f Seal Assessment in the Context of Underground CO2 Storage - Challenges and Existing Methods

Capture of C02 from large point sources and subsequent long-term underground storage is at present the most promising option to reduce greenhouse-gas emissions without major sudden changes of our energy system. Two main types of subsurface CO2 reservoirs exist: emptied hydrocarbon fields and (saline) aquifers. In addition, some minor quantities of CO2 can be stored in enhanced oil recovery (EOR) projects. In all these cases, the existente of a tight seal is mandatory, to restrict buoyancy-driven upward migration of the CO2 into the atmosphere.