Influence of the flow rate on dissolution and precipitation features during percolation of CO2-rich sulfate solutions through fractured limestone samples

Variation in fracture volume induced by calcite dissolution and gypsum precipitation was measured by X-ray computed microtomography (XCMT) and aqueous chemistry. An increase in flow rate led to an increase in volume of dissolved limestone per unit of time, which indicated that the calcite dissolution rate in the fracture was transport controlled. Moreover, the dissolution pattern varied from face dissolution to wormhole formation and uniform dissolution by increasing the flow rate (i.e., Pe from 1 to 346). Fracture permeability always increased and depended on the type of dissolution pattern.