Effect of Wave Kinematics on the Response of Spar Platform

The exploration of hydrocarbon reservoirs in ultra deep water requires the use of innovative floating platform configurations. The hydrodynamic interaction of such platforms with ocean waves and the understanding and quantification of the nonlinear components of theses interactions have been a subject of continuing research. This paper examines these non-linear interaction components for a typical deep-draft spar platform type that is increasingly being used in the oceans now. The motion responses of the spar platform in different environmental conditions have been determined using a time-domain simulation method. The numerical method presented here can consider several nonlinearities such as free surface force integration, displaced position force calculation and nonlinearities in the equation of motion. Wave forces are calculated using Morison’s equation. The effect of using different wave kinematics methods on the predicted surge, heave and pitch responses are presented and discussed.