Heave motion analysis of a new-style floater based on semi-physical simulation

In order to evaluate the heave motion performance of a dry wellhead deck in the conceptual design of a new-style floating drilling production storage and offloading system(FDPSO),we established a theoretical model for the analysis of a complex tension system and constructed a large-scale experimental platform with a semi-physical simulation technique,which simulated the hull's heave motion on a motion platform controlled by an electro-hydraulic servosystem and applied a large-scale physical model to the dry wellhead system.The comparison between experimental and numerical results of the theoretical model under simple harmonic excitation proved the rationality of the model because they were in accordance with engineering reality.Results of the numerical analysis performed on the oceanic condition of the South China Sea with the theoretical model indicate that the conceptual design that tension is supplied to the riser system of a dry wellhead deck through the balance weight suspended on the outside of a hull is of automatic compensation to the hull's heave motion,which can reduce the heave motion amplitude of a dry wellhead deck.