DE102022203221B3 - PROCESS AND PLANT FOR RECOVERING HYDROGEN FROM A HYDROCARBON RESERVOIR - Google Patents

Abstract

A method and system for recovering hydrogen from a hydrocarbon reservoir is provided. In the method, a liquid containing or consisting of water and at least one catalyst and a fluid containing or consisting of an oxidant is injected into at least a first well and/or at least a second well of a hydrocarbon reservoir. Thereafter, the hydrocarbon reservoir is ignited, creating a hydrogen-containing gas. The hydrogen-containing gas is conveyed via the at least one first well and/or the at least one second well of the hydrocarbon reservoir and hydrogen is obtained from the hydrogen-containing gas. The plant may contain a controller configured to control these process steps. The method and the system have the advantage that hydrogen can be obtained more efficiently from hydrocarbon reservoirs, which means that the method and the system are particularly suitable for (already) depleted oil deposits.

Description

A method and system for recovering hydrogen from a hydrocarbon reservoir is provided. In the method, a liquid containing or consisting of water and at least one catalyst and a fluid containing or consisting of an oxidant is injected into at least a first well and/or at least a second well of a hydrocarbon reservoir. Thereafter, the hydrocarbon reservoir is ignited, creating a hydrogen-containing gas. The hydrogen-containing gas is conveyed via the at least one first well and/or the at least one second well of the hydrocarbon reservoir and hydrogen is obtained from the hydrogen-containing gas. The plant may contain a controller configured to control these process steps. The method and the system have the advantage that hydrogen can be obtained more efficiently from hydrocarbon reservoirs, which means that the method and the system are particularly suitable for (already) depleted oil deposits.

The US 2017/0037719 A1 discloses a system and method for gasifying a feedstock in an underground hydrocarbon reservoir to produce synthesis gas. An injection well is inserted into the hydrocarbon reservoir to inject an oxidizer into the reservoir, provide an ignition source, and produce the feedstock. In addition to water, the starting material includes a starting material selected from the group consisting of biomass, plastic waste, coal, bitumen and petroleum coke. Volatilized hydrocarbons and syngas containing hydrogen are simultaneously withdrawn from a production well from the hydrocarbon reservoir to the surface.

The US 2021/0047905 A1 and US 2021/0189856 A1 disclose a system and method in which a hydrocarbon reservoir is heat treated to induce gasification, water-gas conversion, and/or aquathermolysis reactions to produce hydrogen.

The systems and methods described in the prior art have the disadvantage that the production of hydrogen in the hydrocarbon reservoir is not very efficient.

The U.S. 6,719,047 B2 discloses methods and systems for the recovery of hydrocarbons, hydrogen and/or other products from various hydrocarbonaceous formations.

The WO 2019/224326 A1 discloses a hydrogen production process in which a catalyst or a precursor thereof is introduced into a hydrocarbon-containing zone in a subterranean hydrocarbon reservoir.

Proceeding from this, it was the object of the present invention to provide a method and a plant which do not have the disadvantages of the prior art. In particular, a method and a system should be provided that allow hydrogen to be extracted more efficiently from a hydrocarbon reservoir, in particular from a (already) exhausted fossil hydrocarbon deposit.

The object is achieved with the method having the features of claim 1 and the system having the features of claim 8. The dependent claims show advantageous developments.

1. a) Injizieren einer Flüssigkeit, die Wasser und mindestens einen Katalysator enthält oder daraus besteht, in mindestens ein erstes Bohrloch und/oder in mindestens ein zweites Bohrloch eines Kohlenwasserstoffreservoirs, wobei der Katalysator geeignet ist, eine Bildung von Wasserstoff zumindest aus Verbindungen zu katalysieren, die ausgewählt sind aus der Gruppe bestehend aus Verbindungen, die durch eine Verbrennung von Kohlenwasserstoffen entstehen, Kohlenwasserstoffen und Kombinationen hiervon, und wobei der Katalysator eine Partikelgröße von maximal 1 mm aufweist, wobei sich die Partikelgröße auf eine über optische Mikroskopie bestimmte Partikelgröße bezieht;
2. b) Injizieren eines Fluids (z.B. eines Gases und/oder einer Flüssigkeit), das ein Oxidationsmittel (z.B. Sauerstoff) enthält oder daraus besteht, nach Schritt a) in das mindestens eine erste Bohrloch und/oder das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs;
3. c) Zünden des Kohlenwasserstoffreservoirs durch
   • i) Warten bis zur Selbstzündung des Kohlenwasserstoffreservoirs; oder
   • ii) Temperierung des Fluids aus Schritt b) auf eine Temperatur, die gleich oder größer einer Zündtemperatur des Kohlenwasserstoffreservoirs ist; oder
   • iii) Zugabe eines Zünders in das mindestens eine erste Bohrloch und/oder in das mindestens eine zweite Bohrloch, wobei der Zünder ausgewählt ist aus der Gruppe bestehend aus elektrischer Zünder, chemische Zünder, thermischer Zünder und Kombinationen hiervon;
4. d) Förderung von Wasserstoff-haltigem Gas über das mindestens eine erste Bohrloch und/oder über das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs; und
5. e) Gewinnung von Wasserstoff aus dem Wasserstoff-haltigen Gas.

