Abstract:
A jack system may provide subsea or surface operation. The jack system includes a top plate and a base plate with at least two pistons disposed between the base and top plate. The pistons are extendable to increase a separation distance between the base and top plate, and said pistons are retractable to decrease the separation distance between the base and top plate. The jack system also includes a bottom slip bowl assembly, a top slip bowl assembly, and rotary assembly. The top slip bowl and rotary assembly are rotatably coupled to the top plate wherein the rotary assembly and the top slip bowl assembly rotate relative to the top plate.

Description:
FIELD OF THE INVENTION 
     This invention relates to a jacking system. More particularly, to a method or system for subsea or surface jacking. 
     BACKGROUND OF INVENTION 
     In an oil and/or gas well, it may be desirable to run tubulars, pipes, tubing, or the like into the wellbore. A jack is utilized to run or retrieve tubulars into or out of a well. A jack may provide slip bowl assemblies that allow the jack to grip a tubular, and the jack may impart axial force on tubulars to run or retrieve from the well. As the wellbore may be under pressure, the jack may be capable of imparting sufficient axial force to overcome wellbore pressure. 
     Jacks, such as a casing jack, snubbing jack or hydraulic jack, may be utilized in conjunction with a rig, platform, or vessel. The rig, platform, or vessel may provide various additional tools, such as a top drive, rotary, cutters, tongs, power swivel, clamps, swage, rollers, or the like, utilized in conjunction with the jack to perform various oil and/or gas well operations. 
     SUMMARY OF THE INVENTION 
     In one implementation, the jack system includes a top plate and a base plate with at least two pistons disposed between the base and top plate. The pistons are extendable to increase a separation distance between the base and top plate, and said pistons are retractable to decrease the separation distance between the base and top plate. The jack system also includes a bottom slip bowl assembly placed on the base plate, a top slip bowl assembly, and rotary assembly. The top slip bowl and rotary assembly are rotatably coupled to the top plate wherein the rotary assembly and the top slip bowl assembly rotate relative to the top plate. The jack system may be suitable for surface or subsea operations, as well as operations with or without a rig. 
     In another implementation, a jack system may be utilized in a method for disconnecting a workstring at a desired location. The method includes securing a jack to a wellhead, and securing a workstring with the top slip bowl assembly of the jack; extending the at least two pistons to exert a predetermined amount of tension on the workstring. The method also includes rotating the rotary assembly and the top slip bowl assembly, wherein the rotation of the rotary assembly and the top slip bowl assembly causes the workstring to disconnect at a desired location. Note that the jack system may be suitable for any operations requiring tubulars or the like to be pushed, pulled, and/or rotated. The jack system is in no way limited specifically to use for a method of disconnecting a workstring at a desired location. 
     The foregoing has outlined rather broadly various features of the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions to be taken in conjunction with the accompanying drawings describing specific embodiments of the disclosure, wherein: 
         FIG. 1   a - 1   d  are isometric, cross-sectional, front, and side views of an illustrative implementation of a jack system; and 
         FIG. 2   a - 2   b  are front and side views of an illustrative implementation of a jack system. 
     
    
    
     DETAILED DESCRIPTION 
     Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views. 
     Referring to the drawings in general, it will be understood that the illustrations are for the purpose of describing particular implementations of the disclosure and are not intended to be limiting thereto. While most of the terms used herein will be recognizable to those of ordinary skill in the art, it should be understood that when not explicitly defined, terms should be interpreted as adopting a meaning presently accepted by those of ordinary skill in the art. 
     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 invention, as claimed. In this application, the use of the singular includes the plural, the word “a” or “an” means “at least one”, and the use of “or” means “and/or”, unless specifically stated otherwise. Furthermore, the use of the term “including”, as well as other forms, such as “includes” and “included”, is not limiting. Also, terms such as “element” or “component” encompass both elements or components comprising one unit and elements or components that comprise more than one unit unless specifically stated otherwise. 
     A subsea or surface jacking system or method allows one to push, pull, and/or rotate tubulars, pipes, tubing, or the like. The system or method may allow operation with or without the use of a rig, platform, or vessel. The system or method also provides non-vertical or vertical access to a well. For example, an exemplary implementation of the system or method may allow operations such as, but not limited to, blind backoff, tubing recovery, swaging, non-vertical or vertical intervention, tube cutting, subsea or surface operation, and/or the like. 
