Modular arctic structures system
First Claim
1. A floatable and reusable modular offshore oil and gas production or exploration platform system, said system being particularly adapted for arctic environments, said system comprising in combination:
- (a) a floatable base member towable to an exploration or production site, said base member including;
i. ballasting means for lowering the base member below the water plane to an offshore ocean floor;
ii. said floatable base member defining a first massive base that extends upwardly to a predetermined distance below the main water plane for supporting said offshore exploration or production platform, said first massive base providing lateral load resistance therefor by gravity engagement with the ocean floor; and
iii. an upwardly extending annular rim;
(b) a plurality of temporary buoyancy caissons which are attached to said first base member before ballasting;
(c) means for filling the annular space defined by said rim with sea water to provide an interior lake on the top surface of said base, said interior lake and said buoyancy caissons balancing said base member as it is ballasted below the water plane;
(d) an offshore exploration or production platform, said platform member towable to said exploration or production site, said platform member comprising;
i. ballasting means for lowering the platform onto said first base member;
ii. a steel gravity structure having a conical sloping surface at the mean water plane defined by the height of said first base member and said platform, said sloping surface forming an ice shield upon use in an arctic environment; and
(e) said base member and said platform including at least one vertically extending aperture for oil and gas exploration or production,whereby the platform and the first base member are separately deballastable at the end of the exploration or production service and refloatable to a new exploration or production site.
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Accused Products
Abstract
A modular and floatable offshore exploration and production platform system for use in shallow arctic waters is disclosed. A concrete base member is floated to the exploration or production site, and ballated into a predredged cavity. The cavity and base are sized to provide a stable horizontal base 30 feet below the mean water/ice plane. An exploration or production platform having a massive steel base is floated to the site and ballasted into position on the base. Together, the platform, base and ballast provide a massive gravity structure that is capable of resisting large ice and wave forces that impinge on the structure. The steel platform has a sloping hourglass profile to deflect horizontal ice loads vertically, and convert the horizontal load to a vertical tensile stress, which assists in breaking the ice as it advances toward the structure.
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Citations
18 Claims
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1. A floatable and reusable modular offshore oil and gas production or exploration platform system, said system being particularly adapted for arctic environments, said system comprising in combination:
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(a) a floatable base member towable to an exploration or production site, said base member including; i. ballasting means for lowering the base member below the water plane to an offshore ocean floor; ii. said floatable base member defining a first massive base that extends upwardly to a predetermined distance below the main water plane for supporting said offshore exploration or production platform, said first massive base providing lateral load resistance therefor by gravity engagement with the ocean floor; and iii. an upwardly extending annular rim; (b) a plurality of temporary buoyancy caissons which are attached to said first base member before ballasting; (c) means for filling the annular space defined by said rim with sea water to provide an interior lake on the top surface of said base, said interior lake and said buoyancy caissons balancing said base member as it is ballasted below the water plane; (d) an offshore exploration or production platform, said platform member towable to said exploration or production site, said platform member comprising; i. ballasting means for lowering the platform onto said first base member; ii. a steel gravity structure having a conical sloping surface at the mean water plane defined by the height of said first base member and said platform, said sloping surface forming an ice shield upon use in an arctic environment; and (e) said base member and said platform including at least one vertically extending aperture for oil and gas exploration or production, whereby the platform and the first base member are separately deballastable at the end of the exploration or production service and refloatable to a new exploration or production site. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of installing a floatable and reusable offshore oil and gas exploration or production platform, said method comprising:
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(a) dredging a cavity in the ocean floor, said cavity being dredged to a predetermined level below the mean water plane of the ocean; (b) floating a massive base member to said cavity and ballasting said base member into said cavity, said base member extending upwardly to a predetermined level below the mean water plane; (c) attaching a plurality of buoyancy caissons to the upper surface of said base member; (d) pumping sea water into an annular cavity defined by the upper surface of said base member to form an interior lake on the upper surface thereof; (e) filling a plurality of internal buoyancy chambers defined within said base member with water, sand, or a mixture thereof to ballast the base member below the water plane into said cavity; and (f) floating said oil and gas exploration or production platform over said base member, and ballasting said platform into gravity engagement with said base member, whereby the platform and the base member are separately reballastable at the end of the exploration or production service period and refloatable to a new exploration or production site. - View Dependent Claims (15, 16, 17, 18)
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Specification