Reliability analysis of a deep water flexible riser system

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:264162

Karunakaran, D; Leira, B J ^[1]; Olufsen, A; Nordsve, N T ^[2]

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1. SINTEF, Trondheim (Norway)
2. Statoil, Trondheim (Norway)

Oil companies all over the world are increasingly looking towards developing deep water oil and gas fields. Floating systems offer an efficient alternative for deep water production. Flexible risers are an important part of the floating production systems. Presently, flexible risers are designed by allowing a utilization factor, which is based on experience from laboratory tests, theoretical pipe mechanics and engineering know-how, not based on reliability or risk assessment. Hence, it is very important to assess the safety level in current design practice and to aim at a rational and safe design procedure. In this paper, a reliability analysis procedure for flexible riser systems based on response surface and FORM/SORM methods is outlined and it is applied to a deep water riser system for ULS condition. A failure criterion at the top end only is considered; this location being critical for this riser in ULS. The results indicate a sufficient safety level in the design for the top end of the riser. However, it is emphasized that this is not a conclusive result with respect to riser safety. A more comprehensive study is required to assess the overall safety level for flexible riser systems. Such a study should include a number of different riser configurations and limit states, especially FLS criteria, to arrive at more general conclusions.

• OSTI ID: 264162
• Report Number(s): CONF-950604--; ISBN 1-880653-20-6
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
42 ENGINEERING
DESIGN
FAILURE MODE ANALYSIS
MARINE RISERS
NATURAL GAS INDUSTRY
OFFSHORE PLATFORMS
OIL WELLS
PETROLEUM INDUSTRY
SAFETY ANALYSIS
SAFETY ENGINEERING