Absolute Permeability Calculation by Direct Numerical Simulation in Porous Media

Abstract

Simulating fluid flow at micro level is an ongoing problem. Simplified macroscopic flow models like Darcy’s law is unable to estimate fluid dynamic properties of porous media. The digital sample reconstruction by high resolution X-ray computed tomography scanning and fluid-dynamics simulation, together with the increasing power of super-computers, allow to carry out pore-scale simulations through digitally-reconstructed porous samples. The pore-scale flows which derived from computational fluid dynamic are then evaluated using the finite volume method implemented in the open-source platform OpenFOAM®. In this work to verify the solver in porous media we simulated fluid flow around sphere in body-centered cubic (bcc) lattice and calculated the dimensionless permeability for a wide range of radius and porosity; the results are comparable with those obtained by using carman-kozeny equation. Then this solver is performed on realistic sample to investigate the effect of sample size on calculated permeability and tortuosity and the mesh refinement levels for a fixed image resolution.

Keywords

• cfd
• computed micro-tomography
• digital rock physics
• finite volume method
• openfoam
• permeability