Hot CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method

Abstract

The invention discloses a hot CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method, belongs to the technical field of oil and gas reservoir in-situ carbon storage and hydrogen production, and solves the problem that CO2 and other gases can be generated during oxygen injection combustion reservoir in-situ hydrogen production at present. The method comprises the following steps: selecting a target reservoir, digging a well and distributing hydrogen production collaborative equipment, transforming and developing the target reservoir based on the type of the target reservoir, injecting high-temperature CO2, starting a microwave emission device of an electromagnetic heating hydrogen production and hydrogen production well to continuously heat the reservoir to a hydrogen production temperature, and keeping the current reservoir temperature and pressure condition to produce hydrogen. Starting an electromagnetic heating hydrogen production and hydrogen production well for production; closing the well to stop production when the hydrogen yield is rapidly reduced; according to the invention, the production of CO2 gas in the hydrogen production process is avoided, and multiple injection processes of oxygen-containing gas, water vapor and the like are simplified at the same time; the electromagnetic heating cost is reduced by injecting high-temperature CO2 to preheat the reservoir, and meanwhile, the utilization and geological storage of CO2 can be realized, so that the synergistic effect of geological storage of CO2 and in-situ hydrogen production is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-situ carbon storage and hydrogen production in oil and gas reservoirs, and specifically relates to a thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method. Background Art

[0002] Greenhouse gas emissions have led to an increasingly serious global climate change problem. "Carbon peak and carbon neutrality" will help reduce greenhouse gas emissions and slow down global warming. At the same time, hydrogen (H2) is considered to be the most promising clean energy in the 21st century. About 95% of hydrogen in the United States is produced by steam methane reforming (SMR) using natural gas and water as raw materials. The disadvantage of this technology is that it has high carbon dioxide emissions, about 9-10kgCO2e / kgH2, which increases the burden of CCUS to reduce the negative impact of greenhouse gas footprint. The integration of SMR and CCUS is a relatively mature technology, and it is a huge challenge to significantly reduce its cost.

[0003] Converting oil and natural gas into clean hydrogen through underground thermal cracking and other methods is a technical solution that is expected to achieve decarbonization of the oil industry by 2050. In-situ hydrogen production in reservoirs can generate and extract hydrogen directly from oil and gas reservoirs, while using downhole hydrogen membrane separators to lock all carbon products underground. Based on the existing infrastructure of oil and gas fields, there is no need to extract, separate, or transport hydrocarbons, which can significantly reduce the cost of hydrogen production. At present, the in-situ hydrogen production technology in reservoirs is mostly to inject air into coal reservoirs, heavy oil reservoirs, or abandoned oil reservoirs for ignition, that is, to produce hydrogen using the in-situ combustion gasification (ISCG) method. Although the technical and economic assessment (TEA) shows that the cost of the ISCG method can be significantly reduced under different experimental assumptions. However, even underground, the hydrogen production process using the in-situ combustion gasification (ISCG) method will inevitably produce a large amount of CO2 due to the injection of air.

[0004] Chinese patent 202311482466.5 discloses a method for in-situ hydrogen production underground in an oil reservoir, which discloses an in-situ hydrogen production method in which three horizontal wells, upper, middle and lower, and a temperature detection well are set in the same reservoir, wherein a heating device is set in the middle horizontal well, and a close-cut volume fracturing is performed around the well and a catalyst and a thermal conductor are filled to form a reaction zone; the lower horizontal well is in-situ ignited and oxygen-containing gas is injected to make it incompletely burn to produce CO and CO2 and form a gasification zone; the temperature is raised to above 450°C by a heating and heating device, and when the gas in the gasification zone enters the reaction zone, water vapor is injected to efficiently produce hydrogen; however, this method has the following shortcomings: (1) This technology requires drilling four horizontal wells, which has poor economic benefits; (2) Its essence is still to inject oxygen to burn and heat the reservoir, and the generation of CO2 gas cannot be avoided. Although it can be prevented from being mined to the ground through hydrogen filtration membranes, the utilization of CO2 cannot be achieved either; (3) Reservoir ignition and combustion has high requirements for organic matter and is not universally applicable to oil reservoirs.

