Top drive stand compensator with fill up tool

A compensation and fill up assembly comprises a slip assembly for engaging a tubular and a compensation assembly for supporting a weight of the tubular when engaged by the slip assembly. The compensation and fill up assembly further comprises a fluid swivel and a fill up tool coupled to the fluid swivel by a fluid shaft. The fill up tool is insertable into and rotatable with the tubular using the fluid swivel.

BACKGROUND OF THE INVENTION

Field of the Invention

Embodiments of the invention relate to methods and apparatus for making up tubular connections.

Description of the Related Art

In the construction and completion of oil and gas wells, a drilling rig is used to facilitate the insertion and removal of tubular strings into a wellbore. Tubular strings are constructed by inserting a first tubular into a wellbore until only the upper end of the tubular extends out of the wellbore. A gripping member close to the surface of the wellbore then grips the upper end of the first tubular. The upper end of the first tubular has a threaded box end for connecting to a threaded pin end of a second tubular. The second tubular is lifted over the wellbore center, lowered onto or “stabbed into” the upper end of the first tubular, and then rotated such that the pin end of the second tubular is threadedly connected to the box end of the first tubular.

This process may be repeated to form a tubular string of desired length. However, it is critical not to damage the threads when the pin end is stabbed into the box end, or when torque is applied to overcome the weight of the second tubular resting on the threads. It is also critical that the drilling rig operator lowers the second tubular at the same rate at which the threads draw together.

During make up of these tubular connections, the tubular string may be filled with a drilling fluid, such as mud. A fill up tool is inserted into the tubular string for supplying the drilling fluid. The fill up tool may include a sealing member, such as a packer, that engages the inner diameter of the tubular string to prevent drilling fluid from flowing out of the upper end of the tubular string. The sealing member, however, remains stationary as the tubular string rotates when making up a tubular connection and/or when being lowered into the wellbore. Wear of the sealing element is greatly enhanced by rotation of the tubular string relative to the stationary sealing element, which increases the risk of a seal failure.

Therefore, there is a need for new and improved methods and apparatus for making up tubular connections.

SUMMARY OF THE INVENTION

A compensation and fill up assembly, comprising a slip assembly for engaging a tubular; a compensation assembly for supporting a weight of the tubular when engaged by the slip assembly; a fluid swivel; and a fill up tool coupled to the fluid swivel by a fluid shaft, wherein the fill up tool is insertable into and rotatable with the tubular using the fluid swivel.

A method of making up a tubular connection, comprising lowering a compensation and fill up assembly into engagement with a tubular, wherein the compensation and fill up assembly comprises a slip assembly, a compensation assembly, a fluid swivel, and a fill up tool coupled to the fluid swivel by a fluid shaft; inserting the fill up tool into the tubular; engaging the tubular using the slip assembly; supporting a weight of the tubular using the compensation assembly; and rotating the tubular, the slip assembly, the fluid swivel, and the fill up tool to connect the tubular to a tubular string.

DETAILED DESCRIPTION

FIG. 1is a perspective view of a drilling rig1having a rig floor10with a gripping apparatus20located substantially at the center of the rig floor10. The gripping apparatus20grips and supports the weight of a tubular string100. The gripping apparatus20is typically a spider having slips, but can be any other similar apparatus configured to support the weight of the tubular string100. The tubular string100comprises one or more tubulars, such as tubular101(having flush joints or tool joints), that are coupled together and subsequently lowered into a wellbore2.

A handling system30having gripping members35is disposed on the drilling rig1. The gripping members35may be operable to retrieve the tubular101from a stack of tubulars located on or near the drilling rig1. The handling system30assists with positioning and/or connecting the tubular101to the tubular string100.

A rotation mechanism25may be provided on the drilling rig1for rotating the tubular101and/or the tubular string100. The rotation mechanism25rotates the tubular101to make up a threaded connection with the tubular string100. The rotation mechanism25may be any apparatus for rotating a tubular, including but not limited to, a pipe spinner, a power tong, a pipe wrench, or a rotary table. Alternatively, or in addition to the rotation mechanism25, the tubular101and/or tubular string100may be rotated using a top drive or a power swivel.

