Patent Publication Number: US-2015075803-A1

Title: Compensating well intervention method and apparatus

Description:
CROSS REFERENCES TO RELATED APPLICATION 
     Priority of U.S. Provisional Patent Application Ser. No. 61/878,846, filed Sep. 17, 2013, incorporated Herein by reference, is hereby claimed. 
    
    
     STATEMENTS AS TO THE RIGHTS TO THE INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     None 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to a compensating well intervention structure assembly. More particularly, the present invention pertains to a structure that supports well intervention activities, typically when a drilling rig or derrick is not present or has previously been removed from a location or well site. More particularly still, the present invention pertains to a hydraulic clamp assembly that can be used to anchor a well intervention structure or other equipment in place. 
     2. Brief Description of the Prior Art 
     It is often beneficial to conduct downhole operations in oil and/or gas wells. Frequently, such operations are conducted using a continuous length of flexible tubing. Such continuous or coiled tubing is generally stored on a reel, and can be translated in and out of a wellbore in a virtually continuous manner without the need to continually connect and/or disconnect individual pipe sections. 
     Such continuous or coiled tubing can be used to conduct numerous downhole operations. For example, continuous tubing can be concentrically inserted within a well (or pipeline), when it is desired to provide a flow path for circulating fluid within said well or pipeline, such as when washing out sand or other debris, or when operating fluid-actuated tools. 
     In other instances, it is often beneficial to convey wireline (including, without limitation, slickline, braided line or electric line) and associated tools within oil and/or gas wells in order to perform downhole operations in such wells. Like continuous tubing, such wireline is also stored on a reel, and can be translated in and out of a wellbore in a virtually continuous manner using an array of beneficially positioned sheaves or pulleys. In other instances it is beneficial to utilize a snubbing unit or hydraulic workover unit, entering the wellbore with jointed pipe to conduct intervention and workover activities. 
     In order to perform such intervention activities including, without limitation, continuous tubing and/or wireline operations and hydraulic workover unit/snubbing operations, it is frequently beneficial to employ an intervention support assembly. An intervention support assembly is a structural framework erected at, near or around a wellhead in order to support equipment such as a coiled tubing injector head or other device. Conventional intervention support assemblies can be large and inconvenient to transport to and from a remote location. Moreover once mobilized to a work location, such conventional intervention support assemblies can be difficult and time consuming to rig up and secure to an underlying platform or other structure. Following completion of an intervention operation, such conventional intervention support assemblies can also be difficult and time consuming to rig down and demobilize. 
     Oil and gas wells are increasingly being drilled in challenging environments. Many onshore wells are frequently drilled in remote locations and/or hostile conditions, while offshore wells are often drilled in water depths of several thousand feet. When offshore wells are drilled in deep water, setting of conventional production platforms—that is, support structures permanently anchored to the sea floor—can be extremely difficult. Beyond certain water depths, installation of conventional production platforms is not possible using available technology. 
     In many cases, offshore wells are drilled using floating vessels such as semi-submersible drilling rigs, drill ships and the like. Further, such wells are generally completed using “subsea” completion equipment. In such cases, wellheads and related equipment are situated at or near the sea floor, while an extensive array of flow lines and umbilical control lines connect such subsea equipment to floating production facilities, pipeline interconnection points and/or other subsea completions. 
     When an intervention operation is conducted on a well that is tied back or otherwise supported by a fixed platform that is anchored to the sea floor, an intervention support assembly can likewise have fixed dimensions as movement of the platform/structure relative to the wellbore does not occur. However, when a well is connected or tied back to a floating vessel, waves or tidal action will frequently cause such movement. In such instances, intervention support assemblies can compensate for such movement; in other words, said intervention support assemblies extend or retract in length in response to said movement in order to keep a coiled tubing injector head or other equipment stationary relative to a wellbore. 
     Conventional compensating intervention support assemblies are accessories to the well intervention support structure—located either above, below, or around said structure. This results in a very large equipment layout, a more involved and less efficient installation, as well as additional safety hazards. 
