SYSTEMS AND METHODS FOR MAKING AND BREAKING THREADED JOINTS USING ORBITAL MOTIONS

A method for making a threaded joint between first and second tubulars, each tubular including a central axis, a first end, a second end, a throughbore extending between the first second ends, an internally threaded box-end connector at the first end, and an externally threaded pin-end connector at the second end, the method including: (a) moving the first tubular axially relative to the second tubular to position the pin-end connector of the first tubular at least partially within the box-end connector of the second tubular. In addition, the method includes (b) orbiting the pin-end connector of the first tubular about the central axis of the second tubular; and (c) rotating the first tubular about the central axis of the first tubular during (b). Further, the method includes (d) threading the pin-end connector of the first tubular into the box-end connector of the second tubular dining (b) and (c).

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Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent application Ser. No. 61/906,696 filed Nov. 20, 2013, and entitled “Systems and Methods for Making and Breaking Threaded Joints Using Orbital Motions,” which is hereby incorporated herein by reference in its entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND

The invention relates generally to the makeup and breakup of threaded joints and connections. More particularly, the invention relates to the makeup and breakup of threaded joints in tubular strings used in oil and gas drilling and production operations.

A variety of conduits, flowlines, and tubular strings used in oil and gas operations, such as drillstrings, risers, conductors, tubings and casings, are formed threadably connecting tubular members end-to-end. For example, when drilling an oil and gas well, a plurality of rigid elongate drill pipe sections are typically threadably connected end-to-end to form a drillstring with a drill bit disposed at the lower end thereof. During drilling operations, the drill bit is rotated (e.g., by a top drive or a mud motor) about a central axis with weight on bit (“WOB”) applied such that the bit engages the earthen formation to lengthen the borehole. As the newly formed borehole lengthens, additional pipe sections are threadably connected to the upper most end of the drillstring. Specifically, during such “makeup” operations, each new pipe section is lowered such that its lower end engages the upper most end of the drillstring and is coaxially aligned with the central axis of the drillstring. Thereafter, the new pipe section is rotated about the central axis of the drillstring such that threads disposed on its lower end engage with corresponding threads on the upper most end of the drillstring. Once the new pipe section is threaded onto the drillstring, a final makeup torque is applied (e.g., by a wrench or other similar tool) to ensure that the connection is fully made up. This process is repeated with new pipe sections being added to the upper end of the drilistring as the drill bit lengthens the borehole until the desired depth is achieved.

To remove the drillstring from the borehole the drillstring is lifted from the borehole as pipe sections at the upper end of the drillstring are de-coupled therefrom. During such “breakup” operations, torque is applied to each threaded connection to rotate each section of drill pipe about the central axis of the drillstring in order to disengage the threaded connection between the drill pipe section and the rest of the drilistring. In this manner the drillstring is disassembled as it is withdrawn from the borehole. During conventional breakup operations, coaxial alignment of each drill pipe section and the rest of the drillstring is substantially maintained as each successive drill pipe section is rotated to de-couple the same from the drillstring.

During both makeup and breakup operations, frictional forces resist threaded engagement and disengagement, respectively, of the pipe joints being threaded to and unthreaded from, respectively, the drillstring. Relatively large torque loads may be necessary to overcome the frictional forces. However, the application of excessive torque loads can result in damage and/or excessive wear to the pipe joint threads. Further, as the applied torque loads increase, the tools (e.g., wrenches, power tongs, etc.) used to apply torque to the pipe joints can leave gouges and/or scratches to the outer surface of each drill pipe section, potentially decreasing the useful life of the pipe joints.

BRIEF SUMMARY OF THE DISCLOSURE

Some embodiments are directed to a method for making a threaded joint between a first elongate tubular and a second elongate tubular, each tubular including a central axis, a first end, a second end opposite the first end, a throughbore extending between the first end and the second end, an internally threaded box-end connector at the first end, and an externally threaded pin-end connector at the second end. In an embodiment, the method comprises (a) moving the first tubular axially relative to the second tubular to position the pin-end connector of the first tubular at least partially within the box-end connector of the second tubular, in addition, the method comprises (b) orbiting the pin-end connector of the first tubular about the central axis of the second tubular. Further, the method comprises (c) rotating the first tubular about the central axis of the first tubular in the opposite direction during (b). Still further, the method comprises (d) threading the pin-end connector of the first tubular into the box-end connector of the second tubular during (b) and (c).

Other embodiments are directed to a method for breaking a threaded joint between a first elongate tubular and a second elongate tubular, each tubular including a central axis, a first end, a second end opposite the first end, a throughbore extending between the first end and the second end, an internally threaded box-end connector at the first end, and an externally threaded pin-end connector at the second end. In an embodiment, the method comprises (a) orbiting the pin-end connector of the first tubular about the central axis of the second tubular. In addition, the method comprises (b) rotating the first tubular about the central axis of the first tubular during (a) in the opposite direction. Further, the method comprises (c) unthreading the pin-end connector of the first tubular from the box-end connector of the second tubular during (a) and (b). Still further, the method comprises (d) moving the first tubular axially relative to the second tubular to remove the pin-end connector of the first tubular from the box-end connector of the second tubular.