According to the invention, a method for obtaining hydrogen from a hydrocarbon reservoir is provided, comprising the steps or consisting of the steps:

1. a) Injecting a liquid containing or consisting of water and at least one catalyst into at least a first well and/or into at least a second well of a hydrocarbon reservoir, the catalyst being suitable for catalyzing a formation of hydrogen at least from compounds which are selected from the group consisting of compounds resulting from the combustion of hydrocarbons, hydrocarbons and combinations thereof, and wherein the catalyst has a particle size of at most 1 mm, the particle size relating to a particle size determined via optical microscopy;
2. b) injecting a fluid (eg a gas and/or a liquid) containing or consisting of an oxidizing agent (eg oxygen) after step a) into the at least one first well and/or the at least one second well of the hydrocarbon reservoir;
3. c) igniting the hydrocarbon reservoir
   • i) waiting for the hydrocarbon reservoir to auto-ignite; or
   • ii) temperature control of the fluid from step b) to a temperature which is equal to or greater than an ignition temperature of the hydrocarbon reservoir; or
   • iii) adding an igniter to the at least one first well and/or to the at least one second well, the igniter being selected from the group consisting of electrical igniter, chemical igniter, thermal igniter and combinations thereof;
4. d) production of hydrogen-containing gas via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir; and
5. e) recovery of hydrogen from the hydrogen-containing gas.

The method according to the invention has the advantage that the injection of the catalyst into the hydrocarbon reservoir results in more efficient hydrogen formation in the hydrocarbon reservoir and more hydrogen can be obtained from the hydrocarbon reservoir per unit of time. The alternating injection of water and fluid increases the effectiveness of the catalyst, i.e. for maximum efficiency, the catalyst is first introduced into the hydrocarbon reservoir over water as the carrier of the catalyst and then brought into contact with the oxidizing agent (e.g. oxygen) to form hydrogen to catalyze. The process is similar to wet combustion due to the successive injection of water and fluid.

Steps a) and b) of the method can be carried out in such a way that the liquid and the fluid are injected both into the at least one first well and into the at least one second well (optionally further wells) of the hydrogen reservoir. This embodiment has the advantage that the liquid and the fluid are quickly introduced into the hydrocarbon reservoir at at least two separate locations, which increases the efficiency of the hydrogen production.

It is advantageous if the liquid and the fluid are injected as close as possible to a lower area (e.g. at the bottom and/or at the lower end of the oil-bearing zone) of the hydrocarbon reservoir and/or the hydrogen produced is as close as possible to an upper area (e.g. at a Cover or in the area of the maximum hydrogen concentration) of the hydrocarbon reservoir takes place, since this enables efficient conversion of the hydrocarbons into hydrogen and hydrogen that is as water-free and oxygen-free as possible can be obtained. It is advantageous here if the materials of the hydrocarbon reservoir (formations) have the highest possible permeability and are free of folds and fissures. Permeability differences in the hydrocarbon reservoir would be disadvantageous since they could lead to uncontrolled fire progression and thus to reduced efficiency in the hydrogen yield.

The hydrocarbon reservoir may be a reservoir of fossil hydrocarbons, e.g., a fossil oil reservoir or a fossil natural gas reservoir.

The hydrocarbon reservoir is preferably an (already) exhausted fossil hydrocarbon deposit (e.g. an exhausted fossil oil deposit or fossil natural gas deposit), since in such deposits it is economically worth converting the remaining hydrocarbons in the deposit (mainly heavy oils and light oils) to hydrogen. Fossil petroleum reservoirs with a gas cap are not preferred because the gas cap gas would mix with the injected oxidant (e.g., oxygen or air) and thus the desired fire progression would not occur.

After step c) has been carried out, steps a) and b) can be repeated at least once, preferably several times, before step d) is carried out. This has the advantage that a larger quantity of hydrogen gas is formed in the hydrocarbon reservoir before the start of hydrogen production and the probability that injected fluid is also produced together with the production of hydrogen in the case of gaseous fluid is reduced. Hydrogen can thus be obtained in a purer form with respect to the gaseous fluid.

Furthermore, steps a) to e) can be repeated at least once, optionally several times.

In addition, after step d) it is possible to wait for a certain period of time and after this period of time step d) can be carried out again, optionally several times after waiting for a certain period of time.

The catalyst used can be contained in the liquid in an amount of 1-10 g/l.

Furthermore, the catalyst used can be selected from the group consisting of platinum-tin catalyst, aluminum oxide catalyst and combinations thereof.

According to the invention, the catalyst used has a particle size of at most 1 mm, preferably at most 0.1 mm. The particle size refers to a particle size determined via optical microscopy. Smaller particles are preferred because they expose a larger surface area for catalysis relative to their mass, ie a given surface area for catalysis with a lower mass can be achieved than with larger particles, as well as more effective injection and transport in the reservoir. Smaller particles thus allow the process to be carried out in a more economical and technically more advantageous manner.

The liquid used in step a) can be injected at a pressure in the range from 20 to 350 bar, preferably from 25 to 300 bar. The injection pressures are usually determined endogenously, i.e. an injection under the pressure of the pore fluid is physically not possible and an injection above the smallest principal normal stress would produce an unwanted frac.

Furthermore, the liquid used in step a) can be injected in an amount which corresponds to 5 to 10% of a pore volume of the hydrocarbon reservoir, the pore volume of the hydrocarbon reservoir preferably being able to be determined from known information about the structure of the hydrocarbon reservoir.

The fluid used in step b) can contain oxygen in a proportion of 5-95% by volume, based on the total volume of the fluid. The fluid is preferably a gas, particularly preferably air. Air has the advantage of being inexpensive to use.

