Shale-based supercritical carbon dioxide and carbon dioxide sequestration coupling simulation method

Abstract

The invention provides a shale supercritical carbon dioxide and carbon dioxide storage coupling simulation method. The method comprises the following steps: acquiring simulation information of a target research area; on the basis of the simulation information, physical scenes and chemical reaction scenes related to recovery ratio improvement of SCCO2-CO2 displacement shale gas and CO2 sequestration are simulated, and a physical simulation result and a chemical simulation result are obtained; performing data exchange on the physical simulation result and the chemical simulation result at the same time step length under the coupling effect; updating parameter information corresponding to physical scene simulation of the next time step based on a data exchange result, and returning to re-simulation until numerical simulation of a specified number of time steps is completed; after numerical simulation of the specified number of time steps is completed, a target simulation result is obtained; and calculating a carbon dioxide sequestration value based on the target simulation result. According to the method, the SCCO2-CO2 displacement shale gas can be finely and comprehensively described under the multi-dimensional condition, and the recovery efficiency and the subsequent CO2 storage process are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of numerical simulation, and in particular to a simulation method based on shale supercritical carbon dioxide and carbon dioxide storage coupling. Background Art

[0002] The abundance of shale gas resources provides an important opportunity for the transformation of energy structure. The proven remaining technically recoverable reserves of shale gas are as high as 3659×108m 3 This huge resource reserve indicates that shale gas development has immeasurable value in promoting energy security and ensuring sustainable economic development. However, traditional shale gas development mainly relies on hydraulic fracturing technology. Although it has promoted industrial development to a certain extent, its drawbacks cannot be ignored: the consumption of a large amount of water resources has aggravated the tension in water resources, and improper treatment of waste liquid generated during fracturing can easily cause environmental pollution.

[0003] To solve this problem, supercritical CO2 (SCCO2) fracturing technology came into being. Its high efficiency and environmental protection characteristics have opened up a new path for shale gas extraction. However, the current numerical simulation research on SCCO2-ESGR and CO2 storage technology is still insufficient, mostly limited to single process analysis, ignoring the complex multi-field coupling effects of thermal flow and solidification after SCCO2 injection, especially the detailed characterization of CO2-water-rock interaction, which directly limits the precise application of the technology and efficiency improvement. In addition, the high threshold and operational complexity of multi-field multi-reaction coupling simulation technology are also technical challenges that need to be overcome urgently. Summary of the invention

[0004] The disclosed embodiments at least provide a coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage. By considering the multi-field coupling mechanism of heat flow solidification involved in the CO2 storage process, and the influence of CO2-water-rock interaction on reservoir porosity and permeability, it is possible to accurately and comprehensively characterize the SCCO2-CO2 displacement of shale gas to improve recovery and subsequent CO2 storage process under multi-dimensional conditions, which can provide important support for the theoretical analysis of SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage.

[0005] The embodiment of the present disclosure provides a coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage, including:

[0006] Step 1: Obtain simulation information of the target study area; wherein the simulation information includes hydrological shale information and geological data;

[0007] Step 2: Based on the simulation information, simulate the physical scenarios involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain physical simulation results; and based on the simulation information, simulate the chemical reaction scenarios involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain chemical simulation results;

[0008] Step 3: exchange data of the same time step under the coupling effect of the physical simulation results and the chemical simulation results; update the parameter information corresponding to the physical scene simulation of the next time step based on the data exchange results, and return to step 2 until the numerical simulation of the specified number of time steps is completed;

[0009] Step 4: After completing the numerical simulation of a specified number of time steps, a target simulation result is obtained; and the carbon dioxide storage value is calculated based on the target simulation result.

[0010] The embodiment of the present disclosure provides a shale-based supercritical carbon dioxide and carbon dioxide storage coupling simulation device, comprising:

[0011] An information acquisition module is used to execute step 1: acquiring simulation information of the target study area; wherein the simulation information includes hydrological shale information and geological data;

[0012] A scenario simulation module is used to perform step 2: based on the simulation information, simulate the physical scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain physical simulation results; and based on the simulation information, simulate the chemical reaction scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain chemical simulation results;

[0013] The data exchange module is used to execute step three: exchange data of the same time step under the coupling effect between the physical simulation results and the chemical simulation results; update the parameter information corresponding to the physical scene simulation of the next time step based on the data exchange result, and return to step two until the numerical simulation of the specified number of time steps is completed;

[0014] The numerical calculation module is used to execute step 4: after completing the numerical simulation of a specified number of time steps, obtain the target simulation result; and calculate the carbon dioxide storage value based on the target simulation result.

[0015] An embodiment of the present disclosure provides a computer device, including: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, a coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage is performed as described in any possible implementation manner described above.

[0016] An embodiment of the present disclosure provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage is implemented as described in any of the above possible implementations.

[0017] The coupled simulation method of shale supercritical carbon dioxide and carbon dioxide storage provided in the embodiments of the present disclosure simulates the physical scene and chemical reaction scene of SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage respectively according to the simulation information of the target study area, and realizes the close coupling of physical and chemical simulations through data exchange and iterative update of the same time step, and finally completes the numerical simulation of multiple time steps to calculate and evaluate the carbon dioxide storage value. Not only the multi-field coupling mechanism of thermal flow solidification involved in the CO2 storage process is considered, but also the influence of CO2-water-rock interaction on reservoir porosity and permeability is considered. In this way, it is possible to achieve a detailed and comprehensive characterization of SCCO2-CO2 displacement of shale gas to improve recovery and subsequent CO2 storage process under multi-dimensional conditions, providing important support for the theoretical analysis of SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage.

[0018] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required to be cited in the embodiments. The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present disclosure and are used together with the specification to illustrate the technical solutions of the present disclosure. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A flow chart of a coupled simulation method for shale supercritical carbon dioxide and carbon dioxide storage provided by an embodiment of the present disclosure is shown;

[0021] Figure 2 A flow chart of a method for exchanging simulation result data in a coupled simulation method for shale supercritical carbon dioxide and carbon dioxide storage provided by an embodiment of the present disclosure is shown;

[0022] Figure 3 A schematic diagram of a coupled simulation method for shale supercritical carbon dioxide and carbon dioxide storage provided by an embodiment of the present disclosure is shown;

[0023] Figure 4 A schematic diagram of the structure of a shale supercritical carbon dioxide and carbon dioxide storage coupling simulation device provided by an embodiment of the present disclosure is shown;

[0024] Figure 5 A schematic diagram of the structure of a computer device provided by an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present disclosure clearer, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the present disclosure for protection, but merely represents the selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present disclosure.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] The term "and / or" herein only describes an association relationship, indicating that three relationships may exist. For example, A and / or B may represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C may represent including any one or more elements selected from the set consisting of A, B, and C.

