Decommissioning Partnership to Revolutionize Subsea Cutting

Underwater Laser Cutting (UWLC) is proven as a feasible alternative to conventional methods, bringing a low carbon, quick and clean underwater cutting technology to the decommissioning market.

The technology improves efficiency when used for downsizing activity or applicable subsea decommissioning scopes and offers the flexibility of deployment methods in storage ponds, tanks and offshore. The collaborative development is delivered through a partnership between Claxton, University of Aberdeen, The National Decommissioning Centre and is supported by funding and project oversight by the Net Zero Technology Centre. Claxton is a Cutting and Decommissioning brand in Acteon’s Energy Services division. The partnership aims to design and optimize the gas-jet system for metal-cutting under seep-water conditions.

Successful Trials

The initial phase of the partnership delivered between 2019 and 2021 saw the development of the UWLC system targeted at delivering offshore cutting trials in 70 msw (meters seawater depth). The Net Zero Technology Centre funding supported partners in the development of:

• Underwater capable optics
• Design and manufacturing of an underwater laser cutting head
• Procurement and packaging of a 15KW laser generator for offshore operations
• Design and manufacture of control system software and hardware suitable for 50 bar hyperbaric conditions.
Successful delivery of this phase was demonstrated through subsea cutting performed at 70 msw.

• 250 underwater cuts performed on structural steel up to 120mm thick
• HMI and 500 msw depth capable electronic control system
• Design and manufacture 500 msw rated subsea laser cutting head
• System verified at technology readiness level 6 and suitable for further development

Getting Ready for Commercialization

The next phase of the partnership planned for 2023-24 involves the development of the UWLC system targeted at delivering a cutting tool suitable for a real offshore cutting scope. This again benefits from Net Zero Technology Centre funding and involves the same project partners along with in-kind contribution from a Tier 1 oil and gas producer and vessel operator.

Phase two will include:

• A selection of a suitable cutting opportunity through engagement with our project partners and participants
• Development of the laser cutting head through the incorporation of lessons learned from Phase 1
• Development of a cutting tool to manipulate the laser cutting head to suit the cutting scope
• Integration of the Human Machine Interface (HMI) and electronic control from Phase 1 into the intelligent cutting tool to optimize cutting head manipulation and performance.

Who Will Benefit?

Opportunities that would benefit from laser cutting, as opposed to traditional methods such as water jet or diamond wire cutting, include: single wall pile cuts, jacket or infrastructure downsizing for recovery, and waste size reduction for storage.

The benefits of UWLC:

• Cuts both from outside-in and inside-out of a structure
• Safer, cheaper, and faster than conventional cutting methods
• Cutting technology proven feasible for Nuclear Decommissioning underwater downsizing tasks
• Opportunity to vastly reduce time required to perform on site downsizing cutting program
• Smaller back deck footprint and reduced power consumption and consumables

“It is fantastic to be involved in such a great partnership and work with an inspiring team on this development project. The commitment from all partners builds on Claxton’s drive to bring innovative decommissioning solutions to the market. The technology is showing great promise in delivering cross sector decommissioning work scopes. I am looking forward to delivering an offshore decommissioning work scope through 2023 with a view to commercializing the technology and opening it up as a cutting solution available to the oil and gas, nuclear and offshore wind decommissioning market,” said Craig Baxter – Decommissioning Technical Manager, Claxton.

“It has been great to work with Claxton, with the funding from the NZTC, to take work which we started several years ago as bench top experiments to a near market tool. Being able to deploy the underwater laser cutter in a realistic offshore environment at Kishorn and have it perform so well was a testament to the capability of the partnership. We look forward to continuing the relationship with Claxton in developing the system to a commercial tool,” said Professor Richard Neilson – Centre Director, The National Decommissioning Centre.