Hydrodynamics of Dry Tree Semisubmersibles

This paper presents a hydrodynamics analysis of a conceptual dry tree semisubmersible for drilling and production platforms. Computational analysis shows that the hull form of the dry tree semisubmersible can be optimized to control the cancellation period, magnitude of the heave RAO below the cancellation period and the heave natural period. The relative areas of the column and pontoon are varied to demonstrate the global effects on the hydrodynamic forces acting in these structural components while the area of the heave plate is kept constant. Results show that by keeping the displaced volume of the hull constant the relative areas of the column and pontoon can be varied to affect the magnitude of the hydrodynamic forces on the columns and pontoon and thus the shape of the heave RAO.