[0028] According to the survey and statistics of the Ministry of Natural Resources, the remaining technically recoverable reserves of shale gas in my country have reached 3659×108m3, which has huge mining potential and can provide a stable energy guarantee for sustainable development. In the past, shale gas development mostly used hydraulic fracturing technology, which wasted water resources and caused serious environmental pollution. In recent years, the fracturing characteristics and advantages of supercritical CO2 (Supercritical Carbon Dioxide, SCCO2) fluid have gradually emerged, and SCCO2-ESGR (Supercritical Carbon Dioxide Enhance Shale Gas Recovery) technology has become a hot topic for scholars to study and discuss.

[0029] The study found that the current numerical simulation research on SCCO2-ESGR and CO2 storage technology is still insufficient, mostly limited to single process analysis, ignoring the complex multi-field coupling effect of heat flow solidification after SCCO2 injection, especially the fine characterization of CO2-water-rock interaction, which directly limits the precise application of technology and efficiency improvement. In addition, the high threshold and operational complexity of multi-field multi-reaction coupling simulation technology are also technical challenges that need to be overcome urgently.

[0030] Based on the above research, a coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage is provided in an embodiment of the present disclosure, including: step one: obtaining simulation information of the target study area; step two: simulating the physical scenarios and chemical reaction scenarios involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage based on the simulation information, and obtaining corresponding physical simulation results and chemical simulation results; step three: exchanging data of the same time step under the coupling effect of the physical simulation results and the chemical simulation results; updating the parameter information corresponding to the physical scenario simulation of the next time step based on the data exchange result, and returning to step two until the numerical simulation of the specified number of time steps is completed; step four: obtaining the target simulation result after completing the numerical simulation of the specified number of time steps; and calculating the carbon dioxide storage value based on the target simulation result.

[0031] In the disclosed embodiment, the physical scene and chemical reaction scene of SCCO2-CO2 displacement of shale gas to improve oil recovery and CO2 storage are simulated according to the simulation information of the target study area, and the close coupling of physical and chemical simulations is achieved through data exchange and iterative update of the same time step, and finally the numerical simulation of multiple time steps is completed to calculate and evaluate the carbon dioxide storage value. Not only the multi-field coupling mechanism of heat flow solidification involved in the CO2 storage process is considered, but also the influence of CO2-water-rock interaction on reservoir porosity and permeability is considered. In this way, it is possible to achieve a detailed and comprehensive characterization of SCCO2-CO2 displacement of shale gas to improve oil recovery and subsequent CO2 storage process under multi-dimensional conditions, providing important support for the theoretical analysis of SCCO2-CO2 displacement of shale gas to improve oil recovery and CO2 storage.

[0032] To facilitate understanding of this embodiment, the execution subject of the coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide sequestration provided by the embodiment of the present disclosure is first introduced in detail. The execution subject of the coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide sequestration provided by the embodiment of the present disclosure is a computer device. The computer device can be a server. Among them, the server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud storage, big data and artificial intelligence platforms.

[0033] The following is a detailed description of the coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage provided in the embodiment of the present application in conjunction with the accompanying drawings. Figure 1 As shown, it is a flow chart of a method for coupling simulation of shale supercritical carbon dioxide and carbon dioxide storage provided by an embodiment of the present disclosure, and the method includes the following S101 to S104:

[0034] S101, obtaining simulation information of the target study area.

[0035] Here, the simulation information may include the hydrological shale information and geological data corresponding to the target study area. Among them, the hydrological shale information may include the hydrogeological condition information and the basic physical property information of the shale reservoir in the target study area. The hydrogeological condition information may include the groundwater flow characteristics (water flow, density and other information), and the basic physical property information of the shale reservoir may include the porosity, permeability, density and other information of the shale. The geological data may include well seismic data, outcrop data and core data. Specifically, well seismic data helps to identify the thickness and extension range of the shale layer; outcrop data can provide an intuitive understanding of the stratum and the interlayer relationship of the shale; core data mainly provides the actual physical and chemical properties of the shale (such as porosity, permeability and mineral composition). The specific way to obtain the information can be experimentally determined by professionals, or estimated based on historical data and experience.

[0036] It is understandable that common simulation software in the field of multi-field coupling and reaction can include COMSOL software and PHREEQC software. Among them, COMSOL software is a multi-physics field simulation platform that supports the coupling and simulation of multiple physical phenomena. In the application of geology and environmental sciences, COMSOL can simulate the deformation behavior of rocks under temperature and pressure changes, as well as the accompanying fluid flow and heat conduction processes. PHREEQC software focuses on geochemical reactions and hydrological simulations, and can accurately calculate the concentration of dissolved substances in aqueous solutions, the dissolution and precipitation reactions of minerals, and the effects of these processes on the geochemical parameters of the solution. In environmental science and geological research, these parameters are crucial to understanding the migration and transformation of groundwater pollutants, mineral diagenesis processes, and the impact of geological tectonic activities on hydrogeological conditions.

[0037] Therefore, the method proposed in the present disclosure is implemented based on the above two softwares. First, the COMSOL software and PHREEQC software are configured respectively through the simulation information of the target study area, and the initial conditions and boundary conditions of rock deformation, heat transfer and fluid flow are set in the COMSOL software; the initial and boundary salt solutions, mineral compositions and geochemical reactions are defined in the PHREEQC software. In this way, by finely setting the initial conditions and boundary conditions, such as the initial temperature distribution of the underground rock formation, the fluid pressure gradient, the mechanical parameters of the rock, etc., COMSOL can dynamically simulate the interaction between these physical fields, predict the changes in rock stress, the migration path of the fluid and the heat transfer path; by defining the salt solution composition under the initial and boundary conditions, the existence state of the mineral phase and the possible geochemical reactions, PHREEQC can provide researchers with detailed geochemical evolution paths and prediction results.

[0038] In some other embodiments, other software, such as ANSYS, Fluent, etc., may also be used to simulate physical scenes and chemical scenes, which is not specifically limited here.

[0039] S102, based on the simulation information, simulate the physical scenarios involved in supercritical carbon dioxide displacement of shale gas to improve recovery and carbon dioxide storage to obtain physical simulation results; and based on the simulation information, simulate the chemical reaction scenarios involved in supercritical carbon dioxide displacement of shale gas to improve recovery and carbon dioxide storage to obtain chemical simulation results.

[0040] It is understandable that the physical scenarios involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage can include seepage field, temperature field and stress field. Among them, the seepage field describes the flow of gas in the shale reservoir, including its migration and distribution in the rock pores. The temperature field focuses on the temperature changes of gas and rock at different depths and locations, and the temperature has a direct impact on the viscosity and fluidity of the gas. The stress field involves the changes in mechanical stress that the reservoir is subjected to during gas recovery and injection, which affects the deformation of the rock, the expansion of cracks and the stability of the reservoir.

