Mooring Analysis of a Turret Moored FPSO in a Squall Environment

The transient dynamic response of a FPSO in a squall environment is dependent on several input parameters. Because the response’s dependence on these input parameters is unclear prior to performing the analysis, a large number of parameter combinations need to be considered to find the combination that gives a worst-case load or response as required by reference [1]. Because the required time-domain simulations are computationally intensive, there is often a practical need to limit the number of simulations that are performed, raising questions about how many are necessary to meet the analysis objectives. This study investigates the effect of different squall scenarios on a turret moored FPSO in the West African offshore environment. A large number of cases with selected vessel headings, squall types, squall approach directions and vessel drafts are studied and parameters affecting the critical mooring loads and turret positions are identified. Possible reductions in the load case matrix along with a sensitivity study of a few parameters affecting the results are also discussed.