Pore-network modeling of single-phase reactive transport and dissolution pattern evaluation

摘要

A pore-network modeling approach is proposed to understand mineral dissolution regimes during reactive trans-port, as well as changes in porosity and permeability. The transport problem is implemented with full consideration of the mass balance of the solute in all pore spaces, including pore-bodies and throats. The changes in geometry of the pore network due to calcite dissolution are taken into account based on the rate of the heterogeneous chemical reaction happening at the mineral surface. The networks consider two and three-dimensional domains with a variety of number of pores. The evolution of network geometry and flow properties are investigated under various flow conditions using representative Peclet and Damkohler numbers to understand the interplay of transport and reaction. A behavior diagram is constructed aiming to identify different regimes and their boundaries. The dissolution patterns identified in this study further the applicability of the pore-network model approach as a tool for understanding of reactive transport and dissolution processes.