Quantification of mineral accessible surface area and flow-dependent fluid-mineral reactivity at the pore scale

Accessible surface areas (ASAs) of individual rock-forming minerals exert a fundamental control on the maximum mineral reactivity with formation fluids. Notably, ASA efficiency during fluid-rock reactions can vary by orders magnitude, depending inflow fluid chemistry and velocity field. Due to lack adequate quantification methods, determining mineral-specific ASAs their reaction still remain extremely difficult. Here, we first present novel joint method that appropriately calculates in multi-mineral sandstone. This combines SEM-image processing results Brunauer-Emmett-Teller (BET) area measurements Monte-Carlo algorithm derive scaling factors for at resolution BET measurements. Using these atomic-scale ASAs, then investigate impact flow rate dissolution injection CO2-enriched brine. is done conducting series pore-scale reactive transport simulations, using two-dimensional (2D) scanning electron microscopy (SEM) image this The determined employing domain-averaged effective most phase sandstone (dolomite). As expected, dolomite found increase rate, due average high reactivity. increases slightly reaches relatively stable value about 1%. domain averaged compared in-out (i.e “Black-box” approach), which often used analyzed experimental observations. yields considerable overestimation reactivity, small underestimation efficiency. discrepancy between two methods becoming smaller when increases. Our comparison suggests result interpretation should be contemplated, particular, small. Nonetheless, our proposed determination facilitate accurate calculations fluid-mineral large-scale advise an upscaling needs carefully considered, low