[0005] Chinese patent 202210955852.0 discloses a method for in-situ hydrogen production near the wellbore zone by using downhole electric heating. The method heats the reservoir near the wellbore zone by setting an electric heating device and a temperature monitoring device downhole. When the natural gas in the reservoir passes through the formation near the wellbore zone of the production well, it mixes with the water vapor generated in situ under high temperature conditions, and a hydrogen production reaction occurs under the action of a nanocatalyst on the rock surface, producing outputs including hydrogen and other components mainly composed of carbon dioxide. Finally, the produced hydrogen and other components are separated and the other components are injected back into the formation through a nearby injection well. However, this method has the following shortcomings: (1) The essence of the method is still the heating decomposition of organic matter and water vapor, which cannot avoid the generation of CO2 gas. In addition, the technology cannot achieve in-situ storage of associated gases such as CO2 through filtration membranes. Even if reinjection is performed, it will increase costs and cannot achieve the utilization of CO2.

[0006] (2) This technical method completely uses underground electric heating to heat the reservoir, which is relatively costly.

[0007] To address the above issues, we proposed a thermal CO2-assisted electromagnetic heating method for in-situ carbon storage and hydrogen production. Summary of the invention

[0008] The purpose of the present invention is to address the deficiencies of the prior art and provide a thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method, which solves the problem that the current in-situ hydrogen production in oxygen injection combustion reservoirs will generate gases such as CO2.

[0009] The existing methods cannot avoid the generation of CO2 gas, nor can they achieve in-situ storage of associated gases such as CO2 through filtration membranes. In response to the above problems, we have proposed a thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method, abandoning the conventional organic matter + water vapor thermal cracking hydrogen production technology, using electromagnetic heating technology to avoid the generation of byproducts such as CO2, and at the same time adding a reservoir preheating step for high-temperature CO2 injection on the basis of conventional electric / electromagnetic heating, which not only saves the cost of electromagnetic heating, but also can seal CO2 underground, and ultimately achieves the dual purpose of CO2 geological storage and reservoir in-situ hydrogen production. The present invention breaks through the conventional oxygen injection combustion heating method, avoids the output of CO2 gas in the hydrogen production process, and simplifies the multiple injection processes of oxygen-containing gas, water vapor, etc.; the present invention uses the method of injecting high-temperature CO2 to preheat the reservoir to reduce the cost of electromagnetic heating, and at the same time can achieve the utilization and geological storage of CO2, thereby ensuring the synergistic effect of CO2 geological storage and in-situ hydrogen production.

[0010] The present invention is implemented as follows: a thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method, the thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method comprising: S10, selecting a reservoir: selecting a target reservoir, wherein the target reservoir contains at least two horizontal wells; S20, well layout: drilling wells and arranging hydrogen production coordination equipment, drilling two vertically parallel horizontal wells in the target reservoir, the upper horizontal well being used as an electromagnetic heating hydrogen production well, and the lower horizontal well being used as a high-temperature CO2 injection well; S30, Fracturing and Development: Reconstruction and development of target reservoirs based on target reservoir types; S40, injecting high-temperature CO2, heating the high-temperature CO2 on the ground and making it in a supercritical state, and injecting the high-temperature CO2 into the target reservoir through the high-temperature CO2 injection well by a ground injection device; S50, electromagnetic heating hydrogen production: start the electromagnetic heating hydrogen production and microwave emission device of the hydrogen production well to continue heating the reservoir to the hydrogen generation temperature and maintain the current reservoir temperature and pressure conditions to generate hydrogen; S60, start electromagnetic heating hydrogen production and hydrogen production wells for production: shut down the wells and stop production when the hydrogen production drops rapidly; S70, repeating steps S10-S60 until no industrial hydrogen gas flow is generated.

[0011] The target reservoir types include: oil shale, tight reservoir, heavy oil reservoir, conventional sandstone reservoir, carbonate reservoir; The effective thickness of the target reservoir is greater than 5m, and the burial depth of the target reservoir is less than 6000m.

