Not applicable.
This disclosure relates generally to making and breaking connections between tubular members over a well bore. More particularly, it relates to an apparatus and system for making and breaking connections over a wellbore while reacting against snubbing loads. Still more particularly, this disclosure relates to a snubbing jack, and methods and apparatus for reacting torque loads when tubular connections are made up and broken out.
A snubbing jack is an apparatus having multiple hydraulically-operated piston-cylinder assemblies configured to lift a string of tubular members from a well bore and to push the string down into the well bore, as may be necessitated by downhole fluid pressure or friction in the well bore. Alongside a conventional snubbing jack, a combined, open-faced hydraulic tong and backup clamp unit typically hangs from a davit arm in the work basket at the top of the snubbing jack. When adding a tubular member, such as joint of pipe (i.e. a piece of pipe), to a workstring of tubular members that extends into a wellbore, the workstring is held against gravity by stationary slips located underneath the snubbing jack, and the additional tubular member is positioned above the workstring by a hoist. The combined open-faced tong and backup clamp are swung over well center and around the tool joints of the workstring and the tubular member where the tong and backup clamp can “make-up” a threaded connection. (“Tool joint” refers to the threaded end of a tubular member.) The process of “breaking-out” a threaded connection to remove a tubular member from the workstring is similarly performed, in reverse to the process of making up a connection. Each operation requires manipulation of heavy machinery by an operator in a confined space that is typically shared by three human operators. In the event that the backup clamp slips on its tool joint, the combined tong and backup clamp unit will attempt to rotate around the work string since, in this condition. In some applications, the operators must react quickly to avoid harm to themselves and to avoid damaging the jack.
In a typical conventional arrangement, a rotary drive that serves to rotate the workstring in the well is mounted to the traveling plate of the snubbing jack, and traveling slips are mounted to the hub of the rotary drive. In this way, the workstring can be rotated while it is supported by the traveling slips, and it can be simultaneously moved in or out of the well bore by the jacking cylinders which support the traveling plate. The torque from the rotary drive is reacted through the jacking cylinders in this conventional arrangement. Because standard hydraulic cylinders do not have the ability to support or react against large perpendicular loads (e.g. forces resulting from the torque), conventional jacking cylinders have tended to be complicated, expensive, and require specialized design features. Even with these features, the torque of the rotary drive must be limited as the length that the cylinders extend increases.
One way to eliminate the necessity of swinging the tong and backup clamp through the work basket and on and off the workstring is to mount the tong and backup clamp unit to the snubbing jack itself. Closed-face tong and backup clamp units can then be utilized, with a further advantage that closed-face tongs and backup clamps often provide more torque for their size. Two variations of this system exist in prior art. The first is that the tong and backup clamp are mounted to the traveling plate of the jack but are positioned above the traveling slips. This arrangement has the disadvantage that its mounting structure must extend around the large rotary drive and traveling slips, extending radially outward and axially downward to reach the traveling plate located below the rotary drive. The second variation is to mount the tong and backup clamp to the top of the traveling slips. This arrangement has the disadvantage that the tong and backup clamp will then rotate when the rotary drive is engaged.
An improved snubbing jack that does not require a swinging tong and backup clamp and that effectively reacts the torque load of a rotary drive would be advantageous in the industry, as would a snubbing jack that does not transfer the tong's torque to the jacking cylinders through the traveling plate. in the event that the backup clamp slips on the workstring.
