Drilling, production and oil storage caisson for deep water
In a deep water offshore apparatus for use in drilling, production and oil storage, this patent describes the combination of: an elongated caisson having an upper end portion above the water surface and a lower end portion extending to a water depth subject to only minimal excitation forces caused by wave action, the caisson having an outer surface of uniform configuration for the entire length of the caisson and providing uniform water plane area, the length of the caisson below the water plane area providing a caisson natural period in excess of a selected maximum expected wave period; the caisson including a central well open at the bottom of the casing; means in the caisoon for providing liquid storage compartments; production risers arranged in the central well; a buoyant means for each riser in the upper portion of the central well for supporting and tensioning each riser; mooring means attached to the lower portion of the caisson for anchoring the caisson to a sea bed; and ballast means at the lower end portion of the caisson for maintaining the center of gravity of the caisson below the center of buoyancy thereof.
- Assignee:
- NOV; NOV-88-088551; EDB-88-015117
- Patent Number(s):
- US 4702321
- OSTI ID:
- 5904940
- Resource Relation:
- Patent File Date: Filed date 20 Sep 1985
- Country of Publication:
- United States
- Language:
- English
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