Patent Application
20090114398
The present invention relates to an apparatus and method to grip and/or handle tubular segments, such as tubulars used for forming tubular strings that are used for lining earthen boreholes drilled for oil and gas recovery. The present invention specifically relates to a method and apparatus to assemble tubular strings and/or install them in a borehole, and to disassemble tubular strings.
Tubular strings are critical components in the drilling and completion of wells used for oil and gas recovery from mineral deposits within geologic formations in the earth's crust. Tubular joints, also called tubular segments, are generally joined together using threaded connections to form tubular strings. Tubular strings may be used to line an earthen borehole to prevent collapse of the borehole and/or as a fluid conduit to produce fluid from a geologic formation.
The assembly of a tubular string involves repetitive handling of tubular segments. A tubular segment is secured to a hoist and lifted above the earthen borehole containing the tubular string. An add-on tubular segment is generally positioned over well-center so that the externally-threaded pin end of the lower end of the add-on tubular segment is received within the internally-threaded box end of the previous tubular segment that was added to the tubular string. A power tong may be used to grip and rotate the add-on tubular segment to make up the threaded connection comprising the pin and box ends of the abutting tubular segments. For example, where the “box end up” method is used, when the connection is made up and torqued to the appropriate tightness, the tubular string may be released from the power tong and an elevator may grip the box end of the newly added tubular segment to suspend the tubular string within the borehole and unload a spider that suspends the tubular string in the borehole. Once the spider is disengaged, the elevator may be lowered to dispose the lengthened tubular string deeper into the borehole until the box end of the newly added tubular segment is positioned above the spider for receiving the next add-on tubular segment to be made-up into the tubular string. The newly added tubular segment is gripped by a spider at or above the rig floor so that the box end connection is presented just above the rig floor and ready to receive and couple to a new add-on tubular joint. The elevator is released from the tubular string and the next add-on tubular segment is positioned for being threadably connected into the tubular string. This cycle is repeated until the tubular string achieves the desired length. The lifting, positioning, aligning and/or rotating of a tubular segment to make-up the threaded connection to a tubular string can be referred to as “handling” or “manipulating” the tubular segment.
Various casing running tools have been proposed for use on rigs equipped with top drive assemblies. Top drive assemblies typically comprise rail-mounted motors powering a downwardly disposed and rotatable drive shaft for rotating a pipe or a pipe string. Casing running tools adapted for use with top drives are typically connected to the powered drive shaft so that the top drive can be used to rotate casing segments to make-up threaded connections. A casing running tool for use with a top drive assembly may comprise an internally gripping assembly receivable in the presented end of a casing segment. Casing segments may be lifted onto the rig floor using a single joint elevator or other hoisting device, then the top drive assembly is typically used to manipulate the casing running tool to couple the new segment to the string in the borehole.
During the process of making up and running tubular segments, fluid can be added to the bore of the tubular string to prevent excessive differential pressure from damaging or collapsing the tubular string. The addition of predetermined amounts of fluid into the end of the tubular string accessible to the rig can balance the hydrostatic pressure in the bore of the tubular string with the hydrostatic pressure in the annulus between the tubular string and the borehole wall or, if the borehole is cased, between the tubular string and the casing.
There is a need for an apparatus for gripping and handling tubular segments on a rig which can either be used with a top drive or as a stand-alone tool on a conventional rig that is not equipped with a top drive. The apparatus may be compatible for use with fill-up and circulating tools, cementing heads, wiper plug assemblies, and other devices for delivering and circulating mud and other fluids, such as a cement slurry. A need exists for an apparatus for joining tubular segments to a tubular string that requires no external drive for powering and operating the tool. There is a need for an apparatus for gripping a tubular segment that will not loosen its grip on a tubular segment upon loss of power to operate the gripping assembly of the apparatus. There is a need for an apparatus that uses mechanical advantage to grip a tubular segment with minimal mechanical power requirement compared to conventional, asymmetrically deployed gripping devices. There is a need for an apparatus for gripping a pipe segment that does not cause excessive marking of the gripped surface of the pipe segment. There is a need for an apparatus that uses sufficiently small amount of mechanical power so that a portable energy source, such as a battery, may be used to power the gripping assembly into and out of gripping engagement with the tubular segment. There is a need for an apparatus for gripping a tubular segment that is adapted for use with a fill-up and circulation assembly for introducing and circulating fluid in a borehole.
