OA20214A - In-situ process to produce synthesis gas from underground hydrocarbon reservoirs. - Google Patents

Abstract

A petroleum reservoir is treated with heat to induce gasification, water-gas shift, and/or aquathermolysis reactions to generate synthesis gas comprising hydrogen gas. The synthesis gas is produced to the surface using one or more production wells.

Description

IN-SITU PROCESS TO PRODUCE SYNTHESIS GAS FROM UNDERGROUND PETROLEUM RESERVOIRS

TECHNICAL FIELD OF THE INVENTION

The technical field relates to treatment of a petroleum réservoir to produce synthesis gas.

BACKGROUND OF THE INVENTION

Petroleum réservoirs are abundant globally and many technologies are used to produce oil or gas from these réservoirs, including use of primary processes as well as enhanced oil recovery processes (such as water flooding, steam flooding and Chemical flooding) to produce additional oil from conventional oil and gas réservoirs.

Conventional crude oil is processed by refining it into transportation fuels and feedstocks for the petrochemical industry.

For heavy oil and extra heavy oil (e.g., bitumen) the oil is viscous at original réservoir conditions and the oil cannot be produced using conventional methods, and so heavy oil and bitumen are thermally treated to lower the viscosity so that they flow more easily in the réservoir and can be produced to the surface. Thermal treatment also allows oxygen and other fluids to move within the réservoir more easily.

After heavy oil or bitumen is extracted, it is usually upgraded to synthetic crude oil which in turn is refined into transportation fuels and feedstocks for the petrochemical industry.

The production of oil or gas implies ultimate production of carbon dioxide since the oil or gas or their products are generally combusted to harvest their energy and generate carbon dioxide.

There is an ongoing need to produce fuels from oil and gas réservoirs that hâve relatively low carbon intensity.

-2SUMMARY OF THE INVENTION

According to a first broad aspect of the présent invention, there is provided a method for treating a réservoir to recover synthesis gas therefrom, the réservoir containing Petroleum and water, the method comprising the steps of:

a. heating the réservoir to a température sufficient to cause at least one of gasification, water-gas shift and aquathermolysis reactions to occur within the réservoir, the at least one of the reactions involving at least one of the Petroleum and the water;

b. allowing the at least one of gasification, water-gas shift and aquathermolysis reactions to produce synthesis gas from the petroleum and the water, the synthesis gas comprising hydrogen gas;

c. providing at least one well in the réservoir; and

d. producing at least a portion of the synthesis gas to surface through the at least one well.

In some exemplary embodiments of the first aspect, the step of heating the réservoir comprises injecting an oxidizing agent into the réservoir to oxidize at least a portion of the Petroleum within the réservoir.

In some exemplary embodiments of the first aspect, the step of heating of the réservoir comprises one or more of:

injecting an oxidizing agent into the réservoir to oxidize at least a portion of the Petroleum within the réservoir;

generating electromagnetic or radio-frequency waves with an electromagnetic or radio-frequency antenna placed within the réservoir;

injecting a hot material into the réservoir; and generating heat by using a resistance-based (ohmic) heating System placed within the réservoir.

-3After the step of heating, some exemplary embodiments of the first aspect may comprise the step of delaying producing the produced gas stream to allow for further génération of synthesis gas. The time period for delay may dépend on the operating température but is preferred to be in the time range from 1 week to 12 months. A more preferred time period would be from 1 week to 4 weeks.

In some exemplary embodiments of the first aspect, the method further comprises, after heating, the step of producing the produced gas stream to allow for further génération of synthesis gas. The injection of heat into the réservoir (via an oxidizing agent or radio frequency or résistance heating) may be continuous while synthesis gas production is continuous.

In some exemplary embodiments of the first aspect, dielectric heating is used to heat the réservoir. In these embodiments, the electromagnetic radiation may hâve a frequency in the range of about 60 Hz -1000 GHz. The preferred range of frequencies is in the range of 10 MHz to 10 GHz.

In embodiments wherein resistance-based heating, also referred to as ohmic heating, is used to heat the réservoir, the température may be raised to between 200 and 800°C. The preferred température range is between 400 and 700°C.

