The Application of Large Diameter Steel Catenary Riser (SCR) for Deep-Draft Semi in South China Sea

摘要

This paper focuses on the design and feasibility assessment of 18” steel catenary riser (SCR) hosted by deep draft semi-submersible platform for LS17-2 gas field development plan in water depth of 1422m. The SCR is for high pressure and temperature gas export, the material grade of X65 and thick wall of 1.25” are selected. Strength design analysis has been conducted to confirm that the gas export riser meets API RP 2RD stress criteria. The 18” SCR is suspended at the porch of pontoon with a departure angle of 15deg. A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage A Stake coverage of of of 75% suspend length75% suspend length75% suspend length75% suspend length75% suspend length 75% suspend length 75% suspend length75% suspend length75% suspend length75% suspend length75% suspend length 75% suspend length75% suspend length75% suspend length are installed for VIV suppression.are installed for VIV suppression. are installed for VIV suppression.are installed for VIV suppression. are installed for VIV suppression. are installed for VIV suppression. are installed for VIV suppression.are installed for VIV suppression.are installed for VIV suppression.are installed for VIV suppression.are installed for VIV suppression.are installed for VIV suppression. are installed for VIV suppression.are installed for VIV suppression.are installed for VIV suppression. are installed for VIV suppression. are installed for VIV suppression.are installed for VIV suppression.are installed for VIV suppression. are installed for VIV suppression. are installed for VIV suppression. are installed for VIV suppression.are installed for VIV suppression. Verification of the SCR in touch down region is also conducted by fatigue analysis (including VIV, VIM fatigue and wave induced fatigue) withwith with a commercial riser commercial riser commercial riser commercial riser commercial riser commercial riser commercial riser commercial riser commercial riser software packa software packasoftware packasoftware packa software packa software packasoftware packasoftware packasoftware packasoftware packasoftware package.The present study shows that the 18” riser can be designed with sufficient robustness and fatigue life under the design case environmental conditions. It is concluded that the LS17LS17LS17LS17-2 SCR system is feasible, which may not only benefit future study and design of subsea riser system, but also help accelerate the semi-submersible application in South China Sea.