Abu Dhabi Oil Refining Company (Takreer) is in discussions with bidders over a major project to upgrade the Ruwais refinery to process offshore crude, according to sources familiar with the project.

South Korean groups GS Engineering & Construction and Samsung Engineering, and Spain’s Tecnicas Reunidas all submitted revised prices for the engineering, procurement and construction (EPC) tender in December 2016.

Takreer had asked companies to submit revised prices after receiving the initial commercial EPC bids on the project at the end of 2015. Takreer is thought to have requested new commercial EPC bids as it considered the prices of the initial bids to be too far over its budget for the scheme.

According to two sources, Samsung Engineering submitted the lowest-priced revised bid for the EPC tender in December, but Takreer has been negotiating to bring the price down further. However, it is unclear which of the companies will be awarded the contract at this stage.

When the project was initially tendered, the value of the EPC contract was estimated at about $3bn.

Takreer is planning to upgrade existing units at the Ruwais refinery site in the far west of Abu Dhabi. The work will include modifying existing units in order to process 420,000 barrels a day (b/d) of offshore crude.

The work will include upgrades on units completed in the Ruwais refinery expansion project, which was commissioned in 2015 and which doubled the existing capacity of the site to more than 800,000 b/d.

Insurers are still investigating the damage caused by a fire at the Ruwais refinery site in January. After the insurance investigation Takreer is likely to award a contract to restore the damaged facilities, which is estimated to be worth up to $1bn.