Aquaterra Energy’s new services for legacy wells and its patent-pending Recoverable Abandonment Frame (RAF) can repurpose offshore oil and gas reservoirs for CO2 or hydrogen storage. The technology helps accelerate retrofits of post-combustion carbon capture and storage at fossil-fuelled power stations, as it offers an outlet to safely store the captured CO2.
Economic and technical challenges of re-abandoning problematic legacy wells that pose a leak risk beneath the seabed had derailed many CCS and hydrogen storage projects. Traditional relief well drilling is often infeasible in shallow intersects or where azimuth and depth are unknown, while excavation methods require enormous amounts of material to be removed, at a high cost.
Aquaterra Energy’s solution employs advanced seabed and subsurface surveying technologies, well imaging, marking, and tagging to precisely locate wells. This allows the RAF to adjust to an exact well position and install conduits below the seabed to re-engage the legacy well and then back to the surface to allow for successful re-abandonment via a vertical well re-entry tieback method.
The technology’s modular design allows for shipping worldwide or road transport for quayside assembly. This lowers cost, saving operators of £18-20 million per abandoned well - an estimated 80 percent reduction in comparison to other methods currently deployed. Aquaterra claims the approach could also lead to major reductions in project timelines, estimated to be up to 50 percent quicker per well.
Looking ahead, Aquaterra is in talks with major oil and gas operators and specialist CCS operators as it seeks to set up pilot projects and facilitate CO2-value chains with a view to decarbonising industry and the electric power sector.
