The Hydrodynamic Performance Of The Deepwater Octagonal Floating,Drilling,Production,Storage And Offloading Platform(FDPSO)

The deepwater octagonal floating,drilling,production,storage and offloading platform is a new multifunctional equipment for deepwater oilfield development.It was proposed by China National Offshore Oil Corporation and was expected to be located in the site with water depth of 2000 m.In this paper,the influence of various heave plate configurations on the hydrodynamic performance of the deepwater octagonal FDPSO has been examined.In addition,the hydrodynamics of multi-bodies with various connection systems in tandem offloading operation has also been studied.Numerical simulation and model test methods were adopted to carry out the analysis.The breadth and the draft depth of a single layer heave plate,as well as the spacing of two-layer heave plates are considered as the main variable to study the effect of heave plates on FDPSO hydrodynamics.And the difference of the hydrodynamics of multi-bodies with various connection systems,including the various arrangement of hawser lines,various distance between two bodies and various stiffness of hawser lines,have been investigated respectively.The analysis results indicate that the breadth of the heave plates makes a significant impact on the heave hydrodynamics.With the increasing of breadth,heave performance could be improved greatly.While the draft depth of the single layer heave plate has little effect on changing of the heave motion suppression for the range of depth tested.In the terms of the influence of heave plates spacing,the target FDPSO obtains better heave characteristics as the growth of spacing between two heave plates.And the advantage of two-layer heave plates is no longer prominent when the relative spacing is very small.Furthermore,the multi-bodies get better hydrodynamics with double hawser lines.And either the distance between two bodies decreasing or the stiffness of hawser lines increasing could lead to greatly improvement of the global performance of multi-bodies.At last,outcomes of the studies are expected to give useful advices on the design and construction of FDPSO system in the future.