       FIGS. 1   a - 1   d  are isometric, cross-sectional, front, and side views of an illustrative implementation of a jack system  100 . Jack system  100  provides a bottom plate  1  and a top plate  3  separated by cylinders  2 . Cylinders  2  may be hydraulically operated to extend or retract a rod provided within each cylinder  2 , thereby allowing cylinders  2  to modify the distance between bottom plate  1  and top plate  3 . While the implementation shown provides four cylinders, other implementations may utilize two cylinders or more. 
     Slip bowl assemblies  17   a ,  17   b  may be actuated to grip or release a tubular, pipe, tubing, or the like. When actuated to gripping position, the slips of a slip bowl assemblies  17   a ,  17   b  secures a tubular. When actuated to a released position, tubulars may move without interference from slip assemblies  17   a ,  17   b . While the slip bowl assemblies discussed provide a single slip bowl, it will be recognized by one of ordinary skill in the art that the slip bowl assemblies may provide multiple slip bowls for pushing or pulling tubulars. Slip bowl assembly  17   a  coupled to top plate  3  moves up or down with top plate  3  when cylinders  2  are extended or retracted. However, slip bowl assembly  17   b  placed on or secured to bottom plate  1  with slide plate  16  may remain stationary during operation of jack system  100 . By engaging a tubular with slip bowl assembly  17   a  and leaving slip bowl assembly  17   b  disengaged from the tubular, the tubular may be run into or retrieved from the wellbore by retracting or extending cylinders  2 . Engaging slip bowl assembly  17   b  allows slip bowl assembly  17   a  to be disengaged and cylinders  2  to be extended or retracted without moving the tubular. 
     In contrast to other jacks, jack system  100  allows for operation either with or without a rig, platform, or vessel. Adapter  15  allows jack system  100  to be coupled to the wellhead. For example, adapter  15  may allow jack system  100  to be connected directly to a wellhead, christmas tree, blow out preventer (BOP), or the like. Additionally, jack system  100  provides a rotary assembly. As a result, in contrast to other jacks, the jack system  100  may be operated without the need for rotary tools provided by a rig, platform, or vessel. These features allow the jack system  100  to be operated subsea and/or without a rig, platform, or vessel. The rotary assembly may provide a motor  4  coupled to gear  10  and gear  12 . Motor  4  rotates gear  10 , which causes gear  12  to rotate. Gear  12  is coupled to slip bowl assembly  17   a , which rotates with gear  12 . In other implementations, the gears of a rotary assembly may incorporate belt(s) or chain(s) or may be substituted with a belt or chain, worm gear(s), cam(s), ratchet assembly. 
     When slip bowl assembly  17   a  is actuated to a gripping position and motor  4  is actuated to rotate gears  10 ,  12 , the jack system  100  imparts torque on the tubular, pipe, tubing, or string secured by slip bowl assembly  17   a . Motor  4  rotates shaft  7 , thereby rotating gear  10 . One or more bearings  8 , spacers  9 , or a combination thereof may be provided. Gear  12  may be coupled to slip bowl assembly  17   a  utilizing slip adapter plate  14 . Shaft  6  allows gear  12  and slip bowl assembly  17   a  to rotate relative to top plate  3 . Additionally, one or more spacer plates  5 ,  13  may be provided for spacing gear  12  and slip bowl assembly  17   a . A top portion of slip bowl assembly  17   a  may provide a clamp  18 . Clamp  18  may be utilized to secure a tubular and to prevent slippage of the tubular relative to the rotary assembly. For example, in the implementation shown, clamp  18  is a mill clamp. In other implementations, any suitable type of clamp may be utilized, such as a hydraulically actuated clamp. Further, the jack system  100  may optionally provide more than one clamp. While clamp  18  is positioned above slip bowl assembly  17   a , in other implementations clamp  18  may be relocated or another clamp may be provided in another location. For example, a bar clamp (not shown) may optionally be provided between slip bowl assemblies  17   a ,  17   b  to secure a tubular to prevent rotation or vertical motion, and the bar clamp may be utilized to assist with make up and break out tubulars or the like. While various components of jack system  100  may be hydraulically operated, in other implementations, one or more components of jack system  100  may be electrically operated. 
       FIGS. 2   a - 2   b  are front and side views of an illustrative implementation of a jack system  200 . Gears  210 ,  220  are covered by protective shields to prevent damage to the gears, damage to other nearby devices (e.g. ROV), and items from getting caught in the gears, such as a divers clothing. Motor  230 , slip bowl assemblies  240   a ,  240   b , and pistons  250  may be hydraulically operated. Hydraulic lines  260  may be connected to motor  230 , slip bowl assemblies  240   a ,  240   b , and pistons  250 . Jack system  200  to be coupled to an external device that may be utilized to operate the system, such as a ROV, external power source (electric or hydraulic), hydraulic power pack, hydraulic hose or reel, control panel, or the like. Jack system may be electrically or hydraulically operated. 
