Patent Application
20180087334
Tubular handling equipment is used on an oil rig to lower casing and other tubulars into the wellbore (“trip-in”). During trip-in, an elevator picks up a length of one or more joints of tubular from a rack and brings the tubular into position above a “stump” or open connection of a previously-run tubular. The stump is typically supported at the rig floor by a spider, which transmits the weight of the deployed tubular string to the rig floor. An operator may then guide the new length of tubular (an “add-on” tubular) into position over the stump, i.e., at well center. The operator may then assist in stabbing the add-on tubular into the open connection of the stump.
Once this occurs, the operator may engage a power tong onto the add-on tubular and apply a torque to the add-on tubular. The torque causes the add-on tubular to rotate into connection with the stump. The tong is then disengaged, the elevator engages the add-on tubular, and the spider may disengage from the tubular string, leaving the weight of the tubular string held by the elevator. The elevator then lowers the tubular string into the well, until nearing the rig floor, at which point the spider is re-engaged, and the process starts again.
The aforementioned tongs are designed to impart and withstand high torsional loads. Typically, a tong includes a drive train made of a set of spur gears, which amplify a torque produced by a motor. The amplified torque is then transmitted to a rotary gear, which applies the torque to the tubular. Other tong designs employ a worm-gear drive, in which a helical tooth mates with canted teeth of a driven gear. Thus, rotation of the helical tooth results in rotation of the driven gear, which the tong converts into rotation of the tubular.
Conventional tongs, however, occupy a substantial footprint on a rig. Further, tongs are typically designed to engage a single diameter of pipe, requiring time-consuming equipment changes when the size (diameter) of the pipe being run changes. Additionally, tongs are often designed to allow lateral entry of the pipe to within the tong and exit therefrom, but may not be configured to allow a box-end of a pipe joint to pass axially therethrough.
Embodiments of the disclosure may provide a tong for applying torque to a tubular. The tong includes a rotary ring defining an inner profile through which the tubular is received, the inner profile defining a plurality of pockets extending radially outward and a plurality of cam surfaces circumferentially between the plurality of pockets, and a plurality of engaging members disposed within the rotary ring. The plurality of engaging members are movable from a retracted position at least partially in the plurality of pockets to an engaging position in which the plurality of engaging members are positioned along the plurality of cam surfaces. The tong also includes a plurality of cam followers extending through the rotary ring, and a worm drive including a helical ridge. The plurality of cam followers engage the helical ridge so as to transmit a substantially tangential force to the rotary ring.
Embodiments of the disclosure may also provide a method for rotating a tubular using a tong. The method includes receiving a tubular into a receiving hole in a tong, and activating a motor. Activating the motor causes a helical ridge to rotate in a first direction, the helical ridge applying a linear force on one or more cam followers connected to a rotary ring, causing the rotary ring to rotate relative to a plurality of engaging members. Rotating the rotary ring relative to the plurality of engaging members causes the plurality of engaging members to move radially inwards into engagement with the tubular and to rotate the tubular after engaging the tubular.
Embodiments of the disclosure may further provide a tong that includes a motor, a helical ridge coupled to the motor such that the motor drives the helical ridge to rotate, a rotary ring defining a plurality of pockets and a plurality of cam surfaces in an inner profile thereof, and a plurality of cam followers connected to the rotary ring and extending axially therefrom, the plurality of cam followers being positioned to be engaged by the helical ridge. The helical ridge applies a linear force on the plurality of cam followers when the cam followers are engaged by the helical ridge, and wherein the linear force causes the rotary ring to rotate. The tong also includes a plurality of jaws movable along the inner profile of the rotary ring. The plurality of jaws are positioned at least partially within respective pockets of the plurality of pockets when the tong is in a retracted position, and the plurality of jaws engage the plurality of cam surfaces when the tong is in an engaging position.
The foregoing summary is intended merely to introduce a subset of the features more fully described of the following detailed description. Accordingly, this summary should not be considered limiting.
