A Systems Engineering Framework for Mechanical Equipment Reliability and Operational Risk Reduction in Deepwater Production Facilities

Abstract

Mechanical equipment failures in deepwater production facilities are costly because subsea repair depends on intervention vessels with lead times of weeks to months, and because the same failures can initiate loss of containment. This study develops a systems engineering framework that traces availability, operational risk and cost requirements through architecture alternatives, Bayesian component reliability and a life-cycle model to requirement validation. Failure rates for subsea pumps, gas compressors, water injection pumps and subsea valves were updated from generic priors with operating experience, and four architectures were evaluated by Monte Carlo simulation. Mean availability rose from 0.947 to 0.983 and life-cycle cost fell from USD 791 million to USD 480 million in present value. Only the architecture combining redundant subsea pumps, three 50 percent compressors, condition-based maintenance and pre-positioned spares met the 0.975 availability requirement at 95 percent confidence together with the risk requirements, because adding compressors without condition monitoring increased loss-of-containment frequency. Condition-based maintenance became cost-effective at intervention lead times above about 80 days, and water injection emerged as the next design priority.