WO2014210537A1

WO2014210537A1 - Systems and methods for performance of offshore well operations

Info

Publication number: WO2014210537A1
Application number: PCT/US2014/044708
Authority: WO
Inventors: Merwin Hale WILKINSON, Jr.
Original assignee: MINYARD, Charles, R.
Priority date: 2013-06-27
Filing date: 2014-06-27
Publication date: 2014-12-31

Abstract

Systems and methods for reducing relative movement between a vessel and an offshore structure include use of a sway dampening system, which includes at least partially flexible elongate members attached to the offshore structure and to the vessel or a load spreader associated therewith to synchronize motion between the vessel and offshore structure, such that relative motion between the two objects is minimized. A beam system having outrigger beams extending from a central member can extend between the vessel and offshore structure for performing operations on the offshore structure or a well associated therewith. Guy wires or similar securing mechanisms can be used to attach a tower, derrick, or similar structure erected above or otherwise associated with the offshore structure, to the outrigger beams, such that relative motion of the tower and associated equipment can also be reduced to facilitate performance of operations on the well or offshore structure.

Description

SYSTEMS AND METHODS FOR PERFORMANCE OF OFFSHORE WELL

OPERATIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a Patent Cooperation Treaty (PCT) application that claims priority to co-pending United States provisional patent application, having U.S. Patent Application Serial Number 61/957,266, entitled "Systems and Methods for Performance of Offshore Well Operations," filed on June 27, 2013, the entirety of which is incorporated herein by reference.

FIELD

[0002] Embodiments usable within the scope of the present disclosure relate, generally, to systems and methods usable to stabilize a first object relative to a second, more specifically, to systems and methods for reducing relative motion between two offshore objects, and still more specifically to systems and methods usable to reduce relative motion and/or synchronize motion between an elevated vessel (e.g., a lift boat) and an offshore platform, monopod, and/or caisson, to enable operations (e.g., workover, snubbing, etc.) to be performed on a well associated with the offshore platform, monopod, and/or caisson from the elevated vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] In the detailed description of various embodiments usable within the scope of the present disclosure, presented below, reference is made to the accompanying drawings, in which:

[0004] Figure 1A depicts a diagrammatic side view of an embodiment of a beam structure usable within the scope of the present disclosure.

[0005] Figure 1 B depicts a diagrammatic top view of the beam structure of Figure 1 A.

[0006] Figure 2A depicts a diagrammatic side view of the front outrigger beam shown in

Figures 1A and IB. Figure 2B depicts a diagrammatic top view of the front outrigger beam of Figure 2A.

Figure 3A depicts a diagrammatic side view of the rear outrigger beam shown in Figures 1A and IB.

Figure 3B depicts a diagrammatic top view of the rear outrigger beam of Figure 3A.

Figure 4A depicts a diagrammatic side view of a telescoping member shown in Figures 1A and IB.

Figure 4B depicts a diagrammatic top view of the telescoping member shown in Figure 4A.

Figure 5 A depicts a diagrammatic side view of the main and/or central body shown in Figures 1 A and IB.

Figure 5B depicts a diagrammatic top view of the main and/or central body shown in Figure 5 A.

Figure 6 depicts a top perspective view of an embodiment of a system usable within the scope of the present disclosure, engaged with an offshore structure.

Figure 7 depicts a front perspective view of the system shown in Figure 6.

Figure 8 depicts a right side perspective view of the system shown in Figure 6 and Figure 7.

Figure 9 depicts a back perspective view of the system show in Figures 6 through

[00018] Figure 10 depicts a left side perspective view of the system show in Figures 6 through 9.

[00019] One or more embodiments are described below with reference to the listed

Figures. DETAILED DESCRIPTION OF THE EMBODIMENTS

[00020] Before describing selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein. The disclosure and description herein is illustrative and explanatory of one or more presently preferred embodiments of the invention and variations thereof, and it will be appreciated by those skilled in the art that various changes in the design, organization, order of operation, means of operation, equipment structures and location, methodology, and use of mechanical equivalents may be made without departing from the spirit of the invention.

