DeepOcean Completes Subsea Decommissioning at Spirit Energy North Sea Fields

DeepOcean has completed subsea decommissioning work at Spirit Energy's Seven Seas and Grove West fields in the southern North Sea. The scope involved recovering a wellhead protection structure weighing more than 100 tonnes and disconnecting subsea infrastructure ahead of a planned rig campaign. Carried out from DeepOcean's Aberdeen operations, the work included using a remotely operated vehicle and in-house tooling to avoid diver intervention, with recovered materials sent for reuse, recycling or responsible disposal.

 

Scope of the Decommissioning Work

 

DeepOcean has finished a significant subsea decommissioning scope for Spirit Energy. The work covered two separate fields in the southern North Sea. These were the Seven Seas and Grove West fields. The scope involved recovering a subsea wellhead protection structure and disconnecting subsea infrastructure. This preparation was carried out ahead of a planned rig campaign.

The project was managed from DeepOcean's regional base in Scotland. The company carried out engineering and project management from its Aberdeen operations. It deployed the construction vessel Edda Freya to execute the offshore work. The vessel recovered the remaining wellhead protection structure at the Seven Seas field. It also retrieved associated subsea infrastructure alongside the main structure.

 

The Seven Seas Recovery Operation

 

The Seven Seas scope centred on a substantial subsea structure. The wellhead protection structure recovered weighed more than 100 tonnes. This structure had served the field since 2011. Despite its years in service, it remained in very good condition on recovery. Its longevity reflects the durability of such subsea installations.

The recovery required careful preparation of the seabed connections. The piles securing the structure were cut three metres below the seabed. The structure was then retrieved following this cutting operation. Company leadership described being pleased to support Spirit Energy on the project. They also expressed interest in working with Spirit Energy on future scopes of work.

 

Technology at the Grove West Field

 

At Grove West, DeepOcean applied advanced subsea techniques. The company disconnected a spool from a subsea Christmas tree at the field. This work was performed using a remotely operated vehicle. The operation also relied on proprietary tooling developed in-house by DeepOcean. This combination allowed the disconnection to proceed without divers.

Avoiding diver intervention carries clear safety and efficiency benefits. Using a remotely operated vehicle eliminated the need for divers on the task. This reduces the risks associated with human intervention in subsea environments. In-house tooling gave the company greater control over the operation. This approach reflects a broader industry shift toward remote and automated subsea work.

 

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Field Locations and Conditions

 

The two fields lie at different distances from the UK coastline. The Seven Seas field is located about 80 kilometres off the East Yorkshire coast. It sits in water depths of around 33 metres. This relatively shallow depth is typical of parts of the southern North Sea. The field's location shaped the logistics of the recovery operation.

The Grove West field lies further from shore in slightly deeper water. It is situated about 130 kilometres east of the UK coastline. The field sits in water depths of around 40 metres. These conditions influenced the methods used for the disconnection work. Both fields form part of the same wider decommissioning programme for Spirit Energy.

 

Sustainability and Material Recovery

 

A central theme of the project was maximising material recovery. The recovered materials were transported for reuse, recycling or responsible disposal. DeepOcean emphasised its commitment to minimising waste during decommissioning. This focus applies across all of its decommissioning activities. The good condition of the recovered structure supported its potential reuse.

Spirit Energy highlighted strong recycling outcomes across its programme. The operator said it has safely recycled more than 95 percent of materials from decommissioned assets. This was achieved by working with specialist contractors and the UK supply chain. The approach reduces environmental impact while improving logistical efficiency. It also supports the responsible reuse of valuable resources recovered offshore.