Electrical spectroscopy of porous rocks: a review—I. Theoretical models

The complex dielectric permittivity ε* of porous water-bearing rocks in the frequency range from a few to hundreds of megahertz reveals several intensive relaxation effects and a non-trivial dependence on the water content. At high frequencies, f>10MHz, both the real part of the complex dielectric permittivity ε′ and the conductivity σ of water-bearing rocks are correctly predicted by the Maxwell–Wagner–Bruggeman–Hanai (MWBH) theory of composite dielectrics. This theory takes into account only the bulk properties of components, their partial volumes and the configuration of particles. The theory ignores two important factors: the surface contribution to polarization and the effect of clustering of components. At frequencies f