Technology Qualification: FMECA for Mitigating Potential Failure in Subsea Storage System

Subsea storage is one of main technology in "Subsea Factory" concept that could significantly lower down the field life cycle cost especially in subsea development. An established qualification approach should enable Project Management Team (PMT) to evaluate the technology maturity, aims to reduce significant availability impact during deployment and operational phase. This paper describes the qualification approach adopted to qualify the subsea storage technology to achieve technology readiness level (TRL) 4 as per API 17Q framework, prior to pilot testing at offshore installation. One of important step is to evaluates whether the subsystem and critical components of subsea storage has an impact on Design, Operations and Maintenance. In this context, the evaluation considers the credible failure mode, mechanism, cause, and effect in relation to Risk Priority Number (RPN). Failure Mode, Effect and Criticality Analysis (FMECA) has been applied to evaluate the subsystem and critical component. The higher RPN indicates that the susceptible subsystem and critical components require special attention for improvement. The results pointed out that material for both top and bottom centre pipe flanges should have an ability to operate in cyclical loading and suitable for inspection, maintenance, and replacement program. These results suggest that recommended method of FMECA can be adopted during TRL assessment. Focus also should be on unlisted components which are not part of this assessment including design adequacy and stringent quality assurance and control management system, operations integrity, and maintenance comprehensiveness.