INTEGRATED RISER & MOORING DESIGN FOR FLOATING PRODUCTION SYSTEMS

The design of floating production systems for deep water and hostile environmental conditions requires that the dynamics of riser and mooring line motions and loads be considered together to achieve optimum design for both the risers and the mooring systems. This paper presents a methodology for such design. The American Petroleum Institute RP2FP1 code of practice for the design of mooring systems for floating production systems considers normal maximum allowable offsets for deep water (2000ft - 3000ft) flexible risers to normally range from 10% to 15% of water depth and mooring systems are typically designed with such offsets prescribed. The approach considered in the paper is than an optimum allowable offset of the mooring system is reached if the mooring system is designed to take full advantage of the cost benefits associated with allowable riser top offsets. A resulting synergy is achieved in the combined riser and mooring system design which leads to cost savings for the operator over conventional separately optimised riser and mooring solutions. The method considers both the hydrodynamic force arising from fluid action on risers (and mooring lines) and the effective restraint offered by risers as an aid to the station-keeping capability of the mooring system. Finally, the effect on mooring line design of individual line dynamics under varying load and motion are considered using three-dimensional non-linear domain analysis of the most loaded line.

• Supplemental Notes:
  • FPSO World Congress and Technology Exhibition '95; 11-13 Oct 1995; Aberdeen, UK. Pprs. Publ by OCS Technology Group, UK; ISBN 0906-314-55-24 [15 p, 23 fig]
• Authors:
  • O'Brien, P
• Publication Date: 1995

Language

• English

Subject/Index Terms

• TRT Terms: Floating structures; Integrated systems; Mooring; Moorings; Offshore platforms
• Old TRIS Terms: Risers
• Subject Areas: Bridges and other structures; Marine Transportation;

Filing Info

• Accession Number: 00727929
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Nov 4 1996 12:00AM