The fluid used in step b) can be injected at a pressure in the range from 20 to 350 bar, preferably from 25 to 300 bar.

Furthermore, the fluid used in step b) can be injected in an amount that is suitable for raising a temperature in an interior of the hydrocarbon reservoir to a value in the range from 200° C. to 500° C., preferably to a value in the range from 250° C to 450°C, particularly preferably at a value in the range from 300°C to 400°C. A temperature of <200 °C is disadvantageous because a temperature in this range does not enable efficient activation of the hydrocarbons to form hydrogen and there is a risk of condensation of various components, and a temperature of >500 °C is disadvantageous because at a temperature in this range shift the equilibrium of the particularly relevant gas phase reactions and thus the conditions for the formation of hydrogen are no longer given. A temperature range of 250 °C to 450 °C, even better 300 °C to 400 °C, is ideal for efficient hydrogen formation. The temperature is particularly preferably kept at a value in this range in the method by detecting the temperature of the hydrocarbon reservoir via a temperature sensor or by determining the amount of fluid from known information about the amount and type of hydrocarbons in the hydrocarbon reservoir.

The at least one first borehole and/or at least one second borehole in the hydrocarbon reservoir can be or can be arranged vertically at least in regions, with the vertical arrangement referring to an arrangement along the force of gravity and with a vertical arrangement meaning an arrangement that deviates from a strictly vertical arrangement by a maximum angle of 20°.

Furthermore, the at least one first borehole and/or at least one second borehole in the hydrocarbon reservoir can be or will be arranged horizontally at least in regions, with the horizontal arrangement referring to an arrangement perpendicular to the force of gravity and with a horizontal arrangement meaning an arrangement that is deviates from a strictly horizontal arrangement by a maximum angle of 20°.

Before carrying out step d), the at least one first well and/or the at least one second well (preferably all wells of the hydrocarbon reservoir) can be closed. It is possible that the pumping of hydrogen-containing gas only begins after a waiting period of at least three days, preferably three days to three months. It is also possible that the extraction of hydrogen-containing gas only begins after the reservoir has cooled to a temperature of at most 20° C. above the condensation temperature of at least one fluid in the hydrocarbon reservoir, with the at least one fluid preferably containing or consisting of water consists.

• Gefördertes Wasserstoff-haltiges Gas wird in einem katalytischen oder nicht-katalytischen Prozess des Steam-Reforming und der Wassergas-Shift-Reaktionen reagiert, wobei hierbei entstehendes CO₂ bevorzugt in das mindestens eine erste Bohrloch des Kohlenwasserstoffreservoirs und/oder in mindestens ein zweites Bohrloch des Kohlenwasserstoffreservoirs injiziert wird; oder
• Gefördertes Wasserstoff-haltiges Gas wird durch mindestens einen Wasserstofffilter geleitet, wobei der mindestens eine Wasserstofffilter bevorzugt in dem mindestens einen ersten und/oder in dem mindestens einen zweiten Bohrloch angeordnet ist, insbesondere an einem Kohlenwasserstoffreservoir-seitigen Ende davon.

The recovery of hydrogen from the hydrogen-containing gas may include or consist of any of the following steps:

• Produced hydrogen-containing gas is reacted in a catalytic or non-catalytic process of steam reforming and the water-gas shift reactions, with the resulting CO ₂ preferably being injected into the at least one first well of the hydrocarbon reservoir and/or into at least one second well of the hydrocarbon reservoirs is injected; or
• Produced hydrogen-containing gas is passed through at least one hydrogen filter, with the at least one hydrogen filter preferably being arranged in the at least one first and/or in the at least one second borehole, in particular at a hydrocarbon reservoir side end thereof.

In the method, after injecting the liquid and the fluid, a mixture of water vapor and carbon monoxide can be injected into the at least one first and/or into the at least one well.

Furthermore, in the method, the at least one first well and/or the at least one second well can be controlled for a selective injection and/or a selective production.

In addition, at least part of the hydrogen-containing gas produced can be used for a methanol synthesis in the process.

Apart from that, substances that occur during the production of hydrogen can be used in the process to produce heat and/or electricity.

In addition, exhaust gases from power plants and/or other surface processes can be injected into the at least one first borehole and/or the at least one second borehole in the method.

1. a) eine Flüssigkeitsquelle mit einer Flüssigkeit, die Wasser und mindestens einen Katalysator enthält oder daraus besteht, wobei der Katalysator geeignet ist, eine Bildung von Wasserstoff zumindest aus Verbindungen zu katalysieren, die ausgewählt sind aus der Gruppe bestehend aus Verbindungen, die durch eine Verbrennung von Kohlenwasserstoffen entstehen, Kohlenwasserstoffen und Kombinationen hiervon und wobei der Katalysator eine Partikelgröße von maximal 1 mm aufweist, wobei sich die Partikelgröße auf eine über optische Mikroskopie bestimmte Partikelgröße bezieht;
2. b) eine Fluidquelle mit einem Fluid (z.B. einem Gas und/oder einer Flüssigkeit), das ein Oxidationsmittel (z.B. Sauerstoff) enthält oder daraus besteht;
3. c) ein Fördermittel, das dazu geeignet ist, nacheinander Flüssigkeit aus der Flüssigkeitsquelle und Fluid aus der Fluidquelle in mindestens ein erstes Bohrloch und/oder mindestens ein zweites Bohrloch eines Kohlenwasserstoffreservoirs zu injizieren;
4. d) optional einen Zünder, der dazu geeignet ist, ein Kohlenwasserstoffreservoirs zu zünden, wobei der Zünder ausgewählt ist aus der Gruppe bestehend aus elektrischer Zünder, chemischer Zünder, thermischer Zünder und Kombinationen hiervon;
5. e) ein Mittel zur Förderung von Wasserstoff-haltigem Gas über das mindestens eine erstes Bohrloch und/oder über das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs;
6. f) ein Mittel zu Gewinnung von Wasserstoff aus Wasserstoff-haltigem Gas;
7. g) optional eine Steuereinheit, die konfiguriert ist, die Anlage zu steuern, Flüssigkeit aus der Flüssigkeitsquelle in das mindestens eine erste Bohrloch und/oder in das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs zu injizieren, Fluid aus der Fluidquelle in das mindestens eine erste Bohrloch und/oder in das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs zu injizieren, nach einem Zünden des Kohlenwasserstoffreservoirs ein Wasserstoff-haltiges Gas über das mindestens eine erste Bohrloch und/oder über das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs zu fördern und Wasserstoff aus dem Wasserstoff-haltigen Gas zu gewinnen.

