Pore-space structure and average dissolution rates: A simulation study

摘要: We study the influence of pore-space geometry on sample-averaged dissolution rates in millimetre-scale carbonate samples undergoing reaction-controlled mineral upon injection a CO_2 saturated brine. The representation is obtained directly from micro-CT images with resolution few microns. Simulations are performed particle tracking approach three porous rocks increasing complexity: beadpack, Ketton oolite and an Estaillades limestone. Reactive transport simulated hybrid that combines Lagrangian method for reaction Eulerian flow field by solving incompressible Navier-Stokes equations voxels three-dimensional images. Particle advection semi-analytical streamline diffusion via random walk. Mineral defined terms flux through pore-solid interface, which can be related analytically to batch (intrinsic) rate. The impact heterogeneity reactive illustrated series simulations at different rates. average depend both sample rate. most heterogeneous rock may exhibit decrease up two orders magnitude comparison Furthermore, we provide new insights regime would traditionally characterised as uniform. In cases, pore scale, preferentially enlarges fast-flow channels greatly restricts effective surface available reaction. This article protected copyright. All rights reserved.