shown in FIG- URE 4 with the

seal elements

88 and 89 spanning the side ports 85 to block uid flow. Inasmuch as the valve seals S8 and 89 are arranged to encompass substantially the same areas, uid pressure either within the valve body 52 or externally thereof will act in equal and opposite directions and will not tend to shift the valve sleeve 87.

However, should it be desired to further operate the valve sleeve 87 and if, for some reason, the head portions 95 are located at some point below the upper body groove 108 (e.g., the valve sleeve is either already in open position, or in a position intermediate its open and closed positions) the extension 14 can be again lowered into the body bore 51. When the extension end flange 114 reaches the head portions 95, the tiange will push the head portions and thus the valve sleeve 87 downwardly against the bias of the valve spring 92. When the head portions 95 are moved opposite the lower body groove 109, the head portions will resile into the lower groove and permit the end ange 114 to bypass the inner projections 96. When this occurs, the valve spring 92 will force the valve sleeve 87 upwardly, camming the head portions 95 inwardly, until the head portions are again locked within the extension recess 107 as shown in FIGURE 4. Accordingly, the parts are in relative positions for further and repeated operation.

As was previously noted, a predetermined upward strain on the running-in string 10 without rotation will cause the ratchet nut 71 to release from the upper body threads 73 by repeated contraction or ratcheting action. Therefore, it will be appreciated that the mandrel extension 14 can be quickly removed from the packer body 50 by an upward pull on the running-in string 10 should circulation or reverse circulation above the packer assembly B be desirable. An unlimited number of connections and disconnections of the mandrel extension 14 and packer body 50 can be effected by simply moving the running-in string 10 up and down to engage and disengage the ratchet nut 71 with the upper body threads 73 A new and improved coupling apparatus has been disclosed for releasably coupling elongate members in a well tool so that the members can be selectively moved together, moved relative to one another and released from one another. The apparatus is simple and reliable and can be conveniently remotely operated by rotational and longitudinal movement of one of the members.

Since certain changes or modifications may be made in the invention without departing from the inventive concepts involved, it is the aim of the appended claims to cover all such changes or modifications which fall within the true spirit and scope of the present invention.

I claim:

1. Apparatus for use in a well comprising: inner and outer telescopic members; dirst and second means respectively preventing relative longitudinal movement of said members in one position of said members, one of said means being responsive to relative rotation between said members for permitting movement of said members longitudinally relative to one another to another position, said rotation responsive means having an interconnection with one of said members for permitting longitudinal reciprocation of said members between said positions, said rotation responsive means in said other position being releasable in response to the application of a predetermined force to one of said members to permit removal of one member from the other.

2. Apparatus for use in a well tool in a well bore, comprising: inner and outer elongate members arranged for relative movement; abutment means for limiting relative movement between said members in one longitudinal direction; coupling means between said members arranged to engage said members in one position of said coupling means relative to said members to prevent relative movement between said members in the other longitudinal direction; means responsive to rotation of one of said members for feeding said coupling means along one of said members in said other direction to another position between said members whereby limited reciprocating motion is permitted between said members, said coupling means being further movable along one of said members out of engagement with said other member in response to a predetermined force on one of said members to permit removal of one of said members from the other.

3. Apparatus for use in a well tool in a well 'bore comprising: a body member having a bore; a mandrel movable upwardly and downwardly as well as rotationally within said bore; and means for releasably coupling said mandrel to said body including upper and lower longitudinally spaced thread portions on said body, an annular recess on said mandrel, an expansible and contractible split nut member in said recesses arranged to alternately engage said thread portions and movable longitudinally along both said mandrel and said body, and means for co-rotatively securing said nut member to said mandrel, one of said thread portions being sized relative to said recess so that when said nut member is engaged with said one thread portion, the inner peripheral surface of said nut member is laterally spaced from the inner wall of sai-d recess a distance which is at least as great as the height of the thread on said one portion, whereby said nut member can contract into said recess a suicient amount to enable said nut member to be disengaged from said one thread portion without relative rotation, the other of said thread portions being sized relative to said recess so that said nut member ts snugly between said recess and said other thread portion, whereby said nut member cannot be disengaged from said other thread portion except by relative rotation.

4. The apparatus of claim 3 wherein said upper thread portion is the said one portion which the nut member can be disengaged from without relative rotation.

5. The apparatus of claim 4 wherein said securing means includes a key on said mandrel engaging within the split in said nut member.

