Industry momentum in recent years has been towards the implementation of risk-based integrity management (IM) programs for entire subsea systems (where subsea systems emcompass all hardware from the sand face downhole, to the top of the riser, inclusive of system interfaces, as defined in API RP 17N). This is evident from industry initiatives such as the Subsea Systems Integrity Management JIP (SURF IM JIP) and proposed revisions to industry codes of practice such as ISO 13628/12 "Dynamic Risers for Floating Production Installations" and API RP 17N "Subsea Production System Reliability and Technical Risk Management".
This paper presents a holistic approach to the development of risk-based integrity management programs, consistent with current industry best practice and JIPs that have advanced technology in these areas. The methodology balances the risk-based approach to maintaining asset integrity of the system as a whole with the reliability-based approach often adopted to define the preventative maintenance and sparing strategies for subcomponents of the subsea system.
A risk-based approach to integrity management is typically focused on identifying the IM measures required to manage the risk of catastrophic system failures with adverse safety, environmental, operational or reputational consequences. Reliability methods, in contrast, are typically focused on mitigation or preventative maintenance to avoid the unplanned failure of an asset's subcomponents (e.g. mechanical or electrical subsystems), the failure of which typically would not on their own lead to full system failure. A holistic IM program identifies the inspection, monitoring, analysis, procedural and preventative maintenance measures advocated to manage the integrity of the subsea system in its' entirety, balancing risk-based integrity management with reliability-centered maintenance.
The authors will demonstrate the implementation of this methodology for greenfield and brownfield projects (from the conceptual stage through to decommissioning). Emphasis is placed on how the integrity needs of a system mature over its lifetime to ensure a continuous, practical IM program.