Abstract: The present disclosure provides a comprehensive utilization method and test equipment for surface water, a goaf and geothermal energy in a coal mining subsidence area. The method comprises the following steps: determining a geothermal water collection area, arranging heat energy exchange equipment in a main roadway, and arranging a geothermal water extraction system, wherein the geothermal water extraction system comprises geothermal wells, extraction pipelines and tail water reinjection pipelines, the extraction pipelines are connected with the heat energy exchange equipment, and the tail water reinjection pipelines are connected with a water outlet of the heat energy exchange equipment; arranging a water channel on the surface, and arranging a drainage system on a subsidence trough to guide surface water to flow underground; and controlling directional and ordered flow of surface water through the coal mining subsidence area formed by ground mining to achieve sustainable mining of underground water.

Abstract: A method of sand consolidation is provided. The method includes injecting a consolidating fluid into a subterranean sand formation via a wellbore to saturate a portion of the subterranean sand formation in a target region surrounding the wellbore and displace a formation fluid present in the subterranean sand formation. Herein, the consolidating fluid comprises bitumen dissolved in an aromatic solvent. The method further includes injecting a composition comprising one or more heat-generating chemicals into the subterranean sand formation such that the portion of the subterranean sand formation in the target region is heated to a target temperature of at least 150° C. The method further includes injecting a gas comprising oxygen into the subterranean sand formation for a period sufficient to oxidize the bitumen in the target region into a residue present on sand grains to bind the sand grains together into a consolidated permeable matrix.

Abstract: An injection device, which comprises a nozzle and which is used for an underground coal gasification process; the nozzle and the injection device are used for continuously injecting a high-concentration oxidant into an underground coal layer during the underground coal gasification process, in which case the high-concentration oxidant may be used safely and steadily to obtain a high-quality and stable product gas, while a retraction cycle and/or a retraction distance of a retraction method in the existing technology may be greatly shortened, thus achieving the continuous and steady operation of the underground coal gasification process. Also disclosed is a method for operating the injection device.

Abstract: The invention allows for an increase in formation permeability and well flow rate. In a method for exerting a combined effect on the near-wellbore region of a producing formation, the following are fed separately and consecutively into the near-wellbore region: a process fluid No. 1 with a density of 1.3-1.4 g/cm3, followed by a process fluid No. 2 with a density of 1.6-1.8 g/cm3, which combines with the fluid No. 1. As a result, an exothermic reaction of heat and gas release occurs, producing an increase in temperature and pressure in the near-wellbore region. The process fluids contain hydroreactive mixtures, combustible oxidizing mixtures, and combustion initiators. Process fluid No. 1 contains, as combustion initiator, sodium hydride, NaH, and powdered nanoaluminium, Al. In a second step, a process fluid No. 3, an acidic solution containing hydrochloric acid, is fed into the wellbore.

Abstract: A pressure-up blow-down method for recovering oil from an underground hydrocarbon formation, comprising the steps of: injecting an injection fluid into alternatingly-spaced multiple-induced fractures which extend radially outwardly and along a horizontal portion of a wellbore in the formation; ceasing injection of said injection fluid; recovering to surface oil which flows from remaining of the multiple induced fractures into the wellbore; and successively repeating the foregoing steps one or more times. Gas preferentially is initially used as the injection fluid and after one successive iteration water is then used. A sliding sleeve or sleeves which may be selectively slid open and closed within the wellbore in accordance with the method to allow and prevent, at various time periods in the method, fluid communication with fluid injection fractures and oil production fractures.

Abstract: There is provided a process to recover bitumen from a subterranean hydrocarbon reservoir. The process includes injecting steam and oxygen separately into the bitumen reservoir. When mixed in the reservoir, the mix is in the range of 5 to 50% O2. The process also includes producing hot bitumen and water using a horizontal production well, and producing/removing non-condensable combustion gases to control reservoir pressure.

Abstract: A system for removing methane from subterranean clathrates includes an oxidant source, a feed pipe, a recovery pipe, and an ignition source. The feed pipe includes an inlet end in fluid communication with the oxidant source and an outlet end configured to be disposed within a subterranean deposit that includes a stored methane gas disposed within a clathrate hydrate. The recovery pipe includes a first end disposed within the subterranean deposit and a second end opposite the first end configured to engage a storage device. The ignition source is configured to trigger a combustion reaction to melt the clathrate hydrate to produce a released methane gas. A first portion of the released methane gas travels along a recovery flow path through the recovery pipe and a second portion of the released methane gas combusts with the oxidant in-situ to perpetuate the combustion reaction.