Still other embodiments are directed to a method for assembling a tubular string for an oil and gas operation, wherein the tubular string comprises a plurality of elongate threaded tubulars, each tubular including a central axis, a first end, a second end opposite the first end, a throughbore extending between the first end and the second end, an internally threaded box-end connector disposed at the first end, and an externally threaded pin-end connector disposed at the second end. In an embodiment, the method comprises (a) lowering the tubular string into a borehole. In addition, the method comprises (b) lowering a first tubular axially toward the tubular string to position the pin-end connector of the first tubular into a box-end connector disposed at an upper end of the tubular string. Further, the method comprises (c) orbiting the pin-end connector of the first tubular about the central axis of the tubular string. Still further, the method comprises (d) rotating the first tubular about the central axis of the tubular string during (c). Also, the method comprises (e) threading the pin-end connector of the first tubular into the box end connector of the tubular string during (c) and (d) to lengthen the tubular string.

Embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical advantages of the invention in order that the detailed description of the invention that follows may be better understood, The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which

FIG. 1 is a schematic view of an embodiment of offshore drilling and/or production system;

FIG. 2 is an enlarged schematic cross-sectional view of a segment of the drillstring of FIG. 1;

FIG. 3 is a schematic perspective view illustrating an embodiment of a method in accordance with the principles described herein for making up the segment of FIG. 2;

FIG. 4 is a schematic cross-sectional view, with the gap between the pin and the box magnified for clarity, taken along section IV-IV of FIG. 3;

FIG. 5 is a schematic cross-sectional view also taken along section IV-IV of FIG. 3 at a different point in time than that shown in FIG. 4;

FIG. 6 is a schematic perspective view illustrating an embodiment of a method in accordance with the principles described herein for making up the segment of FIG. 2;

FIG. 7 is a schematic perspective view illustrating an embodiment of a method in accordance with the principles described herein for breaking up the segment of FIG. 2;

FIG. 8 is a schematic cross-sectional view taken along section VIII-VIII of FIG. 7;

FIG. 9 is a schematic cross-sectional view also taken along section VIII-VIII of FIG. 7 taken at a different point in time than that shown in FIG. 8;

FIG. 10 is a schematic cross-sectional view illustrating an embodiment of a method in accordance with the principles described herein for breaking up the segment of FIG. 2;

FIG. 11 is a schematic perspective view illustrating the segment of FIG. 2 undergoing makeup/breakup operations through utilization of an orbit inducing engagement device in accordance with the principles disclosed herein;

FIG. 12 is a schematic perspective view of the drillstring segment of FIG. 2 undergoing makeup/breakup operations through utilization of the orbit inducing engagement device of FIG. 11;

FIG. 13 is a graphical illustration of a method in accordance with the principles disclosed herein for assembling a tubular string;

FIG. 14 is a schematic perspective view illustrating an embodiment of a method in accordance with the principles described herein for making up a threaded connection between a threaded rod and a nut; and

FIG. 15 is an enlarged schematic cross-sectional view of a segment of the drillstring of FIG. 1 showing a different embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.

In the following description and figures, embodiments of systems and methods for making and breaking threaded joints using orbital motions are described for use with a plurality of tubular sections making up a drilistring. However, it should be appreciated that embodiments of the systems and methods described herein may be utilized in wide variety of systems and applications which employ threaded connections to make up adjacent tubular sections while still complying with the principles disclosed herein, such as for example, for production tubing sections and casing pipe sections. In addition, embodiments of the systems and methods described herein may be utilized to facilitate the makeup of other known threaded connections, such as, for example, a threaded connection between a bolt and nut. Therefore, use of embodiments of the systems and methods described herein to facilitate the threaded connection between adjacent drillstring sections is only one of many potential uses thereof. Thus, any reference to drillstrings and related subject matter is merely included to provide context to the description contained herein and is in no way meant to limit the scope thereof.

Referring now to FIG. 1, an embodiment of an offshore system 10 for drilling and/or producing a subsea well 30 is shown. In this embodiment, system 10 includes a floating platform 20 disposed at the sea surface 12, a subsea blowout preventer (BOP) 25 mounted to a wellhead 34 disposed at the sea floor 13, and a lower marine riser package (LMRP) 27 mounted to the upper end of BOP 25. A drilling riser 40 extends from platform 20 to LMRP 27. In general, riser 40 is a large-diameter pipe that connects LMRP 27 to the floating platform 20. During drilling operations, riser 40 takes mud returns to the platform 20. Casing 31 extends from wellhead 34 into subterranean wellbore 14.

