Research On Transportation And Offloading Performance Of Spar Platform By Semi-Submersible Vessel

Since its inception,Spar platform has become one of the most popular deep-sea platform with its excellent performance and relatively low cost.Spar platform has a long and large structure,the weight distribution is uneven along the length,this makes it a typical difference with other platforms from its loadout to offloading.This paper discusses the transportation and offloading performance of Truss Spar platform by Semi-submersible vessels.The Spar platform and the Semi-submersible vessel models are built by the software MOSES.hydrostatic properties of Spar platform and Semi-submersible vessel are calculated.The stability,longitudinal strength and motion amplitude are discussed. Offloading of Spar platform is the main focus of this paper.Firstly,according to the characteristics of the main structure of Spar platform, floating state analysis model are built for offloading.Secondly,the spring units are built to connect the Spar platform and the Semi-submersible vessel, the floating state,connect units force and ballast in the process of offloading are calculated.Thirdly,a single model of Semi-submersible vessel is built,the stability,longitudinal strength in the process of offloading are calculated based on the results of the two-body model.Finally,two different loadout options are analyzed to find the better plan.Foreign companies have accumulated a wealth of experience about Spar platforms,domestic research are still in the initial stage in this area.In this paper,some useful results are obtained,this can provide some reference data for in-depth study.