oa Assessing CO2 Storage Potential in the Leman sandstone Fields of the UK Southern North Sea

The Southern North Sea is a key region for carbon storage in the UK, due to its proximity to CO2 sources, existing infrastructure, and numerous depleted fields. The Leman Sandstone is a key target, with over 100 gas fields. More than half of these are depleted, with many others nearing cessation of production. Collectively, they have a storage capacity exceeding 3 metric gigatons, with license operators reporting planned injection rates above 10 MMtpa. This study evaluates the suitability of Leman Sandstone fields for CO2 storage, focusing on their capacity and geological characteristics.

While over 40 Leman sandstone fields have a theoretical capacity above 10 MMt, the reservoir quality varies significantly due to factors like depositional environment and burial history. On the Inde Shelf the sandstone has excellent reservoir quality, with high permeability and thickness, making it ideal for CO2 storage. In contrast, in the Sole Pit Basin, despite high capacity, the sandstone has low permeability, likely requiring numerous wells to achieve desired storage rates, impacting project economics. Compartmentalization further complicates storage, necessitating multiple injection wells across different compartments. Despite high theoretical capacity, operational complexities and financial considerations may affect economic viability, underscoring the importance of a comprehensive basin-wide comparison approach.