[0012] In S20, a microwave transmitting device is laid in the horizontal section of the electromagnetic heating hydrogen production and hydrogen production well. The microwave transmitting device is used to electromagnetically heat the reservoir to the temperature of organic matter hydrogen production. The heating radius of the microwave transmitting device is 1.2-4m. A hydrogen filter membrane is installed in the electromagnetic heating hydrogen production and hydrogen production well. The hydrogen filter membrane is used to filter other gas products to obtain pure hydrogen.

[0013] The method for transforming and developing a target reservoir based on the target reservoir type comprises: S301, identifying and determining the target reservoir type; S302, if the target reservoir is a low-permeability tight reservoir or a shale reservoir, supercritical high-temperature CO2 is used to perform reservoir fracturing on the target reservoir; S303, if the oil reservoir is an undeveloped oil reservoir or an oil reservoir with exploitation potential, oil and gas development is first carried out after the horizontal well of the target reservoir is drilled, and S302 is carried out after the oil reservoir development is completed.

[0014] When high-temperature CO2 is heated on the ground and brought into a supercritical state, the heating temperature of CO2 exceeds 280°C and the heating pressure is 20MPa.

[0015] In S50, after the heat transfer of the well in S40, the microwave transmitting device of the electromagnetic heating hydrogen production well is turned on. The microwave transmitting device continues to heat the reservoir to the hydrogen generation temperature in the form of electromagnetic waves, and maintains the current reservoir temperature and pressure conditions to carry out electromagnetic heating and thermal cracking of organic matter to generate hydrogen.

[0016] In S50, before the organic matter electromagnetic heating pyrolysis hydrogen reaction, a catalyst is pre-injected into the reservoir to increase the hydrogen reaction rate, and the catalyst includes iron ions and SiC.

[0017] The microwave transmitting device continues to heat the reservoir to the hydrogen generation temperature in the form of electromagnetic waves, and the hydrogen generation temperature is 300-600°C.

[0018] Compared with the prior art, the embodiments of the present application have the following beneficial effects: The present invention abandons the conventional organic matter + water vapor thermal cracking hydrogen production technology, adopts electromagnetic heating technology to avoid the generation of by-products such as CO2, and at the same time adds a reservoir preheating step for high-temperature CO2 injection on the basis of conventional electric / electromagnetic heating, which not only saves the cost of electromagnetic heating, but also can seal CO2 underground, ultimately achieving the dual purposes of CO2 geological storage and in-situ hydrogen production in the reservoir.

[0019] The present invention avoids the production of CO2 gas in the hydrogen production process, and simplifies the multiple injection processes of oxygen-containing gases, water vapor, etc.; the present invention uses the method of injecting high-temperature CO2 to preheat the reservoir to reduce the cost of electromagnetic heating, and at the same time can realize the utilization and geological storage of CO2, thereby ensuring the synergistic effect of CO2 geological storage and in-situ hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the steps of the thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method provided by the present invention.

[0021] Figure 2 This is a schematic diagram of the electromagnetic heating pyrolysis hydrogen reaction of organic matter provided by the present invention.

[0022] Figure 3 It is a schematic diagram of the temperature and hydrogen production variation curve of the whole process provided by the present invention.

[0023] Figure 4 It is a schematic diagram of the implementation process of the thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method provided by the present invention.

[0024] In the figure: 1-high temperature CO2 injection well, 2-target reservoir, 3-microwave emission device, 4-hydrogen filter membrane, 5-electromagnetic heating hydrogen production and hydrogen production well. DETAILED DESCRIPTION

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0026] The existing methods cannot avoid the generation of CO2 gas, nor can they achieve in-situ storage of associated gases such as CO2 through filtration membranes. In response to the above problems, we have proposed a thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method, abandoning the conventional organic matter + water vapor thermal cracking hydrogen production technology, using electromagnetic heating technology to avoid the generation of byproducts such as CO2, and at the same time adding a reservoir preheating step for high-temperature CO2 injection on the basis of conventional electric / electromagnetic heating, which not only saves the cost of electromagnetic heating, but also can seal CO2 underground, and ultimately achieves the dual purpose of CO2 geological storage and reservoir in-situ hydrogen production. The present invention breaks through the conventional oxygen injection combustion heating method, avoids the output of CO2 gas in the hydrogen production process, and simplifies the multiple injection processes of oxygen-containing gas, water vapor, etc.; the present invention uses the method of injecting high-temperature CO2 to preheat the reservoir to reduce the cost of electromagnetic heating, and at the same time can achieve the utilization and geological storage of CO2, thereby ensuring the synergistic effect of CO2 geological storage and in-situ hydrogen production.

