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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
  • B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
  • B63B35/4413—Floating drilling platforms, e.g. carrying water-oil separating devices

Definitions

• the present invention relates generally to floating platform systems for testing and
• the invention relates to a method and system for changing the buoyancy of the
• MODU Drilling Units
• TLP Tendon Leg Platforms
• Drilling and production platforms such as TLP's, are engineered for use
• the platform are based on assumptions which may or may not prove to be accurate once the
• recoverable oil and gas from adjacent deposits may alter the payload requirements for a platform
• a platform can support without redesigning the hull would be highly desirable and significantly reduce the cost of producing offshore oil and gas deposits. Cost reductions can also be had by eliminating the need for completely redesigning the hull and node structure of the platform to accommodate different payload requirements.
• the buoyancy of a floating platform may be increased by extending the column length of the platform rather than redesigning the hull, thereby saving time and engineering costs associated with redesigning the platform hull.
• the increase in payload capacity is accommodated by attaching a column extension to the lower end hull of the platform while in the fabrication yard.
• Such an increase in payload capacity is provided by attaching a buoyancy module to the platform hull rather than redesigning the hull and node structure of the platform.
• the present invention provides a floating platform for recovery of oil and gas from offshore oil and gas fields.
• the platform supports one or more decks above the water surface to accommodate equipment for drilling and processing oil, gas and water recovered from the oil and gas field.
• the platform includes a hull having a portion located substantially below the water surface, and including a portion which extends above the water surface.
• the platform hull includes a base and is anchored to the seabed by one or more tendons secured to the base of the hull at one end thereof and to the seabed at the opposite ends of the tendons.
• the payload carrying capacity of the platform is increased without redesigning the structural design of the platform hull by attaching a column extension to the bottom of the hull
• Fig. 1 is a side view of a floating platform anchored to the seabed;
• Fig. 2 is a side view of the floating platform of the invention including a buoyancy
• Fig. 3 is a partial side view of an alternate embodiment of the platform of the invention.
• Fig. 4 is a top plan view of the platform of the invention shown in Fig. 3;
• Fig. 5 is a partial exploded view of the connector means for securing the buoyancy
• Fig. 6 is a side view of the platform of the invention illustrating riser or flow line support
• the floating platform of the invention is generally identified by the reference numeral 10.
• the platform 10 includes a central column or hull 12 which provides positive buoyancy and vertical support for the platform 10.
• One or more decks 14 are supported on the hull 12 above the water surface 16. Drilling and/or production equipment necessary for the recovery and processing of oil, gas and water recovered from the oil and gas field are secured on the deck 14.
• the hull 12 extends upward from the base or keel of the hull 12.
• the base node of the hull 12 includes pontoons 18 extending radially outward from the hull 12.
• the platform 10 is anchored to the seabed by tendons 20 secured at one end thereof to the pontoons 18 and at the opposite ends thereof to foundation piles (not shown in the drawings) embedded in the seabed.
• the hull 12 provides sufficient buoyancy to support the payload of the platform 10, which payload includes the deck 14, drilling and/or completion equipment, production facilities, production and drilling risers and sufficient excess buoyancy to develop the tendon pre-tension.
• the platform 10 is designed for the environmental and depth conditions at the offshore location of an oil and gas deposit of interest.
• the column extension 22 is a relatively short cylindrical chamber having an outside diameter approximately equal to the outside diameter of the hull 12.
• FIG. 3 an alternate embodiment of the invention depicts a buoyancy module 32 mounted to the bottom of the hull 12.
• the buoyancy module 32 is added to the offshore platform 10 while it is located in the field, to increase the payload capacity of the platform 10 so that additional equipment may be installed on the deck of the platform 10 or so that the platform 10 may be installed at a deeper water site.
• the buoyancy module 32 like the column extension 22 shown in Fig. 2, is a relatively short cylindrical chamber having a diameter approximately equal to the diameter of the hull 12.
• Mounting posts 24 secure the module 32 to the hull 12.
• the mounting posts 24 may be welded or otherwise fixed to the hull 12 and module 32.
• the mounting posts 24 may be pre-installed about the periphery of the hull 12, by welding or other connection means, so that the module 32 may be installed at a later time after the platform 10 is anchored offshore, as required, to increase the payload capacity of the platform 10.
• the buoyancy module 32 shown in Fig.3 , is likewise provided with mounting posts 26 for cooperating engagement with the posts 24 mounted on the hull 12.
• the mounting posts 24 are adapted to be received or telescoped into the posts 26.
• Various connections means such as grout, mechanical connectors or welding, may be employed to lock the post 24 and 26 together and thus secure the buoyancy module 32 to the bottom of the hull 12.
• This manner of connection has the added benefit of permitting the module 32 to be more easily detached from the hull 12 in the event the payload requirements of the platform 10 change and the buoyancy module 32 is no longer needed or to substitute a larger module in the event greater buoyancy is required.
• Two or more modules 32 may also be connected in piggy-back manner in vertical alignment with the hull 12 in the event additional buoyancy is required.
• the column extension 22 and buoyancy module 32 may be provided with the necessary plumbing, including a fill port 28 and vent 30, for connection with the ballast system of the platform 10. Additional riser hangers, such as porches 33, for hanging risers or flow lines 34 therefrom, as shown in Fig. 6, may be installed on the column extension 22 or module 32, as required.
• the shape of the column extension 22 and module 32 is depicted as a closed cylinder or plug for illustrative purposes. It is understood that the extension 22 and module 32 may comprise various shapes. If, for example, the hull 12 includes a moon pool, the extension 22 and module
• extension 22 and module 32 may be provided with an axial passage for matching alignment with the profile of the moon pool.
• the extension 22 and module 32 in such an arrangement would have a shape or profile similar to a donut.
• the extension 22 and module 32 may include radial extensions or arms matching the profile of the pontoons 18, which arms may be secured to the bottom of the pontoons 18.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Earth Drilling (AREA)
• Geophysics And Detection Of Objects (AREA)
• Other Liquid Machine Or Engine Such As Wave Power Use (AREA)

Applications Claiming Priority (3)

Publications (3)

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Citations (6)

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• 2001
  • 2001-02-22 MX MXPA02008141A patent/MXPA02008141A/es active IP Right Grant
  • 2001-02-22 EP EP01914513A patent/EP1259421B1/de not_active Expired - Lifetime
  • 2001-02-22 CA CA002400903A patent/CA2400903C/en not_active Expired - Fee Related
  • 2001-02-22 ES ES01914513T patent/ES2264439T3/es not_active Expired - Lifetime
  • 2001-02-22 BR BRPI0108589-1A patent/BR0108589B1/pt not_active IP Right Cessation
  • 2001-02-22 WO PCT/US2001/006160 patent/WO2001062583A2/en active IP Right Grant
  • 2001-02-22 AU AU3989101A patent/AU3989101A/xx active Pending
  • 2001-02-22 AU AU2001239891A patent/AU2001239891B2/en not_active Ceased
• 2002
  • 2002-08-21 NO NO20023980A patent/NO332002B1/no not_active IP Right Cessation

Patent Citations (6)

Non-Patent Citations (1)

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