Seal, and overburden rock characterization of potential CO2 storage sites in the northern North Sea

Abstract

Building confidence in subsurface geological carbon dioxide (CO2) injection project The anthropogenic atmospheric carbon dioxide (CO2) is one of the major greenhouse gases that are responsible for human-induced global warming. To avoid further damage, we need to cut half of the CO2 emission by 2030 and net-zero emissions by 2050. Subsurface geological storage of CO2 is one of the viable solution that cuts emissions with the lowest possible cost. The injected CO2 will be captured from the point sources, transported, and permanently stored in the suitable subsurface geological formations. However, injecting CO2 into the subsurface has several failure risks. Therefore, a detailed integrated analysis is needed to build confidence for safe and permanent subsurface geological CO2 storage. This doctoral thesis study evaluates the impermeable layers called seals/caprocks, which prevent the less dense CO2 plume from migrating back to the atmosphere. A workflow is developed to characterize target caprock fracture risks by integrating different analytical techniques. Characterizing of the fracture risks help build our knowledge and confidence in safe and permanent subsurface CO2 storage. Without permanently removing the greenhouse gases, we might trigger irreversible environmental tipping points. Crossing the critical threshold might be devastating for the human race. Therefore, this study partially contributes to the fight against human-induced global warming.