[0027] It should be noted that the embodiments of the present invention are applicable to any conventional, unconventional oil, gas and coal reservoirs, such as conventional sandstone reservoirs, oil shale reservoirs, and heavy oil reservoirs. Some reservoirs with poor pore connectivity require pre-fracturing construction.

[0028] The embodiment of the present invention provides a method for in-situ carbon storage and hydrogen production synergistically using thermal CO2-assisted electromagnetic heating. Figure 1 A schematic diagram of the steps of the thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method is shown, and the thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method specifically includes: S10, selecting a reservoir: selecting a target reservoir 2, wherein the target reservoir 2 contains at least two horizontal wells; In this embodiment, the reservoir type of the target reservoir 2 can be any type of reservoir, thereby expanding the applicability of the embodiment of the present invention. The target reservoir 2 type includes but is not limited to oil shale, tight reservoir, heavy oil reservoir, conventional sandstone reservoir, and carbonate reservoir; such as oil shale (which has natural mineral catalysts and is more prone to thermal cracking), tight reservoirs (need fracturing), heavy oil reservoirs (sufficient high carbon number organic matter), conventional sandstone reservoirs (large gas storage space), and carbonate reservoirs (the injected high-temperature carbon dioxide will inhibit the high-temperature decomposition of carbonate rocks, on the one hand reducing the generation of CO2, but at the same time affecting the increase in porosity). The effective reservoir thickness of the target reservoir 2 is greater than 5m, and the burial depth of the target reservoir 2 is less than 6000m.

[0029] S20, well layout: drilling wells and arranging hydrogen production coordination equipment, drilling two upper and lower parallel horizontal wells in the target reservoir 2, the upper horizontal well is used as the electromagnetic heating hydrogen production and hydrogen production well 5, and the lower horizontal well is used as the high-temperature CO2 injection well 1; In this embodiment, a microwave transmitting device 3 is laid in the horizontal section of the electromagnetic heating hydrogen production and hydrogen production well 5. The microwave transmitting device 3 is used to electromagnetically heat the reservoir to the organic hydrogen production temperature. The heating radius of the microwave transmitting device 3 is 1.2-4m. A hydrogen filter membrane 4 is arranged in the electromagnetic heating hydrogen production and hydrogen production well 5. The hydrogen filter membrane 4 is used to filter other gas products to obtain pure hydrogen.

[0030] It should be noted that the microwave emission device 3 is a successfully applied technology in the field of oil and gas field development, and the heating radius can reach 1.2-4m, which can meet the heating range requirements. The hydrogen filter membrane 4 is an existing technology, which has been involved in the existing oxygen injection combustion reservoir in-situ hydrogen production technology and is a molding technology.

[0031] S30, fracturing and development: transforming and developing the target reservoir 2 based on the type of the target reservoir 2; In this embodiment, the method for transforming and developing the target reservoir 2 based on the type of the target reservoir 2 includes: S301, identifying and determining the type of target reservoir 2; S302, if the target reservoir 2 is a low-permeability tight reservoir or a shale reservoir, supercritical high-temperature CO2 is used to perform reservoir fracturing on the target reservoir 2; S303, if the oil reservoir is an undeveloped oil reservoir or an oil reservoir with exploitation potential, after the horizontal well of the target reservoir 2 is drilled, oil and gas development (including but not limited to CO2 flooding, heavy oil thermal recovery and cold recovery, chemical flooding, etc.) shall be carried out first, and S302 shall be carried out after the development of the oil reservoir is completed (it can be identified as a depleted oil and gas reservoir).

[0032] It should be noted that, since the target reservoir 2 of the present invention is universal, it is necessary to carry out reservoir transformation and development according to the actual situation of the reservoir in the early stage of hydrogen production to ensure the best economic benefits. If the target reservoir 2 is a low-permeability tight reservoir or a shale reservoir, if the reservoir has not been fractured or the effective connectivity of the reservoir pores is poor, the reservoir needs to be fractured. Considering the needs of carbon storage and preheating the reservoir, supercritical high-temperature CO2 can be used for reservoir fracturing (the present invention is not limited to this fracturing method, and all fracturing methods that can achieve reservoir fractures can be effectively applied and are within the scope of patent protection).