According to a second broad aspect of the présent invention, there is provided a system for treating a réservoir to recover synthesis gas therefrom, the synthesis gas comprising hydrogen gas, the réservoir containing petroleum and water, the system comprising:

an apparatus for heating the réservoir and generating the synthesis gas from the Petroleum and the water by at least one of gasification, water-gas shift and aquathermolysis reactions; and a well positioned in the réservoir to produce the synthesis gas to surface.

In some exemplary embodiments of the second aspect, the apparatus for heating the réservoir comprises at least one of: an oxidizing-agent injector, an electromagnet, a radio-frequency antenna, or a hot material injector.

-4ln some exemplary embodiments of the first and second aspects, the produced synthesis gas is consumed in a fuel electrochemical cell device or combusted to generate steam for power génération or steam for oil recovery or is used as a Chemical feedstock for the production of Chemicals such as fuel, plastic, methanol, hydrogen, sulphur, and urea.

In some exemplary embodiments of the first and second aspects, oil or other fluids are intermittently or continuously produced from the réservoir either through the same well(s) or additional wells which may be vertical, horizontal, deviated, or other geometries.

Reducing carbon dioxide intensity can, in some embodiments, involve using in situ gasification to produce synthesis gas, comprising steam, carbon monoxide, carbon dioxide, and hydrogen as well as methane and other hydrocarbons sourced as solution gas dissolved in the oil or in free gas phase. If nitrogen is injected it is also generally a component of the synthesis gas. If sulphur is présent, sulphur compounds such as H2S can be part of the synthesis gas. The process then produces a synthesis gas product to the surface.

The produced synthesis gas is an alternative energy vector or feedstock gas for petrochemical products that can be produced to the surface from petroleum réservoirs. The produced synthesis gas can be combusted on surface to generate power or heat or consumed in fuel cell devices for production of power or used as a feedstock for methanol, liquid fuel, plastics, ammonia, hydrogen, graphene, and urea production.

In-situ conversion of oil or gas or both, and in particular, conventional crude oil, heavy oil, and bitumen or natural gas, to synthesis gas is currently considered to be a désirable next-generation technology. However, no commercially-viable process is currently being used.

In broad aspects, methods and Systems described herein view petroleum resources as massive sources of synthesis gas; not only the petroleum but also the formation water which can supply hydrogen to the generated synthesis gas, and supply additional oxidizer within the réservoir.

In general, the présent spécification describes methods to treat oil réservoirs (such as for example conventional oil, heavy oil, oil sands réservoirs, carbonate oil réservoirs,

-5natural gas, hydrogen sulphides) to recover synthesis gas. Some exemplary methods include injection of oxygen or a rich-oxygen stream into the réservoir to combust a fraction of the oxidizable fluids in the réservoir. During this part of the process, no fluids are produced to the surface. After the target température is achieved in the réservoir, injection may stop and the réservoir is allowed to soak during which time the remaining oxygen in the réservoir is consumed and gasification reactions and the water-gas shift reaction may take place. During these reactions, hydrogen and carbon oxides are produced within the réservoir. The production well when opened for production produces a mixture of hydrogen, carbon oxides, water (synthesis gas), hydrocarbon gases, and hydrogen sulphides to the surface. After the synthesis gas production rate drops to a threshold value, then oxygen injection might start once again and the process can be repeated multiple times until the overall synthesis gas production rate drops to a threshold value. Thus, the process yields synthesis gas from the hydrocarbons and water that sit within the réservoir. Water or steam or combustible fuels or waste products such as organic material or sewage or other fluids or particles may be injected into the réservoir with the oxygen or separately from it.

In some exemplary embodiments, ingrédients for synthesis gas production from oil can include heat, oil, and water. Oxidation of the réservoir by injecting oxygen into the réservoir is one means to generate heat within the réservoir. The reactions that occur in the réservoir at elevated températures can include low and high température oxidation, pyrolysis (thermal cracking), aquathermolysis (hydrous pyrolysis or thermal cracking reactions in the presence of water), gasification reactions, and the water-gas shift reaction.