6. Apparatus for use in a well tool in a well bore comprising: Ian outer member having upper and lower longitudinally spaced and coaxially disposed bore sections, said bore sections each having threads formed with the same lead, said bore sections having differing internal diameters; an inner member disposed in said bore sections and adapted for both longitudinal and rotational movement therein, said inner member having an external annular recess; a nut member in said recess arranged and constructed for contraction and expansion, said nut member having external threads engageable with the threads on said lower bore portion when contracted and engageable with the threads on said upper bore portion when expanded; means for co-rotatively securing said nut member to said inner member so that rotation of said nut member by said inner member relative to said outer member will cause said nut member to feed relatively along both of said members; and releasable means initially preventing relative rotation between said inner and outer members to prevent feeding of said nut member along said members.

7. The apparatus of claim 6 wherein said nut member is internally sized, when expanded, relative to said recess so that the threads on said nut member can be ratcheted through the threads on said upper bore section without relative rotation.

`8. Apparatus for use in a well tool, comprising: an outer member; an inner member telescopically and rotatably movable in said outer member; longitudinal spaced threaded portions on one of said members, said threaded portions having respective larger and smaller sizes; an expansible and contractible coupling member on the other of said members engageable with said smaller threaded portion when contracted to couple said inner member against movement relative to said outer member, and with said larger threaded portion when expanded to couple said inner and outer member together for liimted telescoping movement relative to one another; means for co-rotatively and slidably securing said coupling member to said other member so that relative rotation between said members can feed said nut member along both of said members between positions of engagement with respective threaded portions; and stop means on said members for limiting telescoping movement of said members when said nut member is engaging said larger size threaded portion.

9. The apparatus of claim 8 wherein said threaded portions have threads formed on the same lead, and said coupling member has threads alternately engageable with the threads on said portions.

10. The apparatus of claim 8 wherein said coupling member is a ring having a radial opening therein.

11. The apparatus of claim 10 wherein said securing means includes a key on said other member operatively engaged in said opening.

12. Apparatus for use in a well tool comprising: an outer mandrel having a bore; upper and lower thread sections adjacent the upper end of said outer mandrel, said upper thread section having a larger internal size than said lower thread section; an inner mandrel telescoped within the bore of said outer mandrel and having a shoulder engageable with an upper end surface of said outer mandrel to limit downward movement of said inner mandrel within said outer mandrel, said inner mandrel having an external recess co-extensive with said thread sections; an expansible and contractible ring member on said inner mandrel within said recess, said ring member having a threaded periphery in mesh with said lower thread section when contracted to prevent upward movement of said inner mandrel within said outer mandrel; and means for co-rotatively securing said ring member to said inner mandrel whereby rotation of said inner mandrel relative to said outer mandrel will feed said ring member upwardly relative to said outer mandrel to a position adjacent said upper thread section where said ring member can expand into mesh with said upper thread section, said ring member being constructed and arranged whereby sufcient lateral play of said ring member in said recess is permitted in response to a predetermined upward force on said ring member so that said ring member can repeatedly contact and expand and ratchet through said upper thread section without rotation of said inner member.

13. In a well tool apparatus having a valve body with a fluid passage and a valve element in the valve body movable between upper and lower positions to control fluid flow through the passage, the combination comprising: an elongate valve actuating member extending into said passage and arranged for upward and downward movement therein for moving said valve element; coupling means between said member and said valve body engageable with said valve body in one position of said coupling means to prevent longitudinal movement of said member relative to said valve body in one longitudinal direction; and means responsive to rotation of said member for feeding said coupling means along said valve body to another position of engagement with said valve body whereby a limited amount of reciprocating motion is permitted between said member and valve body to allow movement of said valve element by said member, said coupling means being arranged whereby said coupling means can be disengaged from said valve body in response to a force of a predetermined magnitude in said one direction on said coupling means without rotation of said member.

14. The apparatus of claim 13 further including means on said member and valve body engageable to limit movement of said member relative to said valve body in the other longitudinal direction.

15. The apparatus of claim 13 further including means for co-rotatively securing said coupling means to said member.

16. The apparatus of claim 13 further including seal means between said member and valve body for preventing fluid leakage from said passage.

References Cited UNITED STATES PATENTS 2,737,248 3/1956 Baker 285-141 2,893,492 7/1959 Brown 166-129 3,279,542 10/1966 Brown 166--139 3,357,489 12/1967 Brown 166-139 3,361,207 l/l968 Chenoweth l66-l39 JAMES A. LEPPINK, Primary Examiner'.

U.S. Cl. X.R. 166-124, 139