Abstract: In order to scientifically evaluate consequences of explosion accidents in offshore platforms, a dynamic assessment method was proposed considering disaster evolution induced by leak and emergency evacuation of operators. With process area of lower deck in an offshore platform as example, and effects of emergency shut down (ESD) system and blowdown system on dangerous gas profile being considered, explosion simulation was conducted by introducing ignition source. Then, emergency evacuation trajectories were determined with help of grid-based concept and emergency response sequence. Finally, dangerous area was identified and classified based on maximum overpressure loads in real-time position of operators, and simulation results were compared with those obtained from "static" method. The results show that the proposed method gives a better consideration of accident evolution process and emergency evacuation and the latter can greatly reduce dangerous area of explosion but may aggravate consequence severity of operators in local area.

Key words: offshore platform, consequences of explosion accidents, dynamic assessment, emergency evacuation, hazardous area