A tubular handling assembly200comprising a traveling member205, a compensator/fill up assembly220, and an elevator300may be supported by the drilling rig1. The assembly200assists with the connection of one or more tubulars101to the tubular string100. The traveling member205may be any device capable of raising and lowering the assembly200, including but not limited to, a traveling block, a top drive, and/or an elevator. The compensator/fill up assembly220may be any device capable of compensating for the weight of the tubular101and/or filling up the tubular string100with a drilling fluid or other similar working fluid. The elevator300may be any device capable of supporting the entire weight of the tubular string100.

In operation, the handling system30grips and positions the tubular101substantially over the well center, with a pin end103of the tubular101closest to a box end104of the tubular string100. The traveling member205lowers the assembly200until the compensator/fill up assembly220engages the upper end of the tubular101. With the compensator/fill up assembly220supporting the weight of the tubular101, the tubular101is moved so that the pin end103engages the box104of the tubular string100for connection. During stab in and make up of the threaded connection between the tubular101and the tubular string100, the compensator/fill up assembly220supports at least a portion of the weight of the tubular101to prevent and/or minimize the risk of the tubular101weight causing damage to the threads. By supporting at least a portion of the weight of the tubular101, the compensator/fill up assembly also helps increase the amount of torque into making up the threaded connection by reducing the amount needed to overcome sliding friction when rotating the tubular101.

In one embodiment, the rotation of the tubular101is performed by the rotation mechanism25. The rotation mechanism25may be a power tong. With the tubular101rotating, and the compensator/fill up assembly220supporting and compensating the weight of the tubular101, the pin103threads into the box104. The elevator300may then engage the tubular string100, which now includes the tubular101. The compensator/fill up assembly220may disengage the tubular101, and the gripping apparatus20may disengage the tubular string100, such that the entire load of the tubular string100is supported by the elevator300. Although not supporting the weight of the tubular string100, the compensator/fill up assembly220may still be engaged with the tubular101to supply a drilling fluid or other working fluid to the tubular string100.

The traveling member205lowers the tubular string100so that the box end104is near the rig floor10. The gripping apparatus20then engages the tubular string100and the elevator300disengages the tubular string100. The traveling member205lifts the assembly200and the process is repeated until the tubular string100is the desired length.

In one embodiment, the traveling member205may be a top drive which rotates the tubular101during connection such that the rotation mechanism25is not needed. As noted above, the traveling member205may be any apparatus for raising and lowering tubulars, including but not limited to, a top drive, an elevator, a traveling block, and/or any combination of similar systems known in the art. In one embodiment, the handling system30may not be used and the tubular101may be brought to the well center by the elevator300, by manual operation, or by other means known in the art.

FIG. 2illustrates a schematic view of the tubular handling assembly200. The assembly200may include the traveling member205which connects to the compensator/fill up assembly220and the elevator300. An adapter sub215may connect the traveling member205to the compensator/fill up assembly220. In one embodiment, the adapter sub215connects to a drive shaft210of the traveling member205, which may be a top drive configured to rotate the tubular101. The adapter sub215may have threads which screw onto the end of the drive shaft210. Although shown as a threaded connection, the adapter sub215may connect to the drive shaft210in any manner known in the art, such as by welding, pin connectors, or clamps. The adapter sub215comes in any size desired to meet the requirements of the traveling member205and the drilling operation.

Further, the assembly200may include the elevator300. The elevator300connects to the traveling member205by bails305. The elevator300may be a tubular string elevator adapted to support the entire weight of the tubular string100. The elevator300may be any elevator used in drilling operations, capable of supporting the weight of the tubular101or the entire tubular string100. The elevator300may be automated for remote operation.

FIG. 3illustrates one embodiment of the assembly200, including the compensator/fill up assembly220and the elevator300. As illustrated, the elevator300may support the tubular string100. The elevator300may be coupled to the traveling member205, such as a top drive, by bails305.

FIGS. 4A and 4Billustrate one embodiment of the compensator/fill up assembly220in an un-actuated, retracted position. The compensator/fill up assembly220may include the adapter sub215and an upper frame216that is integral with or coupled to the adapter sub215. Compensation cylinders221are supported by a middle frame223, and are coupled to the upper frame216by piston rods219. The middle frame223also supports slip cylinders222, which are operable to actuate a leveling ring229via piston rods217. Although two compensation cylinders221and piston rods219, and two slip cylinders222and piston rods217are illustrated inFIGS. 4A and 4B, the embodiments of the invention may include a single concentric, compensation and/or slip piston/cylinder assembly for compensating for the weight of the tubular101and/or for actuating the slip assembly to grip the tubular101. Additional embodiments include two or more compensation and/or slip piston/cylinder assemblies.

