Quantitative risk analysis of subsea pipeline and riser: an experts' assessment approach using fuzzy fault tree

Risk assessments with subsea pipeline and riser differ widely in various parts of the pipeline. In order to conduct quantitative risk analysis of subsea pipeline and riser, a practical approach of fuzzy fault tree analysis is employed. In the beginning, fuzzy fault tree of subsea pipeline and riser system is constructed. Experts' weighting factors are worked out through analytical hierarchy process. Fuzzy fault tree based on updated model of membership function is therefore completed, obtaining fuzzy failure probability of basic events. Based on PARLOC 2001, results from the updated model are compared with Y.H. Dong's, verifying the accuracy of the updated model. Moreover, probability of the most unexpected event, named failure of subsea pipeline and riser, are worked out. Sensitivity analysis is also completed. In summary, quantitative risk analysis of subsea pipeline and riser based on fuzzy fault tree is completed, providing some practical reference to the subsea pipeline engineering.