The accompanying drawing, which is incorporated in and constitutes a part of this specification, illustrates an embodiment of the present teachings and together with the description, serves to explain the principles of the present teachings. In the figures:
It should be noted that some details of the figure have been simplified and are drawn to facilitate understanding of the embodiments rather than to maintain strict structural accuracy, detail, and scale.
Reference will now be made in detail to embodiments of the present teachings, examples of which are illustrated in the accompanying drawing. In the drawings, like reference numerals have been used throughout to designate identical elements, where convenient. In the following description, reference is made to the accompanying drawing that forms a part thereof, and in which is shown by way of illustration a specific exemplary embodiment in which the present teachings may be practiced. The following description is, therefore, merely exemplary.
In general, the present disclosure provides a tong for rotating a tubular (e.g. a casing) and/or otherwise applying a torque thereto. In some embodiments, the tong includes a worm drive that has input power supplied by a motor (e.g., a hydraulic, electric, or pneumatic motor). The worm drive may engage cam followers attached to a rotary section of the tong. The rotary section generally includes a cage plate assembly, a rotary ring, and jaws. Input rotation of the worm drive may cause the screw thereof to apply a linear force to the cam followers, which is translated to a tangential force on the rotary section, causing the rotary ring of the rotary section to rotate. Initially, the cage plate assembly and the jaws are restrained from rotating, such that rotation of the rotary ring causes jaws to move radially inwards across a range of radial positions. When a tubular is received through the tong, such rotation causes the jaws to engage the tubular. Continued rotation of the rotary ring may, after such engagement, cause cage plate and jaws to rotate along with the rotary ring, and thereby rotate the tubular. The worm drive may be reversed, which may reverse the rotation of the rotary ring and cause the jaws to retract and move radially outward (e.g., into pockets) so as to disengage from the tubular. The jaws may retract far enough away from the tubular to allow passage of the tubular, e.g., including the box end thereof, vertically through the tong. These and other features will be described in greater detail below with reference to several example embodiments.
Turning now to the illustrated embodiments,
In an embodiment, the rotatable section 102 may include a top guard 108, which may be generally disk-shaped and may serve to protect other tong 100 components from damage, e.g., if an elevator or another object lands on the tong 100. The rotatable section 102 may also include a removable cover 110, which may be generally L-shaped in cross section (e.g., extending vertically and then horizontally to meet the top guard 108) and configured to cover an access gap, as will be described in greater detail below. The cover 110 may, for example, be fastened to the top guard 108 via bolts.
Further, the rotatable section 102 may include a guide 112, which may be coupled with or disposed within the top guard 108. The guide 112 may be annular and beveled or tapered, so as to receive and direct an end of a tubular therethrough. The guide 112 may be positioned in alignment with the receiving hole 106, and thus may serve to guide the tubular into the receiving hole 106. Further, the guide 112 may be provided in at least two pieces (e.g., segments 112A, 112B), which may be separately removable, e.g., to allow for lateral removal of a tubular from within the receiving hole 106.
The rotatable section 102 may also include a cage plate 114 and a rotary ring 118. For example, the cage plate 114 may be disposed vertically below and adjacent to the top guard 108. The rotary ring 118 may be below the cage plate 114 and may be seated on the stationary section 104, and configured to rotate with respect thereto. Further, the rotary ring 118 may initially be rotatable relative to the cage plate 114.
The top guard 108 may include openings 119 extending therethrough, and through which backing pins 117A, 117B are received. As will be described in greater detail below, the backing pins 117A, 117B may be held generally stationary with respect to the cage plate 114 and the top guard 108 and may serve to provide an end range for relative movement between the rotary ring 118 and the cage plate 114.
The stationary section 104 may include a brake band 116 and a body 120 to which the rotatable section 102, e.g., the rotary ring 118, may be movably coupled. The brake band 116 may extend at least partially around a circumference of the cage plate 114. The body 120 may support the tong 100 and may be coupled to an external structure, whether stationary (e.g., the rig floor) or mobile (e.g., a lifting assembly, carriage, hoist, etc.). Further, the body 120 may be coupled to a motor 122 via motor mounts 124. The body 120 may also include an access door 126, which may be opened, e.g., to allow lateral movement of a tubular therethrough.
