ANTI-ROTATION DEVICE FOR USE IN WELLBORES

Abstract: An anti-rotation device (20) can be incorporated in a top plug (10) or other well tool. The anti-rotation device (20) comprises a floor (25). A plurality of teeth (22) are mounted on the floor (25) and are surrounded by a load member (30) in the form of a ring. The teeth (22) project beyond the ring (30). When two anti-rotation devices are advanced towards one another the surfaces of the load members engage and absorb compression forces whilst the teeth are free or substantially free from compressive forces and simply act to inhibit relative rotation between the anti-rotation devices.

Description: ANTI -ROTATION DEVICE FOR USE IN WELLBORES This invention relates to an anti-rotation device for use in wellbores and to a well tool including such an anti-rotation device . Once a wellbore has been dri lled , a string of tubular casing is lowered into the wellbore so that operations can be conducted in and through the casing . In one such operation, cement is introduced into the annular space between the interior wall of the wellbore and the exterior surface of the casing . The cement, inter alia forms a protective barrier around the casing; isolates multiple producing formations through which the wellbore extends ; and displaces unwanted fluids or material in the annular space between the wellbore and the casing. A variety o f wel l tool s are inserted in the wellbore during cementing . After cementing is complete these well tools , which include float shoes , f loat collars and plugs are drilled out together with any residual cement, to open the casing . During drilling out , the rotating drill bit first contacts a plug . This can cause the plug to rotate and then slip on the surface with which it is in contact , e. g. the top of a bottom plug or a layer of cement . This slipping is inefficient and wastes time and energy. A variety of prior art devices have addressed this problem . The attempted solutions typically involve the use of some sort of protrusions, projections or teeth on the plug ends to inhibit relative rotation or the use of a plate with teeth on both sides that is placed between a plug and a surface over which a plug could potentially slip . A variety of problems have been encountered with these prior art efforts . Often the teeth on the various devices contact each other and it is then the teeth alone that are forced to bear whatever load is imposed on the plug or plate. These loads can be enormous, crushing or distorting the teeth so that they do not function properly . Other prior art plugs have teeth which are configured and disposed so that the leading edges of the teeth meet and cross , not permitting further engagement of the lateral portions of the teeth on two adj acent plugs; i . e . , the plugs are prevented from accomplishing the desired non-rotating function. With prior art devices in which the teeth are relatively short, slight separation caused for example by a bouncing dri l l bit , can cause di sengagement , relative spinning movement , or ratcheting between the teeth , i . e . , the non- rotation function is not accomplished . Previously used protrusions for piercing or gripping rubber may not have sufficient gripping engagement to prevent rotation. An aim of at least preferred embodiments of the present invention is to reduce at least some of these problems . According to the present invention there is provided an anti-rotation device for use with well tools, said anti-rotation device comprising a body member having a floor, and a plurality of device protrusions extending from said floor, characterised in that said anti-rotation device further comprises : a load member having a load surface above said floor, and said device protrusions extend beyond said load surface, the arrangement being such that upon interengagement of said anti-rotation device with a second anti - rotation device having second device protrusions and a second load member with a second load surface, the load surfaces contact each other and the load members bear a compres s ive load on the anti - rotation device and isolate the device protrusions from some or all of such load . Pre ferably , said load member has a f l at load surface. Advantageous ly , said load member compri ses a continuous circular ring. Preferably, said device protrusions are pointed . Advantageously, said device protrusions are shaped and disposed so that , in use , a foreign obj ect caught between adj acent anti -rotation devices may be contained therebetween without inhibiting the interengagement of the device protrusions on the adj acent anti-rotation devices . Preferably, said anti-rotation device includes a longitudinal channel extending through the body member permitting fluid flow through the anti-rotation device. Advantageously, the device protrusions extend from the load member to the periphery of the longitudinal channel . Preferably , the dimensions of the device protrusions is substantially constant from the load member to the periphery of the longitudinal channel . Advantageously, the anti-rotation device includes a frangible diaphragm secured across said longitudinal channel preventing fluid flow therethrough until it is broken . Preferably , an edge of the recess is bevelled inwardly to facilitate interengagement of the device protrusions with the device protrusions of a second anti -rotation device. Advantageously, the anti-rotation device includes movement inhibition means for inhibiting movement of the anti-rotation device with respect to a material in which the anti -rotational device is to be embedded. Preferably , said movement inhibition means comprises one or more protrusions extending from the body member. Advantageously , said movement inhibition means comprises one or more recesses in the body member in which in use, a portion of the material in which the device is embedded resides . The present invention also provided a well tool provided with an anti-rotation device in accordance with the invention. For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:- Fig. 1 is a side view, half in cross-section, of an anti-rotation device according to the present invention incorporated in a plug; Fig. 2 is a side view, half in cross-section, of two anti-rotation devices according to the present invention incorporated in a plug; Fig. 3A is a top view of a device according to the present invention; Fig. 3B is a side view in cross- section of the anti-rotation device of Fig. 3A; Fig. 3C is a fragmentary view along line C-C of Fig. 3A; Fig. 3D is a side view in cross-section of a modified version of the anti-rotation device of Fig. 3A; Fig. 4A is a top view of an anti-rotation device according to the present invention; Fig. 4B is a view along line B-B of Fig. 4A; Fig. 4C is a view along line C-C of Fig. 4A; Fig. 4D is a view along line D-D of Fig. 4A; Fig. 5 is a side view partially in cross-section of a top plug, bottom plug, and float shoe according to the present invention; Fig. 6A is a top view of an anti-rotation device according to the present invention; Fig. 6B is a side view in cross-section of the anti-rotation device of Fig. 6A. Fig. 7A is a top view of an anti-rotation device according to the present invention; Fig. 7B is a side view in cross-section of the anti-rotation device of Fig. 7A; and Fig. 7C is a fragmentary view along line E-E of Fig . 7A. Referring to Figure 1 of the drawings, there is shown a top plug 10. The top plug 10 comprises a body 12 with a plurality of flexible wipers 14 which are formed integrally with and extend from the body 12. A top member 18 extends across the top of the body 12 and a bottom member 17 extends around the bottom of the body 12. An anti-rotation device 20 according to the present invention is mounted in the bottom of the top plug 10. The anti-rotation device 20 comprises a body member 21 with threads 26 for threadedly engaging a threaded opening 16 in the body 12 of the top plug 10. A plurality of teeth 22 extend downwardly from the floor 25 of the recess 23. A ring 30 having a load surface 31 extends from the body member 21 and defines the periphery of the recess 23. The ring 30 partially extends into an opening 15 in the bottom member 17 of the top plug 10. A shoulder 32 of the body member 21 abuts a face 13 of the body 12 of the top plug 10. In another embodiment the anti-rotation device 20 is disposed so that the load surface 31 is flush with the lower surface 19 of the bottom member 17. Referring now to Fig. 2, a bottom plug 40 comprises a body 42 with a plurality of wipers 44 formed integrally of and extending from the body 42. A top member 48 extends around the top of the body 42 and a bottom member 47 extends around the bottom of the body 42. An anti-rotation device 50 according to the present invention (like the previously described anti-rotation device 20) has a body member 51 with threads 56 for threadedly engaging a threaded opening 46 in the body 42 of the bottom plug 40. A plurality of teeth 52 extend from the floor of the recess 53 . A ring 60 extends from the body member 51 and defines the periphery of the recess 53 and partially extends into an opening 45 in the bottom member 47 of the bottom plug 40. A groove 54, partially defined by a shoulder 58 , in the top of the body member 51 of the anti - rotation devi ce 50 is suitable f or receiving and holding a portion of a diaphragm or other object for closing off a channel 64 which extends longitudinally through the anti-rotation device 50 and is in fluid communication with a channel 41 extending longitudinally through the bottom plug 40 . A shoulder 62 of the body member 51 abuts a face 43 of the body 42 of the bottom plug 40. Another anti-rotation device 70 according to the present invention comprises a body member 71 provided with threads 76 for threadedly engaging a threaded opening 49 in the body 42 of the bottom plug 40 . A plurality of teeth 72 extend from the floor of recess 73 . A ring 80 extends f rom the body member 71 and defines the periphery of the recess 73. The ring 80 has a load surface which is flush with the upper surface of the top member 48 of the body 42 of the bottom plug 40. A groove 74, partially defined by a shoulder 78 , in the bottom o f the body member 71 i s suitable f or receiving and holding a portion of a diaphragm or other obj ect for clos ing of f a channel 84 which extends longitudinally through the anti-rotation device 70 and is in fluid communication with the channel 41 of the bottom plug 40 . A shoulder 82 of the body member 71 abuts a face of the body 42 of the bottom plug 40. Referring now to Figs . 3A , 3B , and 3C , an anti- rotation device 100 has a body member 101 with a threaded periphery 106 for threaded engagement with a female-threaded opening in an apparatus such as a plug or other well tool . Of course it is within the scope of this invention to provide a device without a threaded periphery and to connect, attach, adhere, or incorporate such an anti-rotation device in an apparatus or tool by any appropriate and effective method and means. A plurality of teeth 102 extend from the floor 105 of a recess 103 circumscribed by a side wall 107 of a ring 110. The teeth 102 extend from the side wall 107 (the outer edge of the recess 103) inwardly to the periphery of a channel 114 (see Fig. 3A) which extends longitudinally through the anti-rotation device 100 and through which fluid flow is permitted. A groove 104 is disposed in the bottom of the anti-rotation device 100 and is configured to receive and hold a portion of a frangible diaphragm (not shown) which closes off the channel 114 to fluid flow until it is broken, e.g. by the force of cement. (The "upper portion" and "bottom" of the anti-rotation device 100 refer to its orientation as presented in Fig. 3B - of course it may be inverted as shown in Fig. 2, anti-rotation device 50). The side wall 107 as shown in Fig. 3B is perpendicular to the floor 105, but it is within the scope of this invention for the side wall 107 to slope from the ring 110 to the floor 105; it could, for example, mirror the angle of the teeth 102. It is preferred that the distance a (Fig. 3B) from the floor 105 to the top of the ring 110 is greater than the distance b from the top of the ring 110 to the top of the teeth 102 so that when two anti-rotation devices such as anti-rotation device 100 are disposed adjacent each other with their teeth interengaged, the two rings such as rings 110 meet, contact, and bear any axial load on the anti-rotation devices while the teeth 102 are prevented from contacting the floor 105 of the recess 103 of the adjacent anti-rotation device. In this way the rings 110 bear the axial load rather than the teeth and damage due to such loading on the teeth is substantially eliminated. In one embodiment the distance a is 14.2mm (0.56 inches) and the distance b is 13.48mm (0.531 inches). As shown in Fig. 3A, it is preferred that the teeth 102 have a constant cross-section from the inner edge of the ring 110 to the periphery of the channel 114; i.e., their dimensions are substantially constant from the outer edge of the recess 103 to the periphery of the channel 114. Such teeth 102 are relatively stronger as they approach the channel 114 than would be teeth whose cross-section diminishes from the outer edge of the anti-rotation device towards its interior. The use of a ring such as the ring 110 serves to buttress the outer edge of the teeth, protecting them and strengthening the anti-rotation device. Also, in some prior art devices, teeth with a diminishing cross-section are shorter the nearer they are to a device's center. It is much easier for shorter teeth to either fail to engage or to ratchet across each other. The anti-rotation device 100 as shown in Fig. 3A has six teeth 102. It is within the scope of this invention to provide a device with one or more teeth, but is preferred that a number of teeth be provided and spaced apart so that the space between teeth at the inner edge of a channel (such as a space 111 between the teeth 102 of anti-rotation device 100) and the area between teeth 102 (such as an area 113 between the teeth 102 of the anti-rotation device 100) can accommodate foreign objects and debris which, if it were present on the teeth of prior art devices would inhibit or prevent proper tooth interengagement. The size of a foreign object which can be accommodated in the area 113 is determined by the size of that area. If only one tooth is used, a larger object can be accommodated; but if, e.g., ten teeth were used, the size of such an object would be smaller. Objects from above encountering a pointed tip of a tooth will move and be diverted into one of the areas 113. Since the teeth 102 (or other protrusions) are partially within the anti-rotation device 100, minor axial displacement movement will not result in the disengagement of the teeth of two adjacent anti-rotation devices. Teeth in prior art devices that simply extend from a top surface of the device are more easily disengaged. Referring now to Fig. 3C, the tooth 102 has a cross-sectional profile that includes a perpendicular side 119; a slanted side 120; and a base 121. The angles between sides are: angle 116 - 40°; angle 118 - 90°; and angle 117 - 30°. This profile is advantageous because the torque of drill will be transmitted through a right angle (118) and angle 116 will give support against tooth failure. There will be only a minimal force component (or none) trying to force the teeth up or down to disengage them. Although angles 116 and 117 are shown with a preferred extent, workable preferred ranges for these angles are: angle 116, 20 to 70 degrees; angle 117, 20 to 70 degrees; angle 118, 90 to 45 degrees. As shown in Fig. 3B, the outer edge of the teeth 102 is bevelled inwardly, see bevel 112, to facilitate the interengagement of the teeth on adjacent anti- rotation devices. As shown in Fig. 3B the bevel 112 is 30° from normal, but any bevel which provides this facilitation may be used. As shown in the modified version of the anti- rotation device 100 in Fig. 3D, a cut-out, scoop, indentation, or recess 115 is provided so that when the anti-rotation device 100 is emplaced within a material that sets e.g. concrete or which hardens, e.g. a thermosetting material or plastic, some of the material enters and sets within the recess to inhibit or prevent movement of the anti-rotation device 100 with respect to the material. Although only one recess is shown, several may be used. The recess may be configured as desired. The recess 115 is like a pocket in the body of the anti- rotation device 100, although it could be of a different shape. It may extend partially or entirely around the anti-rotation device 100. A projection 109 extends from the anti-rotation device 100 and is also used to inhibit or prevent movement of the anti-rotation device 100 with respect to materials as already described. One or more projections may be employed and it or they may be disposed as desired on the anti-rotation device 100. Also, although the projection 109 is shown as finger¬ like, any desirable configuration may be used. An anti-rotation device 140 as shown in Figs. 4A, 4B, 4C and 4D is very similar in structure and operation to the anti rotation device 100 previously described; but the anti-rotation device 140 has a plurality of teeth 142 with a slightly different cross- sectional profile. As shown in Fig. 4C, a tooth 142 with sides 159, 160 and 161, as viewed from the end, forms a triangle with angles of 50° (angle 156); 75° (angle 158); and 55° (angle 157). A tooth with this profile has strength for engagement and when torque is applied. Although angles 156, 157, and 158 are shown as preferred workable ranges for these angles are as follows; angle 156, 20 to 70 degrees; angle 157, 20 to 70 degrees; and angle 158, 90 to 45 degrees. The radial extremities of the teeth 142 are provided with a bevel 152 as shown. The anti-rotation device 140 has a body member 141 with threads 146 for threaded engagement with a female- threaded opening in another apparatus. A plurality of teeth 142 extend from a recess 143 defined by a floor 145 and a side wall 147 of a ring 150 which encircles the upper portion of the body member 141 . The teeth 142 extend radially from the side wall 147 ( see Fig . 4A ) inwardly to the periphery of a channel 154 which extends longitudinally through the device and through which fluid can flow . A groove 144 is disposed in the bottom the anti - rotation device 140 and i s conf igured to receive and hold a portion of a frangible diaphragm ( ot shown ) which closes off the channel 154 to fluid flow until it is broken. Referring now to Fig . 5 , a top plug 210 is disposed above, but not yet in contact with, a bottom plug 240. The bottom plug 240 is disposed above, but not yet in contact with, a float shoe 300. The top plug 210 is similar to the plug top 10 , previously described . The top plug 210 has a body 212 with a plurality of flexible wipers 214 extending therefrom. An anti-rotation device 220 ( like the anti- rotation device 20 ) is threadedly engaged in a threaded opening 216 in the bottom of the body 212 by threads 226 on the periphery of a body member 221 of the anti- rotation device 220. A plurality of teeth 222 extend from a recess 223 defined by a floor 225 and a side wall 227 of a ring 230 which encircles the top of the body member 221. The teeth 222 are like the teeth 22 and 142 previously described. The bottom plug 240 is like the plug 40 , previously described . The plug 240 has a body 242 with a plurality