SANS/VSANS investigation of porosity microstructure in rocks from a natural CO2 reservoir

Carbon capture and storage (CCS) is considered a valid option to reduce the CO2 concentration in atmosphere. The gas is collected from industrial plants, then injected and stored underground in geological reservoir. A very wide range of information about chemical-physical characteristics of the sequestration site is therefore needed and, among them, data on porosity microstructure are crucial. Part of the processes which affect micro-porosity and act during and after the rocks formation can be reconstructed by studying the micro-porosity features. We have therefore performed a couple of SANS and VSANS experiments on rocks coming from a CO2 reservoir (which represents a natural analogue of a CCS site) in order to define the role and the possible effects of CO2 alteration in determining the micro-porosity and to check the sealing potential of rocks overlying the reservoir, which act as a barrier with respect to CO2-rich gas. The collected data are expected to be beneficial for developing theoretical model about the effects of CO2 sequestration in deep geological reservoirs.