The leveling ring229is operable to actuate one or more slips245supported in a slip housing225. The slips245may be coupled to the leveling ring229by slip rods227. Axial movement of the leveling ring229raises and lowers the slips245(via the slip rods227) along a tapered inner surface of the slip housing225. The slips245thus may be moved radially inward into engagement with the tubular101when directed into an opening in the lower end of the slip housing225. Other similar slip-type assemblies known in the art may be used with the embodiments described herein.

A support ring224and guide pins226may be provided to stabilize and maintain the leveling ring229in a level position as it is raised and lowered during operation. The piston rods217may be coupled to the leveling ring229by a bearing member218. The bearing member218enables rotation of the slips245, slip housing225, support ring224, guide pins226, and leveling ring229relative to the middle frame223, slip cylinders222, piston rods217, compensation cylinders221, piston rods219, and upper frame216as further described below. Other bearing-type assemblies known in the art may be used with the embodiments described herein.

The compensator/fill up assembly220may further include a fluid swivel230and a swivel joint240. The fluid swivel230may include an outer mandrel231coupled to the lower end of the adapter sub215. One or more bearings/seals232may be supported within the outer mandrel231between the lower end of the adapter sub215and the upper end of a fluid shaft228. The upper end of the fluid shaft228may sealingly engage the lower end of the adapter sub215within the outer mandrel231. The fluid swivel230provides a sealed and rotational interface between the adapter sub215and the fluid shaft228.

The fluid shaft228may extend through the swivel joint240and the slip housing225for connection to a fill up tool250. The swivel joint240may include an inner sleeve241that is coupled to or integral with the slip housing225, and an outer sleeve243that is coupled to or integral with the middle frame223. One or more bearings242may be disposed between a shoulder formed on the inner sleeve241and the outer sleeve243. The fluid shaft228may extend through the inner sleeve241. The swivel joint240provides a rotational interface between the outer sleeve243and the fluid shaft228.

The fill up tool250may be coupled to the lower end of the fluid shaft228. The fill up tool250may be inserted into a tubular, and may include external sealing elements, such as packer cups, to form a seal with the inner surface of the tubular. The fill up tool250may include internal flow control valves for controlling fluid flow through the bore of the fill up tool250and into the tubular string. The fill up tool250may include any tool known in the art that is operable to control and direct the supply of drilling fluid or other similar working fluids into the tubular string100. An exemplary fill up tool is illustrated and described in U.S. Pat. No. 8,141,642, the contents of which are herein incorporated by reference in its entirety.

FIGS. 5A and 5Billustrate one embodiment of the compensator/fill up assembly220in an actuated, extended position. During operation, the compensator/fill up assembly220may be lowered by the traveling member205into engagement with the tubular101that is supported by the handling system30(as illustrated inFIG. 1), another elevator, or some other similar tubular handling tool. In particular, the compensator/fill up assembly220is lowered until the fill up tool250is inserted into the tubular101and the upper end of the tubular101is positioned within the slip housing225. The solid fluid shaft228helps push the fill up tool250into the tubular101so that the upper end of the tubular may be positioned within the slip housing225. Then, the slip cylinders222are pressurized to extend the piston rods217and thereby lower the leveling ring229and slip rods227to move the slips245radially inward into engagement with the tubular101. In one embodiment, the compensator/fill up assembly220may include a camera or other tubular indication device to control and/or verify proper positioning of the upper end of the tubular101in the slip housing225for engagement by the slips245.

When engaged by the slips245, the weight of the tubular101may be supported by the compensation cylinders221. The weight of the tubular101may be transferred to the compensation cylinders221through the slips245, the slip rods227, the slip housing225, the leveling ring229, the piston rods217, the slip cylinders222, and the middle frame223. The compensation cylinders221are compressed by the weight of the tubular101and move in a downward direction. The piston rods219are shown in an extended position relative to the compensation cylinders221inFIGS. 5A and 5B.

