The Energy Act 2008 requires that a large proportion of the North Sea infrastructure will need to be decommissioned in the next 30 years. Only 88 (12 percent) installations have been decommissioned in the UK continental shelf to date, reflecting the nascent nature of the decommissioning market. With more stringent environmental legislation related to global warming and the depletion of oil reserves due to rising demand, it is thought that decommissioning will become a priority for many companies. This will potentially provide substantial decommissioning opportunities for years to come.
There is currently a selection of different subsea cutting methods which could be effectively utilised for decommissioning offshore installations. Three main competing technologies for decommissioning subsea structures are abrasive water jet, diamond wire cutting and plasma arc cutting. However, to couple with varied geometries and thicknesses, a single tool with flexible functionality (ease of remote deployment, operation and maintenance), and capability to cut both from outside-in and inside-out, would be considered highly desirable.
Fibre delivered laser beam cutting has the potential to deliver these benefits by means of cutting safer, cheaper and faster. Moreover, fibre delivered, underwater laser cutting has the potential to develop a system that can cut installations at extreme water depths. As water depth increases by 10m, the hydrostatic pressure increases by approximately one bar.
- Develop a scientific understanding of the underwater laser cutting process and influencing parameters, up to a hydrostatic pressure of 20 bar on steel structures up to 50 mm in thickness
- Advance an existing, state-of-the-art, underwater laser cutting technology with the capability of cutting 50 mm thickness mild steel at depths up to 200 m
- Disseminate the project results and capabilities developed towards post project exploitation