Abstract: A compact catalytic combustor for generating steam downhole in an oil reservoir has steam generating tubes that are attached to a metal catalyst support. The metal support comprises sheets of metal that are spaced apart and transverse to the tubes. Heat from combustion is generated on the metal sheets and is conducted to the steam generating tubes. The steam is injected into the oil reservoir. The combustion gas is vented to ground level.

Abstract: An improved downhole steam injector has an angled water orifice to swirl the water through the device for improved heat transfer before it is converted to steam. The injector also has a sloped diameter reduction in the steam chamber to throw water that collects along the side of the chamber during slant drilling into the flame for conversion to steam. In addition, the output of the flame chamber is beveled to reduce hot spots and increase efficiency, and the fuel-oxidant inputs are arranged to minimize coking.

Abstract: Direct firing downbole steam generator basically comprises an injector assembly axially connected with a combustion chamber. Downstream of the combustion chamber and oriented so as to receive its output is a heat exchanger wherein preheated water is injected into the heat exchanger through a plurality of one-way valves, vaporized and injected through a nozzle, packer and check valve into the well formation.

Abstract: A method and apparatus for conducting such method are disclosed for igniting a fragmented permeable mass of formation particles in an in situ oil shale retort. The method is conducted by forming a hole through unfragmented formation to the fragmented mass. An oxygen-containing gas is introduced into the hole. A fuel is introduced into a portion of the hole spaced apart from the fragmented mass. The fuel and oxygen-containing gas mix forming a combustible mixture which is ignited for establishing a combustion zone in a portion of the hole spaced apart from the fragmented mass. The hot gas generated in the combustion zone is conducted from the hole into the fragmented mass for heating a portion of the fragmented mass above an ignition temperature of oil shale.

Abstract: A downhole steam apparatus for location within the casing of a well borehole to facilitate oil recovery. A housing adapted to be lowered into the borehole includes a combustor for mixing and burning fuel and air, and a heat exchanger having an array of water tubes exposed to the heated gases from the combustor for converting water into steam. The steam is injected downwardly into the borehole, and the spent gases pass into the annulus between the casing and the housing. An expansible packer seals off the annulus between the steam injection area and the spent gas injection area. Compressed air for combustion is supplied at the lower spent gas pressure. Various arrangements are disclosed for the water tube array in the heat exchanger.

Abstract: A catalyst containing steam generator is lowered to the formation to be steamed. A packer is set at the upper extension of the generator to retain the steam. Fuel gas and oxidizing gas are passed through the catalyst which causes combustion within the catalyst bed. Water is passed over the heated tube retaining the hot catalyst bed or through the catalyst bed to produce steam.

Abstract: A method for assembling an ignition system for in situ combustion operation to recover petroleum from a well in a subterranean reservoir, and an ignition system for an elongated combustion chamber suspended from a hollow electrical cable and which cable supplies both electrical means and fuel gas to the chamber. Air inlet ducts in the walls of the air inlet cylinder receive air from the annular space between the hollow cable and the wellbore tubing. An electrical ignitor is temporarily energized automatically or responsive to a thermocouple detecting no burning in the combustion chamber to ignite the fuel-air mixture in the combustion chamber. The ignitor is responsive to the thermocouple detecting burning in the combustion chamber for extinguishing the ignitor. The thermocouple is thus responsive to a flameout for re-energizing the ignitor either manually or automatically such that burner operation is interrupted only momentarily.

Abstract: A multistage gas generator for use in a borehole for recovering hydrocarbons from the subsurface formations. The gas generator has an upper end and a lower restricted outlet. A pilot stage is located at the upper end and a plurality of spaced apart intermediate stages are located between the pilot stage and the lower restricted outlet. Hydrogen and oxygen are fed to the pilot stage for ignition. Oxygen is fed to a first intermediate stage and hydrogen and oxygen are fed to each of the other intermediate stages for injection into the gas generator. Excess hydrogen from the pilot stage is burned in the zone of the first intermediate stage and hydrogen and oxygen of each succeeding stage is ignited by the preceeding stage. Water for cooling purposes also is fed to each intermediate stage. Downhole valves selectively controllable from the surface are provided for the pilot stage and each of the intermediate stages.