At least one embodiment of the present invention provides an apparatus and method that satisfies some or all of the aforementioned needs, and others. An embodiment of the apparatus can internally grip a tubular segment for coupling the tubular segment to a tubular string in a borehole. The apparatus can be self-operable for gripping and releasing, and in one embodiment does not require the apparatus be attached to, supported by or driven by a top drive assembly. In addition to being suitable for use with a top drive, an apparatus may be used as a stand alone tool, e.g., an apparatus that may be suspended from the traveling block of a conventional rotary rig. An apparatus may be used as a single joint elevator and a method of the present invention may be used for making up or running tubular strings into a borehole and/or breaking out or removing tubular strings from a borehole, or any combination thereof. An apparatus and method may be used with conventional tools for introducing fluid into a tubular string and for circulating fluid within a borehole. Moreover, an embodiment can provide the consistent application of sufficient gripping force to lift and/or threadably couple a tubular segment to a tubular string without the use of hydraulic cylinders to power the gripping jaws into engagement with the tubular segment being lifted and/or coupled.
In one embodiment, there is provided an apparatus for gripping and handling tubulars compromising a drive shaft, at least one drive motor for rotating the drive shaft, a first camming body threadably received on a first threaded portion of the drive shaft, a second camming body threadably received on a second portion of the drive shaft, and a plurality of gripping jaws slidably disposed within a jaw space between the first and second camming bodies. The gripping jaws are positioned about the drive shaft such that the first and second camming bodies threadably adduct generally longitudinally along the drive shaft one toward the other when the drive shaft rotates in a first direction, and abduct generally longitudinally along the drive shaft one away from the other when the drive shaft rotates in the reverse direction.
The gripping jaws are slidably engaged by the first and second camming bodies such that, when the drive shaft rotates in the first direction, the first and the second camming bodies adduct to slidably and evenly displace the gripping jaws from the jaw space and radially outwardly away from the drive shaft to bear against the interior wall of a tubular segment into which the apparatus is received. The gripping jaws are radially outwardly displaced to engage the internal wall of the tubular segment with an amount of gripping force sufficient for lifting and coupling the tubular segment to the tubular string. The adduction of the camming bodies, one toward the other with generally synchronous movement, provide an even application of force to the gripping jaws as they engage and grip the interior wall of a tubular segment. This even application of force across the gripping jaws may provide minimal marking of the interior wall of the tubular.
In another aspect, the drive shaft of the gripping apparatus may comprise an axially extending bore there through to allow pressurized fluid to be delivered from the rig, through the bore of the drive shaft, and into the bore of the tubular segment to be gripped and rotated by the gripping apparatus. In another aspect, the gripping apparatus may comprise a fill-up and circulation assembly extending from the distal end of the drive shaft and into the bore of the tubular segment gripped by the gripping apparatus.
In another aspect, there is provided an apparatus for handling tubulars comprising a gripping apparatus including a drive shaft having an axial bore there through, a drive motor for rotating the drive shaft, a first internally-threaded camming body threadably received onto a first externally-threaded portion of the drive shaft, and a second internally-threaded camming body threadably received onto a second externally-threaded portion of the drive shaft, such that the first and the second camming bodies are threadably adducted along the drive shaft one toward the other to narrow a jaw space when the drive shaft rotates in a first direction and abducted one away from the other to widen the jaw space when the drive shaft rotates in the reverse direction, and a plurality of gripping jaws slidably engaged and displaced from the jaw space radially outwardly away from the drive shaft by the first and the second camming bodies when the drive shaft rotates in the first direction and allowed to retract radially inwardly into the jaw space toward the drive shaft when the drive shaft rotates in the reverse direction.
