Bids for the design of the Common Seawater Supply Facility (CSSF), one of Iraq’s most important upstream oil facilities, have been pushed back to January.

The facility is critical to Iraq’s hopes of expanding its crude oil production capacity, but three years after it was first conceived, no front-end engineering and design (feed) contract has been awarded.

The project covers the construction of a giant seawater treatment facility and pipelines. Worth an estimated total of $10bn, the scheme will supply treated water vital to the country’s oil fields to maintain reservoir pressure.

Engineering firms now have until the end of January to submit their proposals for the scheme’s design, which is expected to take between 10 and 12 months, say sources close to the project.

US engineering consultants, CH2M Hill was selected for the scheme’s project management consultancy contract in October 2012, taking the lead from US oil firm ExxonMobil. The company gave a tentative schedule for the project’s milestones in a presentation in March, saying feed contracts were expected to be awarded in the third quarter of 2013 and completed by September 2014.

According to the presentation, engineering, procurement and construction (EPC) contracts are due to be signed in early 2015. The facility and pipelines to the field are due to start commissioning in the middle of 2017, about the same time Iraq’s oil production capacity increase is due to hit its peak. The facility will supply treated seawater for injection into the fields, allowing international oil companies to produce oil from the deeper Mishrif and Yamama reservoirs.

It will be built in phases, with the first providing 6.7 million barrels a day (b/d) of water for five fields; Zubair, Rumaila, West Qurna-1, West Qurna-2 and Majnoon. Further phases will increase supplies to these fields as well as to the Gharraf, Halfaya and Missan oil fields. Depending on Iraq’s targeted oil production levels, the total demand for water could reach 12.5 million b/d.