The motor 122 may be energized to rotate the rotatable section 102 relative to the stationary section 104. Such rotation may result in a reactionary torque load being applied from the rotatable section 102 to the body 120. The stationary section 104 may thus include a load cell 128 positioned between the motor mount 124 and the body 120, which may measure such torque. The measured torque may provide information about the torque load applied by the tong 100 onto a tubular connection, thereby indicating when the connection is fully made. In an embodiment, the motor 122 may be a hydraulic motor, but in other embodiments, other types of drive systems may be employed, including electric motors and/or pneumatic motors.
The rotatable section 102 may include cam followers 206, which may extend downward therefrom, as shown, for example. The cam followers 206 may, in some embodiments, be cylindrical and may or may not include bearing elements between the outer roller and inner shaft of the cam follower. The cam followers 206 may be disposed in a circular pattern near or along the radially outer periphery of the rotatable section 102. In particular, the cam followers 206 may extend downward from the rotary ring 118, and may be coupled thereto such that forces incident on the cam followers 206 are transmitted to the rotary ring 118.
The helical ridge 204 may engage the cam followers 206. Accordingly, the helical ridge 204 may be positioned at least partially axially below the rotary ring 118, such that the helical ridge 204 and the shaft 202 radially overlap the stationary section 104 and the rotatable section 102 (e.g., as seen in a top view of the tong 100), which may provide for a compact footprint of the tong 100. Further, the shaft 202 and the helical ridge 204 may be oriented in a generally tangential direction to the rotary ring 118. As the helical ridge 204 turns, it may engage and apply a linear force on the cam followers 206. The cam followers 206 may transmit this force to the rotary ring 118 as a tangential force applied thereto. This in turn results in a torque force on the rotary ring 118, causing the rotary ring 118 to rotate about the receiving hole 106.
In some embodiments, the cam followers 206 and the helical ridge 204 may be sized and configured such that at least one, at least two, or more cam followers 206 engage the helical ridge 204 at any given point during rotation, e.g., when one cam follower 206 rotates out of the helical ridge 204, another enters into it. This may maintain a smooth rotation of the rotary ring 118 when the helical ridge 204 is turned by the motor 122. The tong 100 may also include a speed reducer and encoder 208, which may measure a speed and/or an angular position of the shaft 202.
It will be appreciated that three or more helical ridges 250, 252 may be employed, with the embodiments above describing one helical ridge and two helical ridges being merely examples. Further, a variety of arrangements for driving the shafts 254, 256 in multi-shaft embodiments are contemplated (e.g., both shafts 254, 256 and the motor 122 could be connected to the gear box 258 such that the gear box 258 is between the motor 122 and the shafts 254, 256) and may be used within the scope of the present disclosure.
In addition,
The brake band 116 may be tight around the cage plate 114, thereby generating friction that prevents the cage plate 114 from rotating relative to the brake band 116, at least initially. In turn, the brake band 116 may be coupled with the body 120 via one or more posts 401 (two are shown), which may prevent the brake band 116 from rotating relative to the body 120. The brake band 116 may be pulled tight between the posts 401 so as to provide the friction on the cage plate 114. In other embodiments, other types of braking structures that initially allow the rotary ring 118 to rotate relative to the cage plate 114 may be employed.
