US20080060818A1 - Light-weight single joint manipulator arm - Google Patents

Abstract

The present invention provides an apparatus and a method for making up tubular strings in a well. The present invention provides a single joint manipulator arm for manipulating and positioning tubing joints for coupling into a tubular string. In one embodiment, a string elevator is supported by a hoist. A single joint elevator is supported on a swing arm that is pivotally secured to the sub-hoist assembly. An actuator rotates the swing arm to an initial position for securing to an add-on tubular joint whereby the single joint elevator engages a proximate end of the add-on tubular joint. As the hoist is lifted, a damper dampens rotation of the swing arm as it finds gravitational equilibrium with the single joint held in a substantially vertical orientation. A distal end of the tubular joint is aligned with a casing string supported by a spider, and the tubular joint is threadably coupled to the tubular string. The actuator may include provisions to power the arm from the vertical orientation to a substantially horizontal orientation and also to dampen the movement of the arm as it moves from the substantially horizontal or an intermediate position to the vertical orientation once the single joint elevator engages the add-on tubular joint and the hoist suspends the joint for rotation.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention provides a device and a method for manipulating tubular segments for make up and installation of a tubular string in a well.
• 2. Description of the Related Art
• Tubular strings installed in wells are made up by threadably coupling individual tubular segments at a well site. For example, a string of drill pipe is made from threadably coupling joints of drill pipe to rotate and advance a drill bit downhole. A casing string is made up by threadably coupling casing segments to line a drilled borehole to prevent collapse and to facilitate cementing. A production string is made up and run through casing strings to provide a conduit from the formation to the surface for producing oil or gas.
• Valuable rig time is consumed in retrieving, positioning and threadably coupling segments of pipe into a string. Since hundreds of segments may be made up and run into a borehole, saving just seconds per connection results in a substantial savings in rig time.
• The amount of time required to engage and rotate the pipe segment and make up the threaded connection to the pipe string is only a portion of the rig time consumed in making a connection. The time consumed in obtaining and positioning each add-on segment atop the string for make up is determined in part by the efficiency of tools used to retrieve and manipulate the segment.
• Tools are available for manipulating and positioning segments for make up into a string. Existing tools typically consist of a single joint elevator suspended by a rope slung beneath a main string elevator. Suspending the single joint elevator by a rope imposes many limitations on the efficiency of the process of adding pipe segments to the pipe string. These existing systems require rig personnel to swing or carry the single joint elevator to the receiving door and place it onto the pipe segment to be added onto the string. Also, once the pipe segment is coupled to the rope and hoisted above the rig floor, the pipe segment will generally not hang vertical due to the force of gravity, and it is difficult and awkward to maneuver the pipe segment into a vertical position atop the pipe string suspended in the borehole. Finally, once the pipe segment is threadably coupled to the pipe string in the borehole, the single joint elevator must be removed from the path of the string elevator or top drive, and rig personnel are required to carry the elevator back to the receiving door or other location on the rig floor.
• An improved method and apparatus are needed for manipulating segments to be made up into a pipe string. The method and apparatus would preferably provide more precise, safe and efficient manipulation of segments and save time in making up the string. The apparatus would preferably be light-weight, so that it can be easily removed from the path of the string elevator or top drive, but sufficiently robust to support and manipulate tubular segments.
SUMMARY OF THE PRESENT INVENTION
• One embodiment of the present invention comprises a single joint manipulator arm having a swing arm supporting a single joint elevator for securing a pipe segment to the swing arm. The swing arm is a strong and generally light-weight arm positionable with one or more cylinders or other actuators for rotatably aligning the segment with the string. In a first embodiment, the present invention provides a single joint manipulator arm that is pivotably securable to one or more bails that support a string elevator for lifting and lowering the pipe string into the borehole after each joint or stand of new pipe is threadably coupled into the string. The present invention provides a light-weight single joint manipulator arm that is easily and efficiently removed from the path of the string elevator or spider elevator. In a second embodiment, the present invention provides a single joint manipulator arm that is pivotably securable to a sub threadably coupled to a top drive shaft or quill. In this embodiment, the manipulator arm is pivotably secured to the sub above other components, such as a fill-up and circulation tool, or it is pivotably secured to a sub positioned below a top drive shaft and above a casing running tool.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a side elevation view of one embodiment of a single joint manipulator arm of the present invention in its aligned position and suspended from the bails on a rig.