Abstract: One or more specific embodiments herein includes a method for hydraulically re-fracturing a shale formation comprising injecting oxidizer through a horizontal wellbore into a fracture in the shale formation comprising pores containing hydrocarbon gas or liquid, and recovering some of the hydrocarbon gas or liquid from the shale formation. Some of the injected oxidizer combusts and increases the temperature of a portion of the shale formation and of the hydrocarbon gas or liquid contained in some of the pores in the shale formation, at least some of the hydrocarbon liquid is heated and turns to hydrocarbon gas, the pressure of some of the hydrocarbon gas increases to a point sufficient to cause formation of new fractures, and some of the hydrocarbon gas passes from the pores through some of the new fractures and can be thereafter recovered.

Abstract: System and method for producing fluids from a hydrocarbon reservoir where an injector well segment and parallel underlying producer well segment are both completed with slotted liners. The injector and producer segments are logically partitioned into corresponding sections to define a plurality of injector-producer section pairs. Injection tubing strings supply stimulating fluid (e.g., saturated steam) to associated sections of the injector segment for injection into the hydrocarbon reservoir. Surface-located control devices control the pressure of the stimulating fluid flowing through the respective injection tubing strings. Production tubing strings (with the aid of artificial lift) carry fluids produced from associated sections of the producer segment. A plurality of controllers is provided for the injector-producer section pairs to control at least one process variable (e.g.

Abstract: In a method for enhancing the efficiency of separation of bitumen from oil sands ore, lipids, lipid by-products, and lipid derivatives are used as process additives for ore-water slurry-based bitumen extraction processes or in situ bitumen recovery processes. These additives act as surfactants reducing surface and interfacial tensions, thus promoting breakdown the oil sands ore structure and resultant liberation of bitumen from the ore. Lipid treatment does not deleteriously affect release water chemistry in bitumen recovery processes, and it does not appreciably affect the fuel value of recovered bitumen. Lipids which may be effectively used as additives include biodiesel, tall oil fatty acids, monoglycerides, vegetable oil, and soap water, and combinations thereof.

Abstract: A steam assisted gravity drainage process that includes the addition of oxygen for recovering hydrocarbons from a hydrocarbon reservoir is described. Steam and an oxygen-containing gas are separately and continuously injected into the hydrocarbon reservoir to heat hydrocarbons and water to drain, by gravity, to a horizontal production well. The process can include controlling the ratio of oxygen and steam from about 0.05 to about 1.00 (v/v). The steam assisted gravity drainage process can further include removing non-condensable combustion gases from the reservoir to avoid undesirable pressures in the reservoir. The non-condensable combustion gases can be removed from the reservoir by at least one separate vent-gas well.

Abstract: The invention relates to compositions and method for construction of an underground coal gasification (UCG) well liner assembly. In particular, a well liner segment for use in the construction of a UCG well liner assembly for conveying product gas to a production well is disclosed. Also disclosed are a system and method for UCG product gas production.

Abstract: An oil shale exploitation method comprises: forming a gas inlet pipeline (1) and a gas outlet pipeline (3) in an oil shale; forming a gasification channel (5) that connects the gas inlet pipeline and the gas outlet pipeline in the oil shale; feeding combustible gas and oxygen into the well through different gas inlet pipelines, and then igniting, in an aerobic environment, the combustible gas fed into the well at the lower opening of the pipeline for conveying the combustible gas, so as to heat the oil shale; and recycling through the gas outlet pipeline an oil-gas mixed product formed after thermal decomposition of kerogen in the oil shale. The method has simple process and low energy consumption, and is capable of heating kerogen in the shale bed, thereby exploiting an oil shale mineral layer to obtain oil and gas products more economically and reasonably.

Abstract: The present invention relates to systems, apparatuses, and methods for providing a reliable, high purity source of CO2 that is used in the recovery of formation deposits, such as fossil fuels. At least a portion of the fossil fuels recovered may be directly combusted or extracted using the same process used to provide the pure source of CO2 without the need to first remove CO2, sulfur, other fossil fuels, or other impurities.