According to the invention, a plant for obtaining hydrogen from a hydrocarbon reservoir is also provided, having or consisting of:

1. a) a liquid source with a liquid containing or consisting of water and at least one catalyst, the catalyst being suitable for catalyzing the formation of hydrogen at least from compounds selected from the group consisting of compounds which are produced by combustion of Hydrocarbons are formed, hydrocarbons and combinations thereof and wherein the catalyst has a particle size of at most 1 mm, the particle size relating to a particle size determined via optical microscopy;
2. b) a fluid source having a fluid (e.g. a gas and/or a liquid) containing or consisting of an oxidant (e.g. oxygen);
3. c) a production means adapted to successively inject liquid from the liquid source and fluid from the fluid source into at least one first well and/or at least one second well of a hydrocarbon reservoir;
4. d) optionally, an igniter suitable for igniting a hydrocarbon reservoir, the igniter being selected from the group consisting of electrical igniter, chemical igniter, thermal igniter, and combinations thereof;
5. e) a means for producing hydrogen-containing gas via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir;
6. f) a means for obtaining hydrogen from hydrogen-containing gas;
7. g) optionally a control unit configured to control the system to inject liquid from the liquid source into the at least one first well and/or into the at least one second well of the hydrocarbon reservoir, fluid from the fluid source into the at least one first well and /or to inject into the at least one second well of the hydrocarbon reservoir, after igniting the hydrocarbon reservoir to produce a hydrogen-containing gas via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir and to extract hydrogen from the hydrogen-containing gas to win.

The system according to the invention has the advantage that due to the catalyst in the liquid of the liquid source, hydrogen can be formed more efficiently in the hydrocarbon reservoir and more hydrogen can be obtained from the hydrocarbon reservoir per unit of time. The suitability of the conveyor for injecting water and fluid sequentially increases the effectiveness of the catalyst, i.e. for maximum efficiency the catalyst can be introduced into the hydrocarbon reservoir first via water as a carrier of the catalyst and then via the conveyance of the fluid by the conveyor for maximum efficiency be contacted with the resulting gases and/or the oxidizing agent (e.g. oxygen) in order to catalyze formation of hydrogen from hydrocarbons. The plant is similar to a wet combustion system due to the successive injection of water and gas.

The control unit of the system can be configured to control the conveying means in such a way that after the hydrocarbon reservoir has been ignited at least once, preferably several times, liquid from the liquid source and fluid from the fluid source repeatedly flow into the at least one first well and/or into the at least one second borehole of Hydrocarbon reservoir is injected before hydrogen-containing gas is pumped through the at least one first well and/or through the at least one second well of the hydrocarbon reservoir.

Furthermore, the control unit of the system can be configured to control the conveying means in such a way that liquid from the liquid source is repeatedly injected at least once, preferably several times, into the at least one first well and/or into the at least one second well of the hydrocarbon reservoir, fluid from the Fluid source is injected into the at least one first well and/or into the at least one second well of the hydrocarbon reservoir, after ignition of the hydrocarbon reservoir, hydrogen-containing gas is pumped through the at least one first well and/or through the at least one second well of the hydrocarbon reservoir, and hydrogen is obtained from the hydrogen-containing gas.

Apart from this, the control unit of the system can be configured to control the conveying means in such a way that after hydrogen-containing gas has been conveyed via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir, a certain period of time is waited for and after this Period again hydrogen-containing gas is promoted via the at least one first well and / or via the at least one second well of the hydrocarbon reservoir, optionally several times after waiting a certain period of time.

The catalyst in the liquid of the liquid source can be contained in an amount of 1 to 10 g/l in the liquid of the liquid source.

Further, the catalyst in the liquid source liquid may be selected from the group consisting of platinum-tin catalyst, alumina catalyst, and combinations thereof.

According to the invention, the catalyst in the liquid of the liquid source has a particle size of at most 1 mm, preferably at most 0.1 mm. The particle size refers to a particle size determined via optical microscopy.

The control unit can be configured to cause the delivery means to inject the liquid from the liquid source at a pressure in the range of 20 to 350 bar, preferably 25 to 300 bar.

Furthermore, the control unit can be configured to cause the conveying means to inject the liquid from the liquid source in an amount corresponding to 5 to 10% of a pore volume of the hydrocarbon reservoir, the pore volume of the hydrocarbon reservoir preferably being determined from known information about a structure of the hydrocarbon reservoir .

