Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
  • B63B21/50—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers
  • B63B21/502—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers by means of tension legs
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02B—HYDRAULIC ENGINEERING
  • E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
  • E02B17/0017—Means for protecting offshore constructions
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
  • F15D1/00—Influencing flow of fluids
  • F15D1/10—Influencing flow of fluids around bodies of solid material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B21/00—Tying-up; Shifting, towing, or pushing equipment; Anchoring
  • B63B21/50—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers
  • B63B21/502—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers by means of tension legs
  • B63B2021/504—Anchoring arrangements or methods for special vessels, e.g. for floating drilling platforms or dredgers by means of tension legs comprising suppressors for vortex induced vibrations

Definitions

• This invention is related to vortex induced vibration suppression systems that can be attached to flexible structures to reduce drag and/or vortex induced vibration (VIV).
• VIV vortex induced vibration
• VIV vortex- induced vibrations
• Drilling for and/or producing hydrocarbons or the like from subterranean deposits which exist under a body of water exposes underwater drilling and production equipment to water currents and the possibility of VIV.
• Equipment exposed to VIV may include structures ranging from the smaller tubes of a riser system, anchoring tendons, hoses, umbilicals, and other flexible members.
• Umbilicals as used herein are defined to be a non-exclusive example of a marine element subject to VIV.
• an umbilical system is used for establishing communication between the surface and the bottom of a water body.
• the principal purpose of the umbilical is to provide a fluid, electrical, and/or optical flow path between a surface vessel and a subsurface structure.
• the first kind of stress as mentioned above is caused by vortex-induced alternating forces that vibrate the underwater structure in a direction perpendicular to the direction of the current. These are referred to as vortex-induced vibrations (VIV).
• VIV vortex-induced vibrations
• the second type of stress is caused by drag forces which push the structure in the direction of the current due to the structure's resistance to fluid flow.
• the drag forces may be amplified by vortex induced vibrations of the structure. For instance, an umbilical that is vibrating due to vortex shedding will disrupt the flow of water around it more so than a stationary umbilical. This results in greater energy transfer from the current to the umbilical, and hence more drag.
• U.S. Patent 5,984,584 discloses a fairing system for protecting multiple, parallel, bundled but separate cylindrical elements deployed in offshore applications.
• the fairing system deploys a plurality of elongated fairing surface elements foldable about an axis with a connection system joining the elongated edges of the fairing surface elements in a folded manner about the axis.
• a plurality of thrust bearings are orthogonally connected across the fairing surface elements at each axial end and an axially extending circular rotational surface is defined by the interior of each of the folded fairing surface elements and a transverse edge of the thrust bearings connected thereto. This rotational surface has a diameter which circumscribes the multiple bundled cylindrical elements.
• a plurality of clamps interconnect the bundled, cylindrical elements and a bearing collar on the axial ends of the clamps is provided to receive the thrust bearings of the axial ends of the fairing elements.
• U.S. Patent 5,984,584 is herein incorporated by reference in its entirety.
• U.S. Patent 7,070,361 discloses an apparatus for suppressing vortex induced vibrations on a marine element of a riser system wherein the riser system comprises at least one umbilical element.
• Systems comprising and methods of using said apparatus to suppress vortex induced vibrations.
• the apparatus, systems, and methods comprise module elements which provide: i) a surface around a marine element for installing VIV suppression devices; and ii) passages for housing the at least one umbilical element.
• U.S. Patent 7,070,361 is herein incorporated by reference in its entirety.
• surface structure 102 is in body of water 100.
• Surface structure 102 is connected to subsurface structure 103 at seabed 108 by connector member 104, such as an umbilical, cable, or tendon.
• Current 1 10 encounters connector member 104.
• fairings 114 have been installed.
• One or more collars may be installed between adjacent fairings.
• VIV suppression devices When VIV suppression devices are installed on umbilicals or other flexible structures, there is a danger that the structure will be damaged during the installation procedure. Each VIV suppression device installation around a structure may damage the structure, for example, if the ROV or other installation tool cuts or crimps the structure, runs into or dislodges the structure, and other damage as can be imagined by a person of skill in the art.
• the invention provides a system comprising a subsea structure defining an interior of the system, the structure subject to a water current; a sleeve exterior to the subsea structure, covering at least a portion of an outside surface of the subsea structure; and a vortex induced vibration suppression device exterior to the sleeve.
• the invention provides a method comprising installing a subsea structure in a body of water, wherein the subsea structure is subject to one or more water currents; installing at least one sleeve exterior to the subsea structure, covering at least a portion of an outside surface of the subsea structure; and installing at least one vortex induced vibration suppression device exterior to the sleeve.
• Advantages of the invention may include one or more of the following: improved apparatus and methods for suppressing VIV; apparatus and methods for suppressing VIV that do not suffer from the disadvantages of the prior art; apparatus and methods for providing VIV suppression to an umbilical or other flexible elements and for providing protection to the flexible elements; systems and methods of installing VIV suppression devices to flexible elements without damaging the flexible elements; and/or systems and methods of installing VIV suppression devices to subsea structures without damaging the structure.