The apparatus may further comprise an apparatus adapted for being suspended from and supported by a pair of elongate bails. The bails each have an upper and a lower connection, the upper connection adapted for being coupled to the traveling block of a conventional rig and the lower connection for coupling to the gripping apparatus of the present invention. This embodiment may be adapted for receiving at least a portion of a fill-up and circulation assembly within the bore of the drive shaft. Specifically, this alternate embodiment may be adapted for receiving a hollow tubular member having an external elastomeric seal within the bore of the externally-threaded drive shaft for creating a seal between the discharge of a fluid pump on or near the rig and the internal wall of the tubular segment gripped by the gripping apparatus. The fill-up and circulation assembly may be suspended from the traveling block and positioned between the bails, and the fill-up and circulation assembly may be adapted for being extendible and retractable for selectively inserting and removing the lower end of the fill-up and circulation assembly from the bore extending longitudinally through the rotatable drive shaft of the gripping apparatus.
In another aspect, there is provided a method of coupling tubular segments to form a tubular string and running the tubular string into a borehole. The method comprises the step of inserting a gripping apparatus into an end of a tubular segment, the gripping apparatus comprising a drive shaft, a drive motor for rotating the drive shaft, a first internally-threaded camming body threadably received on a first externally-threaded portion of the drive shaft, and a second internally-threaded camming body threadably received on a second externally-threaded portion of the drive shaft, such that the first and the second camming bodies adduct axially along the drive shaft, one toward the other, to narrow a jaw space intermediate the first and second camming bodies when the drive shaft rotates in a first direction, and to axially abduct, one away from the other, to widen the jaw space when the drive shaft rotates in the second, opposite direction, and a plurality of gripping jaws slidably engaged by the first and the second camming bodies such that the first and the second camming bodies adduct to slidably cam the gripping jaws from the jaw space radially outward away from the drive shaft when the drive shaft rotates in the first direction, and the first and second camming bodies abduct to accommodate retraction of the gripping jaws into the jaw space when the drive shaft rotates in the second, opposite direction.
The method of the present invention comprises the steps of operating the drive motor of the gripping apparatus to rotate the drive shaft such that the first and the second camming bodies of the gripping apparatus adduct to deploy the gripping jaws into gripping contact with an interior wall of the tubular segment, and then the step of operating a hoist coupled to the gripping apparatus to lift and position the gripping apparatus and the tubular segment. Alternately, the method of the present invention may comprise the steps of operating the drive motor of the gripping apparatus to rotate the drive shaft such that the first and second camming bodies of the gripping apparatus adduct to deploy the gripping jaws into gripping contact with an interior wall of the tubular segment, and then the step of operating a top drive or other torquing tool to rotate the gripping apparatus and the tubular segment to make-up a threaded tubular connection.
Further aspects, features, and advantages of the present invention will be apparent to those of ordinary skill in the art upon examining the accompanying drawings and upon reading the following disclosure.
