Numerical simulation method for carbon-filtering gas production scheme

Abstract

The invention relates to the technical field of oil reservoir and energy utilization, in particular to a numerical simulation method for a carbon-filtering gas production scheme, which comprises the following steps: finding out spatial distribution of a water-bearing layer and a mixed gas reservoir in a target area, and establishing a three-dimensional geologic structure model of a target reservoir; relevant parameters are obtained; establishing a mathematical model for carbon-filtering gas production simulation based on an oil reservoir numerical simulator; depicting an expression of a dissolution process of CO2 in formation water in a carbon-filtered gas production simulation process on the basis of a Henry law; depicting a calculation formula of the residual CO2 amount in the porous medium in the carbon-filtering gas production simulation process based on a Land model; according to the three-dimensional geologic model, the mathematical model, the expression, the calculation formula and the related parameters, constructing a reactive migration model of the CO2 and CH4 mixed gas in the target reservoir under the actual formation temperature and pressure; and based on the reactive migration model, contrastively analyzing the influence of the number, the position and the pressure difference of different production wells on the CO2 dissolution and storage amount and the CH4 mass fraction in the production wells, and screening out a scheme with the maximum CO2 dissolution and storage amount and the maximum CH4 mass fraction in the production wells.

Description

Technical Field

[0001] The invention relates to the technical field of oil reservoir and energy utilization, and more specifically to a numerical simulation method for a carbon filtering gas production scheme. Background Art

[0002] The large-scale emission of greenhouse gases such as CO2 is the main cause of the greenhouse effect, and the underground geological layer has a large storage space and high airtightness, which is suitable for storing carbon dioxide. Compared with oil reservoirs, natural gas reservoirs have the characteristics of wide gas sources and mixed accumulation of various types of gases. Usually there is a certain amount of residual gas that is not economically profitable in gas reservoirs, such as N2, H2S, CO2, etc. The solubility of CO2 in water is much higher than that of CH4, which means that under the same conditions, CO2 is more likely to form a dissolved state in salt water, while CH4 is more likely to be released from water. In addition, supercritical CO2 can undergo a series of chemical reactions in the underground environment. Through the difference in the migration properties of CO2 and CH4 in aquifers, the carbon filter gas recovery scheme can increase the CH4 mass fraction in the gas well and achieve CO2 geological storage.

[0003] Existing technologies mostly focus on the CH4 recovery caused by CO2 displacement and the impact of impurity gases such as CH4 on the CO2 geological storage process, but lack the use of aquifers for carbon filtration and gas recovery to increase the CH4 mass fraction in gas wells and achieve CO2 geological storage. Summary of the invention

[0004] In order to overcome the problem in the prior art that there is a lack of utilizing aquifers for carbon filtration and gas production to increase the CH4 mass fraction in gas production wells and achieve CO2 geological storage, the present invention provides a numerical simulation method for carbon filtration and gas production scheme.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a numerical simulation method for carbon filtering and gas recovery scheme, the method comprising:

[0006] According to the drilling data, logging data, seismic data and hydrogeological data of the target area, the main aquifers and mixed gas reservoirs developed in the target area and the spatial distribution of the aquifers and the mixed gas reservoirs are identified, and the mixed gas reservoirs are CO2 and CH4;

[0007] Establish a three-dimensional geological structure model of the target reservoir based on the obtained aquifer, mixed gas reservoir and the spatial distribution of the aquifer and the mixed gas reservoir, and use the three-dimensional address model to reflect the geological structure, structural characteristics and spatial distribution of lithological parameters of the target reservoir;

[0008] Based on the capillary pressure experiment and displacement experiment at the indoor core scale, the capillary pressure curve and water-gas two-phase relative permeability curve of the target reservoir are obtained;

[0009] Conduct indoor water chemistry testing, XRD mineral analysis and high-temperature and high-pressure reactor experiments to identify the water chemistry composition data of formation water in the target reservoir, the core mineral composition data and the reaction kinetic parameters of the CO2-water-rock interaction process;

[0010] Establish a mathematical model for carbon-filtering gas recovery simulation based on a reservoir numerical simulator;

[0011] The expression based on Henry's law to describe the dissolution process of CO2 in formation water during carbon extraction simulation;

[0012] The calculation formula for the residual CO2 in porous media during carbon-filter gas recovery simulation is described based on the Land model;

[0013] Construct a reactive migration model of a mixture of CO2 and CH4 in a target reservoir at actual formation temperature and pressure based on the established three-dimensional geological model, the mathematical model, the expression, the calculation formula, and the acquired geological structure, structural characteristics, spatial distribution of lithological parameters of the target reservoir, the capillary pressure curve, the water-gas two-phase relative permeability curve, the formation water hydrochemical component data, the core mineral component data, and the reaction kinetic parameters;

[0014] Based on the reactive migration model, the effects of different numbers, locations and pressure differences of production wells on the CO2 dissolution storage capacity and the CH4 mass fraction in the production wells were compared and analyzed, and the scheme with the largest CO2 dissolution storage capacity and the largest CH4 mass fraction in the production wells was screened out.

[0015] Preferably, the mathematical model includes a seepage equation, a phase equilibrium equation, a saturation equation and a molar compatibility equation.

