Abu Dhabi Gas Industries (Gasco) will not change the tender deadline for its nitrogen gas injection project at the Habshan gas field, after solving technical issues with the proposed scheme’s compressors.

The technical bid submission deadlines for the engineering, procurement and construction (EPC) tender were rescheduled several times from 1 March until the final deadline on 10 May. The initial deadline for commercial bids had been on 12 April. Gasco delayed the submission and set a second deadline on 25 July. Contractors now expect no further delays.

“Now they have closed almost all the issues with the compressor vendors, it will be the time,” says a source at a bidding company.

The problems related to the high initial energy consumption when the compressors are started up. At first, vendors were unable to supply compressors that could perform a slow start, in which less energy is used. The issue has now been resolved.

“They wanted a soft start, which [the vendors] couldn’t supply in the beginning, but now they will supply,” says the source.

The Habshan project intends to maintain production levels by pumping nitrogen into the field to create the pressure that pumps oil to the surface. Pressure on depleting oil fields is usually maintained through water and gas and Habshan it is one of the first projects to use alternative feedstock for enhanced oil recovery (EOR) in the Middle East.

The nitrogen injection system at Habshan will have the capacity to pump 670,000 cubic metres an hour of nitrogen into the field. It includes a carbon dioxide recovery system that captures the CO2 for reinjection and for use as an industrial gas.

The nitrogen will be produced by Elixier, a joint venture of Germany’s Linde and Abu Dhabi National Oil Company (Adnoc). Elixier will begin production at its site in Mirfa this year.