Abstract: A method for determining at wellsites the swelling-clay content of shales and shaly sandstones earth formations whereby a sample of the formation is washed with a fluid having a water activity substantially less than that of water, which fluid may contain a soluble cation, and measurements of the sample's dielectric constant are made at a preselected frequency for subsequent comparison to calibration curves, thereby obtaining a measurement of the welling-clay content of the formation. The determinations of the swelling-clay content may be performed at different levels depending on the nature of the samples.

Abstract: A method and system for measuring rock electrical properties using time-domain spectroscopy. The rock to be measured is place in direct contact with the substantially flat face of a sample cell. A voltage pulse is launched into a coaxial line connected to the sample cell. The pulse propagates through the sample cell and reflects from the rock. The incident voltage pulse and reflected voltage signal are analyzed to determine the rock's conductivity as well as the rock's dielectric constant over a broad frequency range.