Subsea services provider DeepOcean has completed a decommissioning project on a Fairfield Energy platform located on the UK continental shelf, with work conducted from a hybrid-battery-powered construction support vessel (CSV).
As part of its scope, 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, on the Dunlin Alpha platform.
The company’s Aberdeen office was responsible for engineering and project management, with support from the Haugesund and Stavanger offices in Norway. Offshore work was conducted from the hybrid-battery-powered CSV Edda Freya .
Subcontractors Claxton, Machtech and Global Energy Group assisted in delivering the scope of work.
According to DeepOcean, the entire 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 guideframes. The scope also required significant shallow water ROV operations for the removal of the upper guideframe and conductors,” said Gary Scott , UK Commercial Manager and Legal Counsel at DeepOcean.
“With high-end subsea engineering involved, together with specialist subsea tools and technologies required to execute the project, coupled with our attention to high quality and safe project delivery, I would classify it as a flagship project for DeepOcean.”
The Dunlin Alpha installation, located approximately 137 kilometers northeast of Shetland and in a water depth of 151 meters, produced its first oil in 1978.
In the 37 years that followed, more than 522 MMbbl of oil was recovered from the Greater Dunlin Area, comprising the Dunlin, Dunlin S/W, Osprey and Merlin fields.
Fairfield Energy acquired the assets in 2008 and took over full operatorship in 2014, maximizing production during its late-life stage and then progressing its subsequent decommissioning programs.