[0033] S40, injecting high-temperature CO2, heating the high-temperature CO2 on the ground and making it in a supercritical state, and injecting the high-temperature CO2 into the target reservoir 2 through the high-temperature CO2 injection well 1 by a ground injection device; It should be noted that when high-temperature CO2 is heated on the ground and placed in a supercritical state, the heating temperature of CO2 exceeds 280°C and the heating pressure is 20MPa. The heating temperature needs to exceed 280°C. Shale reservoirs have a "thermal runaway" phenomenon. After exceeding 280°C, the ability to continue heating it to the hydrogen generation temperature is significantly reduced. There is no report of "thermal runaway" in gas-type reservoirs, but this can be used as a CO2 heating temperature standard. High-temperature CO2 is injected into the reservoir through injection well 1 through a ground injection device and the well is shut down. The injected high-temperature CO2 will enter the reservoir deficit area after oil and gas production and achieve the effect of preheating the reservoir. At the same time, the injected CO2 will be sealed in the reservoir.

[0034] S50, electromagnetic heating hydrogen production: start the electromagnetic heating hydrogen production and microwave emission device 3 of the hydrogen production well 5 to continue heating the reservoir to the hydrogen generation temperature and maintain the current reservoir temperature and pressure conditions to generate hydrogen; In this embodiment, after the S40 well is soaked and heat is transferred, the microwave transmitting device 3 of the electromagnetic heating hydrogen production and hydrogen production well 5 is turned on. The microwave transmitting device 3 continues to heat the reservoir to the hydrogen generation temperature in the form of electromagnetic waves, and maintains the current reservoir temperature and pressure conditions to carry out the organic matter electromagnetic heating thermal cracking hydrogen reaction. Before the organic matter electromagnetic heating thermal cracking hydrogen reaction, a catalyst is injected into the reservoir in advance to increase the hydrogen reaction rate. The catalyst includes iron ions and SiC. The catalyst is a solid powder and can be added to the fracturing fluid and injected into the reservoir. If fracturing is not required, it can be carried to the reservoir through the injection fluid in the development stage (this method will be less effective because the displacement and pressure of fracturing are large, and the carrying effect is good). The injection amount is generally 5-10kg per cubic meter of water, wherein the schematic diagram of the organic matter electromagnetic heating thermal cracking hydrogen reaction is as shown in Figure 2 As shown, the reaction equation is as follows. Indoor experiments show that the concentration of hydrogen can reach more than 60%: Organic matter → light oil (l) + C (s) + H2 (g) + CO (g) Unlike in-situ hydrogen production by injecting oxygen into the combustion reservoir, this reaction does not produce CO2. On the one hand, this reduces the cost of processing hydrogen by-products. On the other hand, the injected high-temperature CO2 will not inhibit the normal occurrence of the reaction, making it more environmentally friendly.

[0035] When the microwave emitting device 3 continues to heat the reservoir to the hydrogen generation temperature in the form of electromagnetic waves, the hydrogen generation temperature may be 300-600°C (sandstone reservoirs are generally about 500°C, and shale reservoirs are generally about 300°C).

[0036] It should be noted that the microwave emitting device 3 can be an electromagnetic wave generator. This microwave emitting device 3 is provided with an electromagnetic wave generator, which is transmitted to the simulated reaction chamber through an electromagnetic waveguide tube and has isolation performance. The electromagnetic wave generator includes two types: magnetron and solid generator. The solid generator is an upgraded version with higher power and frequency, but in the application context of electromagnetic wave heating in this patent, too high frequency is not required, and magnetron is more mature for microwave heating (such as microwave oven). The operating frequency of the microwave generator is 3-5 GHz, and the maximum power is not less than 3kW. Specifically, there is a cathode and a filament inside the magnetron, and the filament heats the cathode to emit electrons. These electrons are accelerated to the anode under the action of the electric field. At the same time, the constant magnetic field generated by the magnet bends the trajectory of the electrons to form a rotational motion. The rotating electron flow excites the coupled cavity chain to generate a high-frequency alternating electromagnetic field in the microwave frequency band. The high-frequency alternating field further interacts with the electrons to decelerate the electrons and convert the kinetic energy of the electrons into microwave energy.