• FIG. 2 is a side elevation view of the single joint manipulator ofFIG. 1 in its removed or “luffing” position.
• FIG. 3 shows the single joint manipulator arm ofFIG. 1 coupled to a casing segment at the staging area.
• FIG. 4 shows the single joint manipulator arm ofFIG. 1 after the bails and the string elevator are elevated and the single joint manipulator arm and casing segment controllably rotated clockwise from its position shown inFIG. 3.
• FIG. 5 is a side elevation view of the single joint manipulator arm ofFIG. 1 after the bails and the string elevator are elevated from the position inFIG. 4, and the single joint manipulator arm and casing segment controllably rotated further clockwise to suspend the casing segment adjacent to the axis of the well.
• FIG. 6 is a side elevation view of the single joint manipulator arm ofFIG. 1 after being rotated further clockwise from its adjacent position shown inFIG. 5 to generally suspend the segment in a vertical position aligned with the string in the well.
• FIG. 7 is a side elevation view of the single joint manipulator ofFIG. 1 illustrating a safety fuse used for preventing tool failure from excessive load being applied.
• FIG. 8 is a perspective view of the single joint manipulator arm ofFIG. 1 showing a bifurcated pivoting attachment to the bails and powered rotation using a pair of actuators.
• FIG. 9 is a perspective view of a modified lower portion of the single joint manipulator arm of the present invention comprising a slew actuator for angular displacement of the stand-offs to position a tubular segment secured within the single joint elevator.
• FIG. 10 is a perspective view of an alternative embodiment of the single joint manipulator arm of the present invention pivotably supported by a sub that is threadably coupled to and suspended from a top drive. The sub also supports a casing running tool that is operated by the top drive to releasably engage and support the pipe string and a fill-up and circulation tool.
• FIG. 11 is a perspective view of another alternative embodiment of the single joint manipulator arm of the present invention pivotably supported by a sub that is threadably coupled to and suspended from a top drive. The sub supports a fill-up and circulation tool that is aligned with the top drive and positioned to enter the proximal end of a pipe string secured within the string elevator.
• FIG. 12 is a high-level method flowchart describing one embodiment of a method of the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
• The present invention provides an apparatus and method for manipulating casing segments to assemble a casing string in a borehole. A single joint manipulator arm may be used to safely and reliably manipulate casing segments as they are made up into a casing string and installed in a well. The embodiments disclosed below describe the manipulation of casing segments to assemble a casing string using the present invention. It is to be understood, however, that other types of tubular segments, including drill pipe and production tubing, may be similarly manipulated to assemble strings without departing from the scope of the invention. For the reason, the terms “pipe”, “tubular” and “casing” are used interchangeably, as are the terms “segment” and “joint.”
• In one embodiment, an apparatus and method of the present invention are used to assemble and run a casing string. Once assembled, the casing string will include a plurality of casing segments threadedly coupled end-to-end and installed in a well. The rig on which this embodiment may be used includes a hoist movably suspending a pair of bails that, in turn, suspend a string elevator. A swing arm, having a proximal end, and a distal end is pivotally coupled at its proximal end to the bails at a location above the string elevator. The swing arm supports a single joint elevator at its distal end, which may be a hinged-body type elevator or a horseshoe elevator. The pivoting swing arm is angularly positionable relative to the bails using one or more actuators, such as cylinders. Control of the swing arm and the hoist enable the operator to efficiently retrieve a casing segment from a staging area and to move the casing joint into abutting alignment with the string for being threadably coupled into the string.
• A segment of large casing to be lifted using the manipulator arm may weigh 2,000 pounds (980 kg). A casing string may weigh 400,000 pounds (181,600 kg). The string elevator is very heavy compared to the single joint manipulator arm, and the moment imposed on the bails by the light-weight single joint manipulator arm and the casing segment do not significantly deflect the string elevator and the heavy bails from the vertical orientation.