[0041] For example, when simulating the physical scenarios involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage based on simulation information, the following (1) to (5) may be included:

[0042] (1) constructing a seepage field simulation formula, a temperature field simulation formula, and a stress field simulation formula respectively according to the geological data and the physical scenario;

[0043] (2) based on the hydrological shale information and the seepage field simulation formula, the seepage field involved in SCCO2-CO2 displacement of shale gas to enhance oil recovery and CO2 storage in the time step is simulated to obtain a physical seepage field;

[0044] (3) Based on the hydrological shale information and the temperature field simulation formula, the temperature field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical temperature field;

[0045] (4) simulating the stress field involved in SCCO2-CO2 displacement of shale gas to enhance oil recovery and CO2 storage in the time step based on the hydrological shale information and the stress field simulation formula to obtain a physical stress field;

[0046] (5) Determine physical simulation results based on the physical seepage field, the physical temperature field and the physical stress field.

[0047] Specifically, when simulating the physical scenarios involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage, simulation formulas corresponding to each physical scenario can be constructed based on the geological data obtained above and the specific physical scenarios, and the interactions between the physical fields can be dynamically simulated by COMSOL software to obtain the physical simulation results corresponding to each physical field. Among them, there are two phases and three components of SCCO2-CO2, water, and shale gas (simplified as CH4) in the seepage field, which complete the flow, diffusion, desorption and other processes in the four media of organic pores, inorganic pores, natural fracture systems, and fracturing fracture systems. Therefore, the seepage field simulation formula includes organic pore simulation formula, inorganic pore simulation formula, natural fracture simulation formula and fracturing fracture simulation formula.

[0048] For example, the main fluids in the organic pores are shale gas and CO2. Due to the generally small pore size and permeability of the organic pores in shale, the seepage process of the fluid in the organic pores is ignored, and only the process of the fluid diffusing into the inorganic pores is characterized. Therefore, the organic pore simulation formula can be expressed as:

[0049]

[0050] Where V sgk It is expressed as the amount of gas adsorption by shale at different temperatures, which can be calculated by the following formula:

[0051]

[0052] Among them, φ or is the porosity of organic matter; ρ gak represents the density of gas adsorbed on the surface of organic pores; ρ s Indicates the density of shale related to gas adsorption or desorption process; M k represents the molar molecular weight of the gas; R represents the gas constant; T represents the absolute temperature of the gas; T0 represents the initial temperature; p ok Indicates the pressure of gas in the organic pore system; p igk represents the pressure of the gas in the inorganic pore system; χ represents the shape factor; D 0k represents the gas diffusion coefficient; b 1k Expressed as gas pressure correction factor; b 2k Expressed as gas temperature correction coefficient; V LK Expressed as the Langmuir volume constant; p LK It is expressed as the Langmuir pressure constant; in each parameter, k=(1, 2), when k=1, it indicates that the parameter describes the properties of CH4, and when k=2, it indicates that the parameter describes the properties of CO2.

[0053] For example, inorganic pores are considered to be a two-phase migration process of gas (shale gas, CO2) and water, so the inorganic pore simulation formula can be expressed as:

[0054]

[0055] Among them, s iorg +s iorw =1, p igk -p iw =p ic ; φ ior Indicates the porosity of inorganic matter; s iorg Indicates the gas phase saturation in the inorganic pore system; p igk Indicates the pressure of the gas phase in the inorganic pores; l irgk Represents the apparent permeability of the gas phase in inorganic pores; μ gk Expressed as gas phase viscosity; Expressed as a divergence operator; S f Expressed as the shape factor of the natural fracture; s irow Indicates the saturation of water phase in the inorganic pore system; ρ w Indicates the density of water; p iw Indicates the pressure of water phase in inorganic pores; l irw Represents the apparent permeability of water phase in inorganic pores; μ w Expressed as the viscosity of water; p Δ Indicates the liquid pressure difference between the inorganic pore system and the natural fracture system; p fgk represents the pressure of shale gas in the natural fracture system; p ic Represents the capillary pressure in the inorganic pore system; in each parameter, k=(1,2), when k=1, it indicates that the parameter describes the properties of CH4, and when k=2, it indicates that the parameter describes the properties of CO2.

[0056] Similarly, natural fractures are also considered to involve the migration of gas (shale gas, CO2) and water phases, so the natural fracture simulation formula can be expressed as:

[0057]

[0058] Among them, s fg +s fw =1, p fgk -p fw =p fc ; φ f Indicates the degree of natural fracture; ρ fgk represents the density of the gas phase in the natural fracture system; l represents the absolute permeability of the shale natural fracture system; l frg Represents the relative permeability of gas phase in natural fractures; l frw Represents the relative permeability of water phase in natural fractures; Dt represents the gas diffusion coefficient; s fg Indicates the residual gas saturation in the natural fracture system; s fw represents the residual water saturation in the natural fracture system; p fw Represents the pressure of water in a natural fracture system; p fc represents the capillary pressure in the natural fracture system; q fg-Fg It is expressed as the exchange amount of shale gas between natural fracture system and hydraulic fracture system; q fw-Fw It is expressed as the amount of water exchanged between the natural fracture system and the hydraulic fracture system; in each parameter, k=(1,2), when k=1, it indicates that the parameter describes the properties of CH4, and when k=2, it indicates that the parameter describes the properties of CO2.

[0059] Exemplarily, to represent the flow in the fracture, the fracture simulation formula is expressed as:

[0060]

[0061] Among them, s Fg +s Fw =1, p Fgk -p Fw =p Fc ;d F It is expressed as the opening of the fracturing crack; s Fg Indicates the saturation of the gas phase in the fracture system; ρ Fgk Indicates the density of the gas phase in the fracturing fracture system; l F Expressed as the absolute permeability of the shale fracture system; l Frg Represents the relative permeability of the gas phase in the fracture; l Frw Represents the relative permeability of water phase in the fracture; s Fw Indicates the saturation of water phase in the fracture system; p Fgk Indicates the pressure of the gas phase in the fracturing fracture system; p Fw represents the pressure of water phase in the fracture system; p Fc Indicates the capillary pressure in the fracturing fracture system; in each parameter, k=(1,2), when k=1, it indicates that the parameter describes the properties of CH4, and when l=2, it indicates that the parameter describes the properties of CO2.