wn in partial
As shown in
The coupling 14 on the embodiment shown in
The gripping apparatus 10 of the present invention may be supported using a thread compensation assembly so that torque and rotation may be applied to the gripping apparatus 10 while accommodating movement of the gripped tubular in a direction generally along the axis of the drive shaft 51. A splined load compensation assembly, for example, utilizing an expandable bladder, cylinders or the like, may compensate for overlapping of threads during the make-up of a threaded connection by permitting extension of the overall length of the thread compensation assembly between the top drive assembly or traveling block and the gripping apparatus. For example, a splined assembly attached to and supporting the sub 12 in
The gripping apparatus 10 illustrated in
The sliding inserts on the camming bodies 32, 34 may comprise a lubricious material adapted for low-friction sliding contact, or the inserts may include one or more channels, grooves, holes, slots or apertures (not shown) for dispensing, directing and/or retaining a lubricant to the sliding surface. The camming bodies 32, 34 may comprise generally frusto-conical portions providing sliding surfaces for engaging and displacing gripping jaws 42 and 44. Alternately, the camming bodies may comprise a camming body having a cam surface and held in place on the shaft, or positioned along the shaft, by a threaded member, such as a threaded nut. The sliding surfaces can be sloped at a cam angle of between about 0 degrees to about 90 degrees off parallel from the axis of the drive shaft 51, e.g., between about 5 and about 45 degrees off parallel from the axis of the drive shaft 51, e.g., between about 10 and about 35 degrees off parallel from the axis of the drive shaft 51 or between about 15 and about 25 degrees off parallel from the axis of the drive shaft 51. The sliding surfaces of the camming bodies 32, 34 can together form an annular jaw space of variable size intermediate the camming bodies 32, 34, and generally circumferentially around the drive shaft 51, for selectively positioning a plurality of gripping jaws 42 and 44 as described in more detail below. As will be discussed later in relation to
The camming bodies 32, 34 may be generally restrained from rotation with the drive shaft 51 to ensure desired adduction or abduction to displace or retract, respectively, the gripping jaws 42 and 44. The first and second internally-threaded camming bodies 32, 34 may be mechanically restrained from rotation with the drive shaft 51 so that the threaded engagement between the first internally-threaded camming body 32 and the first externally threaded portion 52, and the threaded engagement between the second internally-threaded camming body 34 and the second externally-threaded portion 54, results in rotation of the drive shaft 51 relative to the camming bodies 32, 34 thereby producing synchronous axial movement (adduction or abduction) of the camming bodies 32, 34 along the axis of the drive shaft 51. Threads can be any style and/or pitch, as is known in the art.
In the illustrated embodiment, the direction of the mating threads on the first externally-threaded portion 52 and the first internally-threaded camming body 32 are reversed from the direction of the mating threads on the second externally-threaded portion 54 and the second internally-threaded camming body 34. As a result, axial rotation of the drive shaft 51 in a first direction results in axial adduction of the first and second internally-threaded camming bodies 32, 34, i.e., one toward the other along the drive shaft 51, and axial rotation of the drive shaft 51 in the second, opposite direction results in axial abduction of the first and second camming bodies 32, 34, i.e., one away from the other along the drive shaft 51.
The positions of the camming bodies 32, 34, one relative to the other, determines the size of the jaw space there between, and the radial position of the plurality of gripping jaws 42 and 44 that are movably received within the jaw space intermediate the sliding surfaces of the camming bodies 32, 34.
The drive motor 14 that rotates the drive shaft 51 to adduct and abduct the camming bodies 32, 34 of the gripping assembly 10 shown in
The internal grip applied by the gripping assembly 10 of the present invention results in a self-tightening grip; that is, the transfer of the weight of the tubular segment 90 to the gripping jaws 42 and 44 of the gripping assembly 10, or downward force against the gripping assembly 10, causes at least one of the gripping jaws 42 and 44 to be further cammed outwardly according to the cam angle of the sliding contact between the lower sliding surface of the gripping jaws 42 and 44 and the mating sliding surface of the second internally-threaded camming body 34. Also, the gripping assembly 10 of the present invention provides a balanced application of deployment forces on the gripping jaws 42 and 44 so that substantially all of the torque output from the motor that is not converted to friction along the sliding contact surfaces is transferred radially outwardly as engaging force on the gripping jaws 42 and 44 to grip the interior wall of the tubular member 90.
In the embodiment of the gripping apparatus 10 shown in
The camming bodies 32 and 34 may each further comprise one or more elongate apertures extending through the body on a path generally parallel to the axis of the drive shaft 51. Apertures in each of the camming bodies 32 and 34 may receive cam guides 60 and 62, respectively, to rotatably secure the camming bodies one to the other, and to prevent rotation of the camming bodies 32 and 34 with the drive shaft 51 while slidably permitting each camming body to be displaced along the guide rods in response to rotation of the threaded drive shaft 51. Alternately, as is discussed below in relation to
Each gripping jaw 42 and 44 may have a treated, coated or machined surface to provide positive gripping of the internal wall of the tubular segment 90 with minimal inelastic deformation or marking or include a gripping jaw insert 45, which can have a treated, coated or machined surface to provide positive gripping of the internal wall of the tubular segment 90 with minimal inelastic deformation or marking.
A gripping apparatus 10 may also comprise a biasing member (not shown) for biasing the gripping jaws 42 and 44 radially inwardly toward the retracted and disengaged position when the drive shaft 51 is counter-rotated for releasing the tubular segment 90. The biasing features may comprise spring(s) or other elastic members that engage and bias each gripping jaw 42 and 44. For example, but not by way of limitation, one or more elastic members, each having a first end and a second end, such as elastic bands or straps or a coil spring, may be secured at the first end to gripping jaw 42 and at a second end to the other gripping jaw 44 to bias the gripping jaws 42, 44 one toward the other. Elastic deformation of the elastic member allows the gripping jaws to be cammed radially outwardly one from the other by adduction of the camming bodies 32, 34 to engage and grip the internal wall of the tubular segment 90. Subsequently, abduction of the camming bodies 32, 34 one away from the other permits the elastic members to exert a restoring force on the gripping jaws 42, 44 and to thereby restore the gripping jaws 42, 44 to their original positions.
An alternate embodiment of a gripping apparatus 100 is illustrated in
The hollow drive shaft 151 can have an externally-splined portion 49 for mating rotational engagement with an internally-splined sleeve 48 that is the power output element for the motor 112. This configuration can permit sliding engagement between the externally-splined portion 49 on the drive shaft 151 and the internally-splined sleeve 48 of the motor 112. The splined coupling formed by the externally-splined portion 49 of the drive shaft 151 and the internally-splined sleeve 48 of the motor 112 may provide for axial compensation, e.g., during make-up of threaded connections between a tubular segment and a tubular string to which the segment is joined. Rotation of the camming bodies 103, 104 relative to the drive shaft 151 may be prevented using cam guides like those described above, or using flat camming surfaces like those described below in relation to
The fill-up and circulation assembly portion 203 shown in
If cementing operations are desired, the nozzle 220 disposed may be replaced with a cement wiper plug assembly, e.g., as described in U.S. Pat. No. 6,431,626. A wiper plug launcher assembly, e.g., of the type described in that patent, may be disposed to selectively receive a launching member, such as a ball or a dart, into the bore of the drive shaft 208 of the gripping apparatus 200 to selectively launch cement wiper plugs into the bore of the tubular string 206 to manage placement of cement in the borehole/casing annulus. Introduction of launching members may require the replacement of the upper adapter 202 with a cementing head or launching assembly, and/or replacing the fill-up and circulation assembly 203 with, e.g., a wiper plug assembly which may includes a pair of detachable cement wiper plugs. In such an arrangement, a launching member, such as a ball or dart, may be released from the cementing head to be received in a targeted cement wiper plug to launch the targeted wiper plug to isolate the fluid in the bore of the tubular string 203 ahead of the wiper plug from the cement slurry being pumped in behind the wiper plug. As the predetermined volume of cement slurry is being pumped into the tubular string, the first-launched wiper plug can lead the volume of cement slurry down the bore of the tubular string towards the end. Once all of the predetermined volume of cement slurry is pumped into the bore of the tubular string, a second launching member can be introduced to launch the second cement wiper plug into the bore of the tubular string, e.g., to isolate the trailing end of the volume of cement slurry from the fluid used to displace the trailing cement wiper plug and the cement slurry ahead of it down the bore of the tubular string. This system may be used to provide precise placement of uncontaminated cement slurry into the annulus.
The combination gripping and fill-up and circulation assemblies 200 of the present invention can include a passageway extending through the drive shaft 208 for delivering mud, fluid or cement into the tubular drive shaft 208, a drive motor 209 for engaging drive shaft 208 for rotating the drive shaft 208, a stop pad 226 on the bottom of the motor housing 204 for engaging the end of the tubular 214 when the tool 200 is fully inserted, and a pair of opposing ears 230 extending laterally from the housing 204 for pivotably attaching the combination gripping and fill-up and circulation assemblies 200 for being suspended from a pair of bails, or any combination thereof. The bails can extend, for example, from a conventional traveling block and hook assembly which is preferably mounted on rails inside a rig mast or derrick structure so as to accommodate any reactive torque applied by the tool drive motor.
An embodiment of the opposed camming bodies and one gripping jaw for cooperating with and being deployed by adduction of the camming bodies is illustrated in
The gripping tool of the present invention may also comprise an externally gripping tool. An alternate embodiment comprises an externally gripping apparatus having a first generally ring-shaped camming body with a sloped interior cam surface and a second, opposed generally ring-shaped camming body with an oppositely sloped interior cam surface, and a plurality of angularly distributed and radially inwardly deployable gripping jaws intermediate the first and second camming bodies. The tubular segment is receivable within a bore formed by the aligned camming bodies and the gripping jaws intermediate the camming bodies. The oppositely-sloped camming surfaces on the interior of the ring-shaped camming bodies together form a variable jaw space there between, and the jaw space is reduced upon adduction of the camming bodies, one toward the other, to reduce the jaw space and to slidably displace the gripping jaws radially inwardly to engage and grip the external wall of a tubular segment received within the bore. The tubular segment is releasable from the apparatus by abducting the camming bodies, one away from the other, to increase the size of the jaw space to accommodate the radially outwardly retraction of the gripping jaws so that more of the gripping jaws are received into the jaw space formed between the oppositely-sloped interior surfaces of the camming bodies.
The adduction and abduction of the camming bodies may be implemented in one embodiment by forming threads on the radially outwardly exterior of the first camming body, and forming oppositely-pitched threads on the radially outwardly exterior of the second camming body, and then by disposing the camming bodies, along with the gripping jaws intermediate the camming bodies, within the bore of an internally threaded sleeve having a first internally threaded portion for threadably receiving the first camming body and a second internally and oppositely threaded portion for threadably receiving the second camming body. In a manner much like the drive shaft of the internally threaded embodiment described above, rotation of the internally threaded sleeve in a first direction, relative to the two opposing camming bodies received therein, causes the first camming body to move downwardly toward the second camming body and the jaw space, and the second camming body to move upwardly toward the first camming body and the jaw space, to reduce the jaw space and slidably cam and deploy the gripping jaws radially inwardly to engage and grip the external wall of the tubular segment received within the bore.
In an alternate embodiment, the adduction and the abduction of the camming bodies may be implemented using a plurality of externally-threaded drive shafts that are received within internally threaded and aligned apertures through the camming bodies that are generally parallel to, but offset from, the bore. For example, but not by way of limitation, the first camming body may comprise three generally parallel apertures there through that are generally parallel to an axis of the bore of the generally ring-shaped camming body into which the tubular segment is receivable. The apertures of the first camming body are alignable with a similar set of apertures in the second, opposing generally ring-shaped camming body when the two camming bodies are aligned and positioned within the gripping apparatus for receiving a tubular segment therein. Each of the generally parallel apertures of the first camming body are threaded oppositely the threads in the aligned aperture of the second, opposite camming body. An externally threaded drive shaft is received within each pair of aligned apertures so that simultaneous rotation of the three drive shafts in a first direction within the three pairs of aligned apertures results in adduction of the camming bodies, one toward the other, and rotation of the three drive shafts in the second, opposite direction causes the camming bodies to abduct, one away from the other.
Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the appended claims.
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.