• FIG. 1 is a side elevation view of one embodiment of a singlejoint manipulator arm10 the present invention. A perspective view of this same embodiment is shown inFIG. 8. Astring elevator12 is secured to a pair ofbails14,114 atlifting ears16,116. Thestring elevator12 is sized and configured for coupling to and supporting a casing string by securing the proximal end of the casing string (not shown inFIG. 1 or8—seeelement36 inFIGS. 3-6). The bails14,114 are configured for supporting the weight of the string elevator and the casing string, and are coupled at their supported ends to a block suspended by a draw works (not shown).
• The singlejoint manipulator arm10 of the present invention comprises aswing arm18 pivotally coupled at swing arm pivots28b,128bto bails14,114. Theswing arm18 includes anupper portion20 that forms an angle to the swing arm and provides offset clearance around thestring elevator12 when theswing arm18 is generally vertical (seeFIG. 6). Singlejoint elevator22 is supported from stand-offmembers52 and152 pivotally coupled to thedistal end17 of theswing arm18 for releasably securing and supporting a casing segment (not shown inFIGS. 1 and 8 seeFIGS. 3-6).
• Typically, an internally threaded coupling is used to threadably couple two casing segments end-to-end. This coupling structure provides an external circumferential shoulder that a singlejoint elevator22 may engage to support the add-on casing segment. However, it is within the scope of the present invention to use a single joint elevator adapted for securing integral connection segments by clamping along the length of the body of the pipe segment in place of the horseshoe elevator shown inFIG. 1 or the hinged-body type elevator shown inFIG. 9. The string elevator, horseshoe elevator and hinged-body type elevator shown in the drawings are included in the disclosed embodiment of the present invention for illustration only.
• The generally light-weight swing arm18 of the single joint manipulator arm of the present invention may be extendable, such as by axially telescoping. As shown inFIGS. 1 and 8, the length of theswing arm18 may be adjustable in length by telescoping aninner beam member26 from within anouter beam member24, then securing the outer andinner beam members24,26 by, for example, inserting apin28 through a pair of alignable holes27. The use of tubular or squared tubular steel may provide a good strength to weight ratio.
• Theswing arm18 is controllably rotatable about thepivots28b,128busing an actuator, such as a pair of pneumatic orhydraulic cylinders21,121. Thecylinders21,121 each comprise a piston (not shown) coupled to selectively extendable andretractable rods23,123, respectively, that are axially positionable with respect tocylinders21,121. Therods23,123 inFIGS. 1 and 8 are shown in the extended condition to position theswing arm18 in a substantially vertical position generally parallel to thebails14,114.
• FIG. 2 is a side elevation view of the singlejoint manipulator arm10 in a substantially horizontal or luffing position. Therods23 and123 (the latter not shown inFIG. 2) are shown retracted into thecylinders21 and121 (the latter not shown inFIG. 2) to position theswing arm18 generally perpendicular to thebails14 and114 (the latter not shown inFIG. 2). The luffing position illustrated inFIG. 2 serves two purposes. Casing segments are sometimes presented to the rig floor at a receiving door in a substantially horizontal condition. The luffing position shown inFIG. 2, or a position near horizontal, may be suitable for coupling theelevator22 supported by the singlejoint manipulator arm10 to casing segments presented in this condition. Also, the luffing position removes the singlejoint manipulator arm10 and the supportedelevator22 from obstructing the full descent of the string elevator12 (or, in other embodiments, a casing running tool or a top drive) as it lowers a casing string into the borehole after an add-on casing segment is made up into the casing string.
• Receiving doors, or staging areas, on some rigs present add-on pipe segments to the rig floor in a position angled between vertical and horizontal (seeFIG. 3). In use on these rigs, thecylinders21 and121 (the latter not shown inFIG. 3) may be used to position theelevator22 supported by the singlejoint manipulator arm10 to a suitable angled position between vertical and horizontal for coupling to the presented casing joint30. When the singlejoint manipulator arm10 is moved to the desired initial position, a presentedcasing segment30 is secured to the singlejoint manipulator arm10 at the presentedend32 by securing the segment in the singlejoint elevator22.
