BOP System Reliability Planning and Testing

Abstract

Reliability-Availability-Maintainability (R-A-M) is one of the most important sets of functional requirements for a Blowout Preventer (BOP) system. Requirements derived from R-A-M are key for the success of pressure control and the BOP system. Using the design for reliability (DfR) process and system engineering approach, the team established feasible reliability and maintainability requirements based on field performance of similar equipment, performed risk analysis to identify necessary mitigations, and allocated system requirements to the various subsystems. Consequently, the team created system models to assess system reliability as subsystem data is captured. Where necessary, subsystem reliability demonstration tests were executed. The test and analysis results from the components are integrated, via reliability modeling approaches, to the system-level. These results will demonstrate the mean time between maintenance and drilling availability for the BOP system, as well as the probability to perform on-demand for each critical BOP function. The test and analysis results also help identify the weakest link in the system to proactively drive design improvement, and determine the optimal maintenance strategy. The methodology presented in this paper is not only essential to ensure the R-A-M of the BOP system under design, but can be applied to other DfR work.

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

“…Some years later, Fowler and Roche (1993) also used FTA in addition to failure mode and effects analysis (FMEA) to analyse the reliability of a subsea BOP and a hydraulic control system. Zou et al (2016) applied the reliability block diagram (RBD) technique to analyse the reliability of subsea BOPs. The results were then compared against design requirements.…”

“…an uncontrolled flow of liquid and gases during the drilling process) (Holand and Rausand, 1987). BOPs are one of the most critical SISs among all drilling equipment and, as a result, the downtime associated with removal of the BOP stack is known as one of the costliest activities in offshore drilling operations (Zou et al, 2016). The main components of a subsea BOP system are: one or two annular preventers (which work to seal around tubulars in the well and around an open hole); three to six ram preventers (which can seal several pipes within the well and seal an empty hole depending on dressing); the wellhead connector and the lower marine riser package connector (which link the entire BOP to the wellhead and to the riser directly hooked to the drilling platform); and a number of choke and kill valves and lines (which work to manipulate pressurized fluid pumped in and taken out of the well) (Shafiee et al, 2019b).…”

Subsea blowout preventer (BOP): Design, reliability, testing, deployment, and operation and maintenance challenges

“…Some years later, Fowler and Roche [42] applied FTA and Failure Mode and Effects Analysis (FMEA) to assess the reliability of a subsea BOP and a hydraulic control system. Reliability Block Diagrams (RBDs) were also used by Zou et al [74] to model the reliability performance of subsea BOPs and then the results were compared against design requirements. Some advanced reliability analysis techniques which provide more robust solutions have also been applied in recent years, however, gaps still exist with regards to incorporation of maintenance strategies and dynamic operating condition of the BOPs.…”