Malaysia’s Petronas is preparing to release a tender for a new central process facility (CPF) at the Gharraf oil field in the south of Iraq.

The oil firm had previously asked international engineering, procurement and construction (EPC) firms to submit their prequalification documents at the end of 2013, but having revised the scope of the project, it is now seeking new applicants.

Tenders for the estimated $500m-plus scheme are not expected to be launched until the middle of 2014.

The new CPF will include three oil production trains with a capacity of 50,000 barrels a day (b/d) each, as well as an integrated 170 million cubic feet a day (cf/d) gas treatment plant, according to sources close to the scheme. There are currently two crude production trains at the field capable of producing 100,000 b/d in total.

Two of the trains are scheduled to come online in 2017 to meet Petronas’ ramp up plans of reaching 200,000 b/d. Train-5 would be built by 2020 to meet the field’s production plateau target.

The new project has been divided into two packages. The first covers the construction of production trains 3 and 4 by the end of 2017, and train-5 by the beginning of 2020. Package-2 is for the construction of the integrated gas processing plant by early 2018. Interested firms have been asked to state their preference of bidding for one or both of the deals. The project also covers the installation of three oil storage tanks of around 50,000 barrels each.

The EPC work was awarded to US oil field services firm Weatherford International under a $200m contract. Petronas had hoped to produce its first oil from the facility at the end of 2012 at 35,000 b/d and rising to 100,000 b/d by the end of 2014. However, the facilities only began pumping at the end of August 2013, nine months behind schedule.

South Korea’s STX Heavy Industries was awarded a $99.5m deal in the middle of January to build the field’s gas processing plant. It will process 23 million cubic feet a day (cf/d) to produce feedstock for a captive power facility.

Petronas is developing the field in consortium with Japan Petroleum Exploration Company (Japex) and state-owned North Oil Company, which agreed to raise production capacity to 230,000 b/d by 2017.