[0062] For example, the temperature field simulation formula can be expressed as:

[0063]

[0064] Among them, (ρC) M It is expressed as the specific heat capacity of the equivalent unit body; K is expressed as the bulk modulus; ε V Expressed as volumetric strain; qstk represents the isosteric adsorption heat of shale gas; ρ gak Expressed as the density of gas in the adsorption phase; ρ s Expressed as the density of gas in shale; V sgk Expressed as the volume of gas adsorbed or desorbed in shale; λ e Expressed as the thermal conductivity coefficient of the equivalent unit body; η e Expressed as the thermal convection coefficient of the equivalent unit body.

[0065] For example, the stress field simulation formula can be expressed as:

[0066]

[0067] Where:

[0068] p o =p o1 +p o2 ,

[0069] p i =s iorw p iw +s iorg (p ig1 +p ig2 ),

[0070] p f =s fw p fw +s fg (p fg1 +p fg2 );

[0071] Where G is the shear modulus; V is the Poisson's ratio; u i Expressed as the displacement component in the i direction; f i It is represented as the body stress component in the i direction; K is the bulk modulus; α, β, γ are the Biot coefficients of shale organic matter, inorganic matter and natural fractures; p i Expressed as the fluid pressure of an inorganic system; p f Expressed as the fluid pressure in a natural fracture system.

[0072] Here, the average compressive stress on the effective unit volume (REV), the volume strain of each medium, and the overall strain are:

[0073]

[0074]

[0075] in, Expressed as average pressure; ε vf , ε vi , εvo are the volume strains of natural cracks, inorganic matter and organic matter respectively; ε v , ε1 represent the volume strain and linear strain of REV respectively; B1 is determined by the mechanical properties of the shale reservoir and the geometric dimensions of each medium in REV, which can be defined as:

[0076]

[0077] It can be understood that after dynamically simulating the interaction between the various physical fields through COMSOL software and obtaining the physical simulation results corresponding to each physical field, the calculation result files of the concentrations of different components at each node, as well as the saturation and pressure reflecting the flow characteristics of CO2 and CH4, will be generated. These data are transmitted to the input file of PHREEQC through MATLAB, and then the PHREEQC software can be used to simulate the thermodynamic equilibrium simulation scenarios and chemical reaction kinetic simulation scenarios involved in the SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage in the time step based on the hydrological shale information according to the obtained physical simulation results and CO2-water-rock reaction simulation formula. The CO2-water-rock reaction in PHREEQC, component concentrations, water content, temperature, pH, and pE are all listed in an input string, and thermodynamic calculations are performed on each node separately to obtain chemical simulation results. Among them, the CO2-water-rock reaction simulation formula includes:

[0078] r=h·A·m|1-Ω θ | η ;

[0079] Among them, r represents the mineral dissolution rate; h represents the rate constant, which is related to temperature; A represents the specific reaction surface area; m represents the mass of dissolved minerals; Ω represents the kinetic mineral saturation ratio; parameters θ and η represent exponential factors.

[0080] Here, in the disclosed embodiments, the temperature dependence of the mineral dissolution rate constant is characterized using the Arrhenius equation:

[0081]

[0082] Among them, A0 refers to the pre-exponential factor that is independent of temperature; E a Expressed as activation energy; assuming that the activation energy is independent of temperature, the rate constant at the required temperature can be derived as follows:

[0083]

[0084] Under acidic conditions, the dissolution of most minerals is catalyzed by protons, and the overall rate constant for mineral dissolution is the sum of the neutral and acidic mechanisms:

[0085]

[0086] Among them, k 25 is expressed as the dissolution rate constant at 25 °C; nu and H represent neutral and acidic mechanisms, respectively; n is the power term; and finally, the number of moles of mineral dissolved in a given time is the integral of r:

[0087]

[0088] S103, exchange data of the same time step under the coupling effect of the physical simulation results and the chemical simulation results; update the parameter information corresponding to the physical scene simulation of the next time step based on the data exchange result, and return to step S102 until the numerical simulation of the specified number of time steps is completed.

[0089] For example, after obtaining the physical simulation results and the chemical simulation results, they are input into the MATLAB software together to realize the data exchange of the same time step under the re-coupling effect of the two simulation results, referring to Figure 2 As shown, it may specifically include the following S1031 to S1033:

[0090] S1031, establish a dynamic evolution model of shale porosity and permeability under multi-scenario coupling.

[0091] It is understandable that since the dynamic changes of organic pores, inorganic pores and natural fractures need to be considered, the dynamic evolution model of shale porosity and permeability is established according to three different scenarios of organic pores, inorganic pores and natural fractures, that is, the model includes the porosity and permeability dynamic evolution model of organic pores, the porosity and permeability dynamic evolution model of inorganic pores and the porosity and permeability dynamic evolution model of natural fractures.

[0092] S1032, for the physical simulation results and chemical simulation results at the same time step, determine the porosity information of the organic pores based on the porosity and permeability dynamic evolution model of the organic pores and the organic pore information; and determine the porosity information of the inorganic pores based on the porosity and permeability dynamic evolution model of the inorganic pores and the inorganic pore information; and determine the porosity information of the natural fractures based on the porosity and permeability dynamic evolution model of the natural fractures and the natural fracture information.

[0093] Exemplarily, in the same time step, based on the stress changes calculated by COMSOL, the temperature changes of gas adsorption amount and the dissolution rate calculation results of PHREEQC, the corresponding porosity information (organic pore porosity information, inorganic pore porosity information and natural fracture porosity information) is calculated respectively through the porosity and permeability dynamic evolution model of organic pores, the porosity and permeability dynamic evolution model of inorganic pores and the porosity and permeability dynamic evolution model of natural fractures.

[0094] Here, the porosity and permeability dynamic evolution model of organic pores includes:

[0095]

[0096] In the formula,

[0097] Among them, φ or0 is the initial porosity of organic matter; ε vo0 Expressed as the initial volume strain of organic matter; p o0 Expressed as the initial fluid pressure in the organic pore; K' os Expressed as the bulk modulus of organic particles; ε s0 It represents the initial deformation of the shale matrix due to gas adsorption; D t0 It represents the diffusion coefficient of gas in organic matter when solid deformation is not considered; Y and Y0 are both dimensionless constants; α represents the parameter of rate change with time.

[0098] Here, the dynamic evolution model of the porosity and permeability of inorganic pores includes:

[0099]

[0100] In the formula,

[0101] Among them, ε vi0 Expressed as the initial volume strain of inorganic matter; p i0 Expressed as the initial fluid pressure in the inorganic pores; K i ' s Expressed as the bulk modulus of inorganic particles; ε m0 It is expressed as the initial molar content of a mineral in the solid part of the shale reservoir; Expressed as the total porosity of the shale; Expressed as the initial porosity of shale; φ ior0 It represents the initial porosity of inorganic matter; S and S0 are dimensionless constants; β represents the parameter of rate change with time.