The fluid of the fluid source may contain oxygen in an amount of 5-95% by volume based on the total volume of the fluid. The fluid is preferably a gas, particularly preferably air. The fluid source may be the plant environment or may be a fluid tank. The fluid tank can contain (compressed) air, for example. The fluid source can also be a container in which a chemical, gas-generating process takes place and/or can be a power plant.

The control unit can be configured to cause the conveyor to inject the fluid from the fluid source at a pressure in the range of 20 to 350 bar, preferably 25 to 300 bar.

Furthermore, the control unit may be configured to cause the conveying means to inject the fluid from the fluid source in an amount suitable for keeping a temperature in an interior space of the hydrocarbon reservoir at a value in the range of 200° C. to 500° C., preferably to a value in the range from 250°C to 450°C, particularly preferably to a value in the range from 300°C to 400°C. The control unit is particularly preferably configured to maintain the temperature at this value by the control unit detecting the temperature of the hydrocarbon reservoir via a temperature sensor or by the control unit determining the amount of fluid and/or liquid from known information about an amount and type of hydrocarbons in the hydrocarbon reservoir determined (e.g. in the case of heavy oils 50 to 100 moles of oxygen per mole of heavy oil, in the case of lighter oils 20 to 50 moles of oxygen per mole of light oil). The temperature can be controlled both via the fluid and water injections, water usually only cools down.

The facility may include the at least one first well and/or the at least one second well in the hydrocarbon reservoir.

The at least one first borehole and/or at least one second borehole in the hydrocarbon reservoir can be arranged vertically at least in regions, with the vertical arrangement referring to an arrangement along the force of gravity and with a vertical arrangement meaning an arrangement that is characterized by a strictly vertical arrangement deviates by a maximum angle of 20°.

Furthermore, the at least one first borehole and/or at least one second borehole in the hydrocarbon reservoir can be arranged horizontally at least in regions, with the horizontal arrangement referring to an arrangement perpendicular to the force of gravity and with a horizontal arrangement meaning an arrangement that is deviates from a strictly horizontal arrangement by a maximum angle of 20°. The horizontal arrangement is beneficial as it allows for more efficient hydrogen recovery.

The control unit may be configured to cause the at least one first well and/or the at least one second well (preferably all wells of the hydrocarbon reservoir) to be closed prior to the production of hydrogen-containing gas. The control unit can also be configured to only start pumping hydrogen-containing gas after a waiting period of at least three days, preferably three days to three months. Furthermore, the control unit can be configured to start pumping hydrogen-containing gas only after the reservoir has cooled to a temperature of at most 20° C. above the condensation temperature of at least one fluid in the hydrocarbon reservoir, with the at least one fluid preferably containing water or consists of.

The means for recovering hydrogen from hydrogen-containing gas may be adapted to react produced hydrogen-containing gas in a catalytic or non-catalytic process of steam reforming and water-gas shift reactions, the plant being preferably configured is to inject the resulting CO ₂ into the at least one first well of the hydrocarbon reservoir and/or into at least one second well of the hydrocarbon reservoir.

Furthermore, the means for obtaining hydrogen from hydrogen-containing gas can contain or consist of at least one hydrogen filter, the at least one hydrogen filter preferably being arranged in the at least one first and/or in the at least one second borehole, in particular on a hydrocarbon reservoir-side end of it.

The system can be suitable for injecting a mixture of water vapor and carbon monoxide into the at least one first well and/or into the at least one well after injecting the liquid and the fluid.

The system can be suitable, preferably the control unit of the system can be configured to control the at least one first well and/or the at least one second well for a selective injection and/or a selective production.

The plant can be suitable for using at least a portion of the hydrogen-containing gas produced for a methanol synthesis. As a result, the amount of reinjection required can be reduced.

In addition, the plant can be suitable for using substances occurring during hydrogen production for heat production and/or electricity production.

Apart from that, the system can be suitable for injecting exhaust gases from power plants and/or other surface processes into the at least one first borehole and/or the at least one second borehole. After gasification, the hydrocarbon reservoir has good flow properties for future injections. Another advantage is that the yield of hydrogen (and also methane) can be increased and unwanted exhaust gases from power plants and/or other surface processes can be stored in the hydrocarbon reservoir.

The system according to the invention is preferably designed to carry out the method according to the invention. The control unit of the system can be configured to cause the steps required for this to be carried out.

The use of the plant according to the invention for the production of hydrogen from a hydrocarbon reservoir is proposed.

The subject according to the invention is to be explained in more detail on the basis of the following figures and the following example, without wishing to restrict it to the specific configurations shown here.

1 shows schematically an example of a method according to the invention, in which a liquid containing or consisting of water and at least one catalyst is injected via a first borehole 2 (called “injector”) into an oil zone 5 of a hydrocarbon reservoir 1 and then via the first Well 2 (called: "injector") a gas is injected into an oil zone 5 of the hydrocarbon reservoir 1, which contains or consists of oxygen. After igniting the hydrocarbon reservoir (e.g. with an igniter), part of the oil burns and the reactions induced thereby produce a hydrogen-containing gas in oil zone 5, which can be extracted via second borehole 3 (called “producer”). The first well 2 and the second well 3 are here at horizontal in the oil zone 5 of the hydrocarbon reservoir 1, which allows a better development of the hydrocarbon reservoir 1, ie enables a more efficient recovery of hydrogen.