Abstract: A gas generator for use in a borehole for generating steam and other hot gases for use in recovering hydrocarbons or other fluids from underground formations. The gas generator comprises a housing forming a chamber with a combustion zone at one end and a restricted outlet at the other end. A second zone is located downstream of the combustion zone and a gas and water mixing zone is located between the second zone and the restricted outlet. The generator has a cooling annulus surrounding the chamber with passages leading from the annulus to the gas and water mixing zones. Methane is burned in the combustion zone with just enough oxygen to maintain the flame temperature below the decomposition temperature of methane to convert substantially all of the carbon to carbon monoxide and to form hydrogen. In the second zone, the carbon monoxide and hydrogen are burned with an additional supply of oxygen to increase the temperature and to form carbon dioxide and hydrogen.

Abstract: For in situ combustion operation to recover petroleum from a well in a subterranean reservoir, an ignition system for an elongated combustion chamber suspended from a hollow electrical cable and which cable supplies both electrical means and fuel gas to the chamber. Air inlet ducts in the walls of the air inlet cylinder receive air from the annular space between the hollow cable and the wellbore tubing. An electrical ignitor is temporarily energized automatically or responsive to a thermocouple detecting no burning in the combustion chamber to ignite the fuel-air mixture in the combustion chamber. The ignitor is responsive to the thermocouple detecting burning in the combustion chamber for extinguishing the ignitor. The thermocouple is thus responsive to a flameout for re-energizing the ignitor either manually or automatically such that burner operation is interrupted only momentarily.

Abstract: A method for initiating an in situ combustion operation for heating a well to recover petroleum from a subterranean reservoir in the well comprises lowering an elongated combustion chamber suspended from a hollow electrical cable with an air supply tube therearound which supplies electricity, fuel gas, and air to the combustion chamber, mixing an air-fuel mixture in the combustion chamber, and igniting the air-fuel mixture with an ignitor responsive to the thermocouple detecting burning in the combustion chamber for providing an automatic, reliable, and flame-out proof method for initiating heat deep in the well.

Abstract: A combination structure adapted for use in a catalytic process for stimulating the recovery of hydrocarbons from porous and permeable hydrocarbon bearing strata in earth formations utilizing at least one injection well and at least one production well both completed in said hydrocarbon bearing strata and a finely divided hydrocarbon cracking catalyst which is delivered by and through said structural combination of parts and elements to said strata by injection gas controlled at suitable pressure, temperature and O.sub.2 content to promote and advance in place catalytic cracking of hydrocarbons and catalyst regeneration within said strata to be produced by utilizing said combination structure or its equivalent.

Abstract: A method for heating a well or for initiating an in situ combustion operation to recover petroleum from a well in a subterranean reservoir, a method for assembling an ignition system for the in situ combustion, and an ignition system comprises an elongated combustion chamber suspended from a hollow electrical cable which supplies both electrical means and fuel gas to the chamber. Air inlet ducts in the walls of the combustion chamber receive air from the annular space between the hollow cable and the wellbore tubing. An electrical ignitor is temporarily energized to ignite the fuel-air mixture in the air inlet cylinder. An adjacent thermocouple is responsive to a flameout for re-energizing an ignitor manually such that burner operation is interrupted only momentarily .

Abstract: A gas generator for use in a borehole for generating steam and other hot gases for use in recovering hydrocarbons or other fluids from underground formations. The gas generator comprises a housing forming a chamber with a combustion zone at one end and a restricted outlet at the other end. A second zone is located downstream of the combustion zone and a gas and water mixing zone is located between the second zone and the restricted outlet. The generator has a cooling annulus surrounding the chamber with passages leading from the annulus to the gas and water mixing zone. Methane is burned in the combustion zone with just enough oxygen to maintain the flame temperature below the decomposition temperature of methane to convert substantially all of the carbon to carbon monoxide and to form hydrogen. In the second zone, the carbon monoxide and hydrogen are burned with an additional supply of oxygen to increase the temperature and to form carbon dioxide and hydrogen.