• Figure 1 illustrates an oil and/or gas production system.
• Figure 2a illustrates an oil and/or gas production system.
• Figure 2b illustrates an oil and/or gas production system.
• Figure 3a illustrates an oil and/or gas production system.
• Figure 3b illustrates a cross-sectional view of the oil and/or gas production system of Figure 3a.
• Figure 4 illustrates an oil and/or gas production system.
• Figure 5a illustrates an oil and/or gas production system.
• Figure 5b illustrates an oil and/or gas production system.
• System 200 includes surface structure 202 near the surface of the water, which is attached to connector member 204.
• Connector member 204 is also connected to subsurface structure 203 near seafloor 208. Exterior to connector member 204 near seafloor 208, collar 220 has been installed. Exterior to connector member 204, sleeves 222 have been installed, which rest on collar 220.
• fairings 214 have been installed exterior to sleeves 222.
• Sleeves 222 allow fairings 214 to be installed with less risk of damaging connector member 204.
• Fairings 214 act to reduce drag and/or vortex induced vibration acting on connector member 204 due to current 210.
• Fairings 214 and/or sleeves 222 may be heavier than water so that they sink to rest on collar 220.
• System 300 includes surface structure 302 near the surface of the water, which is attached to connector member 304.
• Connector member 304 is also connected to subsurface structure 303 near seafloor 308. Exterior to connector member 304 near surface structure 302, collar 320 has been installed. Exterior to connector member 304, sleeves 322 have been installed, which rest on collar 320. Fairings 314 have been installed exterior to sleeves 322. Sleeves 322 allow fairings 314 to be installed with less risk of damaging connector member 304. Fairings 314 act to reduce drag and/or vortex induced vibration acting on connector member 304 due to current 310. Fairings 314 and/or sleeves 322 may be lighter than water so that they float to rest on collar 320.
• Connector member 304 defines an interior of the system.
• Sleeve 322 has been installed exterior to connector member 304.
• Fairing 314 has been installed exterior to sleeve 322.
• Space 330 is defined between the exterior of sleeve 322 and the interior of fairing 314, which allows fairing 314 to weathervane with varying current directions.
• System 400 includes surface structure 402 near the surface of the water, which is attached to connector member 404.
• Connector member 404 is also connected to subsurface structure 403 near seafloor 408. Exterior to connector member 404 near subsurface structure 403, collar 420 has been installed. Exterior to connector member 404, sleeves 422 and sleeves 424 have been installed, which rest on collar 420.
• Fairings 414 have been installed exterior to sleeves 422 and sleeves 424.
• Sleeves 424 may be installed between every about 1 to about 10 sleeves 422.
• Sleeves 424 have flange 426.
• Flange 426 has a larger diameter than an interior diameter of fairing 414, which acts to provide a bearing surface that the fairing 414 above and/or the fairing below can rotate on.
• Flange 426 may be copper to retard marine growth.
• Sleeves 422 and sleeves 424 allow fairings 414 to be installed with less risk of damaging connector member 404.
• Fairings 414 act to reduce drag and/or vortex induced vibration acting on connector member 404 due to current 410.
• Fairings 414, sleeves 424, and/or sleeves 422 may be lighter than water so that they float to rest on collar 420.
• System 500 includes surface structure 502 near the surface of the water, which is attached to connector member 504.
• Connector member 504 is also connected to subsurface structure 503 near seafloor 508.
• collar 520 has been installed.
• sleeve 522 has been installed, near subsurface structure 503.
• Fairings 514 have been installed exterior to sleeve 522 with tool 530 having attachment mechanism 532, for example arms, to grip fairings 514.
• Sleeve 522 allows fairings 514 to be installed with less risk of damaging connector member 504.
• Fairings 514 act to reduce drag and/or vortex induced vibration acting on connector member 504 due to current 510.
• Fairings 514 may be lighter than water so that they float to rest on collar 520.
• System 500 includes surface structure 502 near the surface of the water, which is attached to connector member 504.
• Connector member 504 is also connected to subsurface structure 503 near seafloor 508.
• Exterior to connector member 504 near subsurface structure 503, collar 520 has been installed.
• Exterior to connector member 504, sleeve 522 has been installed, near surface structure 502.
• Fairings 514 have been installed exterior to sleeve 522 with tool 530 having attachment mechanism 532, for example arms, to grip fairings 514.
• Sleeve 522 allows fairings 514 to be installed with less risk of damaging connector member 504. Fairings 514 act to reduce drag and/or vortex induced vibration acting on connector member 504 due to current 510.