The jaws 400A-C are illustrated in the retracted position. In particular, in this embodiment, the rotary ring 118 includes an inner profile 402 in which one or more pockets (three are shown: 404A, 404B, 404C) are defined, for example, one for each of the jaws 400A-C, although additional pockets could also be provided. The pockets 404A-C may extend radially outward from the inner profile 402, providing a space into which the jaws 400A-C may be retracted and held away from the tubular received through the receiving hole 106. Thus, the pockets 404A-C may allow the jaws 400A-C to retract, which may allow the tong 100 to slide over tubular connections, upsets, couplings, etc. The inner profile 402 may also include one or more cam surfaces (three shown: 406A, 406B, 406C), which may be arcuate segments that have a radius of curvature that is less than the overall inner profile 402, or may otherwise tend to extend radially inwards as proceeding in a circumferential direction around the inner profile 402 of the rotary ring 118. Each of the cam surfaces 406A-C may define an apex 409, where the inner profile 402 may transition from extending radially inward to extending radially outward. The cam surfaces 406A-C provide an extended range of radial dimensions for tubulars that may be gripped using the jaws 406A-C.
The rotary ring 118 may define backing slots 408A, 408B that receive the respective backing pins 117A, 117B therein. As noted above, the backing pins 117A, 117B may be stationary with respect to the cage plate 114, and thus, initially, the rotary ring 118 may rotate relative to the backing pins 117A, 117B. Accordingly, the backing pins 117A, 117B may move within the slots 408A, 408B as the rotary ring 118 rotates relative to the cage plate 114, until the backing pins 117A, 117B engage an end of the respective slots 408A, 408B or the rotary ring 118 is otherwise prevented from continued rotation relative to the cage plate 114 (e.g., by the jaws 400A-C engaging a tubular). Thus, the slots 408A, 408B may be arcuate to accommodate such circumferential movement, and may extend roughly along the maximum range of relative rotation to be allowed between the rotary ring 118 and the jaws 400A-C. It will be appreciated that the illustrated embodiment including two backing slots 408A, 408B and two backing pins 117A, 117B, is merely one example, and any number of slots and/or backing pins may be employed.
Further, the tong 100 may include one or more return springs 410, e.g., two for each of the jaws 400A-C, as shown. Each of the return springs 410 may extend between posts 412, 414, with the post 414 being stationary with respect to and attached to the cage plate 114 (not visible), and the posts 412 being radially movable along with the jaws 400A-C, as will be described in greater detail below. Accordingly, the spring 410 may bias the jaws 400A-C radially outwards, so as to pull the jaws 400A-C back into the pockets 400A-C when they are circumferentially aligned therewith. The return springs 410 may be connected to pins 412, 414. In turn, the pins 412 may be connected to the jaws 400A-C and the pins 414 may be connected to the cage plate 414.
The pinholes 601B, 601D may correspond to a make-up or “make” position (as indicated), which, when a backing pin 117A, 117B is received therethrough and into the corresponding slot 408A, 408B, may allow for a range of rotation of the rotary ring 118 in a first circumferential direction, while initially preventing rotation in a second, opposite circumferential direction. The pinholes 601A, 601C may correspond to a break out or “break” position, which, when a backing pin 117A, 117B is received therethrough, may allow rotation of the rotary ring 118 relative to the cage plate 114 in the second circumferential direction, while initially preventing rotation in the first direction. As noted above, the backing pins 117A, 117B may be removable through the top guard 108 via the openings 119, and thus the direction of rotation allowed by the backing pins 117A, 117B may be readily reversed by removing the backing pins 117A, 117B and putting them in the pinhole that allows the desired rotation. In some embodiments, two backing pins 117A, 117B may be provided, each going through one of the make pinholes 601B, 601D (as shown), or through one of the break pinholes 601A, 601C. In other embodiments, any other number of backing pins, pinholes, and/or backing slots may be employed.
Further, radially-extending spring slots 603 may be provided, which may receive the posts 412 by which the springs 410 are attached to the jaws 400A-C. The posts 414 may be fixed in position relative to the cage plate 114, as noted above, while the posts 412 may be movable radially in the spring slots 603 as the jaws 400A-C move radially.
With continuing reference to
The cam followers 206 may also extend at least partially (e.g., entirely) through the rotary ring 118, and upwards into the passage 302 in the cage plate 114. Accordingly, force in the horizontal plane on the cam followers 206 may be transmitted to the rotary ring 118 through the cam followers 206. In particular, the helical ridge 204 may impart a linear force on the cam followers 206, which in turn generates a tangential force on the rotary ring 118, thereby causing the rotary ring 118 to rotate.