     Thus, there is a need for a compensating intervention assembly that is built into the well intervention structure, thereby providing a more convenient and cost effective assembly to mobilize to a location and rig up on, over or around a wellhead. Said compensating intervention assembly should provide for passive motion compensation, while allowing for quick, efficient and secure installation on a work location. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a motion compensating support structure that provides a support framework, attachable to well platform, floating vessel or other underlying structure, for supporting well intervention operations. In addition to other applications, it is to be observed that the compensating well intervention structure of the present invention can be used aboard floating production facilities and/or other floating structures such as, for example, spars and tension leg platforms (“TLP&#39;s”). 
     The intervention support assembly of the present invention minimizes or eliminates the need for a crane when making/breaking connections, changing out BHA&#39;s and/or switching from one operation to another, while reducing the instances of personnel working under suspended loads. The compensating well intervention support assembly of the present invention can be used to perform many different operations including, without limitation, coiled tubing, snubbing, wire line and/or electric line applications, as well as wellbore abandonment operations. 
     In a preferred embodiment, the compensating well intervention support assembly of the present invention comprises a support framework having support beams and modular sections that can be transported and assembled over or near a wellhead. Modular spacer sections can be installed in proximity to a wellhead to establish a desired height for said intervention assembly (typically dictated by well and/or well location parameters). An upper work section can then be installed over said spacer section(s) if required. 
     Said upper section of the compensating well intervention support assembly of the present invention provides a stable work platform designed to accommodate both well intervention equipment and personnel during well intervention operations. Said upper section is also beneficially equipped with (typically hydraulic) cylinders to allow for both vertical (axial) and horizontal (lateral) movement of said upper section and any equipment supported thereon relative to a well center. 
     In a preferred embodiment, at least one hydraulic clamp assembly can be used to beneficially connect the compensating well intervention support assembly of the present invention to structural member(s) of a platform, floating vessel or other support surface or substructure. Said clamp assemblies utilize hydraulic cylinders to apply a specified amount of clamping force, while providing a safety feature that allows said clamps to be installed “hands free”—that is, actuated without human physical contact—as opposed to traditional plate and bolt clamps which create pinch points and can cause hand injuries. 
     The clamp assemblies of the present invention are capable of performing multiple tasks. For example, said clamp assemblies can be used to secure the intervention support assembly of the present invention to structural member(s) of a platform, other support surface or substructure. Additionally, the clamp assemblies of the present invention can also be used to “skid” the present invention along beams in order to access other wells or different areas of an underlying platform or other support structure. 
     In a preferred embodiment, the present invention offers both a “manual” control mode in which motion compensation cylinders are actuated manually by a human operator using a control panel, as well as an “compensating” control mode in which said motion compensation system is engaged. In said compensating control mode, motion compensation cylinders are set to a designated pressure in order to compensate for a required load and anticipated movement requirements. A remote control system can be used to operate the present invention, which can include use of wireless remote control devices to function the motion compensation system. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS/FIGURES 
       The foregoing summary, as well as any detailed description of the preferred embodiments, is better understood when read in conjunction with the drawings and figures contained herein. For the purpose of illustrating the invention, the drawings and figures show certain preferred embodiments. It is understood, however, that the invention is not limited to the specific methods and devices disclosed in such drawings or figures. 
         FIG. 1  depicts an overhead perspective view of a spacer section of the intervention support assembly of the present invention. 
         FIG. 2  depicts side view of a top section of the intervention support assembly of the present invention. 
         FIG. 3  depicts front view of a top section of the intervention support assembly of the present invention. 
         FIG. 4  depicts an exploded perspective view of a top section of the intervention support assembly of the present invention. 
         FIG. 5  depicts a front view of the intervention support assembly of the present invention installed over a well. 
         FIG. 6  depicts an overhead view of the intervention support assembly of the present invention installed over a well. 
         FIG. 7  depicts a side perspective view of a clamp assembly of the present invention installed on a beam. 
