UK partners developing new system to ‘revolutionize’ subsea cutting

A partnership comprising Acteon’s Claxton, the University of Aberdeen, the National Decommissioning Centre, and the Net Zero Technology Centre is developing a gas-jet system expected to “revolutionize” subsea cutting.

The Underwater Laser Cutting (UWLC) technology is said to improve efficiency when used for downsizing activity or applicable subsea decommissioning scopes and offer the flexibility of deployment methods in storage ponds, tanks and offshore, representing a feasible alternative to conventional methods.

The initial phase of the partnership delivered between 2019 and 2021 saw the system demonstrated through subsea cutting performed at 70 metres seawater depth (msw).

In the summer of 2022, Claxton performed a client-funded desktop feasibility study along with a test program performed at the National Decommissioning Centre, which demonstrated the efficiency of the technology in cutting the client’s targeted 75mm thick stainless steel.

During the trials, cutting was also performed on 25mm thick stainless steel in preparation for the thicker material cutting trials. During the severance of the 25mm material cutting speeds of 300mm/min was achieved, which is the fastest the test arrangement can currently travel, the company said, adding that further optimization of the cutting speed has the potential to allow faster cutting speeds.

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 involves the same project partners along with in-kind contributions from a Tier 1 oil and gas producer and vessel operator.

Phase 2 will include a selection of a suitable cutting opportunity, 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, and integration of the Human Machine Interface (HMI) and electronic control from the first phase into the intelligent cutting tool to optimize cutting head manipulation and performance.

The objective is to demonstrate the system as a proven cutting technology for suitable applications, with the system being verified at technology readiness level 7 and suitable for further commercialization.

“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 commercialising 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 at Claxton.

The collaborative development is supported by funding and project oversight by the Net Zero Technology Centre, which supported 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.

According to the project partners, opportunities arising from laser cutting, as opposed to traditional methods, include single wall pile cuts, jacket or infrastructure downsizing for recovery, and waste size reduction for storage.

“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” said Richard Neilson, Centre Director at The National Decommissioning Centre.