[0037] S60, start electromagnetic heating hydrogen production and hydrogen production well 5 for production: shut down the well and stop production when the hydrogen production drops rapidly; It should be noted that the electromagnetic heating hydrogen production and hydrogen production well 5 is turned on for production. Due to the presence of the hydrogen filter membrane 4, the purity of the hydrogen produced can be high, and the injected CO2 gas can be prevented from being recovered to the ground again. When the hydrogen production drops rapidly, the well is shut down and production is stopped. The main reason for the reduction in hydrogen production is the drop in reservoir temperature due to the shutdown of the electromagnetic heating system. The temperature and hydrogen production curve of the whole process of steps S40-S60 is shown in the figure. Figure 3 shown.

[0038] S70, repeating steps S10-S60 until no industrial hydrogen gas flow is generated.

[0039] In this embodiment, Figure 3 It is shown that the hydrogen generation rate will peak during the heating process and then gradually decrease. This is because of the limit of the thermal cracking chemical reaction. Therefore, it is necessary to heat and crack the well again to generate hydrogen after production, that is, repeat the above steps S40-S60 until no industrial hydrogen flow is generated or according to economic benefits. The benefit of repeating the above steps is that more CO2 can be sealed. Figure 4 As shown, a schematic diagram of the process flow of the thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production collaborative method provided in an embodiment of the present invention is shown.

[0040] At the same time, it should be noted that the present invention can be linked with new energy sources such as wind power generation, relying on wind power generation and other electric energy sources to heat CO2, avoiding the storage and transportation of wind power generation, which is more economical and environmentally friendly.

[0041] In this embodiment, the target reservoir 2 is an undeveloped shale reservoir, and the implementation steps are as follows: S10, construction plan design, the effective thickness of the target reservoir 2 is 10m, including shale and tight sandstone interlayers, the burial depth is about 4500m, the reservoir temperature is about 80℃, the horizontal section of the horizontal well is set to 400m, the well is completed by perforation, and staged volume fracturing transformation is required in the later stage.

[0042] S20, drilling wells and arranging corresponding process flows, drilling two horizontal wells parallel to each other in the target reservoir 2, wherein the lower well is used as a high-temperature CO2 injection well 1, and the upper well is used as an electromagnetic heating hydrogen production and hydrogen production well 5. The electromagnetic heating hydrogen production and hydrogen production well 5 is provided with a microwave transmitting device 3 in the horizontal section for electromagnetically heating the reservoir to the hydrogen production temperature of organic matter, and a hydrogen filter membrane 4 is provided for filtering other gas products to obtain pure hydrogen. It should be noted that the hydrogen filter membrane 4 is generally provided in sections.

[0043] S30, early reservoir transformation and development. Supercritical high-temperature CO2 is used in two horizontal wells to perform reservoir fracturing and lay proppant, and industrial oil and gas flow is obtained through depletion production, CO2 huff and puff, and CO2 flooding. Subsequent steps will be implemented after the reservoir development is completed.

[0044] S40, inject high-temperature CO2 to preheat the reservoir. The upper horizontal well is in a shut-in state. The supercritical CO2 gas is heated to 300°C and 20MPa on the ground (using the "thermal runaway" phenomenon of the shale reservoir). The high-temperature CO2 is injected into the reservoir through the lower high-temperature CO2 injection well 1 through the ground injection device and the well is shut down. The injected high-temperature CO2 will enter the reservoir deficit area after oil and gas production and achieve the effect of preheating the reservoir. At the same time, the injected CO2 will be sealed in the reservoir.

[0045] S50, electromagnetic heating reservoir hydrogen production, after S40 well soaking and heat transfer for 2 hours, turn on the microwave emission device 3 of the electromagnetic heating hydrogen production and hydrogen production well 5 to continue heating the reservoir to 500°C in the form of electromagnetic waves, and maintain the current reservoir temperature and pressure conditions for hydrogen production reaction for 2-3 hours.