Riser 40 has a central axis 45 and includes a first or upper end 40a coupled to platform 20 and a second or lower end 40b coupled to LMRP 27. In this embodiment, riser 40 is made up of a plurality of elongate riser sections 44 coupled end-to-end at joints 46. In some embodiments, joints 46 are threaded joints; however, it should be appreciated that other types of connections are possible, such as, for example, bolted flange connections. Drilling operations are carried out by a tubular string or drillstring 50 supported by platform 20 and extending through riser 40, LMRP 27, BOP 25, and into cased wellbore 14. In this embodiment, drillstring 50 is made up of a plurality of elongate tubular sections 110 coupled end-to-end at threaded joints 120. An annulus 48 is formed between drillstring 50 and riser 40.

During drilling operations, a drill bit 32 disposed at the lower end of drillstring 50 is rotated as weight-on-bit (WOB) is applied to drill wellbore 14. During this process, drilling fluid (e.g., mud) is pumped from platform 20, down drill string 50, out the face of drill bit 32, and back up annulus 48.

Referring now to FIG. 2, an exemplary segment 100 of drillstring 50 including two exemplary sections 110 connected with one threaded joint 120 is shown. Each section 110 is identical. In particular, each section 110 comprises an elongate tubular body 112 having a central, longitudinal axis 125. Each body 112 has a first or upper end 112a, a second or lower end 112b, a radially outer surface 112c extending between ends 112a, 112b, and a radially inner surface 112d extending between ends 112a, 112b. Inner surface 112d defines a throughbore 114 extending between ends 112a, 112b. in addition, each upper end 112a comprises a female box-end connector 116 and each lower end 112b comprises a male pin-end connector 118. Each box-end connector 116 includes internal threads 117, while each pin-end connector 118 includes external threads 119. Connectors 116, 118 and threads 117, 119 are sized and configured to threadably mate and engage to form joint 120.

Outer surface 112c of each body 112 is disposed at an outer diameter D110o, and inner surface 112d of each body 112 is disposed at an inner diameter D110i. Outer surface 112c is cylindrical between upper end 112a and pin-end connector 118, and is frustoconical along connector 118. Thus, outer diameter D110o is uniform between end 112a and pin-end connector 118, but decreases moving axially along pin-end connector 118 toward lower end 112b. Inner surface 112d is cylindrical between lower end 112b and box-end connector 116, and is frustoconical along connector 116. Thus, inner diameter D110i is uniform between end 112b and box-end connector 116, but increases moving axially along box-end connector 116 toward lower end 112a.

For purposes of clarity and further explanation, the upper pipe or drillstring section 110 of segment 100 will be referred to as section 110A, the lower pipe or drillstring section 110 of segment 100 will be referred to as section 110B, and axes 125 of sections 110A, 110B will be referred to as axes 125A, 125B, respectively. When sections 110A, 110B, are threadably connected together end-to-end at joint 120 with mating connectors 116, 118 as shown in FIG. 2, axes 125A, 125B are coaxially aligned and throughbores 114 are aligned to form a continuous flow passage through segment 100.

As previously described, threaded joints between tubulars used in oil and gas operations are conventionally made-up and broke-up with the tubulars coaxially aligned. However, in embodiments described herein, the makeup and breakup of threaded joints between tubulars is performed, at least partially, without the tubulars being coaxially aligned. More specifically, referring now to FIGS. 3-5, an embodiment of a method for making up threaded joints 120 between connectors 118, 116 of sections 110A, 110B, respectively, is shown. In this embodiment, axes 125A, 125B are oriented parallel to each other, but radially spaced apart. In other words, axis USA is offset from axis 125B (i.e., axes 125A, 125B are not coaxially aligned). Thereafter, section 110A is whirled or orbited about axis 125B of lower section 110B in direction 127 such that axis 125A of section 110A orbits about axis 125B as pin-end connector 118 rolls inside the box and is threaded into box-end connector 116 to makeup threaded joint 120.

The method for making up threaded joint 120 shown in FIG. 3 offers the potential to reduce the input torque required to fully make up joint 120. In addition, some embodiments of the method for making up threaded joint 120 in FIG. 3 offer the potential to produce an enhanced residual stress state for joint 120 following makeup. In particular, as best shown in FIGS. 4 and 5, as section 110A is orbited about axis 125B in direction 127, outer surface 112c of section 110A engages inner surface 112d of section 110B such that internal threads 117 on connector 116 of section 110B engage external threads 119 on connector 118 of section 110A at a point of contact 130. Without being limited to this or any other theory, as section 110A orbits about axis 125B, a torque is generated that is applied to section 110A (i.e., a torsional force results from the induced orbital motion) and friction arises between sections 110A, 110B at point 130. Each of the induced torque as well as the resulting friction work to facilitate rotation of section 110A about its own central axis 125A. In particular, the orbit of section 110A about axis 125B results in a torque T130 applied to section 110A about the center 125A. In addition, in at least sonic embodiments, a frictional force F130′ acts at point 130 to resist slipping of threads 117, 119 due to orbit of section 110A in direction 127. As a result, torque T130 and friction force F130′ drive the rotation of section 110A about axis 125A in a direction 129. Rotation of section 110A about axis 125A can be further supplemented by an external device such as a spinner assembly or tongs. The orbiting and rotation can be accomplished by any device known in the art, such as by modified tongs with eccentrics, gears, hydraulic cylinders, radial impacts and resonance machines.

In at least some embodiments, once section 110A begins rotating about axis 125A (whether by torque T130 and/or force F130′ alone or in combination with an external device), a second frictional force F130″ also acts on sections 110A, 110B to resist slipping between threads 117, 119 due to the rotation of section 110A relative to section 110B. Force F130″ is analogous to the friction force that must be overcome during conventional makeup operations. However, as is shown in FIGS. 4 and 5, force F130′ and torque T130 are each operate in the opposite direction as force F130″, and thus, at least partially counteract force F130″. Consequently, the overall or net frictional force directly resisting rotation of section 110A relative to section 110B is reduced. Thus, by inducing section 110A to orbit about axis 125B of section 110B during makeup operations, at least a portion of the friction between threads 117, 119 that resists such operations is reduced, thereby allowing joint 120 to be fully made-up with a reduced amount of input torque (e.g., such as would be applied by an external device).

During makeup of joint 120 according to the method illustrated in FIG. 3, axis 125A is initially radially offset from axis 125B by a radial distance R129, and there is clearance gap X110A-110B radially positioned between sections 110A, 110B diametrically opposite contact point 130. However, since mating threaded connectors 118, 116 of sections 110A, 110B, respectively, are tapered, as joint 120 is made-up, axis 125A moves or translates toward axis 125B, radial distance R129 decreases, and clearance gap X110A-110B decreases. In other words, as joint 120 is made-up axis 125A spirals inward toward axis 125B. As radial distance R129 and clearance gap X110A-110B decrease and axes 125A, 125B come into coaxial alignment, the orbital and rotational motions of section 110A relative to section 110B transition to pure rotation of section 110A relative to section 110B about aligned axes 125A, 125B. The rotation stops when the connection shoulders make contact with sufficient force for the friction forces to stop the relative rotation between the pin and the box.

Referring now to FIG. 6, another embodiment of a method for making up threaded joint 120 between connectors 118, 116 of sections 110A, 110B, respectively, is shown. In this embodiment, upper section 110A is canted or angled relative to lower section such that axis 125A is disposed at an acute angle θ relative to axis 1252 of lower section 1102 during makeup of joint 120. At least initially the beginning of the makeup), angle θ is preferably greater than 0.1°. In some embodiments, the angle θ is chosen such that the moment that generate angle θ has a magnitude which is approximately 10% of the connector capacity (In some embodiments, connector capacity refers to the force that generates a bending moment which results in plastic deformation and/or failure of section 110A). Thereafter, end 112a of section 110A is driven to orbit about axis 125B in direction 127 to produce the same or a similar whirl or orbit of lower end 112b of section 110A relative to section 110B as previously described and shown in FIGS. 4 and 5. In some embodiments, as end 112a of section 110A is rotated about the axis 125B in the direction 127 as described above, the rotational path of section 110A defines a conical shape.

The method for making up threaded joint 120 shown in FIG. 6 offers the potential to reduce the torque required to fully make up joint 120. In particular, without being limited to this or any other theory, as previously described and shown in FIGS. 4 and 5, as section 110A is orbited about axis 125B in direction 127, torque T130 and frictional force F130′ drive the rotation of section 110A about axis 125A in direction 129. Rotation of section 110A about axis 125A can be supplemented by an external device such as a spinner assembly or tongs. In addition, second frictional force F130″ acts on sections 110A, 110B to resist slipping between threads 117, 119 due to the rotation of section 110A relative to section 110B. Torque T130 and Force F130″, each operate in the opposite direction as force F130″, and thus, at least partially counteracts force F130″, thereby reducing the total amount of input torque required to fully make up sections 110A, 110B.

Since mating threaded connectors 118, 116 of sections 110A, 110B, respectively, are tapered, as joint 120 is made-up according to the method illustrated in FIG. 6, angle θ steadily decreases, axis 125A pivots toward axis 125, radial distance R129 decreases, and clearance gap X110A-110B decreases. As the connection is made up the radial force required to keep R129 positive and rotating increases as the radial friction between the threads and between the shoulders increases.

Referring now to FIGS. 7-9, an embodiment of a method for breaking threaded joint 120 between connectors 118, 116 of exemplary pipe joints or sections 110A, 110B, respectively, is shown. In this embodiment, to breakup threaded joint 120, lower end 112b of upper section 110. A is whirled or orbited about axis 125B of lower section 110B.

The method for breakup of threaded joint 120 shown in FIG. 7 offers the potential to reduce the torque required to fully break up joint. In particular, as best shown in FIGS. 8 and 9, without being limited to this or any other theory as section 110A orbits about axis 125B of section 110B in a direction 131, a torque T131 is generated that is applied to section 110A (i.e., a torsional force results from the induced orbital motion) and a force F131′ act on sections 110A, 110B at a contact point 130 to resist slipping of threads 117 and 119, and thus, facilitate rotation of section 110A about its own axis 125A in direction 133. Rotation of section 110A about axis 125A can he supplemented by an external device such as a spinner assembly or tongs.

Further, as section 110A rotates about its axis 125B, a second frictional force F131″ resists slipping between threads 117, 119 due to rotation of section 110A about axis 125A relative to section 110B. Force F131″ is analogous to the friction that resists relative rotation of sections 110A, 110B during conventional breakup operations. However, as is shown in FIGS. 8 and 9, torque T130 and force F131′ operate in the opposite direction as force F130″, and thus, at least partially counteract force F130″. Consequently, the overall or net frictional force directly resisting rotation of section 110A relative to section 110B is reduced. Thus, by inducing section 110A to orbit about axis 125B of section 110B during breakup operations, at least a portion of the friction between threads 117, 119 that resists such operations is reduced, thereby allowing joint 120 to be fully broken with a reduced amount of input torque. In other words the breakup is the reverse of the makeup.

Referring now to FIG. 10, another embodiment of a method for breaking up threaded joint 120 between connectors 118, 116 of sections 110A, 110B, respectively, is shown. In this embodiment, upper section 110A is canted or angled relative to lower section such that axis 125A is disposed at an acute angle φ relative to axis 125B of lower section 110B during breakup of joint 120. In some embodiments, towards the end of breakup, angle φ is preferably greater than 0.1°. Thereafter, end 112a of section 110A is driven to rotate about axis 125B in a direction 133 to produce the same or a similar whirl or orbit of lower end 112b of section 110A relative to section 110B in direction 131 as previously described and shown in FIGS. 8 and 9.

The method for breaking up threaded joint 120 shown in FIG. 10 offers the potential to reduce the torque required to fully brake up joint 120. In particular, as previously described and shown in FIGS. 8 and 9, as section 110A is orbited about axis 125B in direction 131, torque T131 and frictional force F131, drive the rotation of section 110A about axis 125A in direction 139. Rotation of section 110A about axis 125A can be supplemented by an external device such as a spinner assembly or tongs. In addition, second frictional force F131″ acts on sections 110A, 110B to resist slipping between threads 117, 119 due to the rotation of section 110A relative to section 110B. Torque T131 and force F131′ are in the opposite direction as force F131″, and thus, at least partially counteract force F131″.

Referring now to FIG. 11, an embodiment of a device 200 in accordance with the principals described herein for inducing the orbital motion of upper section 110A relative to lower section 110B as described above and shown in FIGS. 3, 6, 7 and 10 to makeup and breakup joint 120 is shown. During makeup and breakup operations, lower section 110B is held/maintained in position, while device 200 grasps upper section 110A and induces section 110A to orbit about axis 125B of section 110B. In this embodiment, device 200 can also induce rotation of section 110A about its own axis 125A (in addition to inducing the orbital motion about axis 125B). In general, device 200 can be any suitable device known in the art. For example, device 200 can comprise a power tong that induces rotation of section 110A about axis 125B of section 110B and/or angularly deflects section 110A relative to section 110B such that the axis 125A is canted or angled relative to the axis 125B, while also rotating upper end 112a relative to lower end 112b of section 110A. As another example, device 200 can comprise a motor with an eccentric mass, such that actuation of motor causes a radial rotating shear force and/or being moment at the connection between sections 118, 116 which further induces orbital motion of axis 125A of section 110A about axis 125B of section 110B. As still another example, in other embodiments, device 200 is an impact wrench or other similarly powered tool that engages with section 110A and imparts a force thereto which induces orbital motion of axis 125A of section 110A about axis 125B of section 110B.

In this embodiment, device 200 orients section 110A parallel to section 110B to produce the relative motions of the sections 110A, 110B as described above and shown in FIGS. 3 and 7. It is to be understood that for tapered threads, as for drill pipe connections, that during makeup of joint 120, radial distance R129, and clearance gap X110A-110B steadily decrease from a maximum to zero or a small value, and during breakup of joint 120, radial distance R129, and clearance gap X110A-110B steadily increase from zero or a small value to a maximum. In other embodiments, the device (e.g., device 200) can orient section 110A (or at least the upper portion thereof) at an acute angle θ or φ as described above and shown in FIGS. 6 and 10 to makeup and breakup joint 120, respectively. It is to be understood that in some embodiments, during makeup of joint 120, angle θ, radial distance R129, and clearance gap X110A-110B steadily decrease from a maximum to zero or a small value, and during breakup of joint 120, angle φ, radial distance R129, and clearance gap X110A-110B steadily increase from zero or a small value to a maximum. However, due to the threads being typically triangular and at least in part to the flexibility of the material making up sections 110A, 110B, in some embodiments the angle θ does not decrease from a maximum to zero and the angle φ does not increase from zero to a maximum while still complying with the principles disclosed herein.

In the manner described, upper section 110A is manipulated and moved relative to a stationary lower section 110B to makeup and breakup threaded joint 120. However, it should be appreciated that such relative motion of sections 110A, 110B can also be accomplished by manipulating lower section 110B or manipulating both sections 110A, 110B. For example, lower section 110B can be manipulated and moved relative to a stationary upper section 110A (lower section 110B orbited about axis 125A of upper section 110A with section 110B parallel to section 110A or with sections 110A, 110B skewed or angled relative to each other). Referring briefly to FIG. 12, device 200 is shown grasping and moving lower section 110B such that it orbits about axis 125A of stationary upper section 110A in a direction 227 to makeup threaded joint 120. As lower section 110B orbits about axis 125A in direction 227, upper section 110A rotates about its axis 125A in direction 129 (e.g., by torque T130 and/or force F130′ alone or in combination with some other input force, each as previously described). In the same manner as previously described, this method offers the potential to reduce the total input torque necessary to makeup joint 120. As yet another example, both sections 110A, 110B can be manipulated and moved relative to each other such that they orbit about each other's axis 125B, 125A, respectively (lower section 110B orbited about axis 125A of upper section 110A and upper section 110A orbited about axis 125B with sections 110A, 110B parallel to each other or with sections 110A, 110B skewed or angled relative to each other).

Referring now to FIG. 13, an embodiment of a method 300 for making up a tubular string (e.g., drillstring 50) is shown,. Method 300 begins at block 305 by inserting (i.e., lowering) the tubular string at least partially into a bore hole with the upper end of the tubular string extending upward therefrom. In general, the tubular string can be formed from one or more tubular section(s) (e.g., tubular section 110A or 110B). Next, in block 310, a new tubular section is lowered until the lower end of the new tubular section axially abuts and engages the upper end of the tubular string. Once the new tubular section has engaged the tubular string, the new tubular section is orbited about the central axis of the tubular string at block 315 in the manner previously described above for sections 110A, 110B. In addition, in block 320, the new tubular section is rotated about its central axis while orbiting about the central axis of the tubular string. As a result of the orbiting and rotating in blocks 315, 320, respectively, a threaded joint between new tubular section and the tubular string is madeup in block 325, thereby lengthening the tubular string. Next, the tubular string with the newly incorporated tubular section is lowered further into the borehole in block 330. Thereafter, the steps 310, 315, 320, 325, and 330 are repeated to integrate additional new tubular sections into the tubular string until the string is fully assembled. In general, method 300 can be performed in reverse to unthread and remove tubular sections from the tubular string. While making up the orbit drive can be started just when the connection make up torque start to rise rapidly to assist in the torqueing up of the connection. While breaking the orbit motion can be done just at the beginning to assist in the break up.

In the manner described, systems and methods described herein offer the potential to reduce the total torque necessary to makeup and breakup threaded joints between tubular sections by inducing orbital motion(s) in one or both tubular sections (e.g., sections 110A, 110B). Reduced torque loads in turn offer the potential to increase the useful life of the tubular sections by reducing damage and/or wear on the mating threads (e.g., threads 117, 119) and outer surfaces (e.g., surface 112c) of tubular sections. In addition, the reduced torque loads also results in a reduced value of the resulting residual stresses which occur within such threaded connections, which thereby guards against subsequent loosening of the joint after makeup.

While embodiments disclosed herein have included methods of makeup and breakup of tubular sections 110A, 110B, it should be appreciated that embodiments of the systems and methods disclosed herein may be utilized to facilitate the makeup for other types of threaded connections. For example, referring now to FIG. 14, a nut 402 is shown threadably engaged with a threaded rod 410. In this embodiment, nut 402 is a standard, conventional hexagonal nut but may be any suitable type of bolt known in the art. In addition, in this embodiment nut 402 has a central axis 405 and includes a first or upper side 402a, a second or lower side 402b opposite the upper side 402a, and a throughbore 404 extending axially between the sides 402a, 402b, and further including a set of internal threads (not shown). Rod 410 has a central axis 415, a first end 410a, a second end 410b opposite the first end 410a, and a radially outer surface 410c extending between the ends 410a, 410b. A set of external threads (not shown) are disposed about the surface 410c and are configured to engage with the internal threads (not shown) disposed within throughbore 404 of nut 402. During operation, nut 402 is disposed on rod 410 such that the axis 405 is parallel to the axis 410. Thereafter, axis 405 of nut 402 is orbited about the axis 415 of rod 410 along an orbital path 418 which further results in the rotation of nut 402 about axis 405 along the direction 420, For the same reasons previously described above for sections 110A, 110B, the orbital motion of nut 402 along path 418 operates to rotate the nut 402 around the rod 410 as it rolls without slipping around the rod 410, and thus reduces the effective amount of friction opposing the engagement between the corresponding threads of nut 402 and rod 410 which therefor reduces the required amount of input torque necessary to threadably engage nut 402 and rod 410 during operations.

While embodiments disclosed herein have been described as being used in an offshore drilling and/or production system system 10) in other embodiments, the principles disclosed herein may be applied to any drilling and/or production system (e.g., a land-based drilling and/or production system) while still complying with the principles disclosed herein. Thus, any reference in the above disclosure to offshore drilling and/or production systems is merely included to provide context to the description above and is in no way meant to limit the scope thereof. Additionally, while embodiments disclosed herein have described the methods and/or devices as being carried out on sections of drill pipe, it should be appreciated that in other embodiments, the methods and/or device disclosed herein may be used to perform makeup/breakup operations for any type of elongate threaded tubular member, such as, for example, tubing, casing pipes, risers, etc. Thus, any mention of drill pipes is not meant to limit the application of the principles disclosed herein in any way, and is only included to provide context to the description above.

Further, while embodiments disclosed herein have included threaded connections 118, 116 that are tapered, it should he appreciated that in other embodiments, threaded connections 118, 116 are not tapered as for the nut and threaded rod example while still complying with the principles disclosed herein. Referring to FIG. 15, for threaded connections that are not tapered, outer surface 112c of each body 112 is disposed at an outer diameter D110o, and inner surface 112d of each body 112 is disposed at an inner diameter D110i. Outer surface 112c is cylindrical between upper end 112a and pin-end connector 118a, and is cylindrical along connector 118a. Thus, outer diameter D110o is uniform between end 112a and lower end 112b. Inner surface 112d is cylindrical between lower end 112b and box-end connector 116a, and is cylindrical along connector 116a. Thus, inner diameter D110i is uniform between end 112b and lower end 112a.

During makeup of joint 120 with cylindrical threaded connections according to the method illustrated in FIG. 3, axis 125A is radially offset from axis 125B by a radial distance R129, and there is clearance gap X110A-110B radially positioned between sections 110A, 110B diametrically opposite contact point 130. As joint 120 is made-up, axis 125A remains a constant distance from axis 125B, radial distance R129 stays constant, and clearance gap X110A-110B stays constant until the shoulders make contact. The orbit radius is reduced as the triangular thread contact surfaces force the pin and box axis together. Rotation stops when the friction between the threads and the shoulder exceed the combine twisting torque and the orbital radial force.

The embodiments described in reference to FIGS. 6 and 9 apply in the same fashion for threaded connections that are not tapered. The orbit radius is reduced as the triangular thread contact surfaces force the pin and box axis together. Rotation stops when the friction between the threads and the shoulder exceed the combine twisting torque and the orbital radial force.

The embodiments described in reference to FIGS. 7 and 10 apply in the same fashion to break up a joint 120 with threaded connections that are not tapered.

While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.

Claims

1. A method for making a threaded joint between a first elongate tubular and a second elongate tubular, each tubular including a central axis, a first end, a second end opposite the first end, a throughbore extending between the first end and the second end, an internally threaded box-end connector at the first end, and an externally threaded pin-end connector at the second end, the method comprising:

(a) moving the first tubular axially relative to the second tubular to position the pin-end connector of the first tubular at least partially within the box-end connector of the second tubular;
(b) orbiting the pin-end connector of the first tubular about the central axis of the second tubular;
(c) rotating the first tubular about the central axis of the first tubular during (b); and
(d) threading the pin-end connector of the first tubular into the box-end connector of the second tubular during (b) and (c).

2. The method of claim 1, further comprising maintaining the central axis of the first tubular parallel to the central axis of the second tubular during (b) and (c).

3. The method of claim 2, further comprising:

radially offsetting the central axis of the first tubular from the central axis of the second tubular by a radial offset distance;
decreasing the radial offset distance during (d).

4. The method of claim 1, further comprising orienting the first tubular at an acute angle θ relative to the second tubular during (b) and (c).

5. The method of claim 4, further comprising decreasing angle θ during (d).

6. The method of claim 1, further comprising spiraling the central axis of the second tubular inward relative to the central axis of the first tubular during (b) and (c).

