Dynamic analysis of a DP-FPSO: offloading with DP and non-DP shuttle tankers in the Gulf of Mexico

The present paper addresses a comprehensive analysis carried out with a DP-FPSO (Dynamic Positioned-FPSO) for the Gulf of Mexico (GoM). As an outcome of this, a methodology for evaluating the DP-FPSO response and its offloading alternatives was devised, including different failure possibilities. Fully time-domain dynamic simulations were carried out in order to analyze the DP-FPSO stationkeeping ability under different environmental conditions, to determine drifting times after a blackout and to analyze the behavior of the vessel in drive-off situations. Simulations also allowed determining limit environmental conditions for offloading operations, considering either a non-DP or a DP Shuttle Tanker (ST), restrained within the boundaries of the allowable excursion that is dictated by the riser/flexible jumper design.

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