The effects of wave parameters on motion performance of semi-submersible platforms

Abstract

Zhang et al. (2008), Agarwal & Jain (2003), presented the importance of hull/mooring coupling analysis and the rate of damping of mooring lines. According to them, for analyzing a semisubmersible platform, it is practical to consider them as a rigid body. It is worth noting that in rigid body dynamics, body motion is mostly controlled by forces and moments applied by the wave and also body inertia mechanism. Matos et al. (2011)1 INTRODUCTIONOffshore oil and gas industry has been developed extensively in the last 50 years, so this progress is referred as the renaissance of this industry. Nowadays, deep offshore technology has become an important part of this industry. Semi-floating platforms such as TLP, Spar and Semi-Submersible platforms are mostly used in deep waters in order to extract offshore hydrocarbon resources. The semi-submersible platforms are less affected by wave loadings than a normal ship, because of its hull submerged at a deep draft. Submersibles are composed of various members such as: pantones, columns, truss members and mooring lines. The mooring lines are used to connect the platform to the seabed and restrict its lateral motions.