[00021] As well, it should be understood that the drawings are intended to illustrate and plainly disclose presently preferred embodiments of the invention to one of skill in the art, but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views, as desired for easier and quicker understanding or explanation of the invention. As well, the relative size and arrangement of the components of each embodiment may differ from that shown and still operate within the spirit of the invention as described throughout the present application.

[00022] Moreover, it will be understood that various directions such as "upper", "lower",

"bottom", "top", "left", "right", and so forth are made only with respect to explanation in conjunction with the drawings, and that the components may be oriented differently, for instance, during transportation and manufacturing as well as operation. Because many varying and different embodiments may be made within the scope of the inventive concept(s) herein taught, and because many modifications may be made in the embodiments described herein, it is to be understood that the details herein are to be interpreted as illustrative and non- limiting.

[00023] Embodiments usable within the scope of the present disclosure include systems and methods usable to reduce relative motion and/or synchronize motion between a first object (e.g., an elevated vessel) and a second object (e.g., an offshore structure, such as a platform, monopod, or caisson), such that operations (e.g., workover, snubbing, and/or other wellbore operations) can be performed on the second object using the first object and/or a structure associated therewith. Conventionally, performing operations on an offshore platform or other structure using a lift boat or similar vessel is impossible during all but the most calm of conditions due to the presence of relative motion between the lift boat and the offshore structure. A monopod, especially, can experience a great deal of swaying, rotational, and/or pendulum-like movement, imparted by waves, current, winds, and/or other forces, while a lift boat, from which performance of operations on a well associated with the monopod may be attempted, is subject to similar forces, causing movement relative to that of the monopod, but with different directions and magnitude. Even when performing operations on a well associated with a generally stable offshore platform (e.g., a structure having four or more legs anchored to the sea floor) that experiences minimal movement, a workover rig or similar structure is required in lieu of an elevated vessel due to the motion of the vessel. A need therefore exists for systems and methods usable to enable operations to be performed on a well associated with an offshore structure (and/or the offshore structure itself) using a vessel, such as an elevated vessel (e.g., a lift boat). To compensate for relative motion between a first object (e.g., a vessel) and a second object (e.g., an offshore structure), a sway dampening system can be provided between the two objects, which can be used to reduce relative motion therebetween, e.g., by "synchronizing" motion between the two objects. For example, a physical attachment between an elevated vessel and an offshore structure, such as a monopod, can effectively cause the two objects to move as a single object when subjected to wave motion, currents, winds, and/or other forces. In an embodiment, the sway dampening system can include a plurality of elongate members, such as nylon ropes and/or cables, that are secured at one end to the offshore structure, and at the opposing end to a "load spreader" (e.g., a platform that includes pad eyes) or similar structure associated with the vessel. Generally, from four to six lines can be used, that are typically seventy to eighty feet in length, though the length and number of lines can be varied depending on the relative height/elevation between objects and the shape/dimensions thereof. Each line can be provided with up to 1000 pounds of tension, or more (e.g., using a winch or similar mechanism), to prevent any significant amount of slack from occurring in the lines responsive to movement of the vessel or offshore structure. Preferably, in each location where a line is provided, two lines can be used for redundancy purposes, such that if one member breaks and/or otherwise fails, the sway dampening system can continue to operate.

[00025] While the exemplary embodiment above describes use of nylon lines, ropes, and/or cables, it should be understood that other materials and/or other types of structures could be used without departing from the scope of the present disclosure. For example, cables, lines, and/or ropes formed from rubber, composite, and/or polymeric components could be used. In other embodiments, hydraulic cylinders can be provided between a vessel and an offshore structure and used to compensate for relative motion. Generally, components having at least a slight degree of flexibility can be used to ensure that components of the sway dampening system do not fail and/or break under a sudden force, such as a large wave that rapidly moves the vessel and/or the offshore structure.

[00026] To prevent small motions (e.g., slight vertical movements imparted by the surface of a body of water) of the vessel from hindering operations, components of the sway dampening system can be attached to a load spreader, as described above, rather than directly to a lift vessel. In an embodiment, a load spreader can be clipped to a vessel, rather than welded thereto, such that a small amount of relative movement between the load spreader and the vessel is permitted, e.g., by providing a small space (e.g., about 0.5 inches) between at least one surface of the clips of the load spreader and the vessel.

