DeepOcean concluded subsea removal operations at the Seven Seas and Grove West fields, operated by Spirit Energy in the southern North Sea. The project included the recovery of a wellhead protection structure weighing over 100 tons and the disconnection of subsea infrastructure using tools developed by the company itself for decommissioning work.
Campaign prepared for the next phases of subsea decommissioning
As part of Spirit Energy’s comprehensive decommissioning program, operations were executed from Aberdeen, United Kingdom. DeepOcean handled the engineering, planning, and project management, while the construction vessel Edda Freya performed the recovery maneuvers for the subsea equipment.
Furthermore, the company reported that all removed materials were sent for reuse, recycling, or responsible disposal, in line with the sustainability strategies adopted by both companies.
Robin Mawhinney, DeepOcean’s Executive Vice President for the EMEA region, explained that the Seven Seas well protection structure had been in service since 2011 and remained in good condition. After cutting the piles three meters below the seabed, the team fully recovered the installation.
Proprietary technology to reduce operational risks
The scope of work also included the disconnection of a spool belonging to a subsea Christmas tree at Grove West.
For this activity, DeepOcean employed a remotely operated vehicle (ROV) along with specialized tools developed in-house. This methodology avoided diver intervention, improving operational efficiency and reducing personnel exposure during subsea tasks.
Øyvind Mikaelsen, CEO of DeepOcean, noted that some of these tools were designed during the decommissioning project of the FPSO Gryphon Alpha floating unit and are now continuing to expand their application in new offshore projects.
More than 95% of materials were recycled
Spirit Energy highlighted that material recovery constitutes one of the pillars of its decommissioning strategy.
According to Ceri Wheaton, the company’s Decommissioning Director, collaboration with specialized suppliers and the UK supply chain has enabled the safe recycling of more than 95% of materials from retired assets and infrastructure.
The executive indicated that this approach contributes to reducing environmental impact, optimizing logistics, and favoring the responsible reuse of high-value industrial resources.
Operations in the southern North Sea
The structure recovered at Seven Seas was located approximately 80 kilometers off the coast of East Yorkshire, at a depth of nearly 33 meters.
For its part, Grove West is located around 130 kilometers east of the UK coast and operates at a depth of about 40 meters, where DeepOcean completed the final subsea disconnection tasks that prepare the area for future drilling campaigns.
Source and photo: DeepOcean
