Structure for offshore exploitation
A structure is disclosed for use in exploiting arctic offshore areas where floating ice masses may be present. The structure is comprised of a floating hull having ice-breaking capabilities which is moored by a plurality of mooring means which extend vertically from a moonpool in the hull to the marine bottom directly under the hull. The mooring means comprises flexible lines, e.g. nylon, steel, or the like or rigid conduits, e.g. drill pipe. Means are provided within the moonpool for tensioning the mooring means to thereby draw the hull downward to a position below its normal buoyant position thereby substantially eliminating vertical heaving of the hull. When an ice mass contacts the hull, tension on the mooring means is relaxed to thereby allow the hull to rock upward against the ice thereby generating the forces necessary for the ice-breaking operation. Due to the present mooring means, the hull moves only a relatively short lateral distance in breaking an approaching ice mass. This is important in floating drilling operations. Further, if repair or replacement of a mooring means is required, this can be accomplished even when ice surrounds the hull since the mooring means are anchored directly below the hull and are easily accessible through the moonpool.
- Assignee:
- Mobil Oil Corp.
- Patent Number(s):
- US 4433941
- OSTI ID:
- 6768448
- Resource Relation:
- Patent File Date: Filed date 20 Dec 1982; Other Information: PAT-APPL-451372
- Country of Publication:
- United States
- Language:
- English
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