The présent method can also be used in oil or gas réservoirs where the water content of the réservoir is considered high such that in normal practice, these réservoirs would not be produced for oil or gas, respectively. The method taught here can be used in high water content petroleum réservoirs since hydrogen is sourced not only from the Petroleum but also the water within the réservoir. Thus, the method taught here can be used in réservoirs where the high water content renders them less valuable than rich-oil saturated réservoirs. Thus, the method converts previously less valuable petroleum réservoirs to valuable energy and Chemical feedstock sources since the hydrogen is sourced from both the petroleum as well as the water in the réservoir.

-6Where synthesis gas includes sulphur compounds such as H2S, the hydrogen can be separated from the H2S to create a valuable source of hydrogen.

A detailed description of exemplary embodiments of the présent invention is given in the following. It is to be understood, however, that the invention is not to be construed as being limited to these embodiments. The exemplary embodiments are directed to particular applications of the présent invention, while it will be clear to those skilled in the art that the présent invention has applicability beyond the exemplary embodiments set forth herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of embodiments of the présent application will become apparent from the following detailed description and the appended drawings, in which:

FIG. 1A to FIG. 1C are diagrammatic représentations of stages of a first exemplary embodiment of the présent invention wherein petroleum réservoir is heated by oxidizing a fraction of the petroleum within the réservoir.

FIG. 2 is a diagrammatic représentation of a second exemplary embodiment of the présent invention wherein the petroleum réservoir is heated by using an electromagnetic / radio frequency antenna placed within the réservoir.

FIG. 3 is a diagrammatic représentation of a third exemplary embodiment of the présent invention comprising multiple production wells.

FIG. 4 is a diagrammatic représentation of a fourth exemplary embodiment of the présent invention wherein an oxidizing agent is continuously injected into the oil or gas réservoir to produce hydrogen.

FIG. 5 is a diagrammatic représentation of a fifth exemplary embodiment of the présent invention wherein one of the wells has a resistance-heating cartridge within the well which is used to heat the réservoir to produce synthesis gas.

FIG.6 i s a diagram illustrating some of the reactions that may occur in the methods described herein which occur within the réservoir to produce synthesis gas.

Exemplary embodiments of the présent invention will now be described with reference to the accompanying drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Throughout the following description spécifie details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known éléments may not hâve been shown or described in detail to avoid unnecessarily obscuring the disclosure. The following description is not intended to be exhaustive or to limit the invention to the précisé form of any exemplary embodiment. Accordingly, the description and drawings are to be regarded and interpreted in an illustrative, rather than a restrictive, sense.

The présent invention relates to treatment of an oil or gas réservoir for production of synthesis gas from the petroleum and water within the réservoir. The treatment includes heating the réservoir to enable gasification and water-gas shift reactions to produce synthesis gas within the réservoir and then using a production well to produce hydrogen from the réservoir.

High water content in oil and gas réservoirs is typically thought to be disadvantageous for oil or gas production. The methods described herein show that high water content is a benefit for the production of synthesis gas since water supplies hydrogen. Many of the reactions that produce synthesis gas source the hydrogen from the water in the réservoir - under the températures of the reactions, the formation water is converted to steam which then participâtes through steam reforming reactions with the hydrocarbons in the réservoir.

High H₂S content in oil and gas réservoirs is typically thought to be disadvantageous for oil and gas production. The methods described herein show that hydrogen can be separated from the H₂S and provide the benefit of carbonless energy and/or petrochemical feedstock.

Existing in-situ energy production processes from oil and gas réservoirs produce either oil or gas or both to the surface.

ln some embodiments, the présent methods take a different approach with respect to the following factors: timing of heating of the réservoir, timing of in-situ gasification and water-gas shift reactions, and production of synthesis gas from the réservoir. Ail of the methods here hâve several common steps.

First, the réservoir is heated - one exemplary method would be oxygen injection where in-situ combustion occurs in the réservoir for a period of time; another exemplary method would be to use electromagnetic or radio frequency radiation; another exemplary method would be to inject high pressure, high température steam or another high température material into the réservoir; another exemplary method would be to use electrical résistance heating.

If an oxidizing agent is injected into the réservoir, the gasification and water-gas shift reactions are permitted to continue after oxygen injection is stopped.