Abstract: Method for producing hydrocarbon fluids from an organic-rich rock formation include providing a plurality of in situ heat sources configured to generate heat within the formation so as to pyrolyze solid hydrocarbons into hydrocarbon fluids. Preferably, the organic-rich rock formation is heated to a temperature of at least 270° C. Heating of the organic-rich rock formation continues so that heat moves away from the respective heat sources and through the formation at a first value of effective thermal diffusivity, ?1. Heating of the formation further continues in situ so that thermal fractures are caused to be formed in the formation or so that the permeability of the formation is otherwise increased. The method also includes injecting a fluid into the organic-rich rock formation. The purpose for injecting the fluid is to increase the value of thermal diffusivity within the subsurface formation to a second value, ?2.

Abstract: The present invention is directed towards methods and apparatus to release energy into wells using combustion of monopropellants. More specifically, this invention is directed to industrial methods to enhance the extraction of well fluids from wells by using the in-situ energy released from this inventions apparatus, methods, catalyst, and fluids blends for subterranean catalytic combustion of monopropellants.

Abstract: There is provided herein a method for recovering petroleum from a formation, wherein said formation is intersected by at least one wellpair consisting of a horizontal production well and a horizontal injection well, and wherein said formation comprises at least one steam chamber developed by a steam-assisted process, said method comprising: providing an oxidizing agent near the top of said formation; initiating in situ combustion (ISC); and recovering petroleum from said at least one production well.

Abstract: An underground reservoir is provided comprising an injection well and a production well. The production well has a horizontal section oriented generally perpendicularly to a generally linear and laterally extending, upright combustion front propagated from the injection well. The method relates to controlling location of inflow into a production well during in situ combustion. The horizontal section of the production well includes blocking agents to prevent well failure.

Abstract: The invention relates to methods and apparatuses for the subterranean injection of reactive substances like propellants into wellbores and subterranean reservoirs. These methods and apparatuses controls the temperature of a reactive substance for safe handling at surface and controls the decomposition rate of the substances in the subterranean environment. In addition, these methods and apparatuses provide a means for safe dilution of reactive fluids in the event of a leak or spillage of the reactive substance.

Abstract: A method of heating a portion of a subsurface formation includes drawing fuel on a fuel carrier through an opening formed in the formation. Oxidant is supplied to the fuel at one or more locations in the opening. The fuel is combusted with the oxidant to provide heat to the formation.

Abstract: Enhanced recovery of crude oil from an oil well is provided by in-situ cracking of an oxygenated organic compound to form hydrogen. The crude oil is then hydrogenated and hydrogenation reaction products and crude oil are recovered from the oil well.

Abstract: The invention provides methods for natural gas and oil recovery, which include the use of air injection and in situ combustion in natural gas reservoirs to facilitate production of natural gas and heavy oil in gas over bitumen formations.

Abstract: The invention provides methods for natural gas and oil recovery, which include the use of air injection and in situ combustion in natural gas reservoirs to facilitate production of natural gas and heavy oil in gas over bitumen formations.

Abstract: An apparatus, system, and method are disclosed for in-situ extraction of hydrocarbons from a hydrocarbon-bearing formation. The system includes a well drilled through a hydrocarbon-bearing formation, and a completion unit that places an injection tube near a fluid injection point near the bottom of a target zone and a production tube near a fluid production point near the top of the target zone. An isolation unit isolates the fluid injection point from the fluid production point such that injected fluid flows through the target zone. The system further includes a heat source, and a fluid that delivers thermal energy from the heat source to the hydrocarbons in the target zone to entrain the hydrocarbons in the fluid. The resulting production fluid is heated, free hydrogen is added, and the production fluid is treated on a catalytic reactor to reduce the size of the hydrocarbon chains.

Abstract: The invention provides methods for natural gas and oil recovery, which include the use of air injection and in situ combustion in natural gas reservoirs to facilitate production of natural gas and heavy oil in gas over bitumen formations.

Abstract: A method for in situ heating of an organic-rich rock formation is provided. Preferably the organic-rich rock formation comprises kerogen. The method may include the steps of providing a first wellbore extending at least to a depth of the organic-rich rock formation, and providing a second wellbore also extending to a depth of the organic-rich rock formation and intersecting the first wellbore. The method may also include injecting air and a combustible fuel into the first wellbore, and providing a downhole burner in the wellbore so as to cause the air and the combustible fuel to mix and to combust at substantially the depth of the organic-rich rock formation. The method may further include, circulating combustion products into and up the second wellbore such that a pyrolysis zone is created from the first wellbore and second wellbores that provides substantially complete pyrolysis of the organic-rich rock formation between the first wellbore and the second wellbore.

