Most of the present-day mobile drilling rigs maintain position while drilling by means of anchoring or mooring systems using from eight to twelve lines of chain, wire rope, or a combination of both. The system must provide enough restoring force to deep the rig in position, even in the most adverse conditions, with a circle centered over the wellhead with a radius of 5 or 6% of the water depth. The theory of such mooring systems is briefly explained, wire-rope and chain systems are compared, and the 8-line moorings used for four semi-submersible drill rigs operating at a depth of 600 ft are compared in respect of their chain lengths and diameters.

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  • Corporate Authors:

    Compass Publications Incorporated

    1117 North 19th Street, Suite 1000
    Arlington, VA  United States  22209
  • Authors:
    • Holder, F W
  • Publication Date: 1977-4

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00173666
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Apr 26 1978 12:00AM