Synthesis gas production is enabled through production wells. Thus, the process produces energy and Chemical feedstock in the form of synthesis gas from the réservoir; a relatively clean fuel and useful and valuable Chemical feedstock that can be used to generate heat and power or valuable Chemicals, respectively.

Throughout this spécification, numerous terms and expressions are used in accordance with their ordinary meanings. Provided below are définitions of some additional terms and expressions that are used in the description thatfollows.

“Oil” is a naturally occurring, unrefined petroleum product comprising hydrocarbon components. Bitumen and heavy oil are normally distinguished from other petroleum Products based on their densities and viscosities. Heavy oil is typically classified with density which is between 920 and 1000 kg/m³. Bitumen typically has density greater than 1000 kg/m³. For purposes of this spécification, the terms “oil”, bitumen and heavy oil are used interchangeably such that each one includes the other. For example, where the term bitumen is used alone, it includes within its scope heavy oil. Non-hydrocarbon éléments entrained in the oil either through suspension, sorption, émulsion, molecular bonding, or other means, which can be co-produced or mobilized by or with the oil, are included within this définition.

As used herein, petroleum réservoir refers to a subsurface formation that is primarily composed of a porous matrix which contains petroleum products, namely oil and gas. As used herein, heavy oil réservoir refers to a petroleum réservoir that is primarily composed of porous rock containing heavy oil. As used herein, oil sands réservoir refers to a petroleum réservoir that is primarily composed of porous rock containing bitumen. The water phase in a réservoir rock is the interstitial water présent in the porous réservoir rock.

The natural réservoir température is an ambient température of a cold or unheated réservoir. The “réservoir température” may refer to natural réservoir température, or the température of a heated réservoir.

Cracking refers to splitting larger hydrocarbon chains into smaller-chained compounds. Hydrogénation refers to an addition of hydrogen to a hydrocarbon or refers to a substitution reaction where hydrogen is consumed.

The term in situ can refer to the environment of a subsurface oil sand réservoir. “In-situ” means “in position” or “in its original place”.

FIG. 1A to FIG. 1C illustrate an exemplary embodiment of the présent invention for treating an oil réservoir in which oil and water within the réservoir are converted to synthesis gas.

In the embodiment illustrated in FIG. 1A to FIG. 1C, the technology is using an inverted Steam-Assisted Gravity Drainage well configuration. The exemplary embodiment in FIG. 1A to FIG. 1C includes three stages per cycle. In Stage 1 (FIG. 1A), oxygen is injected into the réservoir where a portion of the bitumen is combusted to generate the températures (for example, >700°C) required for the gasification, water-gas shift, and/or aquathermolysis reactions. In Stage 2 (FIG. 1B), oxygen injection is stopped and the remaining oxygen in the réservoir is consumed. Since the réservoir in the near well région is hot, gasification, water-gas shift, and aquathermolysis reactions continue. The gas products from the reactions accumulate in the réservoir. Thereafter, Stage 3 (FIG. 1C) is initiated, when the production well is opened which then produces synthesis gas to surface. After the synthesis gas production has dropped to non-commercial rates, the process may be re-started with Stage 1. The method is not limited to horizontal wells but also can be

- 10done with vertical and deviated and multilatéral wells. The method can be equally applied in a gas réservoir. The injection of an oxidizing agent can continue even during production of the synthesis gas, as illustrated in FIG. 4.

Another embodiment of the method is shown in FIG. 2. In this implémentation, heat provided to the réservoir is done by using electromagnetic / radio frequency antenna. The hot réservoir undergoes gasification, water-gas shift, and aquathermolysis reactions which generate hydrogen, carbon oxides, and other gases within the réservoir. The generated synthesis gas is produced to the surface through the production well. The method is not limited to horizontal wells but also can be done with vertical and deviated and multilatéral wells. The method can be equally applied in a gas réservoir.

Another embodiment is illustrated in FIG. 3, shown in the cross-well direction, illustrâtes electromagnetic/radio frequency heaters positioned between a plurality of hydrogen production wells. The method is not limited to horizontal wells but also can be done with vertical and deviated and multilatéral wells. The method can be equally applied in a gas réservoir.

