A system for recovering gas trapped within the earth includes a casing (24) sized and configured to be positioned within a borehole in the earth, the casing (24) formed of a material that is transmissive to electromagnetic energy and gas within the earth; an antenna (40) sized and configured to be positioned within the casing (24). The antenna (40) has a distal end and a proximal end and including a radiating element at the distal end of the antenna (40) which, in operation, transmits electromagnetic energy toward a desired area of the earth, and an interior channel for allowing gas to be conveyed from the distal end to the proximal end of the antenna (40).
The extraction of hydrocarbon fuel products such as kerogen oil and gas from a body of fixed fossil fuels such as oil shale is accomplished by applying a combination of electrical energy and critical fluids with reactants and/or catalysts down a borehole to initiate a reaction of reactants in the critical fluids with kerogen in the oil shale thereby raising the temperatures to cause kerogen oil and gas products to be extracted as a vapor, liquid or dissolved in the critical fluids. The hydrocarbon fuel products of kerogen oil or shale oil and hydrocarbon gas are removed to the ground surface by a product return line. An RF generator provides electromagnetic energy, and the critical fluids include a combination of carbon dioxide (CO.sub.2), with reactants of nitrous oxide (N.sub.2O) or oxygen (O.sub.2).
