A Framework for Pore‐Scale Simulation of Effective Electrical Conductivity and Permittivity of Porous Media in the Frequency Range From 1 mHz to 1 GHz

Author(s)

Qifei Niu, Chi Zhang, Manika Prasad

Abstract

Geoelectrical methods are broadly used in earth sciences for various purposes. To correctly interpret field geoelectrical data, it is essential to have a mechanistic understanding of the effective electrical conductivity and permittivity of geological materials over a broad frequency range. Recently, the pore-scale numerical simulation, which utilizes the digital microstructural images of the material, has become a powerful tool in studying the effective electrical properties of geological media. However, it is still difficult to incorporate surface-related electrochemical processes in a pore-scale simulation. In this study, we develop a general framework to consider these electrochemical processes in pore-scale simulations, which enable the calculation of broadband effective electrical conductivity and permittivity of porous geological media. A Berea sandstone sample is utilized to demonstrate the use of the proposed framework. Laboratory experiments of the effective electrical conductivity and permittivity of the sample in the frequency range from 10

⁻³ to 10

⁹ Hz provided valuable measurement data for validating the simulation. The good agreement between our simulated spectra and the experimental data provides validation for the numerical simulation to reproduce the variations in the effective electrical conductivity and permittivity of porous geological materials induced by both the electrochemical polarizations and the interfacial polarization. This work thus provides a useful tool for studying the effective electrical properties of porous geological materials featuring complex microstructures.

Organisation(s)

Department of Meteorology and Geophysics

Journal

Journal of Geophysical Research: Solid Earth

Volume

125

ISSN

2169-9313

DOI

https://doi.org/10.1029/2020jb020515

Publication date

10-2020

Peer reviewed

Yes

Austrian Fields of Science 2012

105906 Environmental geosciences, 105126 Applied geophysics

Keywords

ASJC Scopus subject areas

Geochemistry and Petrology, Geophysics, Earth and Planetary Sciences (miscellaneous), Space and Planetary Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/c48072a1-2b1e-4ea6-a5ce-e591a2ab86fe