Kozeny–Carman and empirical formula for the permeability of computer rock models

Increasing interest in physical properties of rocks for purposes such as reservoir engineering and environmental geophysics has stimulated increased use of computer modeling of rock microstructure. Three-dimensional rock microstructure models based on spherical and non-spherical grain models are presented in this paper. The models are used to calculate the permeability. Important parameters such as tortuosity, which is difficult to measure in the laboratory, can be calculated easily by means of Lattice Boltzmann Method applied to the constructed models. The Kozeny–Carman formula gives lower prediction than the measured permeability. Modified power laws of porosity give better estimates if divided into two separate formulas, one for porosities lower than 20% and another for porosities higher than 25%. This new empirical formula gives better prediction for all models, except pigeon-hole.

► Various computer models as representatives of real rock microstructure.
► Lattice Boltzmann Method to calculate tortuosity.
► Modified Kozeny–Carman relation to estimate permeability.