Pore-scale Modelling to Simulate Reactive Flow in Porous Media

Pore to core scale approach is used to calculate the multiphase flow properties and the transport parameters of mass transfer with surface reaction of a real sandstone sample cored from gas field reservoir. The approach uses a simplified micro-structure of the porous medium. The pore-network (void space of the porous medium) is composed of pore-bodies joined by pore-throats with idealized geometry. Parameters defining the pore-bodies and the pore-throats distribution are determined by an optimization process aiming to match the experimental mercury intrusion capillary pressure (MICP) curve and petrophysical properties of the rock such as intrinsic permeability and formation factor. The flow is calculated by using Kirchhoff laws. Transport is determined in the asymptotic regime where the solute concentration undergoes an exponential evolution with time. The generated network is then used first to simulate the multiphase flow, the capillary pressure, relative permeability and resistivity index curves are derived. Then, reactive transport is addressed to infer pore evolutions and changes of petrophysical properties resulting from dissolution processes involved in CO2 storage. Finally, the role of the Peclet and Peclet-Damköhler dimensionless numbers on the reactive flow properties is highlighted.