[0102] Here, the permeability or diffusion coefficient expression corresponding to the flow mechanism can be expressed as:

[0103]

[0104] In the formula, k i , D F and D K are the absolute permeability, Fick diffusion coefficient and Knudsen diffusion coefficient of inorganic substances, respectively. i0 , D F0 and D K0They are the initial absolute permeability, initial Fick diffusion coefficient and initial Knudsen diffusion coefficient of the inorganic matter respectively.

[0105] The porosity and permeability dynamic evolution model of the natural fracture includes:

[0106]

[0107] Among them, φ f Represents the porosity of the current fracture; φ f0 Expressed as the porosity of the initial fracture; ε vf Expressed as the current volume crack strain; ε vf0 Expressed as the initial volume crack strain; ε vm Expressed as the current volume matrix strain; ε vm0 is represented by the initial volume matrix strain; k is represented by the current permeability; k0 is represented by the initial permeability.

[0108] In this way, the above equations jointly constitute a numerical theoretical model for CO2 injection and CO2 storage. The basic variables solved by this model are CO2, CH4, water saturation, partial pressure, temperature, and the mass percentage of each mineral in shale. By combining the above equations with numerical simulation methods, a detailed description of the CO2 injection and CO2 storage process can be achieved.

[0109] S1033: Update parameter information corresponding to the physical scene simulation of the next time step based on the organic pore porosity information, the inorganic pore porosity information and the natural fracture porosity information.

[0110] It is understandable that after obtaining the organic pore porosity information, inorganic pore porosity information and natural fracture porosity information, MATLAB can transfer these updated parameters to COMSOL for realizing the physical scene simulation for the next time step. Specifically, in addition to the porosity information, the parameter information can also include CO2 information (density, specific heat capacity, viscosity and thermal conductivity) and rock information (elastic modulus, permeability and thermal conductivity).

[0111] Specifically, after completing the updating of the parameter information corresponding to the physical scene simulation of the next time step, return to step S102 to continue the simulation of the next time step. This cycle will be repeated until the numerical simulation of a predetermined number of time steps is completed. After the simulation is completed, the system will save the COMSOL and PHREEQC calculation results corresponding to each time step for subsequent detailed post-processing and analysis of the data. In this way, the consistency of the simulation process and the integrity of the data are ensured, providing a comprehensive basis for the final result.

[0112] S104, after completing the numerical simulation of a specified number of time steps, obtaining a target simulation result; and calculating the carbon dioxide sequestration value based on the target simulation result.

[0113] It is understandable that after completing the numerical simulation of the specified number of time steps and obtaining the target simulation results, Python can be used in combination with COMSOL for data analysis and image presentation. Python has powerful data processing libraries, such as numpy for efficient numerical calculations, scipy for various scientific computing functions, and matplotlib for generating high-quality charts and visualizations. Through these tools, the simulation results can be analyzed in detail, key trends and patterns in the data can be identified, and the results can be presented in the form of images. After completing these analyses, the target simulation results are used to calculate the CO2 storage values, including injection volume, storage efficiency, and long-term stability. Specifically, the injection volume and rate of CO2 are determined by simulation data, which are usually included in the simulation results of each time step. Then, according to the changes in injection volume and pore space, the storage efficiency is calculated to evaluate the storage capacity and occupancy ratio of CO2 in the target area. In addition, the analysis of long-term stability includes checking the distribution, migration, and possible leakage risks of CO2 in the storage area, which can ensure the long-term safe storage of CO2 within the simulation time range, thereby ensuring the scientificity and effectiveness of the storage strategy.

[0114] The coupled simulation method of shale supercritical carbon dioxide and carbon dioxide storage provided in the embodiments of the present disclosure simulates the physical scene and chemical reaction scene of SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage respectively according to the simulation information of the target study area, and realizes the close coupling of physical and chemical simulations through data exchange and iterative update of the same time step, and finally completes the numerical simulation of multiple time steps to calculate and evaluate the carbon dioxide storage value. Not only the multi-field coupling mechanism of thermal flow solidification involved in the CO2 storage process is considered, but also the influence of CO2-water-rock interaction on reservoir porosity and permeability is considered. In this way, it is possible to achieve a detailed and comprehensive characterization of SCCO2-CO2 displacement of shale gas to improve recovery and subsequent CO2 storage process under multi-dimensional conditions, providing important support for the theoretical analysis of SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage.

[0115] Combine the following Figure 3, the specific process of this scheme based on COMSOL software, PHREEQC software and MATLAB software to achieve the coupled simulation method of shale supercritical carbon dioxide and carbon dioxide storage is described in detail. First, COMSOL and PHREEQC software need to be initialized, including data preparation and geometric model construction. Data preparation covers the hydrogeological conditions and basic physical properties of the shale reservoir in the study area, which can be determined by experimental measurement or reference to empirical values. The geometric model is constructed based on well seismic data, outcrop data and core data, and the initial conditions and boundary conditions in each software are defined. Next, COMSOL and PHREEQC are used to simulate the physical and chemical reaction processes in the process of SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage, respectively. COMSOL is responsible for simulating physical processes; while PHREEQC is used to simulate chemical reaction processes. Then, MATLAB is used to realize the data exchange between COMSOL and PHREEQC at the same time step to ensure that the coupling effect of multi-physical fields and chemical fields is fully reflected. This includes processing the initial time step and all subsequent time steps, considering the effects of water-rock mineral chemical reactions on porosity, fluid flow, and solute migration, and establishing a dynamic evolution model based on MATLAB to reflect the effects of water-rock mineral chemical reactions on the porosity and permeability of shale reservoirs. Finally, after completing the numerical simulation of the specified number of time steps, all results are imported into COMSOL or other external programs for post-processing for comprehensive analysis and result presentation. This process ensures the integrity and accuracy from data preparation to result analysis, providing a scientific basis for the study of carbon dioxide storage.

[0116] Those skilled in the art will appreciate that, in the above method of specific implementation, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0117] Based on the same inventive concept, the embodiments of the present disclosure also provide a shale supercritical carbon dioxide and carbon dioxide storage coupling simulation device corresponding to the shale supercritical carbon dioxide and carbon dioxide storage coupling simulation method. Since the principle of solving the problem by the device in the embodiments of the present disclosure is similar to the above-mentioned shale supercritical carbon dioxide and carbon dioxide storage coupling simulation method in the embodiments of the present disclosure, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0118] Reference Figure 4 FIG. 4 is a schematic diagram of a shale supercritical carbon dioxide and carbon dioxide storage coupling simulation device 400 provided in an embodiment of the present disclosure, wherein the device comprises:

[0119] The information acquisition module 401 is used to execute step 1: acquiring simulation information of the target study area; wherein the simulation information includes hydrological shale information and geological data;

[0120] The scenario simulation module 402 is used to perform step 2: simulate the physical scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage based on the simulation information to obtain physical simulation results; and simulate the chemical reaction scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage based on the simulation information to obtain chemical simulation results;

[0121] The data exchange module 403 is used to execute step 3: perform data exchange of the physical simulation results and the chemical simulation results at the same time step under the coupling effect; update the parameter information corresponding to the physical scene simulation at the next time step based on the data exchange result, and return to step 2 until the numerical simulation of the specified number of time steps is completed;

[0122] The numerical calculation module 404 is used to execute step 4: after completing the numerical simulation of a specified number of time steps, obtain the target simulation result; and calculate the carbon dioxide storage value based on the target simulation result.