[00027] In use, the sway dampening system can thereby compensate for and/or reduce relative motion between a first object (e.g. , a lift vessel) and a second object (e.g., an offshore structure) by at least partially synchronizing movement between the connected objects. Even when the sway dampening system is used to associate a generally stationary object (e.g., a four- legged offshore platform that contacts the sea floor) with a vessel, movement of the vessel relative to the generally stationary object can be reduced (e.g., by up to 75% or more). Stabilization of a vessel relative to an offshore structure in this manner can enable operations to be performed on a well associated with the offshore structure, from the vessel. [00028] As such, after engagement of the sway dampening system, a beam system or similar support element can be provided between the vessel and the offshore structure, e.g., for use as a surface from which operations can be performed on a well associated with the offshore structure. In an embodiment, a first beam (e.g., an I-beam or similar structure having grating or a similar surface thereon suitable for supporting personnel and/or equipment) can have two or more outrigger beams extending therefrom, and perpendicular thereto. For example, a first outrigger beam can be bolted and/or otherwise attached to a vessel, while a second outrigger beam can be telescopically extendable outward from the vessel (e.g., to a distance of forty feet or more) to define a space therebetween with structural elements suitable for use as a load frame. This space can be positioned over an offshore structure, such as a monopod or caisson, such that operations can be performed on a well associated with the offshore structure from the beam system. Specifically, a tower, derrick, or similar structure can be erected over the load frame and provided with suitable equipment for performing workover, snubbing, and/or other types of operations on the well. To stabilize the tower, guy wires can be attached to the tower at one end, and to the ends of each outrigger beam at the other. In an embodiment, in each location where a guy wire is provided, two wires can be used for redundancy purposes, such that if one member breaks and/or otherwise fails, the second wire can retain the tower.

[00029] It should be understood, however, that in some embodiments, use of outrigger beams, a tower/derrick, and a guy wire system may be unnecessary. For example, when performing operations on a pre-existing offshore platform that includes a tower, a single platform, lacking outrigger beams and an area usable as a load frame for supporting a tower, could be used as a surface from which operations can be performed on a well associated with the offshore platform.

[00030] Figures 1A and IB depict side and top views, respectively, of a beam system usable within the scope of the present disclosure. The depicted beam system is shown having a main and/or central body, defined by a first beam (10A) (e.g., an I-beam) and a second beam (10B), spaced apart and having a support surface (12) (e.g., grating) placed thereon. While Figurers 1A and IB depict two beams (10A, 10B) spaced apart, it should be understood that other configurations, including a generally unitary structure, could be used without departing from the scope of the present disclosure, as could other types of continuous or discontinuous support surfaces. The main body can be provided with side rails (e.g., to facilitate safe transit of personnel across the beam system), and vertical, lateral, and/or diagonal supports as needed to support the weight thereof and the weight of any objects and/or personnel placed thereon.

[00031] A first outrigger beam (14) (e.g., a rear outrigger beam) is shown extending generally perpendicular to the main body. In use, the first outrigger beam (14) can be bolted and/or otherwise secured to a vessel (e.g., a deck of an elevated/lift vessel), defining a rear portion (16) generally positioned over and/or in association with the vessel and a front portion (18) generally extending outward from the edge of the vessel. A second outrigger beam (e.g., a front outrigger beam) is shown at the distal edge of the front portion (18), and is movable between a first, retracted position, denoted as 20A, and a second, extended position, denoted as 20B. Two telescoping members (22A, 22B), such as hydraulic cylinders or similar extendable and retractable members are usable to move the second outrigger beam between the first and second positions (20A, 20B). During typical use, the second outrigger beam can be retained in the retracted position (20A) during transport, and extended to the second position (20B) prior to commencing operations on a well and/or offshore structure. Placement of the first and second outrigger beams (14, 20B) defines a load frame region (24), within which a tower, derrick, or similar structure can be erected (e.g., above a well and/or offshore structure). The tower, derrick, and/or similar structure can be stabilized by attaching guy wires to the ends of each outrigger beam (14, 20B), as described above, such that the main/central beam is usable to support personnel and equipment, while the tower, derrick, etc., can be used to suspend and/or otherwise retain workover and/or snubbing equipment, and/or equipment usable for other wellbore operations.