         FIG. 8  depicts a side view of a clamp assembly of the present invention installed on a beam. 
         FIG. 9  depicts an end view of a clamp assembly of the present invention installed on a beam. 
         FIG. 10  depicts an overhead view of a clamp assembly of the present invention installed on a beam. 
         FIG. 11  depicts an exploded perspective view of a clamp assembly of the present invention. 
         FIG. 12  depicts a partially exploded perspective view of an alternative embodiment clamp assembly of the present invention. 
         FIG. 13  depicts an end view of an alternative embodiment of a clamp assembly of the present invention. 
         FIG. 14  depicts a perspective view of an alternative embodiment of a clamp assembly of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
     As noted above, the present invention comprises a motion compensating support structure that provides a support framework, attachable to well platform, floating vessel or other underlying structure, for supporting well intervention operations. The compensating well intervention structure of the present invention can be used on many different applications including, without limitation, aboard floating production facilities and/or other floating structures such as, for example, spars and TLP&#39;s. In a preferred embodiment, the compensating well intervention support assembly of the present invention comprises a support framework having support beams and modular sections that can be transported and assembled over or near a wellbore within which intervention operations are to be performed. 
       FIG. 1  depicts an overhead perspective view of a spacer section  10  of the intervention support assembly of the present invention. Although spacer section  10  can exhibit many different configurations without departing from the scope of the present invention, as depicted in  FIG. 1  said spacer section  10  generally comprises a three-sided modular support framework. 
     Still referring to  FIG. 1 , spacer section  10  comprises lower base beams  11 , substantially vertical support columns  12  and upper support beams  13 . Support members or struts  14  provide structural strength to spacer section  10 . Spacer section  10  can further include optional ladders  15 , as well as upper connection pins  16  disposed at or near the upper surface of spacer section  10 . When multiple spacer sections are stacked in vertical alignment, said connection pins  16  can be received within mating bores  17  (on an adjacent spacer section) in order connect adjacent spacer sections together. Spacer section  10  can also include lifting pad eyes  18  for connection to a crane or other lifting device when lifting or movement of spacer section  10  is required (such as, for example, from a boat deck to a floating vessel). 
     When installed, at least one modular spacer section  10  can be placed in proximity to a wellhead to establish a desired height for said intervention assembly (typically dictated by well and/or well location parameters). In certain applications, it is to be observed that multiple spacer sections  10  can be stacked to reach a desired height. An upper work section can then be installed over said one or more spacer section(s). 
       FIG. 2  depicts side view of a top section  20  of the intervention support assembly of the present invention, while  FIG. 3  depicts a front view of said top section of said intervention support assembly. As with spacer section  10 , top work section  20  can embody multiple different configurations without departing from the scope of the present invention. In the embodiment depicted in  FIG. 2 , top section  20  comprises a lower frame member  21  having upright post members  22 . A movable support frame  23  having substantially hollow vertical members  26  is movably disposed on said upright post members  22 ; said post members  22  are slidably received within said vertical members  26 , thereby allowing said support frame  23  to move relative to lower frame member  21 . 
     Support frame  23  includes work deck  24  and equipment table  25 , while fluid cylinders  30  connect lower frame member  21  to support frame  23 . Coiled tubing injector head assembly  90  including goose neck guide  91  is disposed on said equipment table  25 . It is to observed that coiled tubing injector head assembly  90  is depicted as an illustrative example of just one type of intervention equipment that can be supported by the intervention support assembly of the present invention. 
       FIG. 4  depicts an exploded perspective view of top section  20  of the intervention support assembly of the present invention. Top section  20  comprises a lower frame member  21  having upright post members  22 . A movable support frame  23  having substantially hollow vertical members  26  is slidably disposed on said upright post members  22 . Support frame  23  includes work deck  24  and equipment table  25 , as well as optional safety hand rails  27  and ladders  28 . Connection pins  29  can be used to secure intervention equipment (such as, for example, injector head assembly  90 , not depicted in  FIG. 4 ) to equipment table  25 . 