The reactions generate gas which then enables gravity drainage (due to density différence) of hot mobilized oil and steam condensate towards the base of the gasification reaction chamber. Thus, the process sustains itself by moving mobilized oil towards the reactive zone above and around the injection well. This helps with gasification reactions and maintains the high température (for example 700+°C) zone near the well pair.

In another implémentation, a single well can be used where oxygen is injected along one part of the well and synthesis gas production occurs along another part of the well. The well can be vertical, deviated, or horizontal.

In a further implémentation, heating of the réservoir can be done by electromagnetic or radio frequency waves.

In a further implémentation, heating of the réservoir can be done by using high pressure, high température steam.

A. Heating the réservoir

- 11 The exemplary methods in a first step heat the réservoir to a température where gasification and/or water-gas shift reactions can take place between the oil and water within the réservoir.

The heat can be delivered to the réservoir through a variety of methods commonly known in the art. Commercially available methods include oxygen injection, and in some exemplary methods the combustion step has oxygen injected into the réservoir for a period of time where a fraction of the petroleum is combusted to generate heat within the réservoir to achieve températures on the order of 400-700°C. Other modes of heating known in the art include electromagnetic or radio frequency based heating. Other modes of heating include injecting hot materials into the réservoir.

After the heat is injected to the réservoir, then if done by combustion, oxygen injection may be stopped and the réservoir left to soak at the elevated température achieved by the combustion step. If heated by electromagnetic heating, then this heating can continue to keep the réservoir hot at the desired température.

B. Gasification, Water-Gas Shift, and Aquathermolysis Reactions Period

During the period of time at which the réservoir is at elevated température, gasification and water-gas shift and aquathermolysis reactions may occur with conséquent génération of hydrogen, hydrogen sulphide, carbon monoxide, carbon dioxide, and steam (water vapour). As the reactions occur in the réservoir, the gas components collect within the réservoir space.

[063] FIG. 6 illustrâtes some of the reactions that may occur in the réservoir. In FIG. 6, fuel for oxidation and gasification is the bitumen and coke that forms from reactions that occur during the process. Bitumen can be represented as a mixture of maltenes (saturâtes, aromatics, and resins) and asphaltenes (large cyclic compounds with large viscosity). During oxidation, maltenes can be converted into asphaltenes. Asphaltenes can be converted, via both low and high température oxidation as well as thermal cracking, into a variety of gas products including methane, hydrogen, carbon monoxide, carbon dioxide, hydrogen sulphide, and high molecular weight gases (e.g., propane, etc.) and coke. The coke can then be converted, through oxidation and gasification reactions, to products including but not limited to methane, water (vapour), carbon monoxide, carbon dioxide, and

- 12hydrogen. Also, methane can be converted, via gasification reactions, to hydrogen and carbon dioxide and carbon monoxide. Carbon monoxide and water (vapour) can be converted, via the water-gas shift reaction, to hydrogen and carbon dioxide. In general, fuel components in the System, e.g., oil, coke, methane, can be gasified to produce mixtures of carbon monoxide, carbon dioxide, hydrogen sulphide, and hydrogen.

C. Production of Synthesis Gas

After enough time has elapsed for the génération of synthesis gas, then the gas is produced from the réservoir through the production well. Since synthesis gas is removed from the réservoir, this promûtes the reactions to generate more synthesis gas. During some embodiments, oil accumulated in the vicinity of the lower oxygen injection well may be produced through the same oxygen injection well, or a separate well, and sold commercially, at the same time that synthesis gas is produced through the upper injection well. This oil can be produced either continuously, or at the same time as the synthesis gas production, or oxygen ports can inject oxygen from within the same well that oil is continuously or intermittently produced from. It may be advantageous to alter the production approach depending on properties such as the synthesis gas chamber évolution, oil mobility, réservoir pressure, or other factors. If done within the same wellbore there may be additional benefits such as downhole partial oxidation and partial upgrading/hydrogenation of the oil within the réservoir or pipe, combustion-gas expansion lift effects (controlled création of some synthesis gas within the rising oil column drives fluid to surface like a geyser and créâtes simultaneous high volume vacuum/siphon), sand isolation or expulsion from the well within the réservoir or to surface by related pressure and mobilization effects, and heating of the oil/emulsion as it rises to surface. Some of the hydrogen may corne from water which is co-produced with the oil. This can be done by adding small amounts of the down-going oxygen to the rising fluids at pyrophoric concentration/temperature conditions.