2 shows schematically another example of a method according to the invention, in which a liquid containing water and at least one catalyst contains or consists of it, is injected and subsequently via the same two boreholes 2, 3 an oxidizing agent is injected into the oil zone 5 of the hydrocarbon reservoir 1, which contains or consists of oxygen. After the hydrocarbon reservoir 1 has been ignited (eg with an igniter), hydrogen is produced in the oil zone 5 and can be obtained via a further borehole 4 (called “producer”). The first borehole 2, the second borehole 3 and the further borehole 4 are here arranged vertically in the oil zone 5 of the hydrocarbon reservoir 1. The somewhat poorer development of the hydrocarbon reservoir 1 with the vertical arrangement than with the horizontal arrangement is compensated for by the fact that a second borehole 3 is present and penetrates into the oil zone of the hydrocarbon reservoir.

3 shows schematically another example of a method according to the invention, in which a liquid containing or consisting of water and at least one catalyst is injected via a first borehole 2 (here: “injector and producer”) into an oil zone 5 of a hydrocarbon reservoir 1 and then via the first well 2 an oxidizing agent is injected into an oil zone 5 of a hydrocarbon reservoir 1 which contains or consists of oxygen. After the hydrocarbon reservoir 1 has been ignited (for example with an igniter), hydrogen is produced in the oil zone 5 and can be obtained via the first borehole 2 . The first borehole 2 is arranged vertically in the deposit.

Example - Process for the recovery of hydrogen from a hydrocarbon reservoir

An application example for a depleted oil deposit is given below. In doing so, a borehole completion of the in 1 variant shown.

1. 1. Injizieren einer Flüssigkeit, die Wasser und mindestens einen Katalysator enthält oder daraus besteht, in mindestens ein erstes Bohrloch und/oder mindestens ein zweites Bohrloch eines Kohlenwasserstoffreservoirs. Die optimale Flüssigkeitsmenge (d.h. Wassermenge) für die Reaktionen sowie der örtlichen Verteilung der Wärmemenge kann vorher berechnet werden. Hierfür ist ein Aufbau eines digitalen Abbilds („Zwillings“) des Kohlenwasserstoffreservoirs vorteilhaft. Notwendig ist ein Wasservolumen, das ca. 5-10% der Porosität des Kohlenwasserstoffreservoirs (d.h. des Gasvolumens des Kohlenwasserstoffreservoirs) entspricht. Je nach Reaktionsregime kann auch eine Justierung des Katalysatortyps (Körnungsgröße, chemische Zusammensetzung) notwendig sein.
2. 2. Injizieren eines Fluids (z.B. eines Gases), das Sauerstoff enthält oder daraus besteht, in das mindestens eine erste Bohrloch und/oder das mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs. Die nötige Fluidmenge (d.h. Sauerstoffmenge), um eine bestimmte Wärmemenge (über Oxidationswärme) zu erzeugen, kann vorher berechnet werden. Notwendig ist ein Erreichen von mind. 250°C, allerdings besser 300-400°C. Die nötige Fluidmenge kann anhand der Molmenge des Öls und der Molekülgröße des Öls in dem Kohlenwasserstoffreservoir abgeschätzt werden. Hierfür ist vorteilhaft, falls bekannt ist, in welcher Menge das Kohlenwasserstoffreservoir Schweröl und Leichtöl enthält. Bei Schwerölen sind dabei ca. 50-100 Mol Sauerstoff je Mol Schweröl sinnvoll, bei leichteren Ölen sind auch 20-50 Mol Sauerstoff je Mol zu verbrennendem Leichtöl möglich.
3. 3. Zünden des Kohlenwasserstoffreservoirs durch
   • i) Warten bis zur Selbstzündung des Kohlenwasserstoffreservoirs; oder
   • ii) Temperierung des Fluids auf eine Temperatur, die gleich oder größer einer Zündtemperatur des Kohlenwasserstoffreservoirs ist; oder
   • iii) Zugabe eines Zünders in das mindestens eine erste Bohrloch und/oder in das mindestens eine zweite Bohrloch, wobei der Zünder ausgewählt ist aus der Gruppe bestehend aus elektrischer Zünder, chemische Zünder, thermischer Zünder und Kombinationen hiervon .
4. 4. Fördern von Wasserstoff-haltigem Gas über das mindestens eine erste und/oder mindestens eine zweite Bohrloch des Kohlenwasserstoffreservoirs und Gewinnung von Wasserstoff aus dem Wasserstoff-haltigen Gas. Um ideale Ergebnisse zu erreichen, kann es sinnvoll sein, die Gasphasenreaktionen zunächst in-situ ablaufen zu lassen und die Gewinnung von Wasserstoff zeitlich zu verzögern. Dafür muss die Produktionsbohrung zunächst verschlossen bleiben. Ein Öffnungszeitpunkt, d.h. der Zeitpunkt der Gewinnung von Wasserstoff, und die Fließmenge können beispielsweise anhand von Simulationen bestimmt werden.

