Abstract: Disclosed is a method for controlling the flame front during the in situ combustion of a subterranean carbonaceous stratum which involves monitoring the extent and movement of said flame front to determine the location of one or more segments of the flame front which exhibit unfavorable combustion characteristics, and injecting one or more gases into the vicinity of one or more of said segments to control and optimize the combustion in said segment.

Abstract: Disclosed is a method for controlling the flame front during the in situ combustion of a subterranean carbonaceous stratum which involves monitoring the extent and movement of said flame front to determine the location of one or more segments of the flame front which exhibit unfavorable combustion characteristics, and injecting one or more gases into the vicinity of one or more of said segments to control and optimize the combustion in said segment.

Abstract: Disclosed is a method of restoring the pressure-composition characteristics of a disproportionated hydride comprising removing substantially all hydrogen from said disproportionated hydride and maintaining said hydride in a substantially hydrogen-free environment at a regeneration temperature sufficient to effectuate desired restoration of the hydride's pressure-composition characteristics. Also disclosed are methods of insitu regeneration of hydrides in process applications.

Abstract: Disclosed is a method for controlling the flame front during the in situ combustion of a subterranean carbonaceous stratum which involves monitoring the extent and movement of said flame front to determine the location of one or more segments of the flame front which exhibit unfavorable combustion characteristics, and injecting one or more gases into the vicinity of one or more of said segments to control and optimize the combustion in said segment.

Abstract: Disclosed is a method and apparatus for controlling flame front advance in underground combustion of hydrocarbonaceous material by passing an oxidizing gas into the combustion area comprising providing a plurality of gas removal means positioned so that gas can be removed in the direction of the desired flame front advance; detecting flame front position in the combustion area; selectively removing gas from the retorting area in response to the detected flame front position through one or more of the gas removal means; so that flow of gas to portions of the flame front can be controlled, thereby controlling the advance of portions of the flame front in the desired manner. This method is especially useful in the underground in situ retorting of oil shale.

Abstract: Disclosed is an apparatus and method for the recovery of hydrocarbon values from underground hydrocarbonaceous deposits comprising forming an underground reaction zone containing a mass of rubblized hydrocarbonaceous material; forming an essentially surface reaction zone containing a mass of rubblized hydrocarbonaceous material in fluid communication with the underground reaction zone; forming an underground product collection zone for the gathering and collection of hydrocarbon values, said zone being in fluid communication with the surface and underground reaction zones; passing a suitable fluid capable of removing hydrocarbon values from the rubblized material through the surface and underground reaction zones so as to effectively remove hydrocarbon values from such material; and passing the hydrocarbon values to the underground collection zone for recovery.

Abstract: Disclosed is a method for detecting the flame front in the in situ combustion of a subterranean carbonaceous stratum which comprises providing two or more resistance probes inserted into the ground electrically connected in one or more circuits capable of measuring the resistance between pairs of said probes, and monitoring the change in resistance in one or more of said circuits as an indication of the extent and movement of said flame front.

Abstract: Disclosed is a method for detecting the flame front during the in situ combustion of a subterranean carbonaceous stratum which involves providing at least one multi-turn coil of wire on the surface of the ground electrically connected into one or more circuits in which an electrical resonance condition is established, and monitoring the change in impedance in one or more of said circuits as an indication of the extent and movement of said flame front.

Abstract: A method for locating the position of a flame front within a rubbled oil shale retort of known dimension and location during an in situ combustion of the retort involving initiating a seismic signal at a selected position on the earth's surface relative to the retort, detecting the reflected seismic energy, and determining the position of the flame front by virtue of a maximum in the received reflected/refracted seismic signal. Repeating the process at a plurality of positions relative to the burning retort establishes the inclination of the flame front.