     Fluid cylinders  30  connect lower frame member  21  to support frame  23 . Although other fluid or air actuation can be used, in a preferred embodiment said fluid cylinders are hydraulically actuated and comprise barrels  31  and extending/retracting shafts  32 . Extension of said shafts  32  of cylinders  30  causes movable support frame  23  to raise relative to base member  21 , while retraction of said shafts  32  causes movable support frame  23  to lower relative to said base member. 
     Said upper work section  20  of the compensating well intervention support assembly of the present invention provides a stable work platform designed to accommodate both well intervention equipment and personnel during well intervention operations. Cylinders  30  allow for vertical (axial) movement of said upper work section  20  and any equipment supported thereon relative to a well center. Although not depicted in the drawings, it is to be observed that additional fluid cylinders can be provided to permit horizontal (lateral) movement of said upper work section  20  relative to a wellbore. 
       FIG. 5  depicts a front view of the intervention support assembly of the present invention installed over a well. Multiple spacer sections  10  are placed in proximity to well  40  and stacked to reach a desired height. Upper work section  20  is installed above said stacked spacer section(s)  10 . Support frame  23  includes work deck  24  and equipment table  25 . Coiled tubing injector head assembly  90  including goose neck guide  91  is disposed on said equipment table  25 . Fluid cylinders  30  connect lower frame member  21  to support frame  23 . Extension of said cylinders  30  causes movable support frame  23  to raise relative to well  40 , while retraction of said cylinders causes movable support frame  23  to lower relative to said well  40 . 
     Still referring to  FIG. 5 , intervention support assembly  100  is attached to support base beams  300  which are positioned at desired distances relative to well  40 . Hydraulic clamp assemblies  200  are attached to beam  310  of an underlying support structure (such as, for example, a marine platform, TLP or floating vessel). Guy wires  80  extend from said clamp assemblies  200  to intervention support assembly  100  and serve to anchor said support assembly  100  to said beam  310  and, additionally, the underlying support structure. Said guy wires  80  provide safety and stability to intervention support assembly  100 . Alternative embodiment clamp assemblies  250  can also be used to secure and anchor support base beams  300  (and the attached intervention support assembly  100 ) to beam  310  and the underlying support structure. 
     After intervention support assembly  100  of the present invention is installed, the weight of any supported equipment is offset with a desired amount of fluid pressure applied to cylinders  30 . This pressure can be adjusted as weight is added or subtracted to any equipment supported by intervention assembly  100 . Fluid is automatically injected into or drained out of cylinders  30  to maintain the required fluid pressure in said cylinders  30  to compensate for said load and to keep said load at a substantially constant position relative to a wellbore situated there below. Once said cylinders  30  are set to the correct pressure to offset a desired load, said cylinders  30  extend or retract along with the motion of the underlying support structure or floating vessel, always maintaining the desired pressure. 
       FIG. 6  depicts an overhead view of the intervention support assembly  100  of the present invention installed over a well. Hydraulic clamp assemblies  200  are attached to beams  310  of an underlying support structure (such as, for example, a marine platform, TLP or floating vessel). Guy wires  80  extend from said clamp assemblies  200  to intervention support assembly  100  to anchor said intervention support assembly  100  to said beam  310  and said underlying support structure. Alternative embodiment clamp assemblies  250  secure and anchor support base beams  300  (and the attached intervention support assembly  100 ) to beams  310  and the underlying support structure. 
       FIG. 7  depicts a side perspective view of a clamp assembly  200  of the present invention installed on a beam  310 . As depicted in  FIG. 7  and the associated drawings, beam  310  comprises an I-beam having a central web member  311 , upper flange  312  and lower flange  313 . Clamp assembly  200  is shown attached to said upper flange member  312  of said beam  310 . 
     Still referring to  FIG. 7 , clamp assembly  200  includes a central pad eye member  205 . Said central pad eye member  205  provides a convenient and secure connection point for a shackle  300  which, in turn, can connect to a lifting cable  320  attached to a crane or other lifting device (not depicted). In this manner, clamp assembly  200  can be quickly and efficiently lifted and moved into position using said crane or other lifting device. 
