LOW MOTION SEMISUBMERSIBLE FLOATING PRODUCTION SYSTEM

摘要

A system includes a semisubmersible (20) with an optimized low motions hull form (82), a plurality of steel catenary risers (30) connected to and extending from the semisubmersible, and a semi-taut mooring system (40) attached to the semisubmersible and extending to the ocean floor (34). The system maintains a motions envelope capable of preventing the steel catenary risers from failing either from fatigue or structural failure. The system is optimized by obtaining the meteorological ocean data at the location of the subsea oil and gas field, determining the number and sizes of steel catenary risers, determining the motions envelope required to prevent failure of the steel catenary risers, and optimizing the combination of the semisubmersible hull form, semi-taut mooring system, and steel catenary risers to maintain the motions of the semisubmersible within the motions envelope required of the steel catenary risers. The low motions semisubmersible incorporates center columns (86a-b) larger that the corner columns (84a-d), and bouyancy elements or pontoons which are wider at the center than the ends.