Projects - Dunbar Systems Upgrade

Tierney Strachan complete live upgrade of Total Dunbar Process Control System from Controle Bailey to Emerson DeltaV

As part of the Dunbar Systems Upgrade (DSU) project, the existing Yokogawa Controle Bailey PCS system was replaced with an Emerson DeltaV PCS system. The objective was to provide a modern system, capable of being maintained and developed over the anticipated life of the installation.

Forvie/Jura Field Layout

As a consequence of the Forvie subsea project (also completed by Tierney Strachan), the existing DeltaV PCS network on the Alwyn platform was extended to the Dunbar platform via subsea fibre-optic cable. The extension of the DeltaV network enabled the Forvie subsea field to be controlled from Alywn 22km to the North of Dunbar. The infrastructure backbone therefore already existed to add additional DeltaV hardware on Dunbar, and on this basis it was decided to extend the DeltaV system to replace the old Dunbar PCS.

The replacement PCS required four new DeltaV controller cabinets to accommodate the 546 I/O and 6 serial links. These cabinets were designed, built and tested at Tierney Strachan’s Aberdeen manufacturing facility.

New PCS Cabinets Prior to Delivery

During the commissioning some 35% of loops were transferred live, with the remaining transfer achieved in a 14 day shutdown, and a like-for-like logic changeover with no inadvertent trips.