       FIG. 8  depicts a side view of clamp assembly  200  of the present invention connected to upper flange  312  of beam  310 , while  FIG. 9  depicts an end view of said clamp assembly  200  of the present invention installed on said beam  310 . Cable  320  from a crane or other lifting device is attached to pad eye  205  using shackle  330 .  FIG. 10  depicts an overhead view of clamp assembly  200  of the present invention installed on beam  310 . 
       FIG. 11  depicts an exploded perspective view of clamp assembly  200  of the present invention. In a preferred embodiment, said clamp assembly  200  comprises body member  201  having substantially planar base plate  202 ; said base plate  202  can have a substantially flat lower surface to beneficially conform to the upper surface of upper flange  312  of beam  310 . At least one wall segment  203  extends from base plate  202 ; said wall segment(s)  203  cooperate to form gaps  204  between said wall segment(s)  203  which receive the upper portion of C-clamps  211 . C-clamps  211 , each having a clamp base  212 , are pivotally mounted to said wall segment(s)  203  using pivot pins  213 . Said C-clamps  211  can rotate or pivot about a pivot axis extending through the longitudinal axis of said pivot pins  213 . 
     At least one fluid cylinder  220  is mounted to said base plate  203  of clamp assembly  200 . Said cylinder(s)  220  each comprise barrel member  223  and piston rod  222  that can extend or retract relative to said barrel member  223 . A substantially planar cylinder pad member  221  is disposed at the base of each piston rod  222 , and is beneficially configured to fit against the upper surface of upper flange member  312 . In a preferred embodiment, said at least one fluid cylinder  220  is hydraulically actuated; however, it is to be observed that said at least one fluid cylinder  220  can be actuated using other fluid(s), or can comprise a linear actuator other than a hydraulic cylinder. By way of illustration, but not limitation, said at least one fluid cylinder  220  can be pneumatically actuated. 
     When installation of said clamp assembly  200  is desired, said clamp assembly  200  can be attached to a cable of a crane or other lifting device via connection to pad eye  206  and moved into a desired position. C-clamps  211  can be rotated about pin  213  and spread outward to allow said clamp member  200  to be placed onto the upper surface of upper flange  312  of beam  310 . Said C-clamps  211  can then be moved inward (rotated about pivot pins  213 ) until clamp bases  212  are positioned under upper flange  312  of beam member  310 . Thereafter, cylinder(s)  220  can be actuated to extend piston rod(s)  222 , thereby forcing plate members  221  toward said clamp bases  212 . As said cylinder(s)  220  are actuated, compressive forces are applied to upper flange  312  of beam  310 , which is positioned between plate members  221  and clamp bases  212 , thereby securing said clamp assembly  200  in place relative to beam member  310 . 
       FIG. 12  depicts a partially exploded perspective view of an alternative embodiment clamp assembly  250  of the present invention. It is to be observed that clamp assembly  200  of the present invention is “bilateral”, in that it provides hydraulic clamping forces on two sides. Conversely, alternative embodiment clamp assembly  250  is unilateral, in that it provides hydraulic clamping forces on only one side of said clamp. 
     In a preferred embodiment, said clamp assembly  250 , like previously discussed clamp assembly  200 , comprises body member  251  having substantially planar base plate  252 ; said base plate  252  can have a substantially flat lower surface to beneficially conform to the upper surface of a beam or other connection surface. At least one wall segment  253  extends from base plate  252 ; said wall segment(s)  253  cooperate to form gaps  254  between said wall segment(s)  253  for receiving the upper portion of C-clamps  261 . C-clamps  261 , each having a clamp base  262 , are pivotally mounted to said wall segment(s)  253  using pivot pins  263 . Said C-clamps  261  can rotate or pivot about a pivot axis extending through the longitudinal axis of said pivot pins  263 . 
