To manage the integrity of assets operating beyond their design life proactive corrosion management is essential. Traditionally topsides process plant, subsea pipelines and onshore terminals have been subjected to individual corrosion management schemes. An holistic approach that brings the corrosion management of these individual components into an integrated Corrosion Management System (CMS) has been developed for a variety of ageing offshore assets.
The CMS comprises a Corrosion Control Scheme (CCS), a Topsides Risk Based Inspection (RBI) scheme, a Corrosion Risk Assessment (CRA) and a Pipeline Risk Assessment (PRA).
The objectives of this integrated CMS process are to:
Proactively identify all corrosion threats and define related risk
Define mitigation controls as necessary and ensure implementation
Ensure mitigation controls are effective
Establish and implement corrective action as necessary
The overall corrosion management strategy is implemented by the CCS for a specific production asset which identifies the corrosion threats. It establishes the control and mitigation procedures required to mitigate internal and external corrosion on topsides process plant, subsea pipelines and related subsea components. The degradation mechanisms, controls and mitigation procedures are mirrored in the other CMS components. The future inspection programme for topsides process plant is driven by the RBI, whilst the CRA and PRA drive the future inspection and monitoring regimes for subsea pipelines. Results from these components are fed back into any review and upgrade of the CCS.
A CMS has been developed and implemented that meets the following objectives:
A transparent and auditable decision making process
Proactively identifies corrosion threats and defines related tasks
Defines mitigation controls as necessary and manages implementation
Ensures mitigation controls are effective
Defines inspection and monitoring regimes to assess asset condition
Establishes and implements corrective actions as necessary
An integrated scheme such that changes in one component are mirrored in the others.