[00032] While Figures 1A and IB depict two positions (20 A, 20B) in which the second outrigger beam can be provided, it should be understood that in various embodiments, non-movable outrigger beams could be used, an outrigger beam could be provided in an intermediate position, or in certain situations (such as when performing operations on an offshore platform having a pre-existing tower and/or derrick), use of outrigger beams could be omitted.

[00033] Figures 2A and 2B depict side and top views, respectively, of the second outrigger beam (20) (shown in Figures 1A and IB as 20 A and 20B, in two possible positions). The second outrigger beam (20) is shown as a generally elongate member (e.g., such as an I-beam or similar type of beam), having a plurality of pad eyes (21A, 21B, 21C, 21D, 21E) generally equally spaced along the length thereof, which are usable for attachment of guy wires to support a tower and/or derrick, as described previously, and/or to facilitate transport and/or installation of the beam (20). While Figure 2A depicts five generally equally spaced pad eyes (21A, 21B, 21C, 21D, 21E), any number, type, and placement of attachment features can be used without departing from the scope of the present disclosure. The second outrigger beam (20) is further shown having two bolted connections (25 A, 25B), usable to attach the beam (20) to telescoping members (22 A, 22B - shown in Figure IB) or other adjacent portions of a beam system.

[00034] Figures 3A and 3B depict side and top views, respectively, of the first outrigger beam (14), which is shown as a generally elongate member (e.g., such as an I- beam or similar type of beam), having a plurality of pad eyes (17A, 17B, 17C, 17D) positioned along the length thereof, which are usable for attachment of guy wires to support a tower and/or derrick, as described previously, and/or to facilitate transport and/or installation of the beam (14). While Figure 3 A depicts four pad eyes (17A, 17B, 17C, 17D) positioned proximate to the ends of the beam (14), any number, type, and placement of attachment features can be used without departing from the scope of the present disclosure. The first outrigger beam (14) is further shown having two bolted connections (19A, 19B), usable to attach the beam (14) to associated bolting locations (11, shown in Figure 5 A) of the beams (10A, 10B, shown in Figures IB and IB) of the main/central body of the beam system.

[00035] Figures 4A and 4B depict side and top views, respectively, of a telescoping member (22A) usable, e.g., to attach the main/central body of the beam system to an outrigger beam (e.g., the second outrigger beam (20)) to enable movement thereof (e.g., between a retracted position (20A) and an extended position (20B)). The depicted telescoping member (22A) is shown including four tubular segments (13A, 13B, 13C, 13D), which can include tubular members, cylinders, pistons, rods, or other similar, generally elongate members sized to nest and/or otherwise fit within one another and/or to otherwise move, expand, retract, etc. to change the overall length of the telescoping member (22 A). A first end of the telescoping member (22A) is shown having a bolting location (23) for securing the telescoping member (22A) to an outrigger beam, while the opposite end can be secured to the main and/or central body of the beam system.

[00036] Figures 5A and 5B depict side and top views, respectively, of the central and/or main body of the beam system (also shown in Figures 1 A and IB). As described previously, the main body includes two beams (10A, 10B), spaced apart and supporting and/or associated with a support surface (12), shown as grating. One or more lateral supports, of which an exemplary support (13) is labeled, can extend between the beams (10A, 10B) to facilitate support of the surface (12) and/or items thereon. Each beam (10A, 10B) is shown including a respective attachment location (15 A, 15B) at an end thereof, at which telescoping members (22A, 22B, shown in Figure IB) can be attached (e.g., using bolts or similar fasteners). Figure 5A also depicts a bolting location (11) along the length of the first beam (10A), which can accommodate engagement with the first outrigger beam (14, shown in Figures 3A an 3B). Specifically, the first bolted connection (19A, shown in Figures 3A and 3B) thereof can engage the bolting location (1 1) on the first beam (10A), while the second bolted connection (19B, shown in Figures 3A and 3B) can engage a similar bolting location on the second beam (10B).

