Reliability analysis of subsea blowout preventers with condition-based maintenance using stochastic Petri nets

• Published in: Journal of loss prevention in the process industries Vol. 63; p. 104026
• Main Authors: Elusakin, Tobi, Shafiee, Mahmood
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2020
• Subjects: Availability; Blowout preventer (BOP); Condition-based maintenance (CBM); Mean-time between failures (MTBF); Reliability; Stochastic Petri nets (SPN); Availability; Mean-time between failures (MTBF); Blowout preventer (BOP); Stochastic Petri nets (SPN); Condition-based maintenance (CBM); Reliability
• ISSN: 0950-4230
• DOI: 10.1016/j.jlp.2019.104026

Blowout Preventer (BOP) has maintained its function as a safety barrier and the last line of defence against oil and gas spills since its development in the early 1900s. However, as drilling and exploration activities move further offshore, challenges pertaining to reliable operation of the subsea BOP systems continue to be a source of concern for stakeholders in the industry. In spite of recent advancements in reliability analysis of safety instrumented systems (SISs), the research on reliability assessment of BOP is still lacking in some regards. There are gaps in the literature with respect to the incorporation of preventive maintenance (PM) strategies as well as dynamic operating conditions into BOP reliability analysis. To address these gaps, this paper develops an advanced analysis method using stochastic Petri nets (SPN) to estimate the reliability of subsea BOP systems subject to condition-based maintenance (CBM) with different failure modes. The BOP system is divided into five subsystems which are connected in series with each other and categorised into degrading and binary units. The performance of the BOP system in terms of availability, reliability and mean-time-between failures (MTBF) is obtained and analysed. A sensitivity analysis is also performed to evaluate the effect of fault coverage factor and redundancy design on system performance. The results show that both the fault coverage factor and redundancy have significant impact on the BOP's reliability, availability and MTBF. •An advanced reliability analysis method using stochastic Petri-net (SPN) and reliability block diagram (RBD) for subsea BOP systems.•To incorporate system degradation and condition monitoring (CM) information in the BOP reliability analysis.•To assess the performance of five BOP subsystems in terms of availability, reliability and mean-time-between failures (MTBF).•To quantify the effect of fault coverage factor and redundancy design on the BOP system performance.