The following steps would then be required:

1. 1. Injecting a liquid containing or consisting of water and at least one catalyst into at least a first well and/or at least a second well of a hydrocarbon reservoir. The optimal amount of liquid (ie amount of water) for the reactions as well as the local distribution of the amount of heat can be calculated beforehand. For this purpose, the construction of a digital image (“twin”) of the hydrocarbon reservoir is advantageous. A water volume that corresponds to about 5-10% of the porosity of the hydrocarbon reservoir (ie the gas volume of the hydrocarbon reservoir) is necessary. Depending on the reaction regime, it may also be necessary to adjust the type of catalyst (particle size, chemical composition).
2. 2. Injecting a fluid (eg a gas) containing or consisting of oxygen into the at least one first well and/or the at least one second well of the hydrocarbon reservoir. The amount of fluid (ie, amount of oxygen) needed to produce a given amount of heat (via heat of oxidation) can be calculated in advance. It is necessary to reach at least 250°C, but preferably 300-400°C. The amount of fluid needed can be estimated based on the mole amount of oil and the molecular size of the oil in the hydrocarbon reservoir. It is advantageous for this if it is known in what quantity the hydrocarbon reservoir contains heavy oil and light oil. In the case of heavy oils, around 50-100 moles of oxygen per mole of heavy oil make sense; with lighter oils, 20-50 moles of oxygen per mole of light oil to be burned are also possible.
3. 3. Ignite the hydrocarbon reservoir
   • i) waiting for the hydrocarbon reservoir to auto-ignite; or
   • ii) temperature control of the fluid to a temperature which is equal to or greater than an ignition temperature of the hydrocarbon reservoir; or
   • iii) adding an igniter to the at least one first borehole and/or to the at least one second borehole, the igniter being selected from the group consisting of electrical igniters, chemical igniters, thermal igniters and combinations thereof.
4. 4. Producing hydrogen-containing gas via the at least one first and/or at least one second well of the hydrocarbon reservoir and obtaining hydrogen from the hydrogen-containing gas. In order to achieve ideal results, it can make sense to initially allow the gas-phase reactions to take place in situ and to delay the production of hydrogen. To do this, the production well must initially remain closed. An opening time, ie the time point of hydrogen production and the flow rate can be determined, for example, using simulations.

Reference List

1

hydrocarbon reservoir;

2

first borehole;

3

second borehole;

4

another borehole;

5

oil zone;

6

water zone; and

7

Caprock or sealing rock of the hydrocarbon reservoir.

Claims (15)

