Patent Application
20150096763
In oilfield operations, elevators are generally employed to connect a tubular to a hoist, enabling the tubular to be lifted into place, made up to a string of tubulars, and run into a wellbore. One type of elevator is a side-door elevator, which latches onto the tubular and engages the box threaded coupling at one end of the tubular. The other end of the tubular includes a pin threaded coupling, which is received and threaded into the box threaded coupling of the previously-run tubular. Once connected (“made-up”) to the rest of the string of tubulars, the string weight is supported by connection between the elevator and the tubular at the threaded coupling.
Another type of elevator is a slip-type elevator, sometimes refereed to as a “YC” elevator. The slip-type elevator includes slips, which may have teeth or be non-marking, that engage the outer diameter of the tubular. Typically, the slips are pushed radially inward into engagement with the outer diameter of the tubular. The radial force is provided by an axial engagement between a setting plate and an upset or shoulder, generally at the end of the shoulder. Using a tapered interface, the axial engagement of the setting plate with the upset is translated into radially-inward force on the slips, causing the slips to engage the tubular. Thus, once made up to the tubular string, the weight of the string is supported by the outer diameter of the tubular, rather than the threaded connection.
However, some tubulars employ an integral swaged or tapered box at the end of the tubular to accommodate the pin of the next tubular. Such integral, swaged box designs incorporate a gradual increase in the inner and outer diameter of the tubular to accommodate the interior threads, allowing the tubular to be made up to the pin connection of the next tubular.
To transfer this type of tubular from a horizontal position (i.e., as stored on the surface) to a vertical position (for being made-up and run in), a threaded insert, referred to as a “lift nubbin” is threaded into the swaged box. The lift nubbin has a larger outer diameter at the top, which serves as the upset. However, this design requires the use of a special bored side door to correctly interface with the shoulder of the lift nubbin, due to the larger outer diameter of the swaged box. Further, slip-type elevators are generally not acceptable for use with the swaged box tubulars, because the taper of the swaged box may cause the slips of the elevator to engage the tapered region of swaged box, resulting in an incomplete engagement of the outer diameter of the tubular. This, in turn, can result in increased local stress in the areas where the slips engage.
Embodiments of the disclosure may provide an apparatus for adapting an elevator for use with a tubular. The apparatus includes one or more axial extensions configured to engage one or more slip bodies of the elevator. The one or more axial extensions include a radial contact surface configured to slide along the tubular and an axial engagement surface configured to bear on an upset of the tubular. The one or more axial extensions are flexible such that the radial contact surface is radially displaceable with respect to the tubular.
Embodiments of the disclosure may also provide an elevator. The elevator includes an elevator body, and a plurality of slip bodies disposed at least partially within the elevator body and configured to move radially inwards when slid in an axial direction relative to the elevator body, so as to engage an outer diameter of a tubular. The elevator also includes an axial extension engaging at least one of the plurality of slip bodies and extending axially therefrom, the axial extension being flexible so as to flex radially outwards when the axial extension encounters a tapered section of the tubular. The axial extension is configured to bear on an upset of the tubular so as to radially displace the plurality of slip bodies.
Embodiments of the disclosure may also provide a method of manufacturing an elevator adapter. The method includes determining a height of a swaged box of a tubular, and selecting a height of the elevator adapter, such that the height is greater than the height of the swaged box. The elevator adapter includes an axial extension that is configured to radially expand when engaged with a tapered section of the tubular and to transfer an axial force to a plurality of slip bodies when the axial extension engage an upset of the tubular.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present teachings, as claimed.
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 as 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.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all sub-ranges subsumed therein.
Further, the base 102 may include one or more plates, for example, a first plate 106 and a second plate 108. The first and second plates 106, 108 may be separated by and connected together via a plurality of posts 110. A bolt 111 may extend through the post 110, so as to secure the first and second plates 106, 108 together; however in other embodiments, the first and/or second plates 106, 108 may be secured to the posts 110 via welding, brazing, adhesives, integral forming, and/or the like. The base 102 may be separated into the first and second plates 106, 108, with the posts 110 of a suitable length, so as to provide a desired overall height for the elevator adapter 100, as will be described in greater detail below. In other embodiments, however, one or both of the plates 106, 108 may have an increased height, such that the posts 110 may be omitted. Furthermore, the base 102 may be provided by a single plate of sufficient thickness to provide the desired height.
The fingers 104 may be coupled to the base 102, for example, to the second plate 108 thereof. For example, the lingers 104 may be fastened to the base 102 via fasteners such as bolts, or may be coupled thereto using any other suitable coupling process or device. Further, the fingers 104 may be circumferentially separated and disposed at approximately uniform angular intervals. For example, in the illustrated four finger 104 embodiment, the arcuate base 102 may extend about 180 degrees. Accordingly, one of the fingers 104 may be disposed at each end of the base 102, with the two remaining fingers 104 disposed at about 60 degrees and at about 120 degrees (i.e., at generally uniform 60 degree intervals). Although four fingers 104 are illustrated, it will be appreciated that three or fewer fingers 104, or five or more fingers 104 may be employed without departing from the scope of the present disclosure and may be disposed at uniform or non-uniform intervals of any angle.
