H-SHAPED PONTOON DEEPWATER FLOATING PRODUCTION SEMISUBMERSIBLE

摘要

This paper presents a new deepwater floating production semisubmersible concept, namely H-Pontoon Semi. The H-pontoon semi consists of an H-shaped pontoon structure which has a pair of parallel longer main pontoons and a pair of shorter secondary central pontoons disposed inwardly from the outer ends of the main pontoons and supported by the two main pontoons. The H-pontoon includes four columns placed at or inboard of the edge of main pontoons. The H-shaped pontoon structure improves the hydrodynamic performance of the platform as compared to conventional ring pontoon structures. The asymmetric pontoon spacing in the horizontal plan provides a reduced horizontal and angular motion in one direction over the other. Additionally, the inward position of the secondary central pontoons facilitates the support of SCR and allows a reduced vertical motion at the SCR fairlead locations. This reduced vertical and horizontal motion at the SCR fairlead help the SCR fatigue and strength design and consequently reduce the SCR associated cost. Numerical results for the global performance of the H-Pontoon platform are presented to illustrate the advantages of the newly developed H-Pontoon Semi concept over the conventional semisubmersible.