Microscopy and image analysis of the micro-fabric and composition of saline rocks under different phaseCO2-Brine states

Abstract Using different phaseCO2-brine, the effect of stress corrosion on the micro-fabric, topology of the minerals and the elemental composition of saline rock was evaluated, to understand how this affect transport properties of rocks. Image analysis was used to evaluate changes in micro-fabric, topology of mineral and elemental composition from SEM images. The micro-fabric of all the CO2 bearing samples changed significantly according to the different phaseCO2-brine. Grain roundness, grain smoothness, and pore smoothness increased after compression while the roundness of pores reduced. There was a significant change in the weight percentage of silicon, carbon and oxygen in the CO2-bearing samples compared to the brine sample. Change in the shape, solidity and roundness of the pores led to a change in permeability of rocks by altering the tortuosity of the pores. This study provides an understanding of changes in micro-fabric and elemental changes occurring in saline CO2 storage sites under different possible phaseCO2-brine and highlights their implication for storage and properties of the rock.