An embodiment of a snubbing jack comprises a jack assembly comprising a base plate, a traveling plate, an axis extending through the base plate and the traveling plate, and a plurality of piston-cylinder assemblies configured to move the traveling plate axially with respect to the base plate, a rotary drive comprising a rotary base and a hub, wherein the rotary drive is configured to rotate the hub relative to the rotary base, and wherein the rotary base is coupled to the traveling plate to travel axially with the traveling plate, a clamp coupled to the rotary base and configured to grip a first tubular member, a power tongs coupled to the rotary base and configured to grip a second tubular member and to rotate the second tubular relative to the rotary base, and a torque transfer device coupled between the rotary drive and the jack assembly and configured to allow the rotary drive to move axially relative to the base plate and configured to restrict rotation of the rotary drive relative to the jack assembly. In some embodiments, the rotary base is coupled to the traveling plate by a rotary coupling configured to restrict the rotary drive from moving axially relative to the traveling plate and configured to allow rotation of the rotary drive relative to the traveling plate. In some embodiments, the rotary base comprises an annular shoulder, and
wherein the rotary coupling includes an attachment member coupled to the traveling plate and having a shoulder slidingly engaging the annular shoulder of the rotary base. In certain embodiments, the attachment member comprises a ring, and wherein the shoulder of the attachment member of the rotary coupling extends circumferentially around a majority of the shoulder of the rotary base. In certain embodiments, the torque transfer device comprises a lower torque member rigidly coupled to the base plate, an upper torque member disposed along the lower torque member and rigidly coupled to the rotary base, and a linearly sliding coupling configured to allow the upper torque member to move axially relative to the lower torque member and configured to restrict rotation of the upper torque member relative to the lower torque member. In some embodiments, the linearly sliding coupling comprises an axial slot disposed in the lower torque member and a pin extending from the upper torque member and slidingly received in the slot. In certain embodiments, the lower torque member and the upper torque member are concentric tubular members, the upper torque member includes a flange that is rigidly coupled to the rotary base, the rotary base comprises an annular shoulder, and the rotary coupling comprises an attachment member coupled to the traveling plate and having a shoulder slidingly engaging the annular shoulder of the rotary base, and a bearing disposed between the traveling plate and the flange of the upper torque member. In certain embodiments, the snubbing jack further comprises a mounting frame rigidly coupled to the rotary base and extending to the clamp and the power tongs, wherein the mounting frame couples the clamp and the power tongs to the rotary base for rotational and axial support, and wherein the mounting frame is configured to allow the clamp and the power tongs to move axially relative to one another while restricting the clamp and the power tongs from rotating relative to one another. In some embodiments, the clamp and the power tongs are configured to be releasably coupled to and decoupled from the rotary base independently of each other. In some embodiments, the clamp is coupled to the rotary base by a first mounting frame extending between the clamp and the rotary base, and the power tongs is coupled to the rotary base by a second mounting frame extending between the power tongs and the rotary base, and the second mounting frame is independent of the first mounting frame. In certain embodiments, the torque transfer device comprises a reaction member laterally offset from the axis, and wherein the reaction member is engaged by a roller coupled to the traveling plate. In certain embodiments, the snubbing jack further comprises a tool retrieval assembly configured to move at least one of the clamp and power tongs laterally relative to the axis.
An embodiment of a snubbing jack comprises a jack assembly comprising a base plate, a traveling plate, an axis extending through the base plate and the traveling plate, and a plurality of piston-cylinder assemblies configured to move the traveling plate axially with respect to the base plate, a rotary drive comprising a rotary base and a hub, wherein the rotary drive is configured to rotate the hub relative to the rotary base, and wherein the rotary base is coupled to the traveling plate to travel axially with the traveling plate, a clamp coupled to the rotary base and configured to grip a first tubular member, a power tongs coupled to the rotary base and configured to grip a second tubular member and to rotate the second tubular relative to the rotary base, and a tool retrieval assembly configured to move at least one of the clamp and power tongs laterally relative to the axis. In some embodiments, the snubbing jack further comprises a first tool frame extending from the rotary drive, and a second tool frame supported by the first tool frame, wherein the second tool frame is laterally moveable relative to the first tool frame. In some embodiments, the tool retrieval assembly comprises a pair of arms extending laterally from the first tool frame, and a sliding jack coupled between the first tool frame and the second tool frame, wherein the sliding jack is configured to move the second tool frame laterally along a rail of each arm to dispose the second tool frame in a laterally offset position relative to the axis. In certain embodiments, the tool retrieval assembly comprises a lifting jack coupled between the second tool frame and a slip bowl, wherein the lifting jack is configured to move the slip bowl axially relative to the first tool frame. In certain embodiments, the snubbing jack further comprises a torque transfer device coupled between the rotary drive and the jack assembly and configured to allow the rotary drive to move axially relative to the base plate and configured to restrict rotation of the rotary drive relative to the jack assembly. In some embodiments, the torque transfer device comprises a pair of I-beams and wherein each I-beam is engaged by a roller coupled to the traveling plate.
