Application of integrated STAMP-BN in safety analysis of subsea blowout preventer

Blowout preventer (BOP) plays a key role in preventing blowout accidents from occurring during offshore or deepwater drilling. The safety of BOP is affected by diverse components and interactions among them. It is vital to identify the crucial failure modes using safety assessment method. To perform a qualitative, quantitative, and systematic safety assessment of BOP, this paper presents an integrated method—using the system-theoretic accident model and process (STAMP)-Bayesian network (BN)—for evaluation of the structure safety and prediction of the failure scenarios. In the proposed method, STAMP is used to identify the failure scenarios by establishing a hierarchical control and feedback model that tallies with the BOP structure, while BN is adopted to calculate the probabilities of potential failure modes based on the outcomes of STAMP. The approach is then explored in a case study where factors regarding humans, components and control systems, and constraints and control relationships among them are all considered. The results demonstrate the feasibility of the integrated method as a way of performing a safety analysis for BOP. This research overcomes the deficiencies of traditional methods that cannot effectively evaluate the interactions of components, thereby providing a reference for safety/risk analyses of complex systems.