[00037] Figures 6 through 10 depict various views of an embodiment of a system usable within the scope of the present disclosure, engaged with an offshore structure. Specifically, Figure 6 depicts a top perspective view of the system, Figure 7 depicts a front perspective view of the system (e.g., the side of the system that faces a lift boat or similar vessel), Figure 8 depicts a left side perspective view of the system, Figure 9 depicts a rear perspective view of the system (e.g., the side of the system that extends outward from a vessel), and Figure 10 depicts a right side perspective view of the system. [00038] As shown in Figures 6, 8, and 10, the depicted embodiment includes a beam system having two central beams (10A, 10B) (e.g., I-beams or similar elongate members), spaced apart and supporting a surface (12, shown in Figure 6), such as grating or a similar traversable surface. The beams (10 A, 10B) and surface (12) extend between an elevating vessel (40, shown in Figure 8) at one end and an offshore structure (30), which can include a monopod, a caisson, an offshore platform, or any other type of structure. In the depicted embodiment, the offshore structure (30) is associated with a wellbore and related conduits, risers, equipment, etc.

[00039] As described above, a first and/or rear outrigger beam (14, shown in Figures 8 and 9) can extend generally perpendicular to the central beams (10 A, 10B) proximate to the vessel (40), while a second and/or front outrigger beam (20, shown in Figures 6, 9, and 10) can be positioned outward from the first outrigger beam (14) (e.g., telescopingly movable relative thereto and/or otherwise positioned to define a space between the outrigger beams (14, 20) with structural elements suitable for use as a load frame).

[00040] A tower (32), derrick, or similar elevated structure can be erected over the offshore structure (30), and the tower (32) can be stabilized by securing a series of guy wires between the tower (32) and the outrigger beams (14, 20). Specifically, first and second guy wires (34A, 34B) are shown extending between the tower (32) and respective ends of the second outrigger beam (20), while third and fourth guy wires (34C, 34D) are shown extending between the tower (32) and respective ends of the first outrigger beam (14). As described previously, in an embodiment, multiple guy wires can be used in place of the depicted guy wires to provide redundancy and/or additional stabilization. The tower (32), derrick, and/or similar structure is thereby usable to retain equipment and/or perform operations on a well associated with the offshore structure (30). In an embodiment, the offshore structure (30) could include a pre-existing tower, such that erection of a tower (32) and/or use of guy wires and outrigger beams may be omitted without departing from the scope of the present disclosure.

[00041] To facilitate performance of operations on a well associated with the offshore structure (30), the offshore structure (30) can be stabilized relative to the vessel (40) e.g., through use of a sway dampening system, as described above. As shown in Figures 8 through 10, two nylon cables and/or wires (36A, 36B) extend between the offshore structure (30) and a load spreader (38), which is hooked and/or otherwise movably attached to the vessel (40). Use of a load spreader (38) that is clipped, hooked, and/or otherwise movably attached to the vessel (40) enables a small degree of "play" and/or movement between the vessel (40) and load spreader (38) such that small vertical wave motions imparted to the vessel (40) are not transmitted to the offshore structure (30) via the cables and/or wires (36A, 36B).

[00042] Connection of the vessel (40) to the offshore structure (30) via the cables and/or wires (36A, 36B) stabilizes the movement of the vessel (40) and offshore structure (30) relative to one another, e.g., synchronizing movement therebetween, such that movement imparted to one of the vessel (40) or the offshore structure (30), e.g. via wind, waves, currents, or other forces, is transmitted to the other object, such that relative motion therebetween is minimized if not eliminated. Synchronization of motion between the vessel (40) and offshore structure (30) and/or reduction/elimination of relative movement therebetween enables operations to be performed on a well associated with the offshore (30) structure from the beam system, vessel (40) and/or tower (32), unhindered by motion of the vessel (40) and/or offshore structure (30). Use of elongate members formed from a material that is at least slightly flexible (e.g., nylon, rubber, etc.) enables the sway dampening system to withstand sudden motions without failing. To enhance the effectiveness thereof, the cables and/or wires (36A, 36B) can be pre-tensioned (e.g., provided with a force of up to 1000 pounds, or more).

[00043] While Figures 8 through 10 show two nylon cables and/or wires (36A, 36B) that are attached to the load spreader (38) and to the offshore structure (30), it should be understood that any number and configuration of attachment members can be attached to any portion of the offshore structure (30), tower (32), and/or any associated equipment, conduits, etc., and to any portion of the vessel (40) or any structure attached thereto (including the outrigger beams and/or the central beams), without departing from the scope of the present disclosure. While various embodiments usable within the scope of the present disclosure have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention can be practiced other than as specifically described herein.

