This application claims priority to U.S. Provisional Patent Application Ser. No. 61/481,216, which was filed May 1, 2011. This priority application is hereby incorporated by reference in its entirety into the present application, to the extent that it is not inconsistent with the present application.
In oilfield applications, for example, in deep-sea locations, heavy tubulars extend downward from the platform and may be supported by engagement with a landing string. Depending on the particular application (i.e., drilling, completion, etc.), the landing string may be provided by drill pipe or other high-tensile tubulars. Such landing strings are often required to support a heavy load, such that traditional running systems, which generally employ slips or bushings to hold the tubular by engaging the outer diameter thereof, are inadequate. Further, as offshore drilling operations continually push into deeper water, the tensile load transmission from the landing string to the rig continues to increase in order to support the increased string weight, which is increasingly causing “slip crushing,” whereby the slips and/or bushings engage the tubular body with such force that the tubular body is crushed or otherwise damaged.
To avoid this, landing strings are typically lowered by engagement with an upset (i.e., a shoulder) on the tubular body of the landing string. One way to do this is to employ dual-upset tubulars, allowing the tubular to be lowered by engaging one upset with the elevator and the second with the spider. Another common method shuttles or circulates a pair of elevators to ensure that only the upset is engaged, thereby obviating the need for special dual-upset tubulars. The first elevator begins suspended by the bails, while the second elevator acts as a spider, resting on the rotary table and supporting the landing string by the upset of the upper-most tubular of the landing string (i.e., the most recently run-in segment). The first elevator engages a new tubular segment, positions it with the top drive, and the top drive makes it up to the exposed box of the landing string. The slips or bushings of the second elevator are then disengaged from the upset and the second elevator is removed; thus, the weight of the landing string is transmitted through the new tubular segment to the first elevator. The first elevator then lowers until it abuts the rotary table, and, as such, now acts as a spider. The bails are then switched to the second elevator, which engages another new tubular segment, and the process is repeated.
Such known processes have significant drawbacks, requiring special dual-upset tubulars or time-consuming switching of bails between elevators. What is needed are faster, more cost-effective methods and apparatus for lowering such heavy tubulars, while avoiding slip crushing.
Embodiments of the disclosure may provide an exemplary tubular running system. The tubular running system may include an elevator suspended from a rig and including a body defining a bore to receive a tubular and wedges defining channels therebetween, with the wedges being configured to engage the tubular. The tubular running system may also include a spider including a body defining a bore to receive the tubular and wedges defining channels therebetween. The wedges of the spider may be configured to engage the tubular, and the wedges of the elevator may be configured to slide axially at least partially in the channels of the spider. The wedges of the spider may be configured to slide axially at least partially in the channels of the elevator.
Embodiments of the disclosure may also provide an exemplary method for running a tubular. The method may include engaging an upset of the tubular with an elevator, and moving the tubular by vertically moving the elevator. The method may also include engaging the upset of the tubular with a spider while still engaging the upset with the elevator, and disengaging the upset of the tubular from the elevator, such that the upset is supported by the spider.
Embodiments of the disclosure may further provide an exemplary apparatus for longitudinally moving a tubular. The apparatus may include a first tubular engagement device suspended from a rig and including a plurality of gripping assemblies spaced apart and defining first channels therebetween. The first gripping assemblies may be configured to engage at least an upset of the tubular to support the tubular. The apparatus may also include a second tubular engagement device including second gripping assemblies spaced circumferentially apart and defining second channels therebetween. The second gripping assemblies may be configured to engage at least the upset of the tubular to support the tubular. The second tubular engagement device may be configured to engage the upset while the first tubular engagement device is also in engagement with the upset.
The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.
Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, 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.” All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Furthermore, as it is used in the claims or specification, the term “or” is intended to encompass both exclusive and inclusive cases, i.e., “A or B” is intended to be synonymous with “at least one of A and B,” unless otherwise expressly specified herein.
As shown, the elevator 12 includes a body 16, which may have a generally cylindrical shape and opposing flats 18, 20. Ears 22, 24 for engagement with bails (not shown) extend from the flats 18, 20, for example outward, such that the elevator 12 may be suspended from the rig (e.g., via a traveling block and/or top drive, not shown) and movable vertically toward or away from the spider 14. The body 16 defines a central bore 26 therethrough, in which gripping assemblies 28, 30, 32, 34 are positioned. As the term is used herein, “gripping assembly” is intended to be broadly defined to include any configuration of one or more slips, bushings, or any other device(s) used to engage a tubular, whether including teeth or not. Channels 36, 38, 40, 42 are defined by the bore 26, between adjacent gripping assemblies 28, 30, 32, 34.
As indicated for the gripping assembly 28, each of the gripping assemblies 28, 30, 32, 34 may generally include a tapered housing 44, a bracket 46, a piston 48, and a wedge 50. As the term is used herein, “wedge” is intended to be broadly defined to include slips, bushings, bushing segments, or any like structures capable of applying a gripping force to a tubular, whether including teeth or not. In the illustrated embodiment, the wedge 50 is free from teeth or other marking structures. The tapered housing 44 is generally positioned in the bore 26 and bears on the body 16; further, the tapered housing 44 may be integral with a remainder of the body 16 and/or may be coupled thereto. The tapered housing 44 is tapered such that it extends radially inward, proceeding downwards, and provides a channel 45 in which the bracket 46 and piston 48 are at least partially disposed. The bracket 46 is moved in the channel 45 by movement of the piston 48. In various embodiments, the piston 48 may be moved or articulated by a hydraulic assembly, as is well-known in the art. In other embodiments, the piston 48 may be driven by pneumatics, motors, springs, linkages, combinations thereof, or the like. Further, the bracket 46 may be configured to transmit longitudinal, for example, upward, force on the wedge 50, to disengage the wedge 50 from a tubular (not shown), as will be described in greater detail below. Although four gripping assemblies 28, 30, 32, 34 are shown, it will be appreciated that fewer or additional gripping assemblies, for example, two, three, five, six or more gripping assemblies, may be used without departing from the scope of the disclosure.