An embodiment of a method for drilling a wellbore comprises (a) rotating a tubular member with a power tong of a snubbing jack, (b) reacting rotational torque transmitted from the power tong with a torque transfer device coupled to a jack assembly of the snubbing jack, and (c) moving the tubular member axially relative to a base plate of the jack assembly during (b). In some embodiments, the method further comprises (d) actuating a lifting jack to lift a slip bowl relative to a tool frame of the snubbing jack, and (e) actuating a sliding jack to move the slip bowl laterally relative to the tool frame.
Thus, embodiments described herein include a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The various features and characteristics described above, as well as others, will be readily apparent to those of ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings.
For a detailed description of the disclosed exemplary embodiments, reference will now be made to the accompanying drawings, wherein:
The following description is exemplary of certain embodiments of the disclosure. One of ordinary skill in the art will understand that the following description has broad application, and the discussion of any embodiment is meant to be exemplary of that embodiment, and is not intended to suggest in any way that the scope of the disclosure, including the claims, is limited to that embodiment.
The figures are not necessarily drawn to-scale. Certain features and components disclosed herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. In some of the figures, in order to improve clarity and conciseness, one or more components or aspects of a component may be omitted or may not have reference numerals identifying the features or components. In addition, within the specification, including the drawings, like or identical reference numerals may be used to identify common or similar elements.
As used herein, including in the claims, the terms “including” and “comprising,” as well as derivations of these, are used in an open-ended fashion, and thus are to be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” means either an indirect or direct connection. Thus, if a first component couples or is coupled to a second component, the connection between the components may be through a direct engagement of the two components, or through an indirect connection that is accomplished via other intermediate components, devices and/or connections. As used herein, including in the claims, to describe a connection between two components or other items, the phrase “rigidly coupled” means that the two items are connected such that the first cannot move translationally or rotationally relative to the other. The recitation “based on” means “based at least in part on.” Therefore, if X is based on Y, then X may be based on Y and on any number of other factors. The word “or” is used in an inclusive manner. For example, “A or B” means any of the following: “A” alone, “B” alone, or both “A” and
In addition, the terms “axial” and “axially” generally mean along or parallel to a given axis, while the terms “radial” and “radially” generally mean perpendicular to the axis. For instance, an axial distance refers to a distance measured along or parallel to a given axis, and a radial distance means a distance measured perpendicular to the axis. Furthermore, any reference to a relative direction or relative position is made for purpose of clarity, with examples including “top,” “bottom,” “up,” “upward,” “down,” “lower,” “clockwise,” “left,” “leftward,” “right,” “right-hand,” “down”, and “lower.” For example, a relative direction or a relative position of an object or feature may pertain to the orientation as shown in a figure or as described. If the object or feature were viewed from another orientation or were implemented in another orientation, it may be appropriate to describe the direction or position using an alternate term.
Referring to
Snubbing jack 100 is mounted on well head 54 and configured to grasp and manipulate workstring 56 and tubular members received from or delivered to trailer 65 when making or breaking a threaded connection between workstring 56 and a separate tubular member 68 in order to extend or reduce the length of workstring 56. Axis 57 represents the longitudinal axis of workstring 56. Optionally, the term “combined tubular member” may be used to describe workstring 56 or any combination of two or more tubular members 68 threadingly coupled together. For convenience, each separate tubular member 68 on trailer 65 may include 1, 2, 3 or more pieces of pipe or other individual tubular members combined together.
