James Fisher Decommissioning successfully completes subsea well abandonment project for major operator, utilising pioneering new SEABASS system.

  • James Fisher Decommissioning successfully completes the abandonment of two subsea wells in the North Sea for major operator
  • The recently launched SEABASS well plug and abandonment system successfully performed vessel-based operations on an offshore subsea construction vessel
  • SEABASS can provide up to 25% efficiencies against comparable solutions, delivering considerable savings and negating costly rig time


James Fisher Decommissioning (JF Decom), a trusted global partner for the decommissioning of offshore assets – and a part of James Fisher and Sons plc, has successfully completed a subsea wells abandonment project in the North Sea utilising its patented SEABASS system.

The SEABASS system provides environmental barriers to single or multiple annuli in one trip and is typically operated from a vessel. It is designed to deliver time savings of up to 25 percent when compared to competing solutions, thanks to a reduced operational period that has the additional benefit of decreasing a project’s carbon footprint.

Vessel-based operation

This subsea well abandonment project marks a milestone for JF Decom as it was the first time deploying their pioneering single-trip subsea well-plug and abandonment tool, SEABASS. SEABASS completed the subsea abandonment of two wells, from a subsea construction vessel, including well fluid filtration, cementing, perforating, back deck equipment and control system services.

All services including project planning and engineering prior to mobilisation were provided by JF Decom’s multi-skilled offshore team. This includes providing a single point of contact for the provision of environmental plugs and supporting services, resulting in the successful completion of the project.

This additional capability further enhances JF Decom’s position as a leading decommissioning service provider. The project followed SEABASS’s successful build and factory acceptance testing in October 2022. The completion gives JF Decom an established track record, builds on their strong customer relationships and enables them to offer complete subsea well abandonment solutions from a vessel including severance.

Ruth Christie, product line director at JF Decom, said:

“We’re really proud of the success of SEABASS’s inaugural project, where we were able to prove not only the capability of the innovative, ‘best-in-class’ plug and abandonment system, but also to deliver a partnership level service. We are focused now on building on this success with more UK and international scopes.”

Commercial benefits of SEABASS

The SEABASS system has been carefully designed with the operator and vessel provider in mind to provide a safer, more reliable option that can improve quality and reduce operating time, which is essential for risk-based abandonment activities. The system has dual failsafe safety valves, and a mechanical lock, coupled with a complete disconnect and reconnect system. In the event of a drive-off or well control situation the vessel can disconnect from the tool leaving well fluid and pressure locked within the wellbore. Re-engagement can be achieved by either vessel or rig with multiple recovery options including drill pipe. The system can be run through a moonpool or over the side.

JF Decom offer a solution that meets global regulatory requirements and can be provided as a service by JF Decom through its strategically placed global locations. JF Decom supports its clients throughout and helps them make key decisions – using their vastly experienced team and reliable products.