Turning to the spider 14, the spider 14 includes a body 100, which may be generally cylindrical in shape and may have an increased-radius shoulder 101 defining at least a portion of the top of the body 100. The shoulder 101 of the body 100 defines flats (three are visible: 102, 104, 106) on its outer diameter for engagement with various tools or other structures, as will be described in greater detail below. Further, the shoulder 101 may define a landing surface 108 on the upper side thereof. The body 100 may also define a bore 103 extending axially therethrough, for receiving a tubular (not shown). Proximal the top of the bore 103, the body 100 may define an annular seat 105, which is recessed from the landing surface 108.
In at least one embodiment, the body 100 may be split, as shown, defining two or more generally arc-shaped segments 109a, 109b. As will be described in greater detail below, the segments 109a,b may be held together by an interior surface defined in the rotary table (not shown), as is known in the art. In other embodiments, however, other structures such as a retaining collar or the like may be used to secure the position of the body 100. Additionally, in still other embodiments, the segments 109a,b may be coupled together via a hinge (not shown) or any other coupling mechanism.
Gripping assemblies (e.g., bushing or slip assemblies) 110, 112, 114, 116 may extend upward from the landing surface 108 and the seat 105 and inward from the bore 103. Channels 118, 120, 122, 124 are defined between adjacent gripping assemblies 110, 112, 114, 116. As indicated for the gripping assembly 110, each gripping assembly 110, 112, 114, 116 may include a tapered housing 126, a bracket 128, a wedge 130, and a piston 132. Further, the housing 126 provides a channel 135 therein for guiding longitudinal movement of the bracket 128. The bracket 128 is coupled to the wedge 130 and may be configured to transfer longitudinal force from the piston 132 to the wedge 130, for example, to raise or lower the wedge 130 into or out of engagement with a tubular (not shown). The piston 132 may be driven to move the bracket 128 by pneumatics, hydraulics, motors, mechanical linkages, springs, combinations thereof, or the like.
Referring now specifically to
As also illustrated in
With continuing reference to
Accordingly, the gripping assemblies 110, 112, 114, 116 of the spider 14 may be engaged when the elevator 12 comes into proximity with, for example lands on, the landing surface 108 (
Referring to
Moreover, it will be appreciated that either or both of the tubular engagement devices 12, 14 may be movable, without departing from the scope of the disclosure. Furthermore, in various embodiments, the first tubular engagement device 12 may be stationary, while the second tubular engagement device 14 is movable. Additionally, the illustrated views of running system 10 may be flipped, such that the first tubular engagement device 12 is moved upward to the second tubular engagement device 14, or the second tubular engagement device 14 is lowered to the first tubular engagement device 12.
Turning now to
The wedges 308, 310 each define upper and lower interior surfaces 314, 316 and 318, 320, respectively. The upper interior surfaces 314, 318 may be tapered, converging toward a central axis 322, proceeding downwardly. The lower interior surfaces 316, 320 may be generally parallel to the axis 322. In other embodiments, however, the lower interior surfaces 316, 320 may also be tapered, converging toward the central axis 322, proceeding downward. In some embodiments, one, some, or all of the upper and/or lower interior surfaces 314, 316, 318, 320 may be free from teeth or other marking structures; however, in various other embodiments, any of the surfaces 314, 316, 318, 320 may include such teeth or other marking structures (none shown) to facilitate engagement with the tubular 200.
The upper interior surfaces 314, 318 may be shaped to abut and engage an upset 324 of the tubular 200. The upset 324 may be a radial protrusion extending radially outward from a remaining tubular body 326, as shown, but in other embodiments may extend radially inward. In various embodiments, the upset 324 may be disposed on (e.g., fastened, welded, brazed, or otherwise connected to, integral with, or otherwise part of) the tubular 200. The upset 324 may be capable of withstanding greater tensile forces than the tubular body 326 and transmitting such axial forces to the gripping assemblies 301, 302. Accordingly, the upset 324 may represent an area desirable for the gripping assemblies 301, 302 to engage, to avoid slip crushing the tubular 200.
To provide further load distribution, the lower interior surfaces 316, 320 may engage the tubular body 326, as shown. Accordingly, some of the axial load of the tubular 200 weight is transmitted via the radial gripping force applied by the gripping assemblies 301, 302 onto the tubular body 326. By simultaneously engaging the upset 324 with the upper interior surfaces 314, 318, and the tubular body 326 with the lower interior surfaces 316, 320, the gripping assemblies 301, 302, the tubular engagement device 300, and ultimately the rig may be able to support and run the tubular 200, while supporting strings having a greater weight than that which a simple engagement with the upset 324, let alone engagement only with the tubular body 326 by itself, is capable of safely handling.
The method 400 further includes vertically moving, for example, lowering the tubular through a second tubular engagement device by lowering the first tubular engagement device, as at 404. The method 400 may also include receiving gripping assemblies of the second tubular engagement device into channels defined between gripping assemblies of the first tubular engagement device, as at 406. The method 400 may also include engaging the upset of the tubular with the gripping assemblies of the second tubular engagement device, as at 408. The method 400 may further include disengaging the upset of the tubular from the gripping assemblies of the first tubular engagement device, such that the upset is supported by the second tubular engagement device, as at 410.
The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.
Number | Date | Country | |
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61481216 | May 2011 | US |
Number | Date | Country | |
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Parent | 13459314 | Apr 2012 | US |
Child | 14584636 | US |