Referring now to
Jack assembly 110 includes a jack base plate 112 located at the bottom, a jack top plate 114 above base plate 112 and spaced-apart along axis 101, a jack traveling or load plate 116 above top plate 114, and a plurality of hydraulic piston-cylinder assemblies or “jack cylinders” 120 coupled to plates 112, 114, 116. In the example, assembly 110 includes four jack cylinders 120. Each jack cylinder 120 includes a housing cylinder 122 extending from a base end 123 coupled at base plate 112 to an action end 124 coupled at top plate 114. Jack cylinder 120 further includes a piston and a piston extension shaft 126 slidingly received within cylinder 122 and having an outer end 127 that extends beyond the cylinder's action end 124. The coupled piston and piston extension shaft will be simply called piston 126. Piston outer end 127 extends into one of a plurality of attachment apertures 117 in traveling plate 116, being coupled to plate 116 in a configuration that allows piston 126 both to push plate 116 upward and to pull plate 116 downward with respect to base plate 112. Plate 116 is configured to support the loads that are lifted upward or pulled downward by jack cylinders 120. An aperture 132 centered on axis 101 extends through each of the three plates 112, 114, 116. The arrangement of jack assembly 110 is also shown in the enlarged views of
Continuing to reference
Rotary drive 140 includes a rotary base 145, a rotary hub 170 rotationally mounted within base 145, and a drive assembly 190 configured to rotate hub 170 with respect to base 145. Rotary base 145 includes a generally cylindrical lower section 146 with a lower surface 148 mounted adjacent recess 135 on the top of plate 116 and an upper section 150 extending from a generally cylindrical section 146 to an upper surface 151. A through-bore 152 extends through base 145 from surfaces 148 to surface 151 and includes sections with different diameters. Upper section 150 is larger than lower section 146 and includes a cavity 154 surrounding and intersecting the through-bore 152. An annular end cap 156 partially covers an enlarged portion of through-bore 152 at upper surface 151. With end cap 156 installed, through-bore 152 extends through the end cap 156. An upward-facing, annular shoulder 158 extends around the exterior of lower section 146 between lower surface 148 and upper section 150.
Rotary hub 170 includes a lower, tubular section 172, an upper flange 174 extending radially from the top of section 172, and a through-bore 178 extending axially through section 172 and flange 174. Tubular section 172 is mounted within through-bore 152 of base 145 with a plurality of bearings 182 and is held axially by a removable flange 184. In the example of
In the example of
Referring again to
Traveling slip bowls 250 are clamping devices. They are aligned along axis 101 and are located between rotary drive 140 and backup clamp 240. Slip bowls 250 include a set of lower slips 252 extending axially from a lower end 254 and a set of upper slips 256 extending from lower slips 252 to an upper end 258. The lower end 254 is coupled at the upper flange 174 of rotary hub 170 configuring slip bowls 250 to rotate and travel with hub 170. Lower slips 252 are configured to exert a radial and axial force in a first axial direction (either up or else down), and the upper slips 256 are configured to exert a radial and axial force in a second axial direction, opposite the first axial direction. The backup clamp 240, power tongs 242, frame 244, and slip bowls 250 are directly or indirectly attached to rotary drive 140 as previously described.
During various modes of operation, slip bowls 250 grasp a tubular or, commonly, a tubular string that extends downward through device 100 and allows traveling plate 116 and jack cylinders 120 to lift the tubular string upward or to depress it downward. The grasping of slip bowls 250 also allow hub 170 of drive 140 to rotate the tubular string about axis 101, being reacted by rotary base 145.
Again referencing
Referring to
Lower torque tube 210 is centered on axis 101 and extends axially from a lower end 212 rigidly coupled at base plate 112 to an upper end 213 located proximal the lower surface of top plate 114. An axial slot 214 starts within torque tube 210 adjacent lower end 212 and extends axially through upper end 213. Upper torque tube 220 is centered on axis 101 and extends axially from a lower end 222 within torque tube 220, through plates 114, 116, to an upper end 223 that includes a flange 224, which is rigidly coupled to the lower surface 148 of rotary base 145 so that tube 220 and base 145 rotate together and transfer torque. As best shown in
As best shown in
As described, torque transfer device 200 limits the rotation of tool assembly 199 about axis 101. Even so, the combination of torque transfer device 200, coupling 202, and bearing 206 is configured to allow tool assembly 199 to rotate, at least through acute angles, with respect to base plate 116, isolating jack cylinders 120 from the torque of tool assembly 199. Thus, torque transfer device 200 supports or reacts not only the torque of rotary drive 140 but also torque from backup clamp 240 and power tongs 242, when such torque is exerted in various operational situations. Torque tubes 210, 220 may also double as a guide tube to support workstring 56 against potential buckling when in compression.
Referring to
Typical piston-cylinder assemblies, like jack cylinders 120, have less resistance to torsional loads as they extend to greater lengths. However, in jack 100 the inclusion of torque transfer device 200 aided, at least in some embodiments, by support apparatus 230 overcomes or reduces the torsional strength limitation of jack cylinders 120. Therefore, various embodiments of jack assembly 100, rotary drive 140 may operate even while jack cylinders 120 are partially extended, or jack cylinders 120 are fully extended because torque transfer device 200 reacts the torque of drive 140 and isolates jack cylinders 120 from that torque.