• Fairings 514 may be heavier than water so that they float to rest on collar 520. Fairings may be replaced with strakes, shrouds, wake splitters, tail fairings, buoyancy modules, or other devices as are known in the art. Suitable sleeves, suitable collars, and suitable devices to install exterior to sleeves, and methods of their installation are disclosed in U.S. Patent Application Number 10/839,781 , having attorney docket number TH 1433; U.S. Patent Application Number 1 1/400,365, having attorney docket number TH0541 ; U.S. Patent Application Number 1 1/419,964, having attorney docket number TH2508; U.S. Patent Application Number 1 1/420,838, having attorney docket number TH2876; U.S.
• the collars and/or sleeves may be installed on the connector member before or after the connector member is placed in a body of water.
• the sleeves may be made of a high strength material having a Young's Modulus (or modulus of elasticity) of at least about 2 GPa, for example at least about 5 GPa, for example at least about 10 GPa, for example at least about 25 GPa, for example at least about 50 GPa, for example at least about 75 GPa, for example at least about 100 GPa, for example at least about 200 GPa.
• the sleeves may be round, or have some ovality or a fairing shape.
• the sleeves, collars, fairings and/or other devices exterior to the sleeves may have a clamshell configuration, and may be hinged with a closing mechanism opposite the hinge, for example a mechanism that can be operated with an ROV.
• Collars may be placed between adjacent fairings, or between every 2 to 10 fairings.
• the collar may be a copper ring.
• Fairings may be provided with copper plates on their ends to allow them to weathervane with adjacent fairings or collars.
• Fairings may be partially manufactured from copper.
• a biodegradable spacer may be placed between adjacent fairings to keep them from binding and allow them to weathervane after the spacer has degraded.
• the connector member 404 may be made of a low strength material and/or have a low strength material as a covering, for example having a Young's Modulus (or modulus of elasticity) of less than about 2 GPa, for example less than about 1 GPa, for example less than about 0.5 GPa, for example less than about 0.25 GPa, for example less than about 0.1 GPa.
• a Young's Modulus or modulus of elasticity
• a system comprising a subsea structure defining an interior of the system, the structure subject to a water current; a sleeve exterior to the subsea structure, covering at least a portion of an outside surface of the subsea structure; and a vortex induced vibration suppression device exterior to the sleeve.
• the subsea structure is selected from an umbilical, a riser, and a tendon.
• the sleeve comprises an exterior surface having a Young's modulus of at least 2 GPa.
• the vortex induced vibration suppression device comprises a fairing or a helical strake.
• the subsea structure comprises an exterior surface having a Young's modulus less than 2 GPa.
• the sleeve is buoyant in water, the system further comprising a collar connected to the subsea structure above the sleeve, the collar adapted to retain the sleeve in an axial location along the subsea structure.
• the sleeve is negatively buoyant in water, the system further comprising a collar connected to the subsea structure below the sleeve, the collar adapted to retain the sleeve in an axial location along the subsea structure.
• the sleeve comprises one or more ledges extending exterior to the sleeve, for example circumferential ledges.
• the vortex induced vibration suppression device comprises one or more shoulders adapted to interface with the one or more ledges.
• the system also includes a plurality of sleeves.
• the system also includes a plurality of vortex induced vibration suppression devices exterior to the plurality of sleeves.
• the system also includes a collar between two adjacent vortex induced vibration suppression devices.
• a method comprising installing a subsea structure in a body of water, wherein the subsea structure is subject to one or more water currents; installing at least one sleeve exterior to the subsea structure, covering at least a portion of an outside surface of the subsea structure; and installing at least one vortex induced vibration suppression device exterior to the sleeve.
• the method also includes installing at least one collar exterior to the subsea structure, the collar adapted to retain the sleeve in an axial location along the subsea structure.
• the sleeve comprises an exterior surface having a Young's modulus of at least 2 GPa.
• the subsea structure comprises an exterior surface having a Young's modulus less than 2 GPa.
• the sleeves are installed on the subsea structure before the subsea structure is installed in the body of water.
• the vortex induced vibration suppression device are installed on the subsea structure after the subsea structure is installed in the body of water.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Combustion & Propulsion (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Chemical & Material Sciences (AREA)
• Civil Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Earth Drilling (AREA)
• Transducers For Ultrasonic Waves (AREA)
• Structure And Mechanism Of Cameras (AREA)

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• 2008
  • 2008-02-13 AU AU2008216318A patent/AU2008216318A1/en not_active Abandoned
  • 2008-02-13 GB GB0911626A patent/GB2459583A/en not_active Withdrawn
  • 2008-02-13 US US12/527,058 patent/US20100150662A1/en not_active Abandoned
  • 2008-02-13 WO PCT/US2008/053784 patent/WO2008100976A1/en active Application Filing
  • 2008-02-13 BR BRPI0807475-5A2A patent/BRPI0807475A2/pt not_active IP Right Cessation
• 2009
  • 2009-09-11 NO NO20092995A patent/NO20092995L/no not_active Application Discontinuation

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