of wipers 244 extending therefrom . An anti-rotation device 250 ( l ike the anti - rotation device 50 ) i s threadedly engaged in an opening 246 in the bottom of the body 242 by threads 256 on the periphery of a body member 251 of the anti-rotation device 250. A plurality of teeth 252 extend from a recess 253 defined by a floor 255 and a side wall 257 of a ring 260 which encircles the bottom of the body member 251. The teeth 252 are like the teeth 52 and 142 previously described. The bottom plug 240 has an anti-rotation device 270 (similar to the anti-rotation device 70) which is threadedly engaged in an opening in the top of the body 242 by threads 276 on the periphery of a body member 271 of the anti-rotation device 270. A plurality of teeth 272 extend from a recess 273 defined by a floor 275 and a side wall 277 of a ring 280 which encircles the top of the body member 271. The teeth 272 are like the teeth 72 and 142 previously described. A groove 274 is disposed in the bottom of the body member 271. An upstanding shoulder 281 of a frangible diaphragm 282 is held in the groove 274 to maintain the diaphragm 282 in place over a channel 284 that extends longitudinally through the anti-rotation device 270. Fluid flow is permitted through the channel 284 when it is not closed off by the diaphragm 282. The float shoe 300 has an outer tubular body 302 which is threadedly connected to a casing joint 287. An amount of hardened cement 303 surrounds a check valve 304 mounted substantially in the center of the float shoe 300. An anti-rotation device 310 is mounted on the housing of the check valve 304 as shown. The anti-rotation device 310 has a body member 311 and a plurality of teeth 312 which extend upwardly from the floor 315 of a recess 313. A ring 320 which extends around the top of the body member 311. The teeth 312 are like the teeth 72 and 142 previously described. A channel 314 extends longitudinally through the anti- rotation device 310 and permits fluid flow therethrough. The check valve 304 has a plunger 306 which is urged upwardly by a spring 305 to close off flow through the valve by closing off a channel 308 in and through the float shoe 300. The channel 308 is in fluid communication with the channel 314 in the anti-rotation device 310, which itself is in fluid communication with the interior of the casing joint 287. Pockets 316 and 318 in the body member 311 of the anti-rotation device 310 have hardened cement 303 in them. The hardened cement 303 inhibits movement of the anti-rotation device 310 with respect to the hardened cement 303, particularly during drilling out. An anti-rotation device 400 as shown in Figs. 6A and 6B is similar to anti-rotation devices 100 and 140, previously described; but has a load bearing ring 420 located centrally of the anti-rotation device 400 around a flow channel 404 through the anti-rotation device 400. The anti-rotation device 400 has a body member 411 with threads 406 for threaded engagement with a female- threaded opening in another apparatus. A plurality of teeth 412 extend from a recess 413 defined by a floor 405, a side wall 407 of the ring 420 which encircles the channel 404, and a side wall 421 of a lip 422 extending around the periphery of the anti-rotation device 400. The teeth 412 extend radially from the side wall 421 inwardly to the side wall 407 of the ring 420. The tip of the lip 422 is tapered to a point. By using a reverse taper on an adjacent apparatus (e.g. a plug) better centring of two adjacent devices or apparatuses is achievable and a better seal may be obtained between the two. Although the load members shown in the preferred embodiments are circular and continuous rings, it should be understood that one or more discrete upstanding members which extend sufficiently upward from the recess of the device to take some or all of the load off of the teeth when two devices meet could also be used. As shown in Figs. 7A, 7B and , 7C, teeth for an anti- rotation device according to the present invention may have a surface comprising a plurality of. sub-surfaces and an inwardly tapering lip may be provided around a device ' s recess to facilitate engagement and sealing . Teeth 512 ( shown to scale ) of an anti-rotational device 500 according to the present invention have a body member 514 defined by a substantially straight side surface 509 and a surface 503 comprised of sub-parts 504, 505 and 506. The anti-rotation device 500 comprises a body member 511, a load bearing ring 520, and a recess 513. This anti-rotation device 500 is similar to those previously described herein. It has an inwardly tapering lip 522 extending around the outer periphery of the recess 513. The anti-rotation devices hereinbefore described can be incorporated in a large variety of well tools in addition to those already mentioned, for example jars, stage tool s , liner hangers and clutch devices for packers .