     At least one fluid cylinder  270  is mounted to said base plate  253  of clamp assembly  250 . Said cylinder(s)  270  each comprise barrel member  273  and piston rod  272  that can extend or retract relative to said barrel member  273 . A substantially planar cylinder pad member (not depicted in  FIG. 12 ) is disposed at the base of each piston rod  272 . In a preferred embodiment, said at least one fluid cylinder  270  is hydraulically actuated; however, it is to be observed that said at least one fluid cylinder  270  can be actuated using other fluid(s). By way of illustration, but not limitation, said at least one fluid cylinder  270  can be pneumatically actuated. 
       FIG. 13  depicts an end view of an alternative embodiment clamp assembly  250  of the present invention, while  FIG. 14  depicts a perspective view of said alternative embodiment clamp assembly  250  of the present invention. Beam  400 , which has upper flange member  401 , web member  402  and lower flange member  403 , is disposed on beam  410  that has upper flange member  411 , web member  412  and lower flange member  413 . Lower flange member  403  of beam  400  is disposed on the upper surface of flange member  411  of beam  410 , and said beams  400  and  410  are oriented substantially perpendicular to each other. 
     C-clamps  261  can be rotated outward to allow cylinders  270  of said clamp member  250  to be placed onto the upper surface of lower flange  403  of beam  400 . Said C-clamps  261  can then be rotated inward until clamp bases  262  are positioned under upper flange  411  of beam member  410 . Thereafter, cylinder(s)  270  can be actuated to extend piston rod(s)  272 , thereby forcing plate members  271  against the upper surface of lower flange  403  of beam  400 . As said cylinder(s)  270  are actuated, compressive forces are applied to both lower flange  403  of beam  400  and upper flange  411  of beam  410 , thereby securing said clamp assembly  250  and said beam members in place. Spacer bolts  280  are received within threaded bores  281 ; said spacer bolts  280  can be extended until they contact the upper surface of upper flange  411  of beam  410 . Said spacer bolts  280  act to balance and stabilize clamp assembly  250 , while providing some additional compressive forces. 
     Hydraulic clamp assemblies  200  and  250  can be used to beneficially connect the compensating well intervention support assembly  100  of the present invention to structural member(s) of a platform, floating vessel or other support surface or substructure. Said clamp assemblies  200  and  250  utilize hydraulically actuated cylinders to apply a desired amount of clamping force. Further, said clamp assemblies  200  and  250  can be installed “hands free”—that is, actuated without direct human physical contact—as opposed to traditional plate and bolt clamps which create pinch points and can cause injuries to personnel. 
     It is to be observed that clamp assemblies  200  and  250  of the present invention are capable of performing multiple tasks. For example, said clamp assemblies can be used to secure the intervention support assembly  100  of the present invention to structural member(s) of a platform, other support surface or substructure. Additionally, said clamp assemblies can also be used to “skid” intervention assembly  100  of the present invention along beams or other surfaces in order to access other wells or different areas of an underlying platform or other support structure. 
     In a preferred embodiment, the compensating intervention support assembly of the present invention offers both a “manual” control mode in which motion compensation cylinders are actuated manually by a human operator using a control panel, as well as an “compensating” control mode in which said motion compensation system is activated. In said compensating control mode, motion compensation cylinders are set to a designated pressure in order to compensate for a required load and anticipated movement requirements. A remote control system can be used to operate the present invention, which can include use of wireless remote control devices to function the motion compensation system. 
     The intervention support assembly of the present invention minimizes or eliminates the need for a crane when making/breaking connections, changing out BHA&#39;s and/or switching from one operation to another, while reducing the instances of personnel working under suspended loads. The compensating well intervention support assembly of the present invention can be used to perform many different operations including, without limitation, coiled tubing, snubbing, wire line and/or electric line applications, as well as wellbore abandonment operations. 
     The above-described invention has a number of particular features that should preferably be employed in combination, although each is useful separately without departure from the scope of the invention. While the preferred embodiment of the present invention is shown and described herein, it will be understood that the invention may be embodied otherwise than herein specifically illustrated or described, and that certain changes in form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention.