DeepOcean has completed the recovery of the remaining subsea wellhead protection structure at the Spirit Energy-operated Seven Seas field and disconnected subsea infrastructure at the nearby Grove West field in the southern North Sea, using proprietary decommissioning tooling developed in-house.
The project included onshore engineering, project management and offshore execution by DeepOcean, with the company's high-specification construction vessel Edda Freya deployed to recover the wellhead protection structure, which weighed more than 100 tonnes, along with associated subsea infrastructure. All recovered materials have been transported for reuse, recycling or responsible disposal. The work was managed and carried out by DeepOcean's Aberdeen-based operations in the UK.
The activities form part of Spirit Energy's broader decommissioning programme for the Seven Seas and Grove West fields, with both scopes completed in preparation for an upcoming rig campaign.
"The wellhead protection structure at Seven Seas has served the field since 2011 and remains in very good shape. The piles were cut three metres below the seabed and the subsequent retrieval of the structure was conducted. We were delighted to support Spirit Energy on this project and look forward to working with Spirit Energy on future scopes of work," said Robin Mawhinney, Executive Vice President for DeepOcean's EMEA region.
The project also involved disconnecting a spool from a subsea Christmas tree at Grove West. The operation was carried out using a remotely operated vehicle (ROV) together with specialised tooling, eliminating the need for diver intervention that would traditionally be required for this type of work.
Spirit Energy's Decommissioning Manager, Ceri Wheaton, said: "We are committed to maximising material recovery and minimising waste throughout our decommissioning activities. By working closely with specialist contractors such as DeepOcean and leveraging the UK supply chain, we have safely recycled more than 95% of materials from decommissioned assets and infrastructure. This approach not only reduces environmental impact but also improves efficiency through streamlined logistics and the responsible reuse of valuable resources."
"At Grove West, we disconnected two subsea flanges using methodologies and proprietary tooling developed during the Gryphon Alpha FPSO removal project last year. This project adds to DeepOcean's growing track record of meeting project objectives across subsea decommissioning campaigns," said Øyvind Mikaelsen, Chief Executive Officer at DeepOcean.
The Seven Seas wellhead protection structure was located approximately 80 km offshore the East Yorkshire coast in water depths of around 33 metres, while the Grove West infrastructure is situated about 130 km east of the UK coastline in water depths of approximately 40 metres.