Abstract: A recovery process and system wherein hydrogen and oxygen are introduced into a vented pressure vessel, known as a gas generator, located at the bottom of a borehole, and ignited and burned to produce steam. The hydrogen and oxygen may be introduced either as a stoichiometric mixture or the combustible mixture may be hydrogen-rich. Remotely controlled valves are located downhole near the gas generator for positive control of the hydrogen and oxygen. Provision is made for maintaining the desired hydrogen-oxygen ratio either by a hydrogen flow control slaved to a downhole thermocouple or by a special hydrogen-oxygen flow control employed in the event that ignition is carried out by a DC power supply located downhole. Although the preferred embodiment employs a fuel-oxidizer combination of hydrogen and oxygen, provision is made for employing other fuel-oxidizer combinations.

Abstract: A process and system for insitu hydrogenation employing a gas generator in a borehole for burning a hydrogen-rich mixture of hydrogen and oxygen. The gas generator comprises a housing forming a chamber with a combustion zone at one end and a restricted outlet at the other end. Hydrogen and oxygen are supplied downhole to the generator to form a hydrogen-rich combustible mixture in the combustion zone which is burned whereby hydrogen and steam are injected from the restricted outlet. The flow of hydrogen and oxygen to the generator is controlled to maintain the temperature of the exhaust gases at a level sufficient to crack the hydrocarbons in the formation into lighter segments for reaction with the excess hot hydrogen to form lighter and less viscous end products which are recovered from a production well.

Abstract: A process and system for insitu hydrogenation employing a gas generator in a borehole for burning a hydrogen-rich mixture of hydrogen and oxygen. The gas generator comprises a housing forming a chamber with a combustion zone at one end and a restricted outlet at the other end. A cooling annulus surrounds the chamber with passages leading from the annulus to the chamber. Hydrogen and oxygen are supplied downhole to the generator to form a hydrogen-rich combustible mixture in the combustion zone which is burned whereby hydrogen and steam are injected from the restricted outlet. Hydrogen also is supplied to the cooling annulus. The flow of hydrogen and oxygen to the generator is controlled to maintain the temperature of the exhaust gases at a level sufficient to crack the hydrocarbons in the formations into lighter segments for reaction with the excess hot hydrogen to form lighter and less viscous end products which are recovered from a production well.

Abstract: The specification discloses a recovery process and system wherein hydrogen and oxygen are introduced into a vented pressure vessel, known as a gas generator, located at the bottom of a borehole, and ignited and burned to produce steam. The hydrogen and oxygen may be introduced either as a stoichiometric mixture or the combustible mixture may be hydrogen-rich. The gas generator comprises a cooling annulus surrounding a combustion and mixing zone for cooling the gas generator and the combustion products. Hydrogen or water may be supplied to the cooling annulus for cooling purposes. Remotely controlled valves are located downhole near the gas generator for positive control to the gas generator of the hydrogen and oxygen and of the water, if it is employed for cooling purposes. The well casing is sealed just above the gas generator by an inflatable packer.

Abstract: An apparatus and method for injecting pressurized fluid into a well are disclosed. The apparatus to inject pressurized fluid into a well comprises a combustion chamber, having a coolant jacket positioned to circulate coolant over outer walls of the combustion chamber and into the combustion chamber around the burner such that vapor flows between a flame and inner walls of the combustion chamber. The injected coolant forms a vapor barrier between the flame and the combustion chamber walls and is pressurized for delivery into a well. The combustion chamber can be affixed to the well casing at the surface or the combustion chamber can be used as a "down-hole" vapor generator apparatus.

Abstract: A technique is described for igniting the oil shale rubble pile in an in situ oil shale retort. A gas-air burner is lowered through a hole to a plenum over the oil shale to be ignited. An excess of air is passed through the hole and around the burner so that it is kept cool as the flame from it impinges on the rubble pile. The air also transfers heat downwardly into the rubble pile and provides oxygen for combustion of carbonaceous material in the shale. Preferably the burner is in a cylindrical housing having a flame exit at its lower end so that a hot flame is ejected downwardly.