Measurement of Dielectric Properties (MHz–MHz) of Sedimentary Rocks

The dielectric property is a useful parameter that can be used to infer other properties of porous media such as water saturation, permeability, etc. The dielectric properties (mHz to MHz) of isotropic porous media have been extensively studied. However, related studies are very rare for anisotropic porous media. In this study, we have measured the directional dielectric spectra of two sedimentary rocks (one Bakken shale sample and one Lyons sandstone sample) using the combination of 2-and 4-electrode methods in the frequency range between 10-3 and 107 Hz. It is shown that the dielectric constant of these two samples generally increases as the frequency decreases. This is because, as the frequency decreases, more polarization mechanisms start to contribute to the measured dielectric constant. It is also shown that the dielectric anisotropy in these samples decreases as the frequency increases, indicating that different polarization mechanisms induce different degrees of dielectric anisotropy.