Change of Two-Phase flow Properties Due to Pore-Space Evolution in Reacting Porous Media

Progress of chemical reactions in reacting porous media causes change in pores sizes and porosity/permeability evolution. Potential applications are geological sequestration of CO2 and acid-gas injection during enhanced oil recovery. Pore-size distribution determines the form of capillary pressure-saturation as well as relative permeability-saturation curves. Van Genuchten parameters may be used to describe these relations to fit the observed data.

This study presents a pore-scale model to relate change in two-phase flow proprieties due to changes in pore size distribution due to the dissolution reactions. The pore space is represented using a multi-directional pore-network model which is composed of a large number of interconnected pore elements. Averaging over the pore network domain, upscaled parameters such as saturation is obtained. We will show how regime of flow and reaction (characterized using Damköhler number and Péclet-Damköhler number) may result in different responses such as uniform dissolution, shaper front dissolution as well as formation of channels or wormholes. Each of these reaction regimes affects pore-size distribution differently controlling van Genuchten parameters of two-phase flow.