A new modular floating offshore platform, which can be used for deep-sea oil exploration/production or MOB (Mobile Offshore Base), is introduced and its motion/stability characteristics are investigated. The example platform consists of 20 cylindrical tanks arranged semidodeeahedrously forming six pentagons (10g-degree lock angle). The platform is assumed to be moored by taut-leg polyester or chain-wirechain lines in 5,000-fi or greater water depth. For hydrodynamics/motion/stability analysis, the wetted surface of the platform was diseretized by quadrilateral panels and the hydrodynamic analysis was carried out by using the second-order diffraction/radiation panel program. The hull/mooring coupled dynamic analysis was done in the time domain by a newly developed computer program. The stability was checked for several hull inclination angles without mooting lines. The computed RAOs (Response Amplitude Operator) were compared with conventional floating platforms, such as typical semi-submersibles and spars. The responses of the platform for a typical 100-year storm (winds, waves, and currents) were also investigated. The overall motion and stability characteristics of the new dodecahedrons floating platform turned out to be very favorable.
At the dawn of a new millenium, we humans are facing a variety of new challenges. In particular, with the increase in world population everywhere, the amount of energy needed to cater to the increased population is likely to be one of the biggest problems in the future. During the past decade, the offshore industry has fortunately found substantial amount of oil and gas in deep (>3000ft) and ultra-deep (>6000ft) water depths. However, as we go deeper and deeper into the ocean, we face new, harder technical and economical challenges to overcome. The existing platform may not adequately function or its cost may be too high in such a waterdepth.