• FIGS. 3-6 are sequential side elevation views of the singlejoint manipulator arm10 ofFIG. 1 showing the process of manipulating a casing segment from an initial position in a staging area (FIG. 3) to an aligned position for rotatably coupling to a casing string in a well (FIG. 6). To retrieve a casing segment from the staging area of a rig, an actuating member first moves the swing arm outwardly away from vertical to position an end of the swing arm in proximity to a staging area wherein casing joints are presented.FIG. 3 shows one embodiment of the singlejoint manipulator arm10 in an initial position for retrieving acasing segment30 from arig staging area35. Thehorseshoe elevator22 is engaged just below acollar32 of the presentedcasing segment30. Once the segment is secured to theswing arm18, the hoist raises thebails14,114 (the latter not shown inFIG. 3) theswing arm18 and thecasing segment30. As thecasing segment30 is raised, it slides alongramp37, and theswing arm18 controllably rotates in the clockwise direction against the damping force ofcylinders21 and121 (the latter not shown inFIG. 3). This clockwise rotation of theswing arm18 against the damping force controllably moves thecasing segment30 in the direction of the casing string34 (seeFIG. 6). A damping member, such as a hydraulic, pneumatic or inert gas-charged cylinder, is used to dampen and control movement of the swing arm as it rotates from the initial position the equilibrium position. The damping member provides controlled and manageable movement in manipulating the casing segment.
• FIG. 4 is a side elevation view of the singlejoint manipulator arm10 ofFIG. 3 showing thebails14 and114 (the latter not shown inFIG. 3) elevated from their initial position shown inFIG. 3, and the singlejoint manipulator arm10 rotated further clockwise against the damping force of the cylinders. Thecasing segment30 inFIG. 4 is shown substantially raised alongramp37 from its initial position shown inFIG. 3. As thebails14 and114 (the latter not shown inFIG. 3) raise the singlejoint manipulator arm10 and thecasing segment30 alongramp37 instaging area35, the weight of thecasing segment30 increasingly urges theswing arm18 to rotate clockwise. Thecylinders21 and121 (the latter not shown inFIG. 4) dampens the rate of clockwise swing of theswing arm18, and the damping action provided bycylinders21 and121 will prevent rapid or uncontrolled swing of thecasing segment30 across the rig floor after thecasing segment30 clears theramp37.
• FIG. 5 is a side elevation view of the singlejoint manipulator arm10 ofFIGS. 3 and 4 showing thebails14 and114 (the latter not shown inFIG. 5) raised from the position shown inFIG. 4 and theswing arm18 rotated further clockwise from its position shown inFIG. 4. Thecasing segment30 shown inFIG. 5 hangs from singlejoint elevator22 substantially vertically in an equilibrium position, but it is not aligned with thecasing string34 in the well supported by thespider36 because of the offset provided by theangled portion20 at the top of theswing arm18. As shown inFIG. 5, this equilibrium position is not aligned with thecasing string34, and thecasing segment30 hangs offset from alignment with the top connection with thecasing string34. Thecasing segment30 hangs slightly suspended from the singlejoint elevator22 like a pendulum, and the singlejoint elevator22 imparts generally negligible torque on thecasing segment30. The equilibrium position of theswing arm18 shown inFIG. 5 and the amount of offset is determined by the dimensions and weights of both the singlejoint manipulator arm10 and thecasing segment30 whencylinders21 and121 (the latter not shown inFIG. 5) are inactive. Since thecasing segment30 is generally significantly heavier than theswing arm18, thecasing segment30 will generally hang near vertically below thepivots28band128b(the latter not shown inFIG. 5) securing thepivot arm18 to thebails14 and114 (the latter not shown inFIG. 5).
• FIG. 6 is a side elevation view of the singlejoint manipulator arm10 ofFIGS. 3-5 with thecasing segment30 vertically positioned above and axially aligned with thecasing string34, positioned to be lowered by the hoist (not shown inFIG. 6) to engage thecasing string34. Theswing arm18 has been rotated slightly further clockwise from its equilibrium position shown inFIG. 5 by energizing thecylinders21 and121 (the latter not shown inFIG. 6) to extend therods23 and123 (not shown inFIG. 6) to rotate theswing arm18 from its equilibrium position ofFIG. 5 to the aligned position shown inFIG. 6. Energizing thecylinders21,121 to extend therods23,123 rotates theswing arm18 further clockwise from its position shown inFIG. 5 and slightly vertically lifts the casing segment from its equilibrium shown position ofFIG. 5 as it vertically aligns the singlejoint elevator22 and thecasing segment30 with thecasing string34. The capacity to rotate the singlejoint manipulator arm10 clockwise from its equilibrium position shown inFIG. 5 provides substantially all of the rotational movement required to positioncasing segment30 may be alignment with thecasing string34. A lower,distal end33 of the casing joint30 is positioned to be threadably coupled with the proximal end ofcasing string34. Thestring elevator12 is substantially axially aligned withcasing string34 so that the hoist (not shown) and bails14 and114 may be lowered, along with thestring elevator12, to provide abutting contact for casing make up.
