Understanding Fluid-Structure Interaction for high amplitude wave loadings on a deep-draft paired column semi-submersible platform:a finite element approach

This paper presents a detailed study of high amplitude wave loadings on the hull of a paired column semisubmersible platform, for material selection during scantling. The recent development of deep draft paired column semisubmersible platform for dry trees application in the Gulf of Mexico has opened a new phase in the functionalities of semisubmersible platforms in the oil & gas industry. Its innovation nevertheless is not without the high cost of steel for hull columns and reinforcement during construction. A technique for hull weight reduction has been postulated with the possible application of composite girders and stiffeners on regions with less stress profile during high amplitude ocean loading for hull reinforcement. The column deformations and stress profile from fluid structural interactions have been studied, and a precise understanding of the material and structural deformation of the hull component has been recorded using FEA. Results have suggested that the drag effect of flow circulation within the hull formation is more dominant on the inner columns, and minimum steel reinforcement might be required on the sensitive areas around the inner columns. As expected, the un-submerged surface area received no significant stress variation irrespective of the wave amplitude profile and the bulking tendencies of the inner part of the outer column is also reduced