Decom Engineering dive into subsea Chopsaw development following Gyda platform success

Decom Engineering (Decom) is developing a new lighter Chopsaw capable of cutting piping and infrastructure in excess of 30” following a successful project on the Pioneering Spirit heavy-lift vessel on behalf of offshore contractor Allseas.

Decom was part of the project team commissioned to remove Repsol Norge’s 30,000-tonne Gyda platform in the North Sea – providing cutting expertise to safely remove conductors from the seabed.

The decommissioning specialist’s C1-24 Chopsaw conducted clean cuts on 20” conductors as part of a wider campaign to remove and transport the Gyda’s platform jacket to Aker Solution’s disposal yard in Norway.

Conductor removal is a new market for Decom and following the Gyda workscope the firm has invested in developing an updated Chopsaw which will be manufactured primarily from aluminium and capable of operating in more restricted spaces.

Sean Conway, Decom Engineering Managing Director, said: “The lessons learned from working on the Gyda project was extremely valuable and we appreciate Allseas’ willingness to support new technologies and young innovative companies.

“We believe we can offer contractors involved in conductor removal operations safe, efficient and environmentally friendly cutting options in what is often challenging conditions.

“We have committed to adapting our C1-24 Chopsaw design to be even more versatile and the updated model will be capable of cutting a minimum of 30” infrastructure, with the weight of the saw significantly reduced due to a high aluminium content.

“The main challenge on this type of project is the tight space in between each conductor but the new saw has been designed with this in mind. The weight-saving measures also reduce the need for buoyancy, in addition to being self-supporting when attached to the conductors.”

Decom has designed and developed a range of cold cutting saws which have been deployed on a variety of energy sector decommissioning projects in the North Sea, the Gulf of Thailand and offshore west Africa.

Recent technical trials at the National Hyperbaric Centre in Aberdeen have demonstrated the Chopsaws can perform cutting operations in water depths of up to 800 metres and are adept at accessing difficult to access subsea infrastructure.

Headquartered in Northern Ireland, earlier this year Decom invested £250,000 on a 6,000 sq ft equipment testing and storage base near Aberdeen to target North Sea clients. The facility is managed by decommissioning sector expert Andy Clucas, who was appointed last month (Sept) to build relationships with potential UKCS customers.