Those skilled in the art will know that various synthesis gas components may be separated through a wide variety of well-known processes including cryogénie distillation, pressure-swing absorption/adsorption, temperature-swing absorption/adsorption, membranes, molecular sieves, centrifuges, magnetic fields, gravity/buoyancy stratification/distillation, Chemical reactions, thermal break-down, résonant fields,

- 13irradiation, electrical fields, acoustical destruction, acoustical ségrégation, and other methods.

D. New cycle

If the heating is done in a cyclic manner, for example, from in situ combustion using oxygen injection as illustrated in FIGS. 1A to 1C, then after the température of the réservoir has dropped such that the gasification, water-gas shift, and aquathermolysis reaction rates hâve dropped so that synthesis gas production drops below a threshold value, then a new cycle of oxygen injection and conséquent in situ combustion will start leading to heating of the réservoir. Thereafter, Steps A to C are repeated. If continuous heating is done by oxidization agent injection or electromagnetic or radio frequency or résistive heating methods, then continuous synthesis gas production can occurfrom the reservoir.

FIG. 5 illustrâtes an implémentation of the présent methods for treating an oil reservoir in which oil and water within the reservoir are converted to synthesis gas.

Some exemplary methods heat the reservoir to a température where gasification and water-gas shift reactions take place involving the oil and/or water within the reservoir by continuously injecting oxygen into the reservoir (as shown in FIG. 4) to cause in situ combustion reactions to occur that heat the reservoir to the preferred température between 400 and 700°C. This température range may be transiently reached or exceeded at interstitial scale or within régions of a reservoir and does not necessitate the entire average reservoir température to be within this range.

While the reservoir is being heated and is at elevated température, gasification and water-gas shift and aquathermolysis reactions occur with conséquent production of hydrogen, hydrogen sulphide, carbon monoxide, carbon dioxide, and steam (water vapour). As the reactions occur in the reservoir, the gas components collect within the reservoir space but tend to rise due to buoyancy effects in the reservoir where the mobilized oil collects around the injection well sustaining the reactions there and the gases rise upwards towards the production well above and collect in the reservoir. The synthesis gas is produced from the reservoir through the production well.

As oxygen is injected into the réservoir, a reactive zone is created within the réservoir. The reactive zone is characterized by the zone with température that is higher than the original réservoir température. In the reactive zone, the température rises above 450°C and at the reaction front, the température can exceed 900°C. With températures more than 400°C, gasification reactions occur within the hot zone which generate hydrogen which is exclusively produced by the upper production well to the surface. Within the hot zone around the injection well, heated oil drains and accumulâtes around the injection well thus supplying more fuel for the reactions that occur around the injection well.

The synthesis gas generated from the methods taught here can be used to generate power, heat, combusted to produce steam which can be used to generate power, or steam for other in situ oil recovery processes, or as a feedstock material for producing other Chemicals including fuel, plastic, methanol, urea, hydrogen, sulphur, etc.

Unless the context clearly requires otherwise, throughout the description and the claims:

• “comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

• “connected”, “coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more éléments; the coupling or connection between the éléments can be physical, logical, or a combination thereof.

• “herein”, “above”, “below”, and words of similar import, when used to describe this spécification shall refer to this spécification as a whole and not to any particular portions of this spécification.

• “or”, in reference to a list of two or more items, covers ail of the following interprétations of the word: any of the items in the list, ail of the items in the list, and any combination of the items in the list.

• the singular forms “a”, “an” and “the” also include the meaning of any appropriate plural form s

Words that indicate directions such as “vertical”, “transverse”, “horizontal”, “upward”, “downward”, “forward”, “backward”, “inward”, “outward”, “vertical”, “transverse”, “left”, “right”, “front”, “back”, “top”, “bottom”, “below”, “above”, “under”, and the like, used in this description and any accompanying daims (where présent) dépend on the spécifie orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly.

