At least nine international engineering firms will bid on the deal to build a base oil refinery at Ruwais for Abu Dhabi Oil refining Company (Takreer), worth more than $500m.

Contractors say they were first told they had been prequalified to bid on the deal on 20 December. A formal invitation to bid on the engineering, procurement and construction (EPC) deal was sent out with bid documents in early January.

Among the prequalified contractors are four South Korean firms: SK Engineering & Construction, Hyundai Heavy Industries, Samsung Engineering, and Hanwha Corporation. Other companies authorised to bid on the deal include Paris-based Technip, Taiwan’s China Technical Consultants, Japan’s Toyo, Germany’s Uhde and the UK’s Petrofac.

A site visit has been arranged on 2 February, after which Takreer will set deadlines for technical and commercial bids.

The winner of the EPC deal will build a 300,000-barrel-a-day base oil refinery. Base oils are heavy grades of oil commonly used as industrial lubricants. Takreer currently blends the base oils into fuel oil and then sells this on the open market.

Abu Dhabi is a net importer of base oils. Takreer wants to use the plant to meet domestic demand and turn the emirate into a net exporter.