Claims

CLAIMS What is claimed is:

1. A system for reducing relative motion between a vessel and an offshore structure, the system comprising: a sway dampening system comprising: at least one elongate member having a first end engaged with the offshore structure and a second end engaged with the vessel, wherein said at least one elongate member transmits forces between the vessel and the offshore structure to synchronize motion thereof, thereby reducing relative motion therebetween.

2. The system of claim 1 , wherein said at least one elongate member comprises a flexible member.

3. The system of claim 2, wherein the flexible member comprises nylon, rubber, composite, polymer, or combinations thereof

4. The system of claim 1 , further comprising a load spreader movably associated with the vessel, wherein the second end of said at least one elongate member engages the load spreader.

5. The system of claim 4, wherein the load spreader is clipped to the vessel, hooked to the vessel, or combinations thereof.

6. The system of claim 5, wherein attachment between the load spreader and the vessel permits relative movement between the load spreader and the vessel within a selected tolerance such that movement of the vessel within the selected tolerance is not transmitted to the offshore structure via said at least one elongate member.

7. The system of claim 1 , further comprising a beam system extending between the vessel and the offshore structure, wherein the beam system is adapted for supporting personnel and equipment, for performing operations of the offshore structure, a well associated therewith, or combinations thereof.

8. The system of claim 7, wherein the beam system comprises: a first elongate member having a first end engaged with the vessel and a second end engaged with the offshore structure; a first outrigger beam extending perpendicular to the first elongate member proximate to the vessel; and a second outrigger beam extending perpendicular to the first elongate member remote from the vessel.

9. The system of claim 8, further comprising an elevated structure associated with the offshore structure and at least one securing member engaged with the elevated structure and at least one of the outrigger beams.

10. The system of claim 9, wherein said at least one securing member comprises a first securing member engaged with a first end of the first outrigger beam and with the elevated structure; a second securing member engaged with a second end of the first outrigger beam and with the elevated structure; a third securing member engaged with a first end of the second outrigger beam and with the elevated structure; and a fourth securing member engaged with a second end of the second outrigger beam and with the elevated structure.

11. The system of claim 8, wherein the second outrigger beam is movable relative to the first outrigger beam.

12. The system of claim 11, further comprising at least one extendable member engaged with the second outrigger beam and usable to increase and decrease a distance between the first outrigger beam and the second outrigger beam.

13. A method for reducing relative motion between a vessel and an offshore structure, the method comprising the steps of: engaging a sway dampening system with the vessel and the offshore structure by attaching a first end at least one elongate member to the offshore structure and a second end of said at least one elongate member to the vessel, a load spreader movably associated with the vessel, or combinations thereof, wherein said at least one elongate member transmits forces between the vessel and the offshore structure to synchronize motion thereof, thereby reducing relative motion therebetween.

14. The method of claim 13, further comprising attaching the loader spreader with the vessel in a manner that permits relative movement therebetween within a selected tolerance such that movement of the vessel within the selected tolerance is not transmitted to the offshore structure via said at least one elongate member.

15. The method of claim 13, further comprising attaching a first end of a beam system to the vessel and a second end of the beam system to the offshore structure for enabling performance of operations on the offshore structure, a well associated therewith, or combinations thereof using the beam system.

16. The method of claim 15, further comprising securing an elevated structure associated with the offshore structure to the beam system using at least one securing member.

17. The method of claim 16, wherein securing the elevated structure using said at least one securing member comprises engaging a first securing member with the elevated structure and with the first end of a first outrigger beam extending from the beam system; engaging a second securing member with the elevated structure and with a second end of the first outrigger beam; engaging a third securing member with the elevated structure and with a first end of a second outrigger beam extending from the beam system; and engaging a fourth securing member with the elevated structure and with a second end of the second outrigger beam.

18. The method of claim 17, further comprising moving the second outrigger beam relative to the first outrigger beam to control a distance between the outrigger beams.

19. The method of claim 18, wherein moving the second outrigger beam comprises extending or retracting at least one extendable member engaged with the second outrigger beam.