7. The method of claim 1, wherein (c) occurs in response to (b).

8. The method of claim 1, further comprising driving the rotation of the first tubular about the central axis of the first tubular during (c) with a device removably coupled to the first tubular.

9. A method for breaking a threaded joint between a first elongate tubular and a second elongate tubular, each tubular including a central axis, a first end, a second end opposite the first end, a throughbore extending between the first end and the second end, an internally threaded box-end connector at the first end, and an externally threaded pin-end connector at the second end, the method comprising:

(a) orbiting the pin-end connector of the first tubular about the central axis of the second tubular;
(b) rotating the first tubular about the central axis of the first tubular during (a); and
(c) unthreading the pin-end connector of the first tubular from the box-end connector of the second tubular during (a) and (b); and
(d) moving the first tubular axially relative to the second tubular to remove the pin-end connector of the first tubular from the box-end connector of the second tubular.

10. The method of claim 9, further comprising maintaining the central axis of the first tubular parallel to the central axis of the second tubular during (a) and (b).

11. The method of claim 10, further comprising increasing a radial offset distance between the central axis of the first tubular and the central axis of the second tubular during (d).

12. The method of claim 9, further comprising increasing an acute angle θ between the central axis of the first tubular and the central axis of the second tubular during (a) and (b).

13. The method of claim 9, further comprising spiraling the central axis of the second tubular outward relative to the central axis of the first tubular during (a) and (b).

14. The method of claim 9, wherein (b) occurs in response to (a).

15. A method for assembling a tubular string for an oil and gas operation, wherein the tubular string comprises a plurality of elongate threaded tubulars, each tubular including a central axis, a first end, a second end opposite the first end, a throughbore extending between the first end and the second end, an internally threaded box-end connector disposed at the first end, and an externally threaded pin-end connector disposed at the second end, the method comprising:

(a) lowering the tubular string into a borehole;
(b) lowering a first tubular axially toward the tubular string to position the pin-end connector of the first tubular into a box-end connector disposed at an upper end of the tubular string;
(c) orbiting the pin-end connector of the first tubular about the central axis of the tubular string;
(d) rotating the first tubular about the central axis of the tubular string during (c); and
(e) threading the pin-end connector of the first tubular into the box end connector of the tubular string during (c) and (d) to lengthen the tubular string.

16. The method of claim 15, further comprising maintaining the central axis of the first tubular parallel to the central axis of the tubular string during (c) and (d).

17. The method of claim 16, further comprising decreasing a radial offset distance between the central axis of the first tubular and the central axis of the tubular string during (e).

18. The method of claim 15, further comprising decreasing an acute angle θ between the central axis of the first tubular and the central axis of the tubular string during (e).

19. The method of claim 15, wherein (d) occurs in response to (c).

20. The method of claim 15, further comprising:

(f) lowering the tubular string further into the borehole after (e);
(g) lowering a second tubular axially toward the tubular string to position the pin-end connector of the second tubular into a box-end connector disposed at an upper end of the first tubular;
(h) orbiting the pin-end connector of the second tubular about the central axis of the first tubular;
(i) rotating the second tubular about the central axis of the first tubular during (h); and
(j) threading the pin-end connector of the second tubular into the box end connector of the first tubular during (h) and (i) to lengthen the tubular string.

21. A method for making a threaded connection between a threaded rod and a bolt, where the threaded rod includes a central axis, a first end, a second end opposite the first end, a radially outer surface extending between the first end and second end, and where the radially outer surface includes a set of external threads, and where the bolt includes a central axis, a first end, a second end opposite the first end, and has a throughbore extending axially between the first end and second end, and where the bolt has a set of internal threads, the method comprising:

(a) disposing the bolt onto the threaded rod such that the axis of the bolt is parallel to the axis of the threaded rod;
(b) orbiting the bolt about the central axis of the threaded rod;
(c) rotating the bolt about the central axis of the bolt during (b); and
(d) threadably engaging the internal threads of the bolt with the external threads of the threaded rod during (b) and (c).

22. The method of claim 21, further comprising maintaining the central axis of the bolt parallel to the central axis of the threaded rod during (b) and (c).

23. The method of claim 21, further comprising decreasing a radial offset distance between the central axis of the bolt and the central axis of the threaded rod during (d).

24. The method of claim 21, further comprising decreasing an acute angle θ between the central axis of the first tubular and the central axis of the tubular string during (d).

Patent History
Publication number: 20150135501
Type: Application
Filed: Nov 20, 2014
Publication Date: May 21, 2015
Applicant: BP Corporation North America Inc. (Naperville, IL)
Inventor: PIERRE A. BEYNET (Houston, TX)
Application Number: 14/548,412
Classifications
Current U.S. Class: Disassembling (29/426.1); Threaded Fastener (29/525.11)
International Classification: E21B 17/042 (20060101);