Risk Evaluation of Explosion in FPSO Based on Failure Model and Effect Analysis

As large offshore drilling facility, Floating Production Storage and Offloading (FPSO) faces with the risk of oil & gas leakage and subsequent effects (e.g. fire and explosion). In order to assess FPSO gas leakage and subsequent chain effects risk scientifically, a FPSO topsides is analyzed, and Failure Model and Effect Analysis (FMEA) method is applied to find out which equipment has high Risk Priority Number (RPN). The results show that gas washing pry of FPSO in operation phase has high RPN and needs significant attention. In this paper, CFD-model of FPSO topsides is established based on computational fluid dynamics (CFD) theory. The leak rate of gas with specified hole diameter is calculated based on appropriate leak source model according to the actual operating conditions of gas washing pry. Then based on the simulation results diffusion behavior is analyzed, as well as distribution law of gas and the hazardous area of gas of gas washing pry under the leakage conditions. Furthermore, one explosion model is selected, and then damaging over-pressure of explosion on each equipment surface and the variation trend and influence scope of explosion over-pressure are derived to evaluate personnel and equipment risk. Targeted technical measures will be put forward to reduce risk.