Abstract: Systems, devices, and methods for filling containers with radioactive materials are described. In certain embodiments, the systems comprise a shielding material that substantially defines a chamber and, preferably, substantially blocks radioactivity, a conduit extending through the shielding material into the chamber, and a securing unit that is disposed in the chamber proximal to the conduit and is adapted to receive a container through the conduit.

Abstract: A method for in situ heating of a selected portion of a targeted organic-rich rock formation such as an oil shale formation is provided. The method includes the steps of providing casing in a wellbore extending to a depth within or below the selected portion of the organic-rich rock formation, and also providing a tubing within the casing. An annular region is formed between the tubing and the surrounding casing. Air or other oxidant and a combustible fuel are injected into the wellbore. Either the air or the combustible fuel is in stoichiometric combustion excess. The method also includes providing hardware in the wellbore so as to cause the air and the combustible fuel to mix and to combust at substantially the depth of the organic-rich rock formation. The hardware may include more than one burner. Insulation may be placed along the tubing adjacent the first burner in order to reduce the heat transfer coefficient within the tubing and to provide a more uniform temperature within the annulus.

Abstract: Methods and systems relate to in situ combustion utilizing configurations of injection and production wells to facilitate the in situ combustion. The wells define vertically deviated lengths that have different orientations from one another. Further, heating processes such as resistive heating and cyclic steam stimulation may take place in one or both of the injection and production wells to precondition a reservoir prior to the in situ combustion.

Abstract: The invention provides methods for natural gas and oil recovery, which include the use of air injection and in situ combustion in natural gas reservoirs to facilitate production of natural gas and heavy oil in gas over bitumen formations.

Abstract: The subject matter relates to an apparatus for insertion of a conduit into a well system bore to introduce a reactant fluid over a subterranean catalyst to initiate decomposition of the reactant fluid which resultant energy release may be utilized to perform work or perform heating of the subterranean environment. The energy released from the catalytic reaction and subsequent combustion of fuels may also be used for cutting, welding, powering pumps, compressors, turbines, generators, or to heat well system fluids, pipes, subterranean reservoir fluids, subterranean solids, and completion devices in the well system.

Abstract: The invention provides a process for the production of hydrogen in a subterranean hydrocarbon reservoir, said process comprising the steps of introducing a metal-based catalyst into a hydrocarbon-containing zone in said reservoir; raising the temperature in said zone to a temperature at which catalyzed conversion of hydrocarbon to hydrogen occurs; and, optionally but preferably, recovering hydrogen from an extraction section of a production well located above said zone.

Abstract: The present invention is directed towards methods and apparatus to release energy into wells using combustion of monopropellants. More specifically, this invention is directed to industrial methods to enhance the extraction of well fluids from wells by using the in-situ energy released from this inventions apparatus, methods, catalyst, and fluids blends for subterranean catalytic combustion of monopropellants.

Abstract: This method deals in recovering energy in-situ from an underground resource and upgrading such resource above ground. It consists of injecting a hot gas to pyrolyze it to produce gases and liquids with high hydrogen content and a residual hot char. The gases and liquids together with the injected hot gas form a mixture of gases and liquids that is brought above ground and treated into a clean mixture of gases and liquids rich in hydrogen and then used as a chemical feedstock and/or transportation fuel. Following the pyrolyzation of the resource, carbon dioxide and air are injected into the residual hot char to convert the CO2 into 2CO+N2, which is brought above ground and treated into a clean lean gas. This lean gas is used to generate efficient electric power, heat the injected gas for pyrolysis, and convert the 2CO+N2 as a feedstock into fertilizer.

Abstract: The invention provides methods for natural gas and oil recovery, which include the use of air injection and in situ combustion in natural gas reservoirs to facilitate production of natural gas and heavy oil in gas over bitumen formations.

Abstract: A method of oil production is provided. The method includes forming an injection well and a production well. The method also includes pumping a mixture of oxygen and carbon dioxide (CO2) into the injection well. In addition, the method also includes minimizing gravity segregation by providing a relatively high level of CO2 in the mixture.

