Self-elevating offshore structure
First Claim
1. An offshore structure suitable for production operations at sea, comprising at least one non-buoyant deck supportable on a transport vessel during transit to a deployment location at sea, a plurality of brace assemblies supporting said deck at an operational level at sea without a buoyant hull, and a plurality of legs supporting said deck and said brace assemblies above sea wave action, each of said plurality of legs being adapted for embedding into a sea bottom while said deck is supported by the transport vessel and being adapted to receiving sufficient loading on leg footings from said transport vessel during embedding into the sea bottom to simulate operating and environmental loads.
3 Assignments
0 Petitions
Accused Products
Abstract
A self-elevating offshore structure supports a deck for production operations at sea in the absence of an elevating hull. A non-buoyant deck is supported by braces and truss legs above wave action. The legs move in relation to the legs and the braces, elevating the deck and the braces supporting the deck. The offshore structure is transported to a deployment site by a buoyant vessel and then released from the vessel once the legs are embedded into the sea bottom.
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Citations
25 Claims
- 1. An offshore structure suitable for production operations at sea, comprising at least one non-buoyant deck supportable on a transport vessel during transit to a deployment location at sea, a plurality of brace assemblies supporting said deck at an operational level at sea without a buoyant hull, and a plurality of legs supporting said deck and said brace assemblies above sea wave action, each of said plurality of legs being adapted for embedding into a sea bottom while said deck is supported by the transport vessel and being adapted to receiving sufficient loading on leg footings from said transport vessel during embedding into the sea bottom to simulate operating and environmental loads.
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11. An offshore structure suitable for production operations at sea, comprising:
- at least one non-buoyant deck for supporting production equipment;
a plurality of brace assemblies supporting said deck at an operational level at sea without a buoyant hull;
a plurality of truss legs supporting said deck and said brace assemblies above sea wave action; and
a means for moving said legs in relation to said deck and said brace assemblies between a position above water surface and a position with footings of the legs embedded into the sea bottom, said truss legs being adapted to receive loadings from said transport vessel during embedment of said footings of the legs in the sea bottom, wherein said loadings received by said legs simulate operational and environmental loads encountered by said offshore structure during offshore operations. - View Dependent Claims (12, 13, 14, 15, 16)
- at least one non-buoyant deck for supporting production equipment;
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17. An offshore structure, comprising:
- at least one non-buoyant deck;
a plurality of brace assemblies supporting said deck at an operational level at sea;
a plurality of truss legs supporting said deck and said brace assemblies above sea wave action;
said offshore structure being adapted for transporting to a deployment site by an independent relesable transport means and is adapted for supporting operations at sea in the absence of a buoyant hull, each of said plurality of legs being adapted for embedding into a sea bottom while said deck is supported by the transport means and being adapted to receiving sufficient loading on leg footings from said transport means during embedding into the sea bottom to simulate operating and environmental loads, said structure further comprising a tension means for temporarily engaging the transport vessel while the transport vessel is being lowered into water without disturbing embedment of the legs into the sea bottom. - View Dependent Claims (18, 19, 20)
- at least one non-buoyant deck;
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21. A method of deploying an offshore structure in a pre-determined location at sea, comprising the following steps:
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providing an offshore structure having at least one non-buoyant deck, a plurality of brace assemblies for supporting said deck and a plurality of truss legs supporting said deck and said brace assemblies, and a means for moving said legs in relation to said deck and said brace assemblies; providing a buoyant transport vessel and positioning said offshore structure on said transport vessel, with the legs of the offshore structure extending above the transport vessel;
providing a securing means for temporarily securing said offshore structure on the transport means;providing a flexible tension means for temporarily operationally connecting said offshore structure to said transport vessel; delivering said offshore structure to the pre-determined location at sea;
ballasting said transport vessel and lowering said legs, while activating said means for moving the legs;transferring loads from the ballasted transport vessel to footings of the legs to simulate operational and environmental loads, while embedding the legs into a sea bottom; elevating the deck, the brace assemblies and the transport vessel to a pre-determined elevation above the water surface, while retaining connection of the transport vessel to the deck through the tension means; and lowering the transport vessel into the water, without disturbing embedment of the legs. - View Dependent Claims (22, 23, 24, 25)
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Specification