The Study on Control Methods to Semi-submersible Vessel Loading 300,000-ton FPSO

FPSO (Floating production storage and offloading) needs to move between oil fields. If the distance is short, tugs usually will be used to move FPSO. But when the distance is far, the way of the tug is expensive and has a high transport risk. So using Semi-submersible vessel to transport FPSO is a better approach. There is a tricky problem to accurately and safely loading FPSO to Semi-submersible vessel, especially in large FPSO(300,000-ton). 300,000-ton FPSO need be transported by the largest Semi-submersible vessel in the world in long distance movement. In this Paper, we studied the P67 transport case to propose and analyze the control methods in the process of loading. During the study, we analyzed environmental factors and give the suggested value. Based on the force calculated by simulating ship motion and safety evaluation got, we designed a scientific load plan to load FPSO. Through this study, a valid control solution was proposed which guide the Semi-submersible vessel to load FPSO successfully.