• Once thecasing segment30 has been brought into aligned contact with thecasing string34, a power tong or other torquing device engages and axially rotates casingsegment30 to make up the threaded connection between thecasing segment30 and thecasing string34. After the connection is made, the singlejoint elevator22 is released from thecasing segment30 and theswing arm18 is rotated counterclockwise usingcylinders21 and121 to its luffing position shown inFIG. 2. The hoist (not shown inFIG. 2) and bails14 and114 may then be lowered to bring thestring elevator12 to theproximal end32 of the casing joint30. Thestring elevator12 may be engaged with theproximal end32 of thecasing segment30, and theentire casing string34 is lifted by the hoist (not shown) and thestring elevator12 to allow disengagement of thespider36. Thestring elevator12 is then lowered until theproximal end32 of thecasing segment30 reaches the same elevation as previously occupied by the proximate end of thecasing string34 shown inFIG. 6. Thespider36 is then engaged to support thecasing string34 in the well, and thestring elevator12 may be disengaged from thecasing segment30.
• The process described above in connection withFIGS. 3-6 is repeated with additional casing segments until thecasing string34 achieves the desired length.
• To further enhance safety, the apparatus may include a safety fuse, such as a shear pin, that will audibly shear if the swing arm supports a load that is substantially heavier than a segment of the casing being made up and run into the well.FIG. 7 is a side elevation view of one embodiment of the singlejoint manipulator arm10 for illustrating aload safety fuse50. A pair of stand-offs52,152 (the latter not shown inFIG. 7) are secured at their first ends52a,152a(the latter not shown inFIG. 7) to thelower portion17 of theswing arm18 atpivot54. A sacrificially failingsafety link58 is pivotally coupled to theswing arm18 atpivot58alocated generally intermediate thepivotal coupling54 of the stand-offs52,152 andangled portion20. Thesafety link58 is coupled betweenpivot58aandshackle57 which is, in turn, coupled to the first ends56a,156aofcables56 and156 (elements156aand156 not shown in FIG.7—seeFIG. 8). The second ends56band156bofcables56 and156 are coupled and supported to the second ends52band152bof stand-offmembers52 and152. Thesafety link58 generally is held by stand-offs52,152 at an angle to theswing arm18. As shown inFIG. 7, that angle is about 20 degrees, with the stand-offs52,152 being supported substantially in positions perpendicular to theswing arm18. The weight of the singlejoint elevator22 biases the stand-offs52,152 generally downwardly when the singlejoint manipulator arm10 is vertical, pullingcables56 and156 taut.
• Thesafety link58 comprises a sacrificially failing member that is designed to fail under a predetermined load. Thus, thesafety link58 is designed to withstand the load produced incables56 and156 when the weight of segment of casing is supported by the singlejoint elevator22. A load significantly heavier than that of a casing segment plus theelevator22 will cause the sacrificial member to fail, such as a shear failure, without dropping the load. The sound of the sacrificial failure is loud enough to alert the rig operator. In response to the sacrificial failure of thesafety link58, the stand-offs52,152 will slightly rotate aboutpivot54 counterclockwise (inFIG. 7) but will remain coupled bysafety link58 to avoid dropping the casing segment coupled to the singlejoint elevator22.
• FIG. 8 is a perspective view of the embodiment of the singlejoint manipulator arm10 inFIGS. 1-7. The liftingear16 on thebail14 is accompanied by asecond lifting ear116 onbail114. These bails are movably suspended from a block (not shown), and are capable of supporting very heavy loads, such as a casing string. Theangled portion20 of theswing arm18 comprises a pair of generallyparallel prongs18a,18bthat are pivotally coupled to bail clamps29,129, respectively, at swing arm pivots28b,128b, respectively. The bail clamps29,129 are secured tobails14,114, respectively, using fasteners. Thehydraulic cylinder21 is accompanied by a second generally parallelhydraulic cylinder121 for balanced damping of swinging loads applied to swingarm18. Thecylinders21 and121 comprise extendable andretractable piston rods23,123 that are pivotally coupled to swingears25,125, respectively, of theswing arm18.Cylinders21,121 are each pivotally coupled to bail clamps29,129, respectively, atpivots28a,128a, respectively. These pivoting cylinder couplings on bail clamps29,129 are each secured to the bails at a spaced distance above swing arm pivots28b,128bthat pivotally secure theprongs18a,18bofswing arm18 to the bail clamps29,129, respectively. Theswing ears25,125 are offset from the swing arm so that pivoting of theswing arm18 toward its equilibrium position (seeFIG. 5) under the force of gravity rotates theswing ears25,125 away from thecylinders21,121 and requires substantial extension of therods23,123 fromcylinders21,121, respectively, for rotation. The resistance to extension of therods23,123 fromcylinders21,121 substantially dampens the rate of rotation of theswing arm18 as compared to unrestrained swinging of theswing arm18. Similarly, force imposed by powered retraction ofrods23,123 into thecylinders21,121 pulls againstswing ears25,125, respectively, to controllably rotate theswing arm18 to the desired angular orientation, either to an initial position (see, for example,FIG. 3) for coupling the singlejoint elevator22 to a presentedcasing segment30, or to the luffing position (seeFIG. 2) for either coupling the single joint elevator to a horizontally presented casing segment or for removing theswing arm18 from obstructing the descent of thestring elevator12 to thespider36.