With the weight of the tubular101supported by the compensation cylinders221, the traveling member205may move the compensator/fill up assembly220and the tubular101into position for threaded connection with the tubular string100. The compensation cylinders221help reduce the amount of tubular weight that is set down on the threads between the pin end103of the tubular101and the box end104of the tubular string100. Also, the compensation cylinders221help increase the amount of torque put into making up the threaded connection by reducing the amount needed to overcome sliding friction.

The rotation mechanism25(schematically illustrated inFIG. 1) may rotate the tubular101to make up the threaded connection. During make up, the compensation cylinders221may also compensate for the downward travel of the tubular101due to the threaded make up to the tubular string100. Further, during make up, the fluid swivel230allows the fill up tool250to rotate with the tubular101. In particular, the fill up tool250is coupled to the fluid shaft228, which rotates against the bearings232relative to the outer mandrel231, the adapter sub215, and the upper frame216. Excessive wear on the sealing elements of the fill up tool250is minimized by allowing rotation of the fill up tool250with the tubular101.

In addition, the swivel joint240and the bearing member218allow the slip housing225, the slips245(when engaged with the tubular101), and the leveling ring229to rotate with the tubular101. In particular, the slip housing225is coupled to or integral with the inner sleeve241, which rotates against the bearings242relative to the outer sleeve243, which is coupled to or integral with the middle frame223. The middle frame223supports the slip cylinders222and piston rods217. Rotation of the slip housing225also rotates the slips245, the slip rods227, the guide pins226, the support ring224, and the leveling ring229. The bearing member218allows the leveling ring229to rotate relative to the slip cylinders222and the piston rods217. Thus, when the compensator/fill up assembly220supports the tubular101, the slips245, the slip housing225, and the leveling ring229may rotate with the tubular101.

Once the threaded connection of the tubular101to the tubular string100is complete, the elevator300may engage the tubular string100, which now includes the tubular101. The compensator/fill up assembly220may disengage the tubular101, and the gripping apparatus20may disengage the tubular string100, such that the entire load of the tubular string100is supported by the elevator300. Although not supporting the weight of the tubular string100, the fill up tool350may still be inserted into the tubular101. The traveling member205may lower the tubular string100so that the box end104is near the rig floor10. The gripping apparatus20then engages the tubular string100and the elevator300disengages the tubular string100. The traveling member205lifts the assembly200and the process may be repeated until the tubular string100is the desired length.

Drilling fluid or other similar working fluids may be supplied through the bore of the traveling member205, the adapter sub215, the fluid shaft228, and/or the fill up tool250into the tubular string100once the threaded connection to the tubular101is complete. Drilling fluid or other similar working fluids may be supplied into the tubular string100as it is being lowered by the traveling member205. The tubular string100also may be rotated as it is being lowered by the traveling member205. As discussed above, the fluid swivel230enables rotation of the fluid shaft228and the fill up tool250with the tubular string100to minimize wear of the sealing elements of the fill up tool250.

FIGS. 6A and 6Billustrate one embodiment of a compensator/fill up assembly420in an un-actuated, retracted position. The compensator/fill up assembly420is similar to the compensator/fill up assembly220described above, the full operation of which is omitted for brevity. Components of the compensator/fill up assembly420that are similar to the compensator/fill up assembly220may include similar reference numerals but with a 400-series designation.

The compensator/fill up assembly420may include an adapter sub415for connection to the traveling member205(such as a top drive), and an upper frame416that is integral with or coupled to the adapter sub415. Compensation cylinders421are supported by a middle frame423, and are coupled to the upper frame416by piston rods419. The middle frame423also supports slip cylinders422, which are operable to actuate a leveling ring429via piston rods417. Although two compensation cylinders421and piston rods419, and two slip cylinders422and piston rods417are illustrated inFIGS. 6A and 6B, the embodiments of the invention may include a single concentric, compensation and/or slip piston/cylinder assembly for compensating for the weight of the tubular101and/or for actuating the slip assembly to grip the tubular101. Additional embodiments include two or more compensation and/or slip piston/cylinder assemblies.