[0046] S60, hydrogen development, opening hydrogen production wells for production. The presence of the hydrogen filter membrane 4 can obtain high-purity hydrogen, while preventing the injected CO2 gas from being recovered to the ground again. When the hydrogen production drops rapidly, the wells are closed and production is stopped.

[0047] S70, repeating the above steps S40-S60 until no industrial hydrogen flow is generated or according to economic benefits.

[0048] In this embodiment, the target reservoir 2 is a low-permeability sandstone reservoir that has been developed by horizontal wells, and the implementation steps are as follows: S10, construction plan design, the effective thickness of the target reservoir 2 is 8m, including 1 sandstone layer, the burial depth is about 3000m, the reservoir temperature is about 50℃, the horizontal section of the horizontal well is set to 400m, the well is completed by perforation, and staged volume fracturing transformation is required in the later stage.

[0049] S20, drilling a well and arranging the corresponding process flow, drilling a parallel horizontal well above the existing production well in the target reservoir 2 as an electromagnetic heating hydrogen production and production well 5, and the original production well below is used as a high-temperature CO2 injection well 1, and the electromagnetic heating hydrogen production and production well 5 is provided with a microwave transmitting device 3 in the horizontal section for electromagnetically heating the reservoir to the hydrogen generation temperature of organic matter, and a hydrogen filter membrane 4 is provided for filtering other gas products to obtain pure hydrogen.

[0050] S30, early reservoir transformation and development, using supercritical high-temperature CO2 to perform reservoir fracturing and lay proppant in two horizontal wells, and obtaining industrial oil and gas flow through CO2 huff and puff and CO2 flooding and other development methods. Subsequent steps will be implemented after the completion of reservoir development. During the reservoir fracturing and development process, iron ions are added to the liquid injected into the reservoir to increase the hydrogen reaction rate.

[0051] S40, inject high-temperature CO2 to preheat the reservoir. The upper horizontal well is in a shut-in state. The supercritical CO2 gas is heated to 300°C and 20MPa on the ground. The high-temperature CO2 is injected into the reservoir through the lower high-temperature CO2 injection well 1 through a ground injection device and the well is shut down. The injected high-temperature CO2 will enter the reservoir deficit area after oil and gas production and achieve the effect of preheating the reservoir. At the same time, the injected CO2 will be sealed in the reservoir.

[0052] S50, electromagnetic heating reservoir hydrogen production, after step S40, after the well is kept warm for 2 hours, the microwave transmitting device 3 of the electromagnetic heating hydrogen production and hydrogen production well 5 is turned on to continue heating the reservoir to 600°C in the form of electromagnetic waves, and the current reservoir temperature and pressure conditions are maintained for hydrogen production reaction for 2-3 hours.

[0053] S60, hydrogen development, opening the hydrogen production well for production, the presence of the hydrogen filter membrane 4 can obtain high-purity hydrogen, while preventing the injected CO2 gas from being recovered to the ground again. When the hydrogen production drops rapidly, the well is closed and production is stopped.

[0054] S70, repeating the above steps S40-S60 until no industrial hydrogen flow is generated or according to economic benefits.

[0055] In summary, the present invention provides a method for synergistic in-situ carbon storage and hydrogen production by thermal CO2-assisted electromagnetic heating. The present invention breaks through the conventional oxygen injection combustion heating method, avoids the output of CO2 gas in the hydrogen production process, and simplifies the multiple injection processes of oxygen-containing gas, water vapor, etc.; the present invention adopts the method of injecting high-temperature CO2 to preheat the reservoir to reduce the cost of electromagnetic heating, while realizing the utilization and geological storage of CO2, thereby ensuring the synergistic effect of CO2 geological storage and in-situ hydrogen production.

[0056] The present invention abandons the conventional organic matter + water vapor thermal cracking hydrogen production technology, adopts electromagnetic heating technology to avoid the generation of by-products such as CO2, and at the same time adds a reservoir preheating step for high-temperature CO2 injection on the basis of conventional electric / electromagnetic heating, which not only saves the cost of electromagnetic heating, but also can seal CO2 underground, ultimately achieving the dual purposes of CO2 geological storage and in-situ hydrogen production in the reservoir.