Abstract: Methods and apparatus relate to in situ combustion. Configurations of the injection and production wells facilitate the in situ combustion. Utilizing wet combustion for some embodiments promotes heat displacement for hydrocarbon recovery with procedures in which one or more of the production and injection wells are configured with lengths deviated from vertical. In some embodiments for either dry or wet combustion, at least the production wells define intake lengths deviated from vertical and that are disposed at staged levels within a formation. Each of the productions wells during the in situ combustion allow for recovery of hydrocarbons through gravity drainage. Vertical separation between the intake lengths of the production wells enables differentiated and efficient removal of combustion gasses and the hydrocarbons.

Abstract: Methods and systems for treating a hydrocarbon containing formation described herein include providing heat to a first portion of the formation from a plurality of heaters in the first portion, producing produced through one or more production wells in a second portion of the formation, reducing or turning off heat provided to the first portion after a selected time, providing an oxidizing fluid through one or more of the heater wells in the first portion, providing heat to the first portion and the second portion through oxidation of at least some hydrocarbons in the first portion, and producing fluids through at least one of the production wells in the second portion. The produced fluids may include at least some oxidized hydrocarbons produced in the first portion.

Abstract: A modified method for in situ recovery of hydrocarbon from an underground hydrocarbon-containing formation. An “L” shaped production well, having a vertical section, and a lower horizontal leg positioned low in the formation, is provided. The horizontal leg connects to the vertical section at a heel portion, and has a toe portion at an opposite end thereof. Oxidizing gas is injected into the formation in or proximate the vertical section. A combustion front sweeps outwardly from the vertical section and laterally within the formation above the horizontal leg, from the heel to the toe, causing hydrocarbons in the formation above the horizontal leg to drain downwardly into the horizontal leg, which are then delivered to surface via production tubing. A non-oxidizing gas is injected into at least the heel portion and preferably additional portions of the horizontal leg via injection tubing contained within the vertical section of the production well.

Abstract: Diluted wet combustion forms a hot process fluid or VASTgas including carbon dioxide (CO2) and fluid water which is delivered to geologic formations and/or to surface mined materials to reduce the viscosity and/or increase hydrocarbon extraction. High water and/or CO2 content is achieved by reducing non-aqueous diluent and/or adding or recycling CO2. Power recovered from expanding the VASTgas may be used to pressurize the VASTgas for delivery by partial expansion through a Direct VAST cycle, and/or by diverting compressed oxidant through a parallel thermogenerator in a Diverted VAST cycle. Pressurized VASTgas may be injected into a well within the hydrocarbon formation or with mined material into a heavy hydrocarbon separator vessel to heat, mobilize, solubilize and/or extract heavy hydrocarbons. Light hydrocarbons may be mixed in with the hot process fluid to enhance hydrocarbon mobilization and recovery. Microwaves may further heat the VASTgas and/or hydrocarbon.

Abstract: A process and system for release and recovery of methane from subterranean methane hydrate deposits in which heated CO2 is used to displace methane from the methane hydrate deposits and a portion of the displaced methane is routed to a combustion device proximate the deposit for combustion in-situ, generating heated CO2 which is introduced into the deposit, displacing additional methane, a portion of which is routed to the combustion device, thereby providing a substantially self-sustaining process. Portions of the displace methane not routed to the combustion device are captured for use elsewhere.

Abstract: Methods and apparatus relate to controlling location of inflow into a production well during in situ combustion. The production well includes intervals closable to the inflow at identified times. Once a combustion front from the in situ combustion passes one of the intervals, a blockage conveyed from surface into the production well forms a barrier to the inflow at the interval that has been passed by the combustion front. An example of the blockage includes a cement plug delivered through coiled tubing into the production well, which may include production tubing that defines the intervals based on at least two consecutive alternating lengths of solid wall sections and slotted or perforated sections of the production tubing.

Abstract: A method of recovering petroleum from dormant oil wells or increasing the production of oil wells is disclosed. An alkali or alkali earth carbonate is introduced into a water layer associated with a subterranean petroleum reservoir and/or an explosive composition is introduced into an oil layer associated with a subterranean petroleum reservoir. CO2 gas is produced by reacting the alkali or alkali earth carbonate with an acid and/or by detonating the explosive composition. Additional explosive composition can be introduced and detonated to achieve sufficient CO2 gas production to increase pressure within the subterranean petroleum reservoir.