Although rotary drive 140 of
Although backup clamp 240 and power tongs 242 are mounted to a common mounting frame 244 in
In
Referring again to
Referring to
In this embodiment, jack assembly 310 of snubbing jack 300 includes a jack base plate 312 located at a lower end of jack assembly 310, a jack mid plate 314 axially spaced from base plate 312, a jack top plate 316 axially spaced from mid plate 314, a jack traveling plate 318 positioned at an upper end of the jack assembly 310, and a plurality of jack cylinders 120 spaced about central axis 305 of snubbing jack 300. The base end 123 of each jack cylinder 120 is coupled to base plate 312 while the action end 124 of each jack cylinder 120 is coupled to top plate 316 of jack assembly 310. The outer end 127 of each piston 126 is coupled to traveling plate 318 of jack assembly 310. In this configuration, traveling plate 318 may be moved axially relative to top plate 316 by actuating jack cylinders 120 to extend and retract pistons 126 relative to their respective housing cylinders 122.
In this embodiment, jack assembly 310 also includes a plurality of elongate jack support members 320 extending axially between bottom plate 312 and mid plate 31 that assist in supporting jack cylinders 120. A lower end of each support member 320 couples to the base end 123 of a corresponding jack cylinder 120 at bottom plate 312. Additionally, an upper end of each support member 320 couples to a corresponding cylinder housing 122 at mid plate 314. In this embodiment, base plate 312 of jack assembly 310 physically supports the components of tool assembly 340. Particularly, at least a portion of the weight of tool assembly 340 is transferred to base plate 312 via traveling plate 318 and jack cylinders 120 of jack assembly 310. In this embodiment, jack assembly 310 also includes a plurality of jack legs 322 that extend at an angle (e.g., axially along and radially away from central axis 305) from a lower surface of traveling plate 318. Particularly, two pairs of jack legs 322 are positioned proximal opposing or lateral ends of traveling plate 318. Additionally, a guide member or roller 324 is coupled to a terminal end of each jack leg 322. As will be described further herein, jack legs 322 interface with torque transfer device 400 to react torque from tool assembly 340.
Similar to the tool assembly 199 shown in
Lower tool frame 350 of tool assembly 340 is disposed about central axis 305 and physically supports upper tool frame 360. In this embodiment, lower tool frame 305 comprises a plurality of coupled elongate members (e.g., tubular members) and has a first or upper end 350A coupled to upper tool frame 360 and a second or lower end 350B axially spaced from upper end 350A that is coupled to the upper end 344A of the rotary housing 344 of rotary drive 342. Although not shown in
Upper tool frame 360 is disposed about central axis 305 and comprises a plurality of coupled elongate members (e.g., tubular members). In this embodiment, upper tool frame 360 has a first or upper end 360A located at an upper end of snubbing jack 300 and a second or lower end 360B axially spaced from upper end 360A. A plurality of guide members or rollers 362 are coupled to the lower end 360B of upper tool frame 360 to permit relative horizontal or lateral movement between upper tool frame 360 and lower tool frame 350. Additionally, in this embodiment, upper tool frame 360 includes a support plate 364 axially positioned between backup clamp 240 and swivel 370, support plate 364 having a central bore or aperture for permitting the passage of tubular members (e.g., workstring 56) therethrough. A plurality of lifting actuators or jacks 366 are circumferentially spaced about central axis 305 and suspended from a lower surface 365 of support plate 364. Each lifting jack 366 includes a piston extension shaft or piston 368 extending axially downwards, away from support plate 364. In this embodiment, the upper end of light slip bowl 372 is coupled to an annular lift plate 374. Particularly, a terminal end of the piston 368 of each lifting jack 366 is coupled to lift plate 374. In this configuration, retraction of the pistons 368 of lifting jacks 366 provides an axially upwards directed or lifting force against swivel 370, slip bowls 372, 376, and load cell 380.
Similar to the functionality provided by the torque transfer device 200 shown in
Rotational torque is transmitted from traveling plate 318 to I-beams 402 of torque transfer device 400 via contact between rollers 324 of traveling plate 318 and the sides 404 of I-beams 402. Additionally, when jack cylinders 120 of jack assembly 310 are actuated to extend or retract traveling plate 318 relative to base plate 312, rollers 324 roll along sides 404 to permit relative axial movement between traveling plate 318 and I-beams 402 while also permitting torque to be reacted against I-beams 402. In this manner, torque transfer device 400 is configured to restrict relative rotation between rotary drive 342 and jack assembly 310. Although in this embodiment torque transfer device 400 comprises a pair of laterally spaced I-beams 402, in other embodiments, a different number of I-beams 402 or other elongate members may be provided to interface with rollers 324. For instance, in another embodiment, torque transfer device 400 comprises four I-beams 402 extending from the corners of mid plate 314.
