The Frequency Dependent Dielectric and Conductivity Response of Sedimentary Rocks

In this paper we describe quantitively how the conductivity and the dielectric constant of water-filled rocks depend on textural and interfacial effects. The grain shape determines the Archie’s exponent for the dc conductivity as well as the frequency dependent dielectric constant. The large values of dielectric constant can arise from platey grains. Platey grains also give rise to large frequency and salinity dependences of the dielectric constant. The interfacial effects are particularly important in clayey systems. The polarization of interfacial ions gives rise to large values of dielectric constant and affects the rock conductivity.