Claims: CLAIMS: 1. An anti-rotation device for use with well tools, said anti rotation device (20,50,70,100,140,220,250,270, 310,400,500) comprising a body member (21,51,71,101,141,221,251,271,311, 411,511) having a floor (25,55,75,105,145,225,255,275, 315,415,515), and a plurality of device protrusions (22,52,72,102, 142,222,252,272,312,412,512) extending from said floor (25,55,75,105,145,225,255,275,315,415,515); characterised in that said anti-rotation device (20,50,70,100,140,220,250,270,310,400,500) further comprises: a load member (30,60,80,110,150,230,260,280,320, 420,520) having a load surface above said floor (25, 55,75,105,145,225,255,275,315,415,515), and said device protrusions (22,52,72,102,142,222,252, 272,312,412,512) extend beyond said load surface, the arrangement being such that upon interengagement of said anti rotation device (20,50,70,100,140,220,250,270,310,400,500) with a second anti-rotation device having second device protrusions and a second load member with a second load surface, the load surfaces contact each other and the load members bear a compressive load on the anti-rotation device and isolate the device protrusions from some or all of such load. 2. An anti-rotation device as claimed in Claim 1, characterised in that said load member (30,60,80,110, 150,230,260,280,320,420,520) has a flat load surface. 3. An anti-rotation device as claimed in Claim 1 or 2, characterised in that said load member (30,60,80,110, 150,230,260,280,320,420,520) comprises a continuous circular ring. 4. An anti-rotation device as claimed in Claim 1, 2 or 3, characterised in that the device protrusions (22,52,72,102,142,222,252,272,312,412,512) are pointed. 5. An anti-rotation device as claimed in Claim 1, 2, 3 or 4, characterised in that the device protrusions (22,52,72,102,142,222,252,272,312,412,512) are shaped and disposed so that, in use, a foreign object caught between the adjacent anti-rotation devices may be contained therebetween without inhibiting the interengagement of the device protrusions on the adjacent anti rotation devices. 6. An anti-rotation device as claimed in any preceding Claim, characterised in that it includes a longitudinal channel (34,64,84,114,154,314) extending through the body member (21,51,71, 101,141,221,251,271,311,411,511) permitting fluid flow through the anti rotation device ( 20, 50, 70, 100, 140, 220, 250, 270, 310, 400, 500 ) . 7. An anti-rotation device as claimed in Claim 6, characterised in that the device protrusions (22,52,72,102,142,222,252,272,312,512) extend from the load member (30,60,80,110,150,230,260,280,320,520) to the periphery of the longitudinal channel (34,64,84,114, 154,314). 8. An anti-rotation device as claimed in Claim 7, characterised in that the dimensions of the device protrusions (22,52,72,102,142,222,252,272,312,512) is substantially constant from the load member (30,60,80, 110,150,230,260,280,320,520) to the periphery of the longitudinal channel (34,64,84,114,154,314). 9. An anti-rotation device as claimed in Claim 6, 7 or 8 characterised in that it includes a frangible diaphragm secured across said longitudinal channel preventing fluid flow therethrough until it is broken. 10. An anti-rotation device as claimed in any preceding Claim, characterised in that an edge of the device protrusions (102,142,222,252,272,312,412,512) at the load member (110,150,230,260,280,320,420,520) is bevelled (112,152) inwardly to facilitate inter-engagement of the device protrusions with another apparatus. 11. An anti-rotation device as claimed in any preceding claim, characterised in that it includes movement inhibition means (109,115) for inhibiting movement of the device with respect to a material in which the device is to be embedded. 12. An anti-rotation device as claimed in Claim 11, characterised in that said movement inhibition means comprises one or more protrusions (109) extending from the body member (21,51,71,101,141,221,251,271,311,411, 511). 13. An anti-rotation device as claimed in Claim 11 or 12, characterised in that said movement inhibition means comprises one or more recesses (115) in the body member (21,51,71,101,141,221,251,271,311,411,511) in which in use, a portion of the material in which the device is embedded resides. 14. A well tool for use in a wellbore, characterised in that it includes an anti-rotation device as claimed in any preceding claim.

Inventors: GLASER MARK C, GLASER, MARK, C.
Applicants: LUCAS BRIAN RONALD, WEATHERFORD US INC, LUCAS, BRIAN, RONALD, WEATHERFORD U.S., INC.
Application year: 1991
Main classification: E21B33
IPC codes: E21B29, E21B33