As mentioned above, and also viewable in
In the embodiment illustrated in
Accordingly, in operation, one of the jaws (e.g., the jaw 400A) may initially sit in the pocket 404A, but may be pushed out of the pocket 404A by the clockwise rotation of the rotary ring 118, as the jaw 400A is held stationary by the cage plate 114. The jaw 400A may thus ride up onto the first surface 700 of the cam surface 406C, until reaching the transition surface 704. The transition surface 704 may abruptly push the jaw 400A radially inward, and then onto the second surface 702. The jaw 400A may then continue to move radially inward as the rotary ring 118 continues to rotate. This stepped profile for the cam surface 406A may be capable of further extending the range of diameters of tubulars that may be effectively gripped by the tong 100.
Referring now to
When the jaws 400A-C engage a tubular, such as tubular 900, shown in
The tong 100 may also be configured to engage a second tubular 1000, as shown in
In either example case (
Embodiments of the disclosure may also include a method for operating such tongs.
The method 1100 may include positioning a tubular within the receiving hole 106 of the tong 100, as at 1102. This may be accomplished, e.g., by vertically translating the tubular through the top of the receiving hole 106, moving the tong 100 upwards (as with a lifting assembly), or by receiving the tubular laterally through the access door 126, with the cover 110 and at least a segment 112B of the guide 112 removed, as well as the access door 126 (with the portion 304 of the cage plate 114 and/or rotary ring 118) removed or swung open.
The method 1100 may then proceed to engaging the tubular using jaws 400A-C of the tong 100 by activating the motor 122 of the worm drive, which causes the helical ridge 204 to rotate in a first direction, as at 1104. Rotation of the helical ridge 204 applies a tangential force on the rotary ring 118 via engagement with the cam followers 206, resulting in the rotary ring 118 rotating in a first circumferential direction. The rotation of the rotary ring 118 in the first circumferential direction causes the jaws 400A-C to move out of the pockets 404A-C and onto the cam surfaces 406A-C as described above. Eventually, the rotation of the rotary ring 118 relative to the cage plate 114 is stopped, either by the jaws 400A-C engaging the tubular or the backing pin(s) 117A and/or 117B engaging an end of the respective slots 408A, 408B, thereby overcoming the resistance to rotation that the brake band 116 applies on the cage plate 114. With the jaws 400A-C engaged with the tubular, and the motor 122 remaining active, the tong 100 may apply a torque to the tubular, causing the tubular to rotate, as at 1106. In turn, threads of the tubular may be advanced into engagement with mating threads of another tubular (e.g., a box-end of a stump).
The method 1100 may then include disengaging the jaws 400A-C of the tong 100 from the tubular, as at 1108, by stopping and reversing the direction of the rotation of the helical ridge 204, e.g., by activating the motor 122 to rotate in a second, reverse direction. The jaws 400A-C may slide back along the cam surfaces 406A-C, and, as they are biased radially outward by the springs 410, may eventually slide back into the respective pockets 404A-C.
With the jaws 400A-C retracted, the tubular may move, relative to the tong 100, such that, for example, an expanded, box-end of the tubular may move through the tong 100, as at 1110. This may occur before or after rotating the tubular using the tong 100. In some embodiments, the tubular may be laterally removed from the tong 100, as described above. The method 1100 may also include engaging and rotating a second tubular of a second diameter that is different from the diameter of the first tubular, again using the tong, and without reconfiguring the tong 100, as at 1112.
While the present teachings have been illustrated with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In addition, while a particular feature of the present teachings may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular function. Furthermore, to the extent that the terms “including,” “includes,” “having,” “has,” “with,” or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” Further, in the discussion and claims herein, the term “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment. Finally, “exemplary” indicates the description is used as an example, rather than implying that it is an ideal.
Other embodiments of the present teachings will be apparent to those skilled in the art from consideration of the specification and practice of the present teachings disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the present teachings being indicated by the following claims.
