Dry Tree Semisubmersible Production Platform Hydrodynamic Performance Research

China has independently designed and built the world's most advanced deepwater semi-submersible drilling platform,followed by a deepwater floating production platform for research.TLP and Spar platform has been developed in the areas of production for many years and has matured yet still flawed.In order to overcome the limitations of TLP and Spar in the deepwater oil and gas production,this paper according to the relevant research,and as the prototype of a deep draft semi-submersible platform,and perfected a new semi production platform with dry-tree,to combine the advantages of the three types platforms will provide better services for the South China Sea oil and gas production operations.This paper applied the three-dimensional radiation and diffraction theory,using frequency-domain Green's function method which solved the equations of floater motion to obtain the hydrodynamic parameters,and the time domain coupled analysis of mooring system was calculated.This paper use SESAM software to calculate six DOFs` performance of the dry semi-submersible platform.The particular type of heave plate was disposed at a different water depths from the bottom of the platform,then calculated and analyzed by comparing their heave natural period,the heave RAOs of wave frequency region and natural period,and ultimately determine the heave plate in the bottom of the 40 m platform at the dry-tree semi-submersible production platform for the best patterns.Dry-tree platforms because the use of TTRs,the relative motion between the platform and risers is must less than 9.144 m in extreme environments of the hundred years storm,the maximum horizontal offset shoud be less than 10% of water depth.By adding heave plate,it increase the heave natural period,make the plateform avoid the common range of wave energy period.Wave frequency region and the natural period of heave extremes are more desirable.Mooring coupled calculation in time domain display the platform motion have good performance both in full mooring state and broken of extreme environment,can support dry-tree system sufficiently.