Fairfield Energy completed a decommissioning project on the Dunlin Alpha platform on the UK Continental Shelf.
Ocean services provider DeepOcean removed six subsea conductors and four vertical supports at varying water depths and removed the upper conductor guide frames with an estimated weight of 400 tonnes, together with the design and installation of bespoke clamps, the services provider said in a release. The project was completed within 12-16 weeks from contract award to offshore execution.
The project “required intensive dynamic and structural analysis to enable the removal of the upper conductor guide frames," said Gary Scott, UK commercial manager and legal counsel at DeepOcean. "The scope also required significant shallow water [remotely operated vehicle] ROV operations for the removal of the upper guide frame and conductors," he continued.
DeepOcean’s Aberdeen office was responsible for engineering and project management, with support from the company’s Haugesund and Stavanger offices in Norway. The offshore work was conducted from the hybrid-battery powered Edda Freya service vessel. Key subcontractors included Claxton, Machtech, and Global Energy Group.
The Greater Dunlin area covers Dunlin, Dunlin South West, Osprey, and Merlin fields in Shetland basin in the northern North Sea. The Dunlin Alpha installation served as the production platform.
Fairfield Energy, a subsidiary of Decom Energy Ltd., became operator at Dunlin in 2008 (OGJ Online, June 15, 2007; Jan. 7, 2008). In 2015, a requirement to invest over $100 million in replacing subsea infrastructure, the urgent need for revised agreements for fuel gas for the Dunlin Fuel Gas Import (DFGI) pipeline, growing conductor integrity issues, and the sub-$40/bbl oil price led to the determination that it was not economically viable to continue production.
Four subsea decommissioning programs have been completed in the Greater Dunlin area, and topsides of the Dunlin Alpha platform have been removed and dismantled onshore.