A method for recovering hydrogen from a hydrocarbon reservoir, comprising the steps or consisting of the steps: a) Injecting a liquid containing or consisting of water and at least one catalyst into at least a first well and/or into at least a second well of a hydrocarbon reservoir, the catalyst being suitable for catalyzing a formation of hydrogen at least from compounds which are selected from the group consisting of compounds resulting from the combustion of hydrocarbons, hydrocarbons and combinations thereof and wherein the catalyst has a particle size of at most 1 mm, the particle size relating to a particle size determined via optical microscopy; b) injecting a fluid containing or consisting of an oxidant after step a) into the at least one first well and/or the at least one second well of the hydrocarbon reservoir; c) igniting the hydrocarbon reservoir i) waiting for the hydrocarbon reservoir to auto-ignite; or ii) temperature control of the fluid from step b) to a temperature which is equal to or greater than an ignition temperature of the hydrocarbon reservoir; or iii) adding an igniter to the at least one first well and/or to the at least one second well, the igniter being selected from the group consisting of electrical igniter, chemical igniter, thermal igniter and combinations thereof; d) production of hydrogen-containing gas via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir; and e) recovery of hydrogen from the hydrogen-containing gas. Method according to the preceding claim, characterized in that i) after step c) has been carried out, steps a) and b) are repeated at least once, preferably several times, before step d) is carried out; or ii) steps a) to e) are repeated at least once, optionally more than once; or iii) after step d) a certain period of time is waited and after this period step d) is carried out again, optionally several times after waiting a certain period of time. Process according to one of the preceding claims, characterized in that the catalyst i) is contained in the liquid in an amount of 0.1 to 10 g/l; and/or ii) is selected from the group consisting of platinum-tin catalyst, alumina catalyst and combinations thereof; and/or iii) has a particle size of at most 0.1 mm, the particle size relating to a particle size determined by optical microscopy. Method according to one of the preceding claims, characterized in that the liquid in step a) i) is injected at a pressure in the range of 20 to 350 bar, preferably 25 to 300 bar; and/or ii) is injected in an amount corresponding to 5 to 10% of a pore volume of the hydrocarbon reservoir, the pore volume of the hydrocarbon reservoir preferably being determined from known information about a structure of the hydrocarbon reservoir. Method according to one of the preceding claims, characterized in that the fluid in step b) i) is injected at a pressure in the range of 20 to 350 bar, preferably 25 to 300 bar; and/or ii) is injected in an amount suitable for raising a temperature in an interior of the hydrocarbon reservoir to a value in the range from 200°C to 500°C, preferably to a value in the range from 250°C to 450°C C, more preferably at a value in the range of 300 °C to 400 °C, wherein the temperature is more preferably kept at this value by detecting the temperature of the hydrocarbon reservoir via a temperature sensor or by the amount of fluid from known information is determined via a quantity and type of hydrocarbons in the hydrocarbon reservoir. Method according to one of the preceding claims, characterized in that the at least one first well and/or at least one second well in the hydrocarbon re servoir is or will be arranged at least in regions i) vertically, wherein the vertical arrangement refers to an arrangement along the force of gravity and a vertical arrangement means an arrangement that deviates from a strictly vertical arrangement by a maximum angle of 20°; and/or ii) is or will be arranged horizontally, where the horizontal arrangement refers to an arrangement perpendicular to gravity and where by a horizontal arrangement is meant an arrangement that deviates from a strictly horizontal arrangement by a maximum angle of 20°. Method according to one of the preceding claims, characterized in that before step d) is carried out, the at least one first borehole and/or the at least one second borehole is closed and only after i) a waiting time of at least three days, preferably three days to three months; and/or ii) cooling of the reservoir to a temperature of at most 20°C above the condensation temperature of at least one fluid in the hydrocarbon reservoir is started, the at least one fluid preferably containing or consisting of water. Plant for the production of hydrogen from a hydrocarbon reservoir, having or consisting of: a) a liquid source with a liquid containing or consisting of water and at least one catalyst, the catalyst being suitable for catalyzing the formation of hydrogen at least from compounds selected from the group consisting of compounds which are produced by combustion of Hydrocarbons are formed, hydrocarbons and combinations thereof and wherein the catalyst has a particle size of at most 1 mm, the particle size relating to a particle size determined via optical microscopy; b) a fluid source with a fluid containing or consisting of an oxidizing agent; c) a production means adapted to successively inject liquid from the liquid source and fluid from the fluid source into at least one first well and/or at least one second well of a hydrocarbon reservoir; d) optionally, an igniter suitable for igniting a hydrocarbon reservoir, the igniter being selected from the group consisting of electrical igniter, chemical igniter, thermal igniter, and combinations thereof; e) a means for producing hydrogen-containing gas via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir; f) a means for obtaining hydrogen from hydrogen-containing gas; g) optionally a control unit configured to control the system to inject liquid from the liquid source into the at least one first well and/or into the at least one second well of the hydrocarbon reservoir, fluid from the fluid source into the at least one first well and /or to inject into the at least one second well of the hydrocarbon reservoir, after igniting the hydrocarbon reservoir to produce a hydrogen-containing gas via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir and to extract hydrogen from the hydrogen-containing gas to win. plant after claim 8 , characterized in that the control unit is configured to control the conveying means in such a way that i) after the hydrocarbon reservoir has been ignited at least once, preferably several times, liquid from the liquid source and fluid from the fluid source repeatedly in succession into the at least one first borehole and/or is injected into the at least one second well of the hydrocarbon reservoir before hydrogen-containing gas is produced via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir; or ii) at least once, preferably several times, repeatedly liquid from the liquid source is injected into the at least one first well and/or into the at least one second well of the hydrocarbon reservoir, fluid from the fluid source into the at least one first well and/or into the at least a second well of the hydrocarbon reservoir is injected, after ignition of the hydrocarbon reservoir, hydrogen-containing gas is produced via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir, and hydrogen is obtained from the hydrogen-containing gas; or iii) after hydrogen-containing gas has been produced via the at least one first well and/or via the at least one second well of the hydrocarbon reservoir, waiting for a certain period of time and after this period hydrogen-containing gas is again pumped via the at least one first well and/or or is produced from the at least one second well of the hydrocarbon reservoir, optionally multiple times after waiting a specified period of time. Plant after one of Claims 8 or 9 , characterized in that the catalyst i) contained in the liquid of the liquid source in an amount of 1-10 g/l; and/or ii) is selected from the group consisting of platinum-tin catalyst, alumina catalyst and combinations thereof; and/or iii) a particle size of at most 0.1 mm, the particle size relating to a particle size determined by optical microscopy. Plant after one of Claims 8 until 10 , characterized in that the control unit is configured to cause the delivery means to inject the liquid from the liquid source i) with a pressure in the range of 20 to 350 bar, preferably 25 to 300 bar; and/or ii) to inject in an amount corresponding to 5 to 10% of a pore volume of the hydrocarbon reservoir, wherein the pore volume of the hydrocarbon reservoir is preferably determined from known information about a structure of the hydrocarbon reservoir. Plant after one of Claims 8 until 11 , characterized in that the control unit is configured to cause the conveyor to inject the fluid from the fluid source i) at a pressure in the range of 20 to 350 bar, preferably 25 to 300 bar; and/or ii) in an amount suitable to raise a temperature in an interior of the hydrocarbon reservoir to a value in the range from 200°C to 500°C, preferably to a value in the range from 250°C to 450°C C, more preferably at a value in the range of 300 ° C to 400 ° C, wherein the control unit is particularly preferably configured to keep the temperature at this value by the control unit detecting the temperature of the hydrocarbon reservoir via a temperature sensor or by the Control unit determines the amount of fluid from known information about an amount and type of hydrocarbons in the hydrocarbon reservoir. Plant after one of Claims 8 until 12 , characterized in that the system comprises the at least one first borehole and/or the at least one second borehole in the hydrocarbon reservoir, the at least one first borehole and/or the at least one second borehole in the hydrocarbon reservoir being arranged at least in regions i) vertically, with the vertical arrangement refers to an arrangement along the force of gravity and by a vertical arrangement is meant an arrangement deviating from a strictly vertical arrangement by a maximum angle of 20°; or ii) arranged horizontally, where horizontal arrangement refers to an arrangement perpendicular to gravity and by horizontal arrangement is meant an arrangement deviating from a strictly horizontal arrangement by a maximum angle of 20°. Plant after one of Claims 8 until 13 , characterized in that the control unit is configured to cause the at least one first borehole and/or the at least one second borehole to be closed prior to the production of hydrogen-containing gas and to start the production of hydrogen-containing gas only after i) a waiting period of at least three days, preferably three days to three months, is started; and/or ii) cooling of the reservoir to a temperature of at most 20°C above the condensation temperature of at least one fluid in the hydrocarbon reservoir is started, the at least one fluid preferably containing or consisting of water. Use of the system according to one of Claims 8 until 14 for the production of hydrogen from a hydrocarbon reservoir.

Images