The companies that applied for prequalification are understood to include Italy's Snamprogetti, Paris-based Technip-Coflexip,with the local National Petroleum Construction Company, Chiyoda Corporation and JGC Corporation, both of Japan, and Fluor Danieland Kellogg Brown & Root, both US-based.

The project is effectively an expanded version of the surface upgrade and gas reinjection schemes, which Adco had been planning to tender separately.

The scope of works on the 32-month contract includes the construction of a new degasification plant with nameplate capacity of 730,000 barrels a day (b/d) and the replacement of the existing two-phase separators of 50,000 b/d each in capacity with four new three-phase separators of 120,000 b/d each. It will also entail the upgrade of the integrated control systems, oil drainage facilities, and effluent water disposal units. Also, facilities will be set up for the reinjection of 95 million cubic feet a day of gas and 120,000 b/d of water into the G, F and D reservoirs.

The project will tackle a rising water cut and falling reservoir pressure at Bu Hasa.