The original ESD system on the offshore installation was supplied by Wormald in 1993. An obsolescence status review had determined that spare parts for the system were no longer available and support of the system in its present form was no longer available from the OEM.
Core (Oil and Gas) Ltd were requested to carry out a FEED to review the options available to remove the risks to the asset from obsolescence.
The FEED would present a recommended solution which would be followed through by Core into design and implementation.
The existing ESD system was based on a Modicon PLC with hardwired matrix for indication of I/O status, inhibit/override and reset facilities. The ESD system hardware was contained in a suite of cabinets with separate cabinets for system and marshalling. The ESD system had a serial interface to the topside DeltaV PCS for event logging.
The FEED reviewed the options for upgrading the system with the main concern to minimise the shutdown time, optimise available space and minimise disruption to operations during implementation.
The recommendation from the FEED was to replace the ESD system with Emerson DeltaV SIS logic solver hardware and integrate this with the DeltaV PCS to provide an integrated system for topside process control & shutdown. The project was sanctioned based on the FEED report.