• In the embodiments discussed in connection withFIGS. 1-8,hydraulic cylinders21,121 provide a dual function. According to a first function, thecylinders21,121 substantially slow and dampen movement of theswing arm18 under the load of a casing segment secured in theelevator22 as the single joint elevator and the load is lifted from a staging area. According to a second function,cylinders21,121 are used as actuators to rotate theswing arm18 beyond its equilibrium (shown inFIG. 5) to selectively position theswing arm18 and thereby align the casing segment with the casing string, and also to rotate theswing arm18 to the luffing position or to an angle for securing the elevator to a presented casing segment. Other embodiments may employ independent devices to actuate theswing arm18 to align with the casing string and to dampen movement of the swing arm under load. For example, it is within the scope of the present invention for one cylinder may be used as an actuator to rotate the swing arm and another cylinder may used to dampen swing rotation of the swing arm.
• As previously mentioned, theswing arm18 may comprise a telescoping portion. Theouter beam24 may slidably receive aninner beam26. In other embodiments, a swing arm may be axially extendable without these beams being concentric as in the embodiments ofFIGS. 1-8. For example, it is within the scope of the present invention for one beam to secure to the other using a slot on one beam and a bolt or pin on the other beam that is receivable and securable within the slot to lock the beams together to form a single load-bearing member.
• An advantage of an extendable swing arm is that it provides the ability to adjust the length of the swing arm to manipulate different lengths of casing segments, to adjust the single joint manipulator arm to cooperate with the height of the spider at the rig floor, or generally to accommodate different drilling rig configurations. Additional versatility is realized by use of the embodiments of the tool of the present invention shown inFIGS. 9-12. The single joint manipulator arm can be adapted for use with fill-up and circulation tools, pipe gripping assemblies and slew actuators that enhance the capacity of the tool to manipulate and position tubular segments for make-up into a tubular string.
• FIG. 9 is a perspective view of a modified lower portion of the single joint manipulator arm of the present invention comprising a slew actuator for angular displacement of the stand-offs to position a tubular segment secured within the single joint elevator.FIG. 9 shows an alternate embodiment of the singlejoint manipulator arm10 of the present invention having enhanced capacity to manipulate and position tubular segments supported in the singlejoint elevator22.FIG. 9 shows alower portion20 of the single joint manipulator arm of the present invention equipped with a slew actuator. A pair of stand-offs52 and152 are pivotally secured at their first ends52a,152a(the latter not shown inFIG. 9) to thelower portion17 of theswing arm18. The second ends56band156bofcables56 and156 are coupled to the second ends52band152bof stand-offs52 and152. The stand-offs52,152 are supported bycables56 and156 in positions generally perpendicular to theswing arm18. The weight of the singlejoint elevator22 and any tubular segment secured therein biases the stand-offs52,152 generally downwardly when the singlejoint manipulator arm10 is vertical, thereby pullingcables56 and156 taut.
• The enhanced capacity for manipulation and positioning of tubular segments provided by the slew actuator shown inFIG. 9 is best understood by consideration of the ranges of controlled movement, relative to a classic x-y-z three-dimensional coordinate system, provided by the single joint manipulator arm. As seen inFIGS. 3-6, thecylinders21 and121 provide controlled rotation of theswing arm18 and the supportedcasing segment30 in the x-y plane. This movement of thetubular segment30 secured in theelevator22 is primarily along the x-axis when thecylinders21 and121 position theswing arm18 in the generally vertical orientations shown inFIGS. 5 and 6. Vertical displacement of the tubular segment secured in theelevator22 along the y-axis is provided by the rig hoist (not shown) that raises and lowers the drawworks, block and the sub and/or bails to which the single joint manipulator arm is secured. The slew actuator shown inFIG. 9 provides for controlled movement along the z-axis.
• FIG. 9 shows the components of one embodiment of the single joint manipulator arm equipped with a slew actuator providing enhanced positioning and manipulation of the suspended tubular joint. The slew actuatorhousing42 generally surrounds a slew actuator43, which may be a cylinder, for positioning a slew rod44 generally perpendicular to the pivotable stand-offs52 and152. While the actual movement of stand-offs52 and152 is radial about stand-off pivots46aand46b, respectively, the movement of a tubular segment (not shown inFIG. 9) secured in theelevator22 upon actuation of the slew actuator43 is substantially along the z-axis as defined above. Accordingly, this embodiment of the present invention provides superior control and manipulation of casing segments for being made up into a casing string.
