Aquaterra Energy, a prominent firm in offshore engineering solutions, has announced the launch of its legacy well re-entry and re-abandonment services along with its new (patent-pending) Recoverable Abandonment Frame (RAF). The combined solution is designed to address challenges in locating, re-entering and re-abandoning legacy wells that penetrate, or pass through, offshore oil and gas reservoirs or saline aquifers that have been earmarked to be repurposed for carbon dioxide or hydrogen storage. It is anticipated that the Recoverable Abandonment Frame technology could reduce abandonment costs by £20 million per well and cut project timelines by 50%
The technology addresses the significant economic and technical challenges of re-abandoning problematic legacy wells that pose a leak risk beneath the seabed could derail many carbon capture and storage and hydrogen storage projects if they intend to use previously penetrated oil and gas or saline aquifer formations. Technical challenges such as traditional relief well drilling could be infeasible in shallow intersects or where azimuth and depth are unknown. Excavation methods require enormous amounts of material to be removed and may also fail to isolate re-abandonment loading from the compromised legacy well, meaning both methods may fall short in addressing technical, environmental, safety, and regulatory issues effectively.
Aquaterra Energy’s solution is said to overcome these challenges by employing 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. Crucially the RAF also protects the legacy well components from environmental, lateral and axial loading generated by wave action on the tieback conduits and the re-abandonment operation itself.
The technology is intended for repeated use across multiple wells or locations with flexibility built in for differing seabed conditions. Its modular design allows for shipping worldwide or road transport for quayside assembly.
Aquaterra Energy is currently in discussions with major oil and gas operators and specialist CCS operators in several global regions, including the North Sea and APAC, to deploy their legacy well re-entry services and RAF technology.