Abstract: The invention relates to a method and system for treating an aqueous liquid containing dissolved minerals and dissolved hydrocarbons. Method steps and apparatus for treating a waste water feed stream are disclosed which utilize a warm lime softening system in fluid communication with the waste water feed stream, wherein sludge from the warm lime softening system is recycled to improve lime utilization and enhance silica and boron removal without the addition of an external source of magnesium. In addition, a microfiltration system and/or an air stripper system may be used in fluid communication with at least one reverse osmosis system to produce a treatment water that meets state and federal guidelines for surface discharge.

Abstract: A method for recovery of hydrocarbons from a subterranean reservoir by operating adjacent injector producer well pairs under conditions of steam assisted gravity drainage (SAGD) with a lateral drainage well between and substantially parallel to them; the lateral drainage well is operated under conditions of intermittent steam injection and alternating oil, water and gas production; NCG is co-injected with steam into both the injector wells and the lateral drainage well at selected intervals, and in selected quantities in order to control the steam saturation of the SAGD steam chamber and the rise of the steam chamber, and to encourage lateral fluid communication between the adjacent well pairs and the LD well; controlling gas injection and production in order to control the rise of the steam chamber to improve production of oil; operating the well pairs and the LD well under conditions of a steam chamber pressure that is initially and briefly high to establish a steam chamber, but thereafter may be reduced to

Abstract: A novel method is provided for in situ combustion and recovery of oil from underground reservoirs including injecting oxygen into the reservoir at a region near the reservoir floor, establishing a combustion front wherein hot combustion gases rise at the combustion front, withdrawing hot combustion gases from a region near the reservoir ceiling, and extracting oil from a horizontal production well near the reservoir floor.

Abstract: A method of heating a portion of a subsurface formation includes drawing fuel on a fuel carrier through an opening formed in the formation. Oxidant is supplied to the fuel at one or more locations in the opening. The fuel is combusted with the oxidant to provide heat to the formation.

Abstract: Methods and systems for enhancing oil recovery are disclosed. A method for enhancing oil recovery in a formation includes placing a catalyst in a wellbore; and introducing an oxidizing agent into the wellbore to contact the catalyst such that a hydrocarbon in the formation is oxidized to produce heat and at least one gas. A system for enhancing oil recovery in a reservoir formation includes a catalyst arranged within a well adjacent the reservoir formation; and an oxidizing agent for engaging the catalyst, the oxidizing agent adapted to generate heat and at least one gas when engaging the catalyst and oxidizing a hydrocarbon. The oxidizing agent may be air or oxygen. The catalyst may be one selected from platinum, palladium, rhodium, ruthenium, lead, manganese, nickel and metal oxides thereof. Further, the catalyst may be in the form of nanoparticles.

Abstract: The present invention is a method and apparatus for the enhanced recovery of petroleum fluids from the subsurface by in situ combustion of the hydrocarbon deposit, from injection of an oxygen rich gas and drawing off a flue gas to control the rate and propagation of the combustion front to be predominantly horizontal and propagating vertically downwards guided by the vertical highly permeable hydraulic fractures. Multiple propped vertical hydraulic fractures are constructed from the well bore into the oil sand formation and filled with a highly permeable proppant containing hydrodesulfurization and thermal cracking catalysts. The oxygen rich gas is injected via the well bore into the top of the propped fractures, the in situ hydrocarbons are ignited by a downhole burner, and the generated flue gas extracted from the bottom of the propped fractures through the well bore and mobile oil gravity drains through the propped fractures to the bottom of the well bore and pumped to the surface.

Abstract: The invention provides hydrocarbon recovery processes that may be utilized in heavy oil reservoirs. Horizontal hydrocarbon production wells may be provided below horizontal oxidizing gas injection wells, with distant combustion gas production wells offset from the injection well by a distance that is greater than the hydrocarbon production well offset distance. Oxidizing gases injected into the reservoir through the injection well support in situ combustion, to mobilize hydrocarbons. The process may be adapted for use in a reservoir that has undergone depletion of petroleum in a precedential petroleum recovery process, such as a steam-assisted-gravity-drainage process, leaving a residual oil deposit in the reservoir as well as mobile zone chambers. Processes of the invention may be modulated so that a portion of the residual oil supports in situ combustion, while a larger portion of the residual oil is produced, by channelling combustion gases along the pre-existing mobile zones with the reservoir.