Tool retrieval assembly 420 of snubbing jack 300 allows components of tool assembly 340 to be displaced horizontally or laterally relative to central axis 305 to conveniently remove said components from or install said components in snubbing jack 300 (e.g., due to component failure, etc.) without needing to use an external crane or hoist mechanism. In this embodiment, tool retrieval assembly 420 comprises a pair of arms 422 extending laterally or horizontally outwards from lower tool frame 350, and a pair of sliding actuators or jacks 430 coupled between lower tool frame 350 and upper tool frame 360. Particularly, each sliding jack 430 has a first end 430A coupled to the upper end of lower tool frame 350 and a second end 430B coupled to a lower end of upper tool frame 360. In this configuration, extension or retraction of the second end 430B of each sliding jack 430 relative to its first end 430A applies a horizontally or laterally directed force against upper tool frame 360.
In this embodiment, a support member or cross-brace 422 extends between terminal ends of arms 422 to provide physical support thereto. Additionally, in this embodiment, an upper end of each arm 422 comprises or forms a rail 426 along which rollers 362 of upper tool frame 360 are permitted to contact or roll. Tool retrieval assembly 420 also includes a plurality of laterally spaced support members or stabilizers 428 coupled to the lower end of upper tool frame 360. A pair of stabilizers 428 are coupled to opposing sides of upper tool frame 360. Particularly, each stabilizer extends axially downwards over the upper end of lower support frame 350 or arms 422 (depending on the relative lateral position between upper tool frame 360 and lower tool frame 350) to prevent upper tool frame 360 from leaning relative to lower tool frame 350. In other words, stabilizers 428 maintain a central or longitudinal axis of upper tool frame 360 parallel with central axis 306 of snubbing jack 300.
Referring particularly to
Once lifting jacks 366 have been actuated into a retracted position, the components of tool assembly 340 suspended from lifting jacks 366 (e.g., swivel 370, slip bowls 372, 376, and load cell 380) are permitted to move horizontally or laterally relative to rotary drive 342 and lower tool frame 350. Thus, with lifting jacks 366 actuated into the retracted position, sliding jacks 430 are actuated to extend the second end 430B of each sliding jack 430 away from its first end 430A, thereby displacing upper tool frame 360, backup clamp 240, power tongs 242, and the components suspended from lifting jacks 366 (e.g., swivel 370, slip bowls 372, 376, and load cell 380) horizontally or laterally relative to lower tool frame 350 and central axis 305, as shown particularly in
Although in this embodiment each of swivel 370, slip bowls 372, 376, and load cell 380 are uncoupled from rotary drive 342 and actuated into the horizontally offset position, in other embodiments, only a subset of these components may be uncoupled from rotary drive 342 and actuated into the horizontally offset position. For instance, in another embodiment, heavy slip bowl 376 may be uncoupled from load cell 380 (e.g., via removing or releasing removable fasteners coupled therebetween, etc.) to permit the actuation of swivel 370 and slip bowls 372, 376 into the horizontally offset position while load cell 380 remains coupled to rotary drive 342 and aligned with central axis 305.
While exemplary embodiments have been shown and described, modifications thereof can be made by one of ordinary skill in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations, combinations, and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. 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. The inclusion of any particular method step or operation within the written description or a figure does not necessarily mean that the particular step or operation is necessary to the method. The steps or operations of a method listed in the specification or the claims may be performed in any feasible order, except for those particular steps or operations, if any, for which a sequence is expressly stated. In some implementations two or more of the method steps or operations may be performed in parallel, rather than serially.
This application claims benefit of U.S. provisional patent application Ser. No. 62/430,038 filed Dec. 5, 2016, and entitled “Snubbing Jack Capable of Reacting Torque Loads,” which is hereby incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/064743 | 12/5/2017 | WO | 00 |
Number | Date | Country | |
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62430038 | Dec 2016 | US |