A novel approach for hazardous area identification of toxic gas leakage accidents on offshore facilities

Abstract

Some attempts have been made to predict the adverse effects of released toxic gas on individuals. However, the classification of the hazardous area considering the dynamic changes and focusing on the whole facility remains a challenging issue. This paper presents a novel approach to classify the hazardous areas on offshore facilities in toxic gas leakage and dispersion accident. By introducing the grid-based concept, each location and its corresponding evacuation trajectory to a fixed destination are considered in this approach. Instead of just considering the accumulation characteristics of released toxic gas, the adverse effects are predicted with a combination of the dynamic factors, including the emergency evacuation and the temporal-spatial variation of toxic gas profile. The proposed approach is applied to a hypothetical H2S leakage and dispersion accident on an offshore platform, a time-varying leakage profile is adopted considering the interference of the process protection measures, an emergency evacuation time model is established with the guideline from International Maritime Organization (IMO). The results suggest that the proposed approach can improve the accuracy of hazardous areas identification and provide support for optimizing emergency plans against toxic gas leakage and dispersion accident on offshore facilities.