Interaction between CO2-rich acidic water, hydrated Portland cement and sedimentary rocks: Column experiments and reactive transport modeling

Percolation experiments, using columns filled with alternating layers of hydrated Portland cement and crushed sedimentary rocks, were conducted at PCO2 = 10 bar 60 °C. Limestone, sandstone marl representative reservoir cap rocks for a geologic CO2 storage site. The injected solution was equilibrium gypsum equilibrated the CO2. main reactions dissolution calcite that constitutes hydrotalcite portlandite cement. resulting porewaters supersaturated respect to aragonite gypsum, leading their precipitation. 2D reactive transport simulations successfully reproduced experimental aqueous chemistry changes caused by major calcite, together precipitation aragonite, dolomite (cement carbonation), alunite. Porosity increased different extents in both rock. Cement degradation noticeable all cases, but even more experiment.