The refrigeration units at the Dimilington terminal will be able to freeze the gas to remove water and hydrocarbon liquids in order to meet the specifications of the National Gas Transmission System.
The units currently use a refrigerant, which will be phased out by the end of 2014, under the EU and UK law resulting from the Montreal Protocol on Substances that Deplete the Ozone Layer.
Earlier the two companies identified a solution to replace the refrigerant and now under the contract, Costain will develop the approach, which will allow a detailed engineering, procurement and construction contract for bidding process.
Perenco UK project and developments manager Bob Price said Costain Natural Resources’ has worked closely with the company to develop a solution that has reduced the project cost.
"The novel bespoke solution has been a testament to the strengths of both Company’s knowledge and expertise and a desire to produce enhanced Environmental and Business results," Price added.
The Dimlington Gas Terminal processes gas from more than 20 offshore fields in the Southern North Sea and has recently been added to Perenco’s portfolio of UK Assets.