Abstract: This invention provides for methods and systems for measuring the dielectric constant of an earth formation. In a preferred embodiment, an alternating current is passed through a portion of the formation and a reference resistor in series with the portion. The capacitance and the dielectric constant of the portion may be determined from the phase difference between the voltage across the reference resistor and the voltage across the portion. This phase difference may be obtained by generating a voltage which is in phase with the voltage across the reference resistor, but which has the magnitude of the voltage across the portion. To obtain the phase difference by an alternate digital method, the voltage across the referenced resistor and the voltage across the portion are each transformed into a square wave signal. The two square wave signals are then compared to obtain the sign and the magnitude of the phase difference between the two square waves.

Abstract: A method is disclosed for recovering carbonaceous material from a subterranean deposit such as oil shale. A first zone of the subterranean deposit is heated to liquefy and vaporize carbonaceous materials contained therein. A substantial portion of the carbonaceous materials are removed from this first zone. Thereafter a second zone of the deposit is rubblized such that material of the second zone occupies a portion of the space occupied by the first zone. The second zone is then heated and carbonaceous materials are removed therefrom.

Abstract: In a subsurface formation, where shaliness affects the results of typical electrical well logging measurements, partial water and partial hydrocarbon saturations are determined from measurements of dielectric constant. The relation between dielectric constant and conductivity due to shaliness in a partially water saturated formation and a relation defining dielectric constant change as a function of partial water saturation are used to determine partial water saturation and partial hydrocarbon saturation of said formation.

Abstract: Disclosed herein in a method for determining the lithology of and the types of fluid contained within a subterranean formation. In the practice of this invention, high energy neutrons bombard the formation matrix and formation fluids. Induced gamma rays from inelastic scattering reactions are indicative of the type of fluid in the formation, and induced gamma rays from neutron capture reactions are indicative of the lithology of the formation matrix. Among other things, this technique permits differentiation between water-saturated limestones and oil-bearing sandstones. Also disclosed herein is a method for detecting the presence of natural gas within a subterranean formation.