The leveling ring429is operable to actuate one or more slips445that are axially movable along the outer surface of a fluid shaft428via a swivel joint440. The slips445may be coupled to an inner sleeve441that is axially coupled to an outer sleeve443of the swivel joint440. The outer sleeve443may be integral with or coupled to the leveling ring429. Axial movement of the leveling ring429raises and lowers the inner sleeve441and thus the slips445along outer tapered shoulders of the fluid shaft428. The slips445may be positioned within and moved radially outward into engagement with the inner surface of the tubular101. A support ring424and guide pins426may be provided to stabilize and maintain the leveling ring429in a level position as it is raised and lowered during operation. In one embodiment, the piston rods417may be coupled to the leveling ring429by a bearing member, such as bearing member218, to enable rotation of the leveling ring429relative to the piston rods417.

The compensator/fill up assembly220may further include a slip joint460, a fluid swivel430and a swivel joint440. The slip joint460may include an inner sleeve461(coupled to or integral with the upper frame416and/or the adapter sub416), an outer sleeve463, and one or more seals462disposed between the inner and outer sleeves. The fluid swivel430may be supported by the middle frame423, and may include an outer mandrel431coupled to the lower end of the outer sleeve463. One or more bearings/seals432may be supported within the outer mandrel431between the lower end of the outer sleeve463and the upper end of an inner mandrel434. The upper end of the inner mandrel434may sealingly engage the lower end of the outer sleeve463within the outer mandrel231. The lower end of the inner mandrel434may be coupled to the upper end of the fluid shaft428. The fluid swivel430provides a sealed and rotational interface between the slip joint460and the fluid shaft428.

The fluid shaft428may extend through the swivel joint440for connection to a fill up tool450, such as fill up tool250. The swivel joint440may include the inner and outer sleeves441,443, and one or more bearings442disposed between a shoulder formed on the inner sleeve441and the outer sleeve443(which may be integral with the leveling ring429). The fluid shaft228may extend through the inner sleeve441. The swivel joint440provides a rotational interface but axial coupling between the inner sleeve441and the outer sleeve443.

FIGS. 7A and 7Billustrate one embodiment of the compensator/fill up assembly420in an actuated, extended position. During operation, the compensator/fill up assembly420may be lowered by the traveling member205until the fill up tool450and the slips445are inserted into the tubular101. The upper end of the tubular101may be stopped by the support ring424with the compensation cylinders421in the retracted position. Then, the slip cylinders422are pressurized to extend the piston rods417and thereby lower the leveling ring429and the inner sleeve441to move the slips445radially outward into engagement with the tubular101.

When engaged by the slips445, the weight of the tubular101may be supported by the compensation cylinders421. The weight of the tubular101may be transferred to the compensation cylinders421through the slips445, the slip joint440, the leveling ring429, the piston rods417, the slip cylinders422, and the middle frame423. The compensation cylinders421are compressed by the weight of the tubular101and move in a downward direction. The piston rods419are shown in an extended position relative to the compensation cylinders421inFIGS. 7A and 7B. The slip joint460compensates for the downward movement of the compensation cylinders421relative to the upper frame416. In particular, the outer sleeve463(which is coupled to the middle frame423via the slip joint430) slides downward relative to the inner sleeve461(which is coupled to or integral with the upper frame416).

With the weight of the tubular101supported by the compensation cylinders421, the traveling member205may move the compensator/fill up assembly420and the tubular101into position for threaded connection with the tubular string100. The compensation cylinders421help reduce the amount of tubular weight that is set down on the threads between the pin end103of the tubular101and the box end104of the tubular string100. Also, the compensation cylinders421help increase the amount of torque put into making up the threaded connection by reducing the amount needed to overcome sliding friction.

The rotation mechanism25(schematically illustrated inFIG. 1) may rotate the tubular101to make up the threaded connection. During make up, the compensation cylinders421may also compensate for the downward travel of the tubular101due to the threaded make up to the tubular string100. Further, during make up, the fluid swivel430allows the fill up tool450to rotate with the tubular101. In particular, the fill up tool450is coupled to the fluid shaft428, which is coupled to the inner mandrel434and rotates against the bearings432relative to the outer mandrel431. Excessive wear on the sealing elements of the fill up tool450is minimized by allowing rotation of the fill up tool450with the tubular101.

In addition, the swivel joint440allow the slips445(when engaged with the tubular101) and the inner sleeve441to rotate with the tubular101. In particular, the inner sleeve441, which rotates against the bearings442relative to the outer sleeve443, which is coupled to or integral with the leveling ring429.

