Experts' opinion-based Bayesian Inference for the Coverage Factor in BOP Reliability

The blowout preventer is an important system for safety assurance in well drilling operations. Therefore, the efficient management of its reliability is an essential issue for risk prevention. In the present paper one considers a dynamic Bayesian network for reliability modeling, approaching corrective maintenance and an imperfect coverage factor, combining with a hierarchical Bayesian inference. Traditionally, the coverage factor in this kind of analysis for well safety is based on belief values. Considering that, we will approach it through a Bayesian analysis for the experts’ opinion. Thus, the present paper presents a fully Bayesian approach for blowout preventer reliability analysis, combining experts’ opinions in a dynamic Bayesian net modeling. In the end, is possible to compare results with and without imperfect coverage factor, and with belief values. The obtained results for a hypothetical case show the importance of considering the estimates’ uncertainties in the context of reliability management of drilling operations.