Motion Response Analysis Of Trussspar In The Process Of Wet-towing And Options For Wet-towing Plan

With the increasing development of petroleum resources in deep-sea, it is necessary to develop the platform structures which adapt to the deep-sea operation as soon as possible. As the special marine structure for exploration, production, process and accumulation of deep-sea petroleum resources, Spar platform is more and more commonly used by many big oil companies at home and abroad. And, in the whole process of the installation of Spar platform, wet towing is very important section. In addition, wet towing is indispensable to some spar platforms which are able to be used repeatedly.Aim on the above-mentioned problems, the paper establishes the mechanical model of marine structure by employing the three-dimensional flow theory. And then, resistance, floating condition, stability, longitudinal strength and motion amplitude in the process of wet towing of spar platform were calculated and analyzed. In the process of calculating resistance, first of all, outer load was determined according to the practical engineering. Then, reasonable resistance of towing was obtained by comparing the results which was got by adopting the estimation formulation of resistance of CCS. In order to confirm the floating condition, the paper established the models of ballast tanks by using the MOSES procedure, and then according to relevant criterion and combining the practical engineering in different situations, a most practicable ballast project was acquired. Furthermore, based on the determined floating condition above, the stability checking and curve of static stability were described. Finally, the longitudinal strength and amplitude of motion were calculated. For the calculations above, a reasonable scheme of towing was defined finally.This study on the process of wet towing of spar platform can direct the theoretical and practical projects which is valuable in engineering.