DEM-LBM simulation of stress-dependent absolute and relative permeabilities in porous media

In this work, stress-dependent absolute and relative permeabilites in porous media are studied using the discrete element method and lattice Boltzmann method. The change of absolute permeability and porosity during compaction is found follow a power-law relation. The stress-dependent absolute permeability in homogeneous pack is in agreement with the prediction of Carman-Kozeny equation. Porosity exponent is increased due to the existence of vugs but is decreased with fractures. Relative permeability, on the other hand, is found not only affected by pore structure of compacted media, but also properties of fluids and rock surface. Our simulations indicate that relative permeability of wetting phase increases slightly with increasing stress, due to the formation of more continuous pathways. Relative permeability of non wetting phase, however, either increases or decreases depending on viscosity ratio and capillary number. It is found that lubrication effects play an important role in the stress sensitivity of relative permeability. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study investigates stress-dependent absolute and relative permeabilities in porous media using two methods, revealing the power-law relation between absolute permeability and porosity during compaction, as well as the complex influences on relative permeability from factors such as pore structure, fluid properties, and rock surface characteristics.