Drilling fluid or other similar working fluids may be supplied through the bore of the traveling member205, the adapter sub415, the slip joint460, the fluid swivel430, the fluid shaft428, and/or the fill up tool450into the tubular string100once the threaded connection to the tubular101is complete. Drilling fluid or other similar working fluids may be supplied into the tubular string100as it is being lowered by the traveling member205. The tubular string100also may be rotated as it is being lowered by the traveling member205. As discussed above, the fluid swivel430enables rotation of the fluid shaft428and the fill up tool450with the tubular string100to minimize wear of the sealing elements of the fill up tool450.

FIGS. 8A and 8Billustrate one embodiment of a compensator/fill up assembly520in an extended position. The compensator/fill up assembly520is similar to the compensator/fill up assemblies220,420described above, the full operation of which is omitted for brevity. Components of the compensator/fill up assembly520that are similar to the compensator/fill up assemblies220,420may include similar reference numerals but with a 500-series designation.

The compensator/fill up assembly520includes a base plate571for setting a portion of the assembly520on top of the elevator300(illustrated inFIG. 3) to utilize the strength of the elevator300frame to support the assembly520and to transfer load through the bails305(illustrated inFIG. 3) connected to the traveling member205. The compensator/fill up assembly520further includes compensation cylinders521that are supported by a middle frame523, and that are coupled to the base plate571by piston rods519. A support ring571is coupled to the base plate571via guide pins573. The middle frame523is movable along the guide pins573upon operation of the compensation cylinders521. Although two compensation cylinders521and piston rods519, and two slip cylinders522and piston rods517are illustrated inFIGS. 8A and 8B, the embodiments of the invention may include a single concentric, compensation and/or slip piston/cylinder assembly for compensating for the weight of the tubular101and/or for actuating the slip assembly to grip the tubular101. Additional embodiments include two or more compensation and/or slip piston/cylinder assemblies.

The middle frame523also supports slip cylinders522, which are operable to actuate a leveling ring529via piston rods517. The leveling ring529is operable to actuate one or more slips545supported in a slip housing525. The slips545may be coupled to the leveling ring529by slip rods527. Axial movement of the leveling ring529raises and lowers the slips545(via the slip rods527) along a tapered inner surface of the slip housing525. The slips545thus may be moved radially inward into engagement with the tubular101when positioned through an opening in the lower end of the slip housing525. A support ring524and guide pins526may be provided to stabilize and maintain the leveling ring529in a level position as it is raised and lowered during operation.

The piston rods517may be coupled to the leveling ring529by a bearing member518. In addition, the slip housing525is disposed on a bearing member575. The bearing members518,575enable rotation of the slips545, slip housing525, support ring524, guide pins526, and leveling ring529relative to the middle frame523, slip cylinders522, piston rods517, compensation cylinders521, piston rods519, and base plate571. Thus, the bearing members518,575allow the slip housing225, the slips245(when engaged with the tubular101), and the leveling ring529to rotate with the tubular101.

The compensator/fill up assembly520may further include a fluid swivel530that is supported by the traveling member205via an adapter sub515. The fluid swivel530may include an outer mandrel531coupled to the lower end of the adapter sub515for connection to the traveling member205, which may be a top drive. One or more bearings/seals532may be supported within the outer mandrel251between the lower end of the adapter sub515and the upper end of a fluid shaft528. The upper end of the fluid shaft528may sealingly engage the lower end of the adapter sub515within the outer mandrel531. The fluid swivel530provides a sealed and rotational interface between the adapter sub515and the fluid shaft528. The fluid shaft528may extend through the slip housing525for connection to a fill up tool550, such as the fill up tools250,450.

FIGS. 9A and 9Billustrate one embodiment of the compensator/fill up assembly520in a retracted position. During operation, the compensator/fill up assembly520and the elevator300may be lowered by the traveling member205into engagement with the tubular101. In particular, the compensator/fill up assembly520is lowered until the fill up tool550is inserted into the tubular101and the upper end of the tubular101is positioned within the slip housing525. Then, the slip cylinders522are pressurized to retract the piston rods517and thereby lower the leveling ring529and slip rods527to move the slips545radially inward into engagement with the tubular101.