• FIG. 10 is a perspective view of one embodiment of the singlejoint manipulator arm10 of the present invention secured to and supported by a top drive and supporting a fill-up and circulation tool and a pipe gripping assembly. The singlejoint manipulator arm10 is pivotably secured to an enlarged portion of asub88 that is threadably coupled at itsinlet88a(above the sub88) to a top drive and supports acasing running tool104 from itsdischarge88b(below the sub88). In this embodiment, thedischarge88bof thesub88 supports acasing running tool104 having a gripping assembly sized for being received into a casing segment (not shown). Thecasing running tool104 comprises a plurality ofpipe gripping shoes105 that are deployable and retractable radially outwardly to grip and release the internal wall of a casing segment to support the casing string or to rotate the casing segment to make up the connection with the casing string.
• The embodiment inFIG. 10 also comprises a fill-up andcirculation tool100 supported underneath the casing running tool. Theelastomeric seal103 is sized for engaging the internal wall of a casing string (not shown inFIG. 10) upon insertion. The seal enables pressurization of the casing string so that pressurized fluid introduced into the bore of the casing string through thebore101 of the fill-up andcirculation tool100 can be circulated down the casing string and back to the surface through the annulus formed between the casing string and the borehole.
• FIG. 11 is a perspective view of another embodiment of the present invention. The singlejoint manipulator arm10 of the present invention is secured to and supported by a top drive, and supports a fill-up andcirculation tool100 comprising anelastomeric seal103. Abore101 formed by aligned bores in the top drive,sub88 and the fill-up andcirculation tool100 provides a conduit for introducing fluid into the casing string. The singlejoint manipulator arm10 is pivotably secured to an enlarged portion of asub88 that is threadably coupled at itsinlet88a(above the sub88) to a top drive and supports the fill-up andcirculation tool100 from itsdischarge88b(below the sub88). In this embodiment, a pair ofbails14,114 is suspended from asupport ring89 that is rotatably supported by the top drive.
• FIG. 12 is a flowchart describing one embodiment of a high-level method of manipulating casing segment to assemble a casing string. Instep60, the swing arm is rotated to an initial position. A hydraulic cylinder or other actuator is used to rotate the pivot arm away from vertical and to a desired angle according to the orientation of a selected joint in the staging area. Instep62, the hoist is lowered as necessary to position a first elevator, such as a horseshoe elevator, near a proximate end of the targeted casing segment. Instep64, the single joint elevator is coupled to the proximate end of the targeted joint. Instep66, the hoist is raised to begin moving the joint into a suspended position. As the joint is lifted along the ramp to leave the staging area, the swing arm rotates clockwise toward an equilibrium position, and the rotation is dampened instep68. Once the swing arm and the casing segment are substantially vertical and the joint is suspended in the offset position, the joint is then aligned with the casing segment by powered rotation of swing arm and lowered to abut the casing string insteps70 and72. Once the distal end of the joint is in contact with the upper end of the casing string, the joint is threadably coupled to the casing string instep74. A power tong may be used to rotate the joint to threadedly couple the joint to the casing string. Then, instep76, the hoist is lowered while the single joint elevator is disengaged from the proximate end of the joint. Lowering the hoist brings the string elevator near the proximate end of the casing string and, instep78, the string elevator engages the proximate end of that uppermost joint of the casing string. Instep80, the casing string is lifted up slightly. This releases the load on the spider so the spider is released according tostep82. Instep84, with the casing string released by the spider, the hoist is lowered to install the casing string further into the borehole to about the position of the casing string prior to connecting the additional joint instep74. The spider slips are moved into contact with the casing string to support it in the well. In thestep86, if the string has achieved the desired length, work stops. Otherwise the process repeats as the swing are is rotated to an initial position instep60.
• Embodiments of the invention provide a safe and efficient way to assemble a casing string. A highly maneuverable single joint manipulator arm retrieves a casing joint from a variety of angles to access a staging area. The single joint manipulator arm then positions the casing joint into alignment with the casing string in a controlled manner using a damper. A casing string may also be assembled quickly and efficiently, minimizing the time and expense associated with casing make up.
• The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
• The terms “segment” and “joint” are used interchangeably to refer to individual portions of casing. The term “casing” is used to refer to casing, production tubing, drill pipe and all other tubulars that may be coupled end-to-end and installed in a well.
• While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the claims.