The fingers 104 may have a generally elongate shape, each defining a root 112 proximal the connection with the base 102 and a tip 114 that is distal from the base 102. At the tip 114, or proximal thereto, the lingers 104 may each define an axial engagement surface 116 and a radial contact surface 118. The radial contact surface 118 may extend radially inward from a remainder of the finger 104, so as to define a radially innermost point thereof. The axial engagement surface 116 may be generally flat; however, in some embodiments it may be rounded, beveled, stepped, etc. Further, the axial engagement sodium 116 may be positioned at the axial extent of the finger 104. In other embodiments, however, other features of the elevator adapter 100 may extend axially beyond the axial engagement surface 116.
The fingers 104 may be constructed of a flexible material. In some embodiments, the flexible material may be a polymer, elastomer, carbon fiber, a composite material, or the like. In one specific embodiment, the flexible material may be cast polyurethane. In other embodiments, the flexible material may be another elastic material, e.g., a metal, such that the fingers 104 may conceptually and/or visually resemble leaf springs. It will be appreciated that the fingers 104 may be constructed from various combinations of these and/or other materials.
Moreover, the fingers 104 may define a relief 120 therein, e.g., extending therethrough, which may decrease a rigidity of the fingers 104, tor example, by reducing a cross-section thereof. The relief 120 may take any suitable form such as, for example, as series of holes, slots, recesses, etc. In the illustrated embodiment, the relief 120 may be formed as a slot with a shape that generally conforms to the exterior contours of the fingers 104.
The flexible Lingers 104, and particularly the tips 114 thereof, may define a radial range of motion R, as indicated, between an unflexed position (indicated in solid) and a flexed position (indicated in dashed lines). Such rate of motion R may enable the tips 114 of the fingers 104 to spread apart when contacting an area of increased outer diameter of the tubular received therein. In at least one embodiment, the radial range of motion R may be sufficient so as to expand the radial contact surface 118 such that it is aligned with the partial inner diameter 105 (
The elevator 200 includes slip bodies 204 (two are visible: 204-1 and 204-2), which may be generally arcuate in shape. Further, the slip bodies 204 may be coupled together, such that axial movement of one of the slip bodies 204 may cause corresponding axial movement of the adjacent slip bodies 204. In an embodiment, the elevator 200 may include four slip bodies 204; however, in various other embodiments, any number of slip bodies 204 may be included. The first plate 106 may extend fully across two of the slip bodies 204 (i.e., the two obscured slip bodies 204), may partially extend across another of the slip bodies 204-1, and may not extend across another one of the slip bodies 204-2. In other embodiments, the first plate 106 may extend at least partially across all of the slip bodies 204 and/or may not extend across two or more of the slip bodies 204. In an embodiment, the first plate 106 (and/or another component of the base 102 (
In some embodiments, the first and/or second plates 106, 108 of the base 102 may engage the slip bodies 204, so as to transfer axial force thereto. For example, the first and/or second plate 106, 108 may be rigid or may radially expand and/or contract to accommodate radial displacement of the slip bodies 204. The first plate 106 may be fixed directly to one of the slip bodies 204, such as by one or more mechanical fasteners (or any other coupling device and/or process), for example, in lieu of a slip setting plate. In other embodiments, the first plate 106 may be coupled to the slip plate. It will be appreciated that a slip setting plate is generally an annular structure disposed at the top of an elevator, which transmits an axial force applied thereto to the slip bodies, so as to drive the slip bodies downwards. Such downward driving of the slip bodies causes teeth, pads, other engagement features of the slip bodies to engage the outer diameter of the tubular so as to hold the weight of the tubular and anything attached thereto (e.g., a string of tubulars).
Further, the elevator 200 may include a body 210, a pin 212, and a spring 214. The body 210 may surround the slip bodies 204 and may include a door to laterally receive the tubular 202. The body 210 may define a tapered inner surface 216, and the slip bodies 204 may each define a reverse-tapered outer surface 218. The slip bodies 204 may slide axially relative to the slip body 204, with the tapered inner surface 216 engaging the reverse-tapered outer surfaces 218 such that the axial movement of the slip bodies 204 results in radial displacement thereof. In particular, axial movement of the slip bodies 204 “downward” with respect to the elevator body 210 may result in the slip bodies 204 being displaced radially inwards, into engagement with the tubular 202. At least when the slip bodies 204 are disengaged from the tubular 202, the slip bodies 204 may define circumferential spaces therebetween, so as to allow for the radial displacement radially inward. It will be appreciated that directional references herein (e.g., downward, upward, etc.) are meant to refer to the orientation of the depiction of the embodiment of the drawings, and are not to be considered limiting unless expressly stated otherwise herein.