     The aforementioned jacking systems and methods can be utilized to push, pull, and/or rotate tubulars. For example, the jacking systems may be utilized to backoff, make up, or break out tubulars. The jacking systems may be utilized subsea or at the surface with or without a rig, platform, or vessel. 
     As an exemplary non-limiting usage of a jacking system may be for performing a blind backoff. In certain situations, such as a stuck workstring or tubular, it may be desirable to backoff or unscrew the workstring at a desired joint. Methods for backing off a workstring may utilize explosives and/or may utilize a means for rotating a tubular in combination with a jack or crane. The workstring may be tensioned with the jack or crane to cause changes in the forces on the threaded joints of the workstring. The workstring may be tensioned to ensure forces at a desired backoff joint are minimal relative to the other joints in the workstring, thereby allowing an operator to provide backoff at a desired joint. Further, explosives may also be utilized at the desired joint. Means for rotating a tubular, such as a top drive, rotary table, or power swivel, are provided on a rig, platform, or a vessel, thereby necessitating the need for a rig, platform, or vessel in backoff operations. These means for rotating a tubular are provided separately from the jack and may be significant in size making the device impractical for subsea operation or incorporation into a jack. As a result, backoff is performed from a rig, platform, or vessel. However, due to rough waters, waves, or the like, it may be difficult to accurately exert a desired amount of tension on a workstring. Further, conventional operations on the surface may expose personnel to stored potential energy, which can cause injury to personnel or damage to equipment if failure results. 
     The aforementioned jacking system overcomes such issues experienced with other jacks. In contrast to other jacks, the jacking system may be coupled directly to the wellhead utilizing an adapter. Since the jacking system is coupled to the wellhead, the jacking system is not subject to vertical forces that may result on a rig, platform, or vessel in rough seas. This allows the jacking system to accurately exert a desired amount of tension on a workstring. The top slip bowl assembly of the jacking system may be closed to secure the workstring, and the pistons may be extended a predetermined amount to exert a desired tension on the workstring. Further, rather that relying on a means for rotating a tubular provided on a rig, platform, or vessel like other jacks, a rotating mechanism is incorporated in the jacking system. Thus, the rotary assembly of the jacking system may rotate the workstring to backoff at a desired joint without the need for rotating means provided on a rig, platform, or vessel. By incorporating a rotating mechanism into the jacking system, the need for rotating tools requiring a rig, platform, or vessel is obviated. 
     Note that the jacking system is in no way limited specifically to backoff operations. The jacking system is suitable for any operations in which pushing, pull, or rotating tubulars is desired. For example, the jacking system may also be suitable for makeup and break out of tubing joints, makeup and breakout within the wellbore, backing off duals, running and retrieving tubulars, conveying tubing in/out of the wellbore, tripping in/out, fishing operations, etc. 
     It will be appreciated by one of ordinary skill in the art that various features may be modified in accordance with a desired use. For example, pistons may be selected to accommodate wide range of axial loads. Rotary motor may be selected to accommodate desired torque ranges. The jack system may utilize a single rotary or dualstring/multistring rotary. For example, a dual rotary may be desirable to allow backoff without the need to cut the other tubular out of the way. Pistons may be selected to provide more or less extension. Bottom and top plates may be made thicker or thinner. Bore size of the slip assemblies may be modified to accommodate larger or smaller tubulars. Adapter may be modified to accommodate connection of the jack system to different BOPs, trees, tubulars, casings or the like. Further, different types of clamps, cutter, swage/roller, and/or slip bowl assemblies may be utilized. 
     Implementations described herein are included to demonstrate particular aspects of the present disclosure. It should be appreciated by those of skill in the art that the implementations described herein merely represent exemplary implementation of the disclosure. Those of ordinary skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific implementations described and still obtain a like or similar result without departing from the spirit and scope of the present disclosure. From the foregoing description, one of ordinary skill in the art can easily ascertain the essential characteristics of this disclosure, and without departing from the spirit and scope thereof, can make various changes and modifications to adapt the disclosure to various usages and conditions. The implementations described hereinabove are meant to be illustrative only and should not be taken as limiting of the scope of the disclosure.