A tubular indication device580may be supported by the base plate571and may be operable to provide an indication of the position of the tubular101relative to the slips545, the slip housing525, the middle frame523, and/or the base plate571. The tubular indication device580may be used to control and/or verify proper positioning of the upper end of the tubular101in the slip housing525for engagement by the slips545. The tubular indication device580may include a pneumatic, hydraulic, and/or electronic sensing arm that is movable from a primary position to one or more secondary positions by the tubular101to generate a signal corresponding to the position of the tubular101. The tubular indication device580may include any proximity-type sensor known in the art, an example including a wheel that rotates along the outer surface of the tubular101as the tubular101moves past the sensor to generate a signal corresponding to the position of the tubular101.

When engaged by the slips545, the weight of the tubular101may be supported by the compensation cylinders521. The weight of the tubular101may be transferred to the compensation cylinders521through the slips545, the slip housing525, the bearing member575, and the middle frame523. The compensation cylinders521are compressed by the weight of the tubular101and move in a downward direction. The piston rods519are shown in a retracted position relative to the compensation cylinders521inFIGS. 9A and 9B.

With the weight of the tubular101supported by the compensation cylinders521, the traveling member505may move the compensator/fill up assembly520, the elevator300, and the tubular101into position for threaded connection with the tubular string100. The compensation cylinders521help reduce the amount of tubular weight that is set down on the threads between the pin end103of the tubular101and the box end104of the tubular string100. Also, the compensation cylinders521help increase the amount of torque put into making up the threaded connection by reducing the amount needed to overcome sliding friction.

The rotation mechanism25(schematically illustrated inFIG. 1) may rotate the tubular101to make up the threaded connection. During make up, the compensation cylinders521may also compensate for the downward travel of the tubular101due to the threaded make up to the tubular string100. Further, during make up, the fluid swivel530allows the fill up tool550to rotate with the tubular101. In particular, the fill up tool550is coupled to the fluid shaft528, which rotates against the bearings532relative to the outer mandrel531and the adapter sub515. Excessive wear on the sealing elements of the fill up tool550is minimized by allowing rotation of the fill up tool550with the tubular101. In addition, the bearing members518,575allow the slip housing525, the slips545(when engaged with the tubular101), and the leveling ring529to rotate with the tubular101.

Once the threaded connection of the tubular101to the tubular string100is complete, the elevator300may engage the tubular string100, which now includes the tubular101. The compensator/fill up assembly520may disengage the tubular101. With the tubular string100supported by the gripping apparatus20, the traveling member205may move the elevator300upward until the upper end of the tubular string100is positioned within the elevator300for engagement to support the entire load of the tubular string100. The tubular indication device580may be used to provide an indication that the upper end of the tubular string100is in the proper position for engagement by the elevator300.

Although not supporting the weight of the tubular string500, the fill up tool550may still be inserted into the tubular101. After disengagement by the gripping apparatus20, the traveling member505may lower the tubular string100so that the box end104is near the rig floor10. The gripping apparatus20then engages the tubular string100and the elevator300disengages the tubular string100. The traveling member205lifts the assembly520and the elevator300, and the process may be repeated until the tubular string100is the desired length.

Drilling fluid or other similar working fluids may be supplied through the bore of the traveling member505, the adapter sub515, the fluid shaft528, and/or the fill up tool550into the tubular string100during operation once the threaded connection to the tubular101is complete.

The compensator/fill up assemblies220,420,520may be used with one or more control elements to help control operation. One or more accumulators may be used to dampen pressure spikes during the operation of the compensation cylinders221,421,521. Reducing valves may be used to limit pressure supplied to the slip cylinders22,422,522when actuated to grip the tubular101. One or more pilots may be used to open check valves to lock the slip cylinders22,422,522and thus the slips245,445,545in open and closed positions to disengage and engage the tubular101. An interlock may be used to prevent actuation of the slip cylinders22,422,522and thus the slips245,445,545from gripping the tubular or otherwise be moved to a closed position when supplying fluid through the fill up tools250,450,550. In particular, the interlock may help prevent the slips245,445,545from getting locked on the tubular101while supplying fluid to the tubular101via the fill up tools250,450,550, and also overstressing the slip assembly.