Abstract: The process and apparatus for extracting the products of kerogen in situ from an oil shale body by supplying energy selectively to the kerogen by high frequency electric fields in the frequency range between 100 kilohertz and 1000 megahertz at an intensity which heats the kerogen to a temperature range between 250.degree. C. and 500.degree. C. to allow pyrolysis of the kerogen prior to substantial heat transfer to the surrounding mineral portions of the oil shale.

Abstract: The disclosure describes a technique for uniform heating of relatively large blocks of hydrocarbonaceous formations in situ using radio frequency (RF) electrical energy that is substantially confined to the volume to be heated and effects dielectric heating of the formations. An important aspect of the disclosure relates to the fact that certain hydrocarbonaceous earth formations, for example raw unheated oil shale, exhibit dielectric absorption characteristics in the radio frequency range. In accordance with the system of the invention, a plurality of conductors are inserted in the formations and bound a particular volume of the formations. The phrase "bounding a particular volume" is intended to mean that the volume is enclosed on at least two sides thereof. Electrical excitation is provided for establishing alternating electric fields in the volume.

Abstract: A novel method for stimulating the flow of oil from the pay zone of a formation traversed by a bore hole which involves the conversion of liquid water into steam in situ in heat transfer proximity to the pay zone. A novel oil tool adapted to be lowered and suspended within the bore hole in proximity to the pay zone having a closed casing or shell within which is contained means for the in situ generation of steam, with the casing being provided with valve means whereby the steam thus generated can pass through the shell and into contact with the pay zone. A novel electrical control system for the operation, regulation and malfunction-detection of the oil tool from the ground surface.

Abstract: A method of producing viscous materials from subterranean formation comprises a plurality of steps. At least two wells are drilled and completed into the subterranean formation that contains the viscous material. At least one of the wells is completed as an injection well and one of the wells is completed as a production well. A plurality of electrode wells are drilled into the subterranean formation with the plurality of electrode wells being generally arranged in a pattern to define at least one path between the production well and the injection well with the length of the path being substantially greater than the distance between the production well and the injection well. The electrode wells are spaced apart along the path at distances that are substantially less than the distance between the production well and the injection well.

Abstract: An apparatus and method utilizes a plasma arc torch as a heat source for recovering useful fuel products from in situ deposits of coal, tar sands, oil shale, and the like. When applied to a coal deposit, the plasma torch is lowered in a shaft into the deposit and serves as a means for supplying heat to the coal and thereby stripping off the volatiles. The fixed carbon is gasified by reaction with steam that is sprayed into the devolatilized area and product gases are recovered through the shaft.When applied to tar sands and oil shale, the torch is lowered in a shaft into the deposit and serves as a heat source to allow the entrapped oil in the tar sand or the kerogen in the oil shale to flow to a reservoir for collection. When economically justified, the carbonaceous matter in the tar sands or oil shale deposits may be partially or completely pyrolyzed and recovered as gaseous fuel products.

Abstract: In one exemplar embodiment, method and apparatus include providing an electrode disposed in a plurality of vertically spaced boreholes penetrating the formation. The plurality of electrodes in contact with the salt water and oil of the formation are connected to a source of electrical power for establishing an AC electrical field of current flow between the spaced elctrodes. The electrodes are insulated from the earth structure surrounding the borehole for preventing an electrical current path between the electrodes and the earth structure for isolating the electrical current path from the electrode into the formation. The AC electrical current path through the formation generates volumes of free hydrogen in the formation where it is trapped for increasing the formation pressure. The increased pressure of the formation will drive the oil into producing boreholes spaced from the electrode boreholes.

Abstract: A method and apparatus is described for sealing boreholes in the earth. The borehole is blocked at the sealing level, and a sealing apparatus capable of melting rock and earth is positioned in the borehole just above seal level. The apparatus is heated to rock-melting temperature and powdered rock or other sealing material is transported down the borehole to the apparatus where it is melted, pooling on the mechanical block and allowed to cool and solidify, sealing the hole. Any length of the borehole can be sealed by slowly raising the apparatus in the borehole while continuously supplying powdered rock to the apparatus to be melted and added to the top of the column of molten and cooling rock, forming a continuous borehole seal. The sealing apparatus consists of a heater capable of melting rock, including means for supplying power to the heater, means for transporting powdered rock down the borehole to the heater, means for cooling the apparatus and means for positioning the apparatus in the borehole.

Abstract: Method for reducing the loss of power accompanying the transmission of electrical energy down a wellbore to heat a subterranean formation via electrical conduction between a plurality of wells completed therein, characterized by providing a low frequency alternating current to the conductors in the wellbore. Also disclosed are specific embodiments of the invention.

Abstract: A method of heating hydrocarbons in situ in an underground hydrocarbon deposit such as bituminous sands or oil shale. A selected part of the deposit is heated by electrical induction coils arranged in a quasi-toroidal configuration to temperatures high enough to facilitate extraction. The coils are preferably comprised of interrupted rectangular turns. A series of generally concentric quasi-toroidal configurations can be used to heat large volumes. A hexagonal honeycomb array of such configurations can be used to heat deposits underlying very large surface areas.

Abstract: Hydrocarbons are recovered from a subterranean formation by providing a plurality of generally horizontal boreholes in the formation. The boreholes are vertically spaced across the thickness of the formation and extend from the top to the bottom thereof. Selected boreholes are heated by means of an external source to drive off hot hydrocarbon gases. The hot gases are fed to selected, unheated boreholes to effect a preheating of the selected boreholes and to cool the hot gases prior to their recovery from the formation.