[0123] In some possible embodiments, the physical scene includes a seepage field, a temperature field, and a stress field; the scene simulation module 402 is specifically used for:

[0124] According to the geological data and the physical scenario, a seepage field simulation formula, a temperature field simulation formula and a stress field simulation formula are respectively constructed;

[0125] Based on the hydrological shale information and the seepage field simulation formula, the seepage field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical seepage field;

[0126] Based on the hydrological shale information and the temperature field simulation formula, the temperature field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical temperature field;

[0127] Based on the hydrological shale information and the stress field simulation formula, the stress field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical stress field;

[0128] A physical simulation result is determined according to the physical seepage field, the physical temperature field and the physical stress field.

[0129] In some possible embodiments, the seepage field simulation formula includes an organic pore simulation formula, an inorganic pore simulation formula, a natural fracture simulation formula, and a hydraulic fracture simulation formula;

[0130] The organic pore mimetic formula comprises:

[0131]

[0132] Among them, φ or is the porosity of organic matter; ρ gak represents the density of gas adsorbed on the surface of organic pores; ρ s Indicates the density of shale related to gas adsorption or desorption process; V sgk It is expressed as the amount of gas adsorption by shale at different temperatures; M k represents the molar molecular weight of the gas; R represents the gas constant; T represents the absolute temperature of the gas; p ok Indicates the pressure of gas in the organic pore system; p igk represents the pressure of the gas in the inorganic pore system; χ represents the shape factor; D 0k Indicates the gas diffusion coefficient; in each parameter, k = (1, 2), when l = 1, it indicates that the parameter describes the properties of CH4, and when l = 2, it indicates that the parameter describes the properties of CO2;

[0133] The inorganic pore simulation formula includes:

[0134]

[0135] Among them, s iorg +s iorw =1, p igk -p iw =p ic ; φ ior Indicates the porosity of inorganic matter; s iorg Indicates the gas phase saturation in the inorganic pore system; p igk Indicates the pressure of the gas phase in the inorganic pores; l irgk Represents the apparent permeability of the gas phase in inorganic pores; μ gk Expressed as gas phase viscosity; Expressed as a divergence operator; S f Expressed as the shape factor of the natural fracture; s irow Indicates the saturation of water phase in the inorganic pore system; ρ w Indicates the density of water; p iw Indicates the pressure of water phase in inorganic pores; l irw Represents the apparent permeability of water phase in inorganic pores; μ w Expressed as the viscosity of water; p Δ Indicates the liquid pressure difference between the inorganic pore system and the natural fracture system; p fgk represents the pressure of shale gas in the natural fracture system; p icIndicates the capillary pressure in the inorganic pore system; in each parameter, k = (1, 2), when l = 1, it indicates that the parameter describes the properties of CH4, and when l = 2, it indicates that the parameter describes the properties of CO2;

[0136] The natural fracture simulation formula includes:

[0137]

[0138] Among them, s fg +s fw =1, p fgk -p fw =p fc ; φ f Indicates the degree of natural fracture; ρ fgk represents the density of the gas phase in the natural fracture system; l represents the absolute permeability of the shale natural fracture system; l frg Represents the relative permeability of gas phase in natural fractures; l frw Represents the relative permeability of water phase in natural fractures; D t represents the gas diffusion coefficient; s fg Indicates the residual gas saturation in the natural fracture system; s fw represents the residual water saturation in the natural fracture system; p fw Represents the pressure of water in a natural fracture system; p fc represents the capillary pressure in the natural fracture system; q fg-Fg It is expressed as the exchange amount of shale gas between natural fracture system and hydraulic fracture system; q fw-Fw It is expressed as the amount of water exchanged between the natural fracture system and the hydraulic fracture system; in each parameter, k = (1, 2), when k = 1, it indicates that the parameter describes the properties of CH4, and when k = 2, it indicates that the parameter describes the properties of CO2;

[0139] The fracturing fracture simulation formula includes:

[0140]

[0141] Among them, s Fg +s Fw =1, p Fgk -p Fw =p Fc ;d F It is expressed as the opening of the fracturing crack; s Fg Indicates the saturation of the gas phase in the fracture system; ρ Fgk Indicates the density of the gas phase in the fracturing fracture system; l F Expressed as the absolute permeability of the shale fracture system; l Frg Represents the relative permeability of the gas phase in the fracture; lFrw Represents the relative permeability of water phase in the fracture; s Fw Indicates the saturation of water phase in the fracture system; p Fgk represents the pressure of the gas phase in the fracturing fracture system; p Fw represents the pressure of water phase in the fracture system; p Fc It represents the capillary pressure in the fracturing fracture system; in each parameter, k=(1,2), when k=1, it indicates that the parameter describes the property of CH4, and when l=2, it indicates that the parameter describes the property of CO2.

[0142] In some possible embodiments, the chemical reaction scenario includes a thermodynamic equilibrium simulation scenario and a chemical reaction kinetics simulation scenario; the scenario simulation module 402 is specifically used for:

[0143] According to the physical simulation results and the CO2-water-rock reaction simulation formula, based on the hydrological shale information, the thermodynamic equilibrium simulation scenario and chemical reaction kinetic simulation scenario involved in the SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step are simulated to obtain the chemical simulation results.

[0144] In some possible embodiments, the CO2-water-rock reaction simulation formula includes:

[0145] r=h·A·m|1-Ω θ | η ;

[0146] Among them, r represents the mineral dissolution rate; h represents the rate constant, which is related to temperature; A represents the specific reaction surface area; m represents the mass of dissolved minerals; Ω represents the kinetic mineral saturation ratio; parameters θ and η represent exponential factors.

