Abstract
In order to reach the global warming mitigation agreement reached at the recent Paris COP convention, capture and storage of CO2 will have to be one of the central measures on offer, at an international scale. The volumes of CO2 to be stored will be such that all possible storage reservoirs will have to be considered; this means that many rock formation types and lithologies will be targeted. In order to reduce risks associated with injection of supercritical CO2 in the subsurface, careful and systematic exposure tests of each candidate rock lithology must be carried out. Potential weakening of a target reservoir formation can have different impacts on the storage operation, depending on whether the weakening is localised or spread out, and whether it leads to stress distribution impacting the sealing caprock above the reservoir or faults bounding it.