Where a component (e.g. a circuit, module, assembly, device, etc.) is referred to herein, unless otherwise indicated, reference to that component (including a reference to a means) should be interpreted as including as équivalents of that component any component which performs the function of the described component (i.e., that is functionally équivalent), including components which are not structurally équivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.

Spécifie examples of methods and apparatus hâve been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to contexts other than the exemplary contexts described above. Many alterations, modifications, additions, omissions and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled person, including variations obtained by: replacing features, éléments and/or acts with équivalent features, éléments and/or acts; mixing and matching of features, éléments and/or acts from different embodiments; combining features, éléments and/or acts from embodiments as described herein with features, éléments and/or acts of other technology; and/or omitting combining features, éléments and/or acts from described embodiments.

The foregoing is considered as illustrative only of the principles of the invention. The scope of the daims should not be limited by the exemplary embodiments set forth in the foregoing, but should be given the broadest interprétation consistent with the spécification as a whole.

Claims (5)

1. A method for treating a petroleum réservoir to recover synthesis gas therefrom, the réservoir containing petroleum and water, the method comprising the steps of:

a. providing at least one production well in the réservoir, the at least one production well situated in an upper part of the réservoir;

b. providing heat supply in the réservoir, the heat supply situated in a lower part of the réservoir;

c. using the heat supply, heating a portion of the réservoir beneath the at least one production well to a température sufficient to cause at least one of gasification, water-gas shift and aquathermolysis reactions to occur within the portion of the réservoir, the at least one of the reactions involving at least one of the petroleum and the water;

d. allowing the at least one of gasification, water-gas shift and aquathermolysis reactions to produce synthesis gas from the at least one of the petroleum and the water in the portion of the réservoir, the synthesis gas comprising hydrogen gas;

e. allowing the synthesis gas to rise toward the at least one production well; and

f. producing at least a portion of the synthesis gas to surface through the at least one production well.

2. The method of claim 1 wherein the heat supply comprises at least one heating well situated beneath the at least one production well and the heating of the portion of the réservoir comprises injecting an oxidizing agent through the at least one heating well into the réservoir to oxidize at least a portion of the petroleum and thereby heating the portion of the réservoir.

3. The method of claim 1 wherein the heat supply comprises at least one heating well situated beneath the at least one production well and the heating of the réservoir

- 17comprises positioning an electromagnetic or radio-frequency antenna in the at least one heating well and thereby generating electromagnetic or radio-frequency waves and thereby heating the portion of the réservoir.

4. The method of claim 1 wherein the heat supply comprises at least one heating well situated beneath the at least one production well and the heating of the réservoir comprises positioning a resistance-based heating System in the at least one heating well and thereby heating the portion of the réservoir.

5. The method of claim 1 wherein step d. takes place for a period of one week to twelve months.

6. The method of claim 2 wherein at least one of water, steam, combustible fuels and waste products is injected with or separately from the injecting of the oxidizing agent.

7. The method of claim 1 further comprising repeating and alternating the steps of heating the portion of the réservoir and producing the portion of the synthesis gas to the surface.

8. The method of claim 1 wherein heating of the portion of the réservoir generates heated oil from the petroleum, the heated oil accumulating in the lower part of the réservoir, the heat supply comprising at least one heating well situated beneath the at least one production well, the method further comprising the step of operating the at least one heating well as an at least one additional production well to produce a portion of the heated oil to the surface through the at least one additional production well simultaneously with production to the surface of the portion of the synthesis gas through the at least one production well.

9. A System for treating a petroleum réservoir to recover synthesis gas therefrom, the réservoir containing petroleum and water, the synthesis gas comprising hydrogen gas, the System comprising:

an apparatus for heating a portion of the réservoir and thereby generating the synthesis gas from at least one of the petroleum and the water by at least one of

- 18gasification, water-gas shift and aquathermolysis reactions, the apparatus positioned in a lower part of the réservoir; and at least one well positioned in an upper part of the réservoir to produce a portion of the synthesis gas to surface.

5 10. The system of claim 9 wherein the apparatus for heating the portion of the réservoir comprises a heat supply selected from the group consisting of an oxidizing-agent injector, an electromagnet, a radio-frequency antenna, and a hot material injector.