[0147] In some possible embodiments, the data exchange module 403 is specifically used for:

[0148] Establishing a shale porosity and permeability dynamic evolution model under the coupling of multiple scenarios; the shale porosity and permeability dynamic evolution model includes a porosity and permeability dynamic evolution model of organic pores, a porosity and permeability dynamic evolution model of inorganic pores, and a porosity and permeability dynamic evolution model of natural fractures;

[0149] For the physical simulation results and chemical simulation results at the same time step, the organic pore porosity information is determined based on the porosity and permeability dynamic evolution model of the organic pores and the organic pore information; and the inorganic pore porosity information is determined based on the porosity and permeability dynamic evolution model of the inorganic pores and the inorganic pore information; and the natural fracture porosity information is determined based on the porosity and permeability dynamic evolution model of the natural fractures and the natural fracture information;

[0150] Parameter information corresponding to the physical scene simulation of the next time step is updated based on the organic pore porosity information, the inorganic pore porosity information and the natural fracture porosity information.

[0151] In some possible embodiments, the porosity and permeability dynamic evolution model of the organic pores includes:

[0152]

[0153] Among them, φ or0 is the initial porosity of organic matter; D t0 It represents the diffusion coefficient of gas in organic matter when solid deformation is not considered; Y and Y0 are both dimensionless constants; α represents the parameter of rate change with time;

[0154] The porosity and permeability dynamic evolution model of the inorganic pores includes:

[0155]

[0156] Among them, φ ior0 represents the initial porosity of inorganic matter; S and S0 are dimensionless constants; β represents the parameter of rate change with time;

[0157] The porosity and permeability dynamic evolution model of the natural fracture includes:

[0158]

[0159] Among them, φ f Represents the porosity of the current fracture; φ f0 Expressed as the porosity of the initial fracture; ε vf Expressed as the current volume crack strain; ε vf0 Expressed as the initial volume crack strain; ε vm Expressed as the current volume matrix strain; ε vm0 is represented by the initial volume matrix strain; k is represented by the current permeability; k0 is represented by the initial permeability.

[0160] Based on the same technical concept, the embodiment of the present disclosure also provides a computer device. Figure 5 , which is a schematic diagram of the structure of a computer device 500 provided in an embodiment of the present disclosure, including a processor 501, a memory 502, and a bus 503. The memory 502 is used to store execution instructions, including a memory 5021 and an external memory 5022; the memory 5021 is also called an internal memory, which is used to temporarily store the operation data in the processor 501 and the data exchanged with the external memory 5022 such as a hard disk. The processor 501 exchanges data with the external memory 5022 through the memory 5021.

[0161] In the embodiment of the present application, the memory 502 is specifically used to store the application code for executing the solution of the present application, and the execution is controlled by the processor 501. That is, when the computer device 500 is running, the processor 501 communicates with the memory 502 through the bus 503, so that the processor 501 executes the application code stored in the memory 502, and then executes the method described in any of the above embodiments.

[0162] Among them, the memory 502 can be, but is not limited to, random access memory (Random Access Memory, RAM), read only memory (Read Only Memory, ROM), programmable read-only memory (Programmable Read-Only Memory, PROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable read-only memory (Electric Erasable Programmable Read-Only Memory, EEPROM), etc.

[0163] Processor 501 may be an integrated circuit chip with signal processing capabilities. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present invention may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0164] It is to be understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the computer device 500. In other embodiments of the present application, the computer device 500 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0165] The embodiment of the present disclosure also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for coupling simulation of shale supercritical carbon dioxide and carbon dioxide sequestration described in the above method embodiment are executed. The storage medium can be a volatile or non-volatile computer-readable storage medium.

[0166] The embodiments of the present disclosure also provide a computer program product, which carries a program code. The instructions included in the program code can be used to execute the steps of the shale supercritical carbon dioxide and carbon dioxide storage coupling simulation method described in the above method embodiment. For details, please refer to the above method embodiment, which will not be repeated here.

[0167] The computer program product may be implemented in hardware, software or a combination thereof. In one optional embodiment, the computer program product is implemented as a computer storage medium. In another optional embodiment, the computer program product is implemented as a software product, such as a software development kit (SDK).

[0168] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in the present disclosure, it should be understood that the disclosed system and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0169] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0170] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0171] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0172] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present disclosure, which are used to illustrate the technical solutions of the present disclosure, rather than to limit them. The protection scope of the present disclosure is not limited thereto. Although the present disclosure is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present disclosure, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A coupled simulation method based on shale supercritical carbon dioxide and carbon dioxide storage, characterized in that: include: Step 1: Obtain simulation information of the target study area; wherein the simulation information includes hydrological shale information and geological data; Step 2: Based on the simulation information, simulate the physical scenarios involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain physical simulation results; and based on the simulation information, simulate the chemical reaction scenarios involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain chemical simulation results; Step 3: exchange data of the same time step under the coupling effect of the physical simulation results and the chemical simulation results; update the parameter information corresponding to the physical scene simulation of the next time step based on the data exchange results, and return to step 2 until the numerical simulation of the specified number of time steps is completed; Step 4: After completing the numerical simulation of a specified number of time steps, a target simulation result is obtained; and the carbon dioxide storage value is calculated based on the target simulation result.

2. The method according to claim 1, characterized in that The physical scenario includes a seepage field, a temperature field and a stress field; the simulation of the physical scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage based on the simulation information includes: According to the geological data and the physical scenario, a seepage field simulation formula, a temperature field simulation formula and a stress field simulation formula are respectively constructed; Based on the hydrological shale information and the seepage field simulation formula, the seepage field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical seepage field; Based on the hydrological shale information and the temperature field simulation formula, the temperature field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical temperature field; Based on the hydrological shale information and the stress field simulation formula, the stress field involved in SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step is simulated to obtain a physical stress field; A physical simulation result is determined according to the physical seepage field, the physical temperature field and the physical stress field.

