Abstract
The North Sea Forties assets, consisting of five platforms, have been in operation for 35 years. Extensive exploration of the Forties field in 2003 indicated that the field life could be extended by 20 years. Consequently, the Operator made substantial investments in these assets for the necessary upgrades to improve efficiency and infrastructure integrity.
The pipework and vessel information and inspection history for the assets was stored in an asset database. This database had not been updated for several years and therefore could not be used as an efficient inspection tool. For the Operator to introduce Risk-Based Inspection (RBI) to the assets, a thorough review of the topside pipework and vessel information was required.
The main scope of work was:
An update of the pipework and vessels equipment list to include upgrades and archiving removed or redundant items
Compiling a deadleg register
Allocating pipework to corrosion circuits
Identifying insulation status changes
Performing Risk-Based Assessments (RBA) on corrosion circuits and vessels to facilitate RBI
Comparisons of the assets’ updated P&IDs with the database equipment list were made to identify the new, redundant or removed items and other changes.
The updated asset equipment lists were uploaded into the database, overwriting the outdated information. It was then possible to start the RBA process using the database.
The RBA sessions were attended by a panel of experts; the Integrity Authority, two Corrosion Engineers, an Inspection Engineer and a Pressure Systems Engineer. Qualitative RBAs were performed on all corrosion circuits and vessels with only limited records of inspection history and with reliance on the knowledge and judgment of the experts.
On completion of the topside assets update/review, together with the RBAs, the Forties field Operator was able to perform full Risk-Based Inspections (RBI) on pipework and vessels, thereby providing an improved operational regime.