Claims (20)

1. An apparatus, for manipulating tubular segments for being made up into a tubular string, the apparatus comprising:

a swing arm having a proximal end pivotally coupled to a hoist at a location above a string elevator or a casing running tool;

an actuator pivotally secured to the swing arm for rotating the swing arm;

a damper pivotally secured to the swing arm, for damping rotation of the swing arm; and

a single joint elevator secured to a distal end of the swing arm for releasably supporting a tubular segment, the swing arm being rotatable to align the tubular segment with another tubular segment to form a tubular string.

2. The apparatus ofclaim 1, wherein the actuator is a hydraulic or a pneumatic cylinder.

3. The apparatus ofclaim 2, wherein the cylinder also functions as the damping member.

4. The apparatus ofclaim 1, wherein the damper comprises a hydraulic or a pneumatic cylinder.

5. The apparatus ofclaim 1, wherein the single joint elevator comprises a horseshoe elevator or a hinged-body elevator.

6. The apparatus ofclaim 1, further comprising:

a sacrificially failing link coupled between the single joint elevator and the swing arm, the single joint elevator being pivotable about the distal end of the swing arm between a first position with the sacrificially failing link intact and a second position assumed upon failure of the sacrificially failing link.

7. The apparatus ofclaim 6, further comprising:

a safety link pivotally secured to the swing arm with the sacrificially failing link coupled to the safety link and also to the swing arm such that the safety link supports the single joint elevator upon failure of the sacrificially failing link.

8. A method of making up a tubing string for installation in a borehole comprising:

suspending a string elevator on bails;

supporting a single joint elevator on a pivot arm pivotally secured to the bails at a location above the string elevator;

rotating the swing arm to a first position wherein an axis of the single joint elevator is substantially angularly misaligned from an axis of the string elevator;

engaging a proximate end of a tubing segment with the single joint elevator; and

rotating the swing arm to substantially align a distal end of the tubing segment with a tubing string positioned in the well, while damping the rotation of the swing arm.

9. The method ofclaim 8, wherein damping the movement of the swing arm results from moving a piston within a cylinder.

10. The method ofclaim 9, further comprising moving the swing arm to the luffing position by energizing the cylinder.

11. The method ofclaim 10, wherein the luffing position is substantially horizontal.

12. The method ofclaim 8, further comprising one or both of raising and lowering the string elevator and the single joint elevator using a hoist.

13. The method ofclaim 8, further comprising:

lowering the hoist to position the distal end of the tubing segment adjacent a proximate end of the tubing string; and

threadedly coupling the distal end of the tubing segment with the proximate end of the tubing string.

14. The method ofclaim 13, further comprising:

Rotating the swing arm to remove it from obstructing descent of the string elevator;

lowering the hoist to position the string elevator about the proximate end of the tubing joint connected with the tubing string;

engaging the proximate end of the tubing segment with the string elevator;

raising the hoist and string elevator to at least partially unweight a spider supporting the tubing string;

disengaging the spider from the tubing string;

lowering the hoist to install the tubing string further into the well; and

re-engaging the tubing string with the spider to support the tubing string in a the well.

15. An apparatus for making up and installing a tubular string is a well comprising:

a vertically movable top drive;

a sub supported by the top drive and pivotably supporting a swing arm coupled to the sub at its proximal end and coupled to a single joint elevator at its distal end;

an actuator for rotating the swing arm about its pivoting coupling to the sub between a luffing position and an aligned position with the well; and

a damper for opposing swing rotation of the swing arm from the luffing position to the aligned position.

16. The apparatus ofclaim 15 wherein the actuator is a hydraulic or pneumatic cylinder.

17. The apparatus ofclaim 16 wherein the cylinder also functions as the damper.

18. An apparatus for manipulating tubular segments for being made up into a tubular string and run into a well comprising:

a swing arm for pivotably coupling at its proximal end to a sub or bail above a string elevator or casing running tool, the swing arm having a distal end coupled to a single joint elevator;

an actuator for powered rotation of the swing arm between a removed position; and a damper for slowing the rotation of the swing arm from the removed position to the aligned position.

19. The apparatus ofclaim 18 wherein the actuator is a pneumatic or hydraulic cylinder.

20. The apparatus ofclaim 19 wherein the cylinder also functions as the damper.

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