[0057] It should be noted that, for the above-mentioned embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described order of actions, because according to the present invention, some steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method, characterized in that: The thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method comprises: S10, selecting a reservoir: selecting a target reservoir, wherein the target reservoir contains at least two horizontal wells; S20, well layout: drilling wells and arranging hydrogen production coordination equipment, drilling two vertically parallel horizontal wells in the target reservoir, the upper horizontal well being used as an electromagnetic heating hydrogen production well, and the lower horizontal well being used as a high-temperature CO2 injection well; S30, Fracturing and Development: Reconstruction and development of target reservoirs based on target reservoir types; S40, injecting high-temperature CO2, heating the high-temperature CO2 on the ground and making it in a supercritical state, and injecting the high-temperature CO2 into the target reservoir through the high-temperature CO2 injection well by a ground injection device; S50, electromagnetic heating hydrogen production: start the electromagnetic heating hydrogen production and microwave emission device of the hydrogen production well to continue heating the reservoir to the hydrogen generation temperature and maintain the current reservoir temperature and pressure conditions to generate hydrogen; S60, start electromagnetic heating hydrogen production and hydrogen production wells for production: shut down the wells and stop production when the hydrogen production drops rapidly; S70, repeating steps S10-S60 until no industrial hydrogen gas flow is generated.

2. The thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method according to claim 1, characterized in that: The target reservoir types include: oil shale, tight reservoir, heavy oil reservoir, conventional sandstone reservoir, carbonate reservoir; The effective thickness of the target reservoir is greater than 5m, and the burial depth of the target reservoir is less than 6000m.

3. The thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method according to claim 1, characterized in that: In S20, a microwave transmitting device is laid in the horizontal section of the electromagnetic heating hydrogen production and hydrogen production well. The microwave transmitting device is used to electromagnetically heat the reservoir to the temperature of organic matter hydrogen production. The heating radius of the microwave transmitting device is 1.2-4m. A hydrogen filter membrane is installed in the electromagnetic heating hydrogen production and hydrogen production well. The hydrogen filter membrane is used to filter other gas products to obtain pure hydrogen.

4. The method for in-situ carbon storage and hydrogen production by thermal CO2-assisted electromagnetic heating as claimed in claim 3, characterized in that: The method for transforming and developing a target reservoir based on the target reservoir type comprises: S301, identifying and determining the target reservoir type; S302, if the target reservoir is a low-permeability tight reservoir or a shale reservoir, supercritical high-temperature CO2 is used to perform reservoir fracturing on the target reservoir; S303, if the oil reservoir is an undeveloped oil reservoir or an oil reservoir with exploitation potential, oil and gas development is first carried out after the horizontal well of the target reservoir is drilled, and S302 is carried out after the oil reservoir development is completed.

5. The method for in-situ carbon storage and hydrogen production by thermal CO2-assisted electromagnetic heating as claimed in claim 3, characterized in that: The high-temperature CO2 is heated on the ground and brought into a supercritical state. Generally, in order to ensure safety, the heating temperature of CO2 does not exceed 350°C, and the heating pressure does not exceed the reservoir fracture pressure or 50MPa.

6. The thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method according to claim 1, characterized in that: In S50, after the heat transfer of the well in S40, the microwave transmitting device of the electromagnetic heating hydrogen production well is turned on. The microwave transmitting device continues to heat the reservoir to the hydrogen generation temperature in the form of electromagnetic waves, and maintains the current reservoir temperature and pressure conditions to carry out electromagnetic heating and thermal cracking of organic matter to generate hydrogen.

7. The thermal CO2-assisted electromagnetic heating in-situ carbon storage and hydrogen production synergistic method according to claim 6, characterized in that: In S50, before the organic matter electromagnetic heating pyrolysis hydrogen reaction, a catalyst is pre-injected into the reservoir to increase the hydrogen reaction rate, and the catalyst includes iron ions and SiC.

8. The method for in-situ carbon storage and hydrogen production by thermal CO2-assisted electromagnetic heating as claimed in claim 7, characterized in that: The microwave transmitting device continues to heat the reservoir to the hydrogen generation temperature in the form of electromagnetic waves, and the hydrogen generation temperature is 200-600°C.

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