3. The method according to claim 2, characterized in that The seepage field simulation formula includes an organic pore simulation formula, an inorganic pore simulation formula, a natural fracture simulation formula and a fracturing fracture simulation formula; The organic pore mimetic formula comprises: Among them, φ or is the porosity of organic matter; ρ gak represents the density of gas adsorbed on the surface of organic pores; ρ s Indicates the density of shale related to gas adsorption or desorption process; V sgk It is expressed as the amount of gas adsorption by shale at different temperatures; M k represents the molar molecular weight of the gas; R represents the gas constant; T represents the absolute temperature of the gas; p ok Indicates the pressure of gas in the organic pore system; p igk represents the pressure of the gas in the inorganic pore system; χ represents the shape factor; D 0k Indicates the gas diffusion coefficient; in each parameter, k = (1, 2), when k = 1, it indicates that the parameter describes the properties of CH4, and when k = 2, it indicates that the parameter describes the properties of CO2; The inorganic pore simulation formula includes: Among them, s iorg +s iorw =1, p igk -p iw =p ic ; φ ior Indicates the porosity of inorganic matter; s iorg Indicates the gas phase saturation in the inorganic pore system; p igk Indicates the pressure of the gas phase in the inorganic pores; l irgk Represents the apparent permeability of the gas phase in inorganic pores; μ gk Expressed as gas phase viscosity; Expressed as a divergence operator; S f Expressed as the shape factor of the natural fracture; s irow Indicates the saturation of water phase in the inorganic pore system; ρ w Indicates the density of water; p iw Indicates the pressure of water phase in inorganic pores; l irw Represents the apparent permeability of water phase in inorganic pores; μ w Expressed as the viscosity of water; p Δ Indicates the liquid pressure difference between the inorganic pore system and the natural fracture system; p fgk represents the pressure of shale gas in the natural fracture system; p ic Indicates the capillary pressure in the inorganic pore system; in each parameter, k = (1, 2), when k = 1, it indicates that the parameter describes the properties of CH4, and when k = 2, it indicates that the parameter describes the properties of CO2; The natural fracture simulation formula includes: Among them, s fg +s fw =1, p fgk -p fw =p fc ; φ f Indicates the degree of natural fracture; ρ fgk represents the density of the gas phase in the natural fracture system; l represents the absolute permeability of the shale natural fracture system; l frg Represents the relative permeability of gas phase in natural fractures; l frw Represents the relative permeability of water phase in natural fractures; D t represents the gas diffusion coefficient; s fg Indicates the residual gas saturation in the natural fracture system; s fw represents the residual water saturation in the natural fracture system; p fw Represents the pressure of water in a natural fracture system; p fc represents the capillary pressure in the natural fracture system; q fg-Fg It is expressed as the exchange amount of shale gas between natural fracture system and hydraulic fracture system; q fw-Fw It is expressed as the amount of water exchanged between the natural fracture system and the hydraulic fracture system; in each parameter, k = (1, 2), when k = 1, it indicates that the parameter describes the properties of CH4, and when k = 2, it indicates that the parameter describes the properties of CO2; The fracturing fracture simulation formula includes: Among them, s Fg +s Fw =1, p Fgk -p Fw =p Fc ;d F It is expressed as the opening of the fracturing crack; s Fg Indicates the saturation of the gas phase in the fracture system; ρ Fgk Indicates the density of the gas phase in the fracturing fracture system; l F Expressed as the absolute permeability of the shale fracture system; l Frg Represents the relative permeability of the gas phase in the fracture; l Frw Represents the relative permeability of water phase in the fracture; s Fw Indicates the saturation of water phase in the fracture system; p Fgk represents the pressure of the gas phase in the fracturing fracture system; p Fw represents the pressure of water phase in the fracture system; p Fc Indicates the capillary pressure in the fracturing fracture system; in each parameter, k=(1,2), when k=1, it indicates that the parameter describes the properties of CH4, and when k=2, it indicates that the parameter describes the properties of CO2.

4. The method according to claim 2, characterized in that: The chemical reaction scenario includes a thermodynamic equilibrium simulation scenario and a chemical reaction kinetics simulation scenario; the simulation of the chemical reaction scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage based on the simulation information includes: According to the physical simulation results and the CO2-water-rock reaction simulation formula, based on the hydrological shale information, the thermodynamic equilibrium simulation scenario and chemical reaction kinetic simulation scenario involved in the SCCO2-CO2 displacement of shale gas to enhance recovery and CO2 storage in the time step are simulated to obtain the chemical simulation results.

5. The method according to claim 4, characterized in that The CO2-water-rock reaction simulation formula includes: r=h·A·m|1-Ω θ | η ; Among them, r represents the mineral dissolution rate; h represents the rate constant, which is related to temperature; A represents the specific reaction surface area; m represents the mass of dissolved minerals; Ω represents the kinetic mineral saturation ratio; parameters θ and η represent exponential factors.

6. The method according to claim 3, characterized in that The data exchange of the physical simulation results and the chemical simulation results at the same time step under the coupling effect; Based on the data exchange results, the parameter information corresponding to the physical scene simulation of the next time step is updated, including: Establishing a shale porosity and permeability dynamic evolution model under the coupling of multiple scenarios; the shale porosity and permeability dynamic evolution model includes a porosity and permeability dynamic evolution model of organic pores, a porosity and permeability dynamic evolution model of inorganic pores, and a porosity and permeability dynamic evolution model of natural fractures; For the physical simulation results and chemical simulation results at the same time step, the organic pore porosity information is determined based on the porosity and permeability dynamic evolution model of the organic pores and the organic pore information; and the inorganic pore porosity information is determined based on the porosity and permeability dynamic evolution model of the inorganic pores and the inorganic pore information; and the natural fracture porosity information is determined based on the porosity and permeability dynamic evolution model of the natural fractures and the natural fracture information; Parameter information corresponding to the physical scene simulation of the next time step is updated based on the organic pore porosity information, the inorganic pore porosity information and the natural fracture porosity information.

7. The method according to claim 6, characterized in that The porosity and permeability dynamic evolution model of the organic pores includes: Among them, φ or0 is the initial porosity of organic matter; D t0 It represents the diffusion coefficient of gas in organic matter when solid deformation is not considered; Y and Y0 are both dimensionless constants; α represents the parameter of rate change with time; The porosity and permeability dynamic evolution model of the inorganic pores includes: Among them, φ ior0 represents the initial porosity of inorganic matter; S and S0 are dimensionless constants; β represents the parameter of rate change with time; The porosity and permeability dynamic evolution model of the natural fracture includes: Among them, φ f Represents the porosity of the current fracture; φ f0 Expressed as the porosity of the initial fracture; ε vf Expressed as the current volume crack strain; ε vf0 Expressed as the initial volume crack strain; ε vm Expressed as the current volume matrix strain; ε vm0 is represented by the initial volume matrix strain; k is represented by the current permeability; k0 is represented by the initial permeability.

8. A coupled simulation device based on shale supercritical carbon dioxide and carbon dioxide storage, characterized in that: include: An information acquisition module is used to execute step 1: acquiring simulation information of the target study area; wherein the simulation information includes hydrological shale information and geological data; A scenario simulation module is used to perform step 2: based on the simulation information, simulate the physical scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain physical simulation results; and based on the simulation information, simulate the chemical reaction scenario involved in SCCO2-CO2 displacement of shale gas to improve recovery and CO2 storage to obtain chemical simulation results; The data exchange module is used to execute step three: exchange data of the same time step under the coupling effect between the physical simulation results and the chemical simulation results; update the parameter information corresponding to the physical scene simulation of the next time step based on the data exchange result, and return to step two until the numerical simulation of the specified number of time steps is completed; The numerical calculation module is used to execute step 4: after completing the numerical simulation of a specified number of time steps, obtain the target simulation result; and calculate the carbon dioxide storage value based on the target simulation result.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer device comprising a storage medium, a processor, and a computer program stored in the storage medium and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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