Subsea Expo

Access. Connect. Grow.

ONS 2010: Ormen Lange Subsea Compressor Taking Shape

25 August 2010

Initial work on the pilot subsea compressor station for the Ormen Lange development is nearing completion, according to a presentation by Aker Solutions at ONS.

Compression will be needed at the giant gas field in the Norwegian Sea as reservoir performance declines. Development operator Statoil is investigating the feasibility of performing this function on the seabed, as a lower-cost alternative to a compressor platform.

Aker Solutions has constructed the pilot station at its new subsea test and assembly hall in Egersund, Norway. This is equivalent to one of four compressor trains that would feature in the full-scale kit, said, Haakon Skofteland, project manager.

The pilot system’s compressor is housed in a hermetically sealed enclosure. Among the various items are a subsea separator, designed to handle the incoming wellstream from Ormen Lange reservoir, with liquids and sands diverted to the bottom of the separator.

Other components include an all-electric subsea control module and subsea electric actuators (tested at the company’s facility in Aberdeen), a pump module and a cooler module – “we need to perform a lot of testing to calculate heat transference from gas to sea water,” Skofteland explained – and sealing technology to safeguard against water ingress.

He added that all piping and cables had been installed. Once all the various modules are in place, full system testing is scheduled to get under way in November, with the program due to be completed by the end of the year.

Under the next phase, the pilot station will be delivered to Statoil for submerged pit testing at Nyhamna on Norway’s west coast during 2011-12.