UK firm sets the stage for offshore CCS and hydrogen storage with new well re-entry and re-abandonment tool 

UK-headquartered offshore energy engineering solutions provider Aquaterra Energy has unveiled a solution, said to cut costs and save time during legacy well abandonment activities, to lend a helping hand in enabling the era of offshore storage for hydrogen and carbon capture and storage (CCS) projects.

To this end, the firm launched legacy well re-entry and re-abandonment services alongside its patent-pending recoverable abandonment frame (RAF), targeting offshore wells that pass through oil and gas reservoirs or saline aquifers for repurposing into carbon dioxide (CO2) or hydrogen storage.

Aquaterra Energy highlights the economic and technical challenges of re-abandoning legacy wells, particularly for CCS and hydrogen storage projects. Wells beneath the seabed can pose significant leak risks, and conventional methods like relief well drilling are often impractical in shallow waters or when the well’s azimuth and depth are unknown.

Traditional excavation methods, which involve removing large amounts of material, often fail to isolate re-abandonment loading from compromised legacy well, leading to issues with technical effectiveness, environmental safety, and regulatory compliance.

Aquaterra Energy said it addressed these challenges by utilizing advanced seabed and subsurface surveying technologies, along with well imaging, marking, and tagging. These methods enable precise identification and location of legacy wells, ensuring safer and more efficient re-abandonment processes.

The RAF can adjust to the exact well position, installing conduits below the seabed for re-engagement and re-abandonment through a vertical tie-back method. According to the UK energy company, RAF directs environmental, lateral, and axial loads from wave action into the frame and surrounding seabed, protecting potentially corroded or fatigued legacy well components during the re-abandonment process.

George Morrison, CEO at Aquaterra Energy commented, “The introduction of the RAF and our re-entry services illustrate our strategy of pivoting decades of offshore expertise to address the wider challenges of the energy transition. Our team is committed to innovating and taking on the tough issues, ensuring that carbon and hydrogen storage can be effectively delivered as part of our broader commitment to driving the energy transition forward.”

Designed for repeated use across various well locations, the RAF’s modular structure is adaptable to different seabed conditions and can be shipped globally or transported by road for quayside assembly, noted Aquaterra Energy. 

This approach allows for the re-abandonment of wells previously considered unfeasible and reduces costs—by as much as 80%, or £18-20 million per well. It also shortens project timelines by up to 50%, enabling faster and more efficient re-abandonment processes.

“The RAF and our associated suite of services for legacy well re-entry represents a significant leap forward in abandonment technology,” noted Ben Cannell, Innovation Director at Aquaterra Energy. 

“Well re-abandonment for CCS is a new challenge, and our solution has been developed to meet it head-on. By reducing project risk, costs and operational time, we’re not only making well abandonment more efficient, but also enabling the viability of carbon or hydrogen storage, as these projects would generally be far more costly or even impossible to deliver.”

Aquaterra Energy confirms its engagement in talks with oil and gas companies, alongside CCS operators, in regions such as the North Sea and APAC, regarding the use of their legacy well re-entry services and RAF technology.

The UK player recently won a three-year contract to provide analysis services across an undisclosed operator’s global offshore operations. Apart from that, it was hired by INEOS for work on repurposing the Nini offshore platform for CO2 injection.