The slip bodies 204 may also define a tab 220, which may receive the pin 212. The pin 212 may also be received into a recess 222 defined in the elevator body 210. The tab 220 may further be received in the recess 222, so as to slide therein, guided by the pin 212. Additionally, the spring 214 may be disposed around the pin 212 in the recess 222. The spring 214 may bear on the tab 220 and the body 210, such that the slip bodies 204 are biased upwards with respect to the body 210.
The tubular 202 may define a nominal OD (outer diameter) section 224, an increased OD section 226, and a tapered section 228 that connects the nominal OD section 224 with the increased OD section 226. The nominal OD section 224 may extend a majority of the length of the tubular 202. Further, the outer diameter (i.e., the outside circumferential surface) of the tubular 202 in the nominal OD section 224 may define as first radius R1. The outer diameter (i.e., the outside circumferential surface) of the tubular 202 at the increased OD section 226 may define a second radius R2.
Further, the increased OD section 226 and at least a portion of the tapered section 228 ma at least partially make up a box connection of the tubular 202, which may be swaged and/or integral with the nominal OD section 224 of the tubular. Further, along with the increased outer diameter, the box connection may also define an area 225 having an increased inner diameter, so as to accommodate threads configured to mesh with threads of a pin end of a superposed tubular having an outer diameter that is the same size as the nominal OD section 224.
More particularly, the box connection, i.e., the tapered section 228 and the increased OD section 226, may have a box height B. A lift nubbin 230 may be threaded temporarily into the increased OD section 226, i.e., the threaded area 225, such that the box height B is defined between the bottom of the lift nubbin 230 and the bottom of the tapered section 228 (i.e., the edge of the tapered section 228 connected to the nominal OD section 224). The lift nubbin 230 may provide an upset 232, e.g., a substantially 90 degree (“square”) shoulder, extending radially outwards with respect to the tubular 202.
Referring now specifically to
Referring to
Accordingly, before the upper extent of the slip bodies 204 comes into contact with the lower edge of the tapered section 228, the axial engagement surfaces 116 of the fingers 104 may engage the upset 232 of the lift nubbin 230. In other embodiments, some contact between the slip bodies 204 and the lower edge of the tapered section 238 may be tolerated but substantial overlapping minimized. Continued upward force applied to the elevator 200, specifically to the elevator body 210, may transmit through the pin 212, to the slip bodies 204, the base 102 of the elevator adapter 100, and the fingers 104. The fingers 104, however, may prevented from continued movement upwards by axial engagement with the upset 23. Accordingly, a reactionary, axial force may be applied onto the slip bodies 204 via the fingers 104. The reactionary force may prevent the slip bodies 204 from further upward axial movement. Thus, the continued axial force on the elevator body 210 may overcome the biasing force of the spring 214, allowing the elevator body 210 to be displaced upwards relative to the slip bodies 204. This may result in the slip bodies 204 being displaced radially inwards via the engagement between the tapered surface 216 and the reverse tapered surface 218, which may cause the teeth 206 to be driven into engagement with the tubular 202.
Accordingly, it will be appreciated that the elevator adapter 100 may prevent the teeth 206 from engaging the tapered section 228, the increased OD section 226, or both of the box connection. Instead, the elevator adapter 100 may have a height H that exceeds the height B of the swaged box, allowing the teeth 206 to engage the tubular 202 below the tapered section 228 and on the nominal OD section 224. This may be accomplished, for example, via flexible extensions (“fingers”) 104, which may flex radially outwards when they encounter the tapered section 228, and may axially engage the upset 232 so as to transmit the axial setting force onto the slip bodies 204.
The method 300 may begin with determining one or more dimensions of the tubular 202 with which the elevator adapter 100 is to be used. For example, the method 300 may include determining a height B of a swaged box of the tubular 202, as at 302 and determining a radial difference D between the radius R2 of the increased OD section 226 and the radius R1 of the nominal OD section 224, as at 304.
The method 300 may then proceed to configuring the elevator adapter 100 for use with the tubular 202, for example, according to the dimensions determined at 302 and 304. For example, the method 300 may include selecting components of the elevator adapter 100 such that the elevator adapter 100 defines a height H that is greater than the height B of the swaged box, as at 306. More particularly, the method 300 may include selecting the height of the base 102, and/or the axial extension (e.g., the plurality of fingers 104), so as to arrive at the appropriate height H.
Such configuring may also include configuring the axial extension (e.g., the plurality of fingers 104) such that the axial extension defines a radial range of motion R proximal an axial extent (e.g., the tip 114) thereof. The radial range of motion R may be selected to be greater than the difference between the radius R2 of the nominal OD section 224 of the tubular 202 and the radius R2 of the increased OD section 226 of the swaged box of the tubular 202, as at 308. Configuring at 308 may include selecting a material for the plurality of fingers 104, such as a polymer (e.g., cast polyurethane), as metal, or both. Configuring at 308 may also include defining (e.g., cutting, casting, etc.) as relief 120 in the axial extension so as to increase a flexibility thereof. Configuring at 308 may include various other selections, such as finger 104 shape, height, or thickness, relief 120 size and/or shape, and others.
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.