[0016] Preferably, for the water component and the components in the oil and gas phase, the finite difference format of the seepage equation is as follows:

[0017]

[0018] Wherein, superscript n represents time n; superscript n+1 represents time n+1; subscript i represents component i; subscript j represents phase j; subscript o represents oil; subscript g represents gas; subscript w represents water; D is depth (m); n c is the total number of components, excluding water; N i is the number of moles of component i in each grid, in mol; is the number of moles of water component in each grid, its unit is mol; p is the pressure, its unit is Pa; P cog is the oil and gas capillary pressure, its unit is Pa; P cwo is the oil-water capillary pressure, in Pa; q is the source-sink term; t is the time, in s; T jis the hydraulic conductivity of phase j, and its unit is m 2 / s; V is the grid volume, its unit is m 3 ;y ij is the mole fraction of component i in phase j; γ is the gravity term; Δt is the time step, and its unit is s; in equations (1) and (2), it is assumed that there is no mass transfer between the water phase and the oil and gas phases. If the superscript m is n, the grid is calculated explicitly; if it is n+1, it is calculated implicitly, N i It is a function of molar density, saturation and component content, and is calculated as follows:

[0019] N i =φ(ρ o S o y io +ρ g S g y ig ),i=1,…n c (3)

[0020]

[0021] Where φ is the porosity; ρ is j is the molar density of phase j (m 3 / mol); S j is the saturation of phase j.

[0022] Preferably, based on the phase equilibrium equation, if the oil and gas system is in the two-phase region, the molar number N of component i in the gas phase is ig and the number of moles N in the oil phase io It can be obtained by solving the following thermodynamic equilibrium equation:

[0023] lnf ig =lnfi io ,i=1,…n c (5)

[0024] N io =N i -N ig (6)

[0025] Where: f ig is the fugacity of component i in phase j, and its unit is Pa.

[0026] Preferably, the degree of saturation is related to the total number of moles of substance in each phase:

[0027]

[0028] In the formula, S w , S o , S gare the saturation of water phase, oil phase and gas phase, respectively, and ρ w , ρ o , ρ g are the molar densities of water phase, oil phase and gas phase under formation conditions, N o and N g are the mole numbers of oil phase and gas phase in each grid, respectively.

[0029] Preferably, the molar compatibility equation, according to N i The definition of can be obtained as follows:

[0030]

[0031] Equation (10) forces the number of moles of component i in each grid to be consistent with the molar density, saturation, and porosity.

[0032] Preferably, the expression is

[0033]

[0034] In the formula, is the mole fraction of CO2 in the water phase; is the fugacity of CO2 in the water phase, its unit is KPa; P ref is the reference pressure, its unit is kPa; is the Henry constant for CO2 at the reference pressure, is the partial molar volume of CO2 at infinite dilution, its unit is m 3 / mol; R is the universal gas constant; T is temperature, its unit is ℃.

[0035] Preferably, the calculation formula is:

[0036]

[0037] In the formula, S gr is the residual CO2 saturation; S gcrit is the critical gas saturation of CO2; S g,max is the maximum gas saturation of CO2; C is the Land parameter calculated from the critical gas saturation.

[0038] Preferably, the three-dimensional geological structure model includes the description of the geological structure, structure, boundary, porosity, permeability, water saturation and well network of the reservoir.

[0039] Preferably, the reaction kinetic parameters include reaction rate constant, activation energy, and reaction specific surface area.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention establishes a CO2 and CH4 mixed gas seepage process model under actual formation temperature and pressure conditions, and proposes an optimal carbon filtration and gas production scheme for the target reservoir by analyzing the effects of different numbers of production wells, different production well locations and different production well pressures on the target reservoir's carbon filtration and gas production capacity. The present invention achieves CO2 geological storage while increasing the CH4 gas mass fraction in the gas production well. DETAILED DESCRIPTION

[0041] Example 1

[0042] A numerical simulation method for a carbon filtering gas recovery scheme, the method comprising:

[0043] According to the drilling data, logging data, seismic data and hydrogeological data of the target area, the main aquifers and mixed gas reservoirs developed in the target area and the spatial distribution of aquifers and mixed gas reservoirs are identified. The mixed gas reservoirs are CO2 and CH4.

[0044] A three-dimensional geological structure model of the target reservoir is established based on the obtained aquifer, mixed gas reservoir, and the spatial distribution of the aquifer and mixed gas reservoir, and the three-dimensional address model is used to reflect the geological structure, structural characteristics, and spatial distribution of lithological parameters of the target reservoir;

[0045] Based on the capillary pressure experiment and displacement experiment at the indoor core scale, the capillary pressure curve and water-gas two-phase relative permeability curve of the target reservoir are obtained;

[0046] Conduct indoor water chemistry testing, XRD mineral analysis and high-temperature and high-pressure reactor experiments to identify the water chemistry composition data of formation water in the target reservoir, the core mineral composition data and the reaction kinetic parameters of the CO2-water-rock interaction process;

[0047] Establish a mathematical model for carbon-filtering gas recovery simulation based on a reservoir numerical simulator;

[0048] The expression based on Henry's law to describe the dissolution process of CO2 in formation water during carbon extraction simulation;

[0049] The calculation formula for the residual CO2 in porous media during carbon-filter gas recovery simulation is described based on the Land model;

[0050] Based on the established three-dimensional geological model, mathematical model, expression, calculation formula, and the acquired target reservoir geological structure, structural characteristics, spatial distribution of lithological parameters, capillary pressure curve, water-gas two-phase relative permeability curve, formation water hydrochemical composition data, core mineral composition data, and reaction kinetic parameters, a reactive migration model of CO2 and CH4 mixed gas in the target reservoir under actual formation temperature and pressure is constructed;

[0051] Based on the reactive migration model, the effects of different numbers, locations and pressure differences of production wells on the CO2 dissolution storage capacity and the CH4 mass fraction in the production wells were compared and analyzed, and the scheme with the largest CO2 dissolution storage capacity and the largest CH4 mass fraction in the production wells was screened out.

[0052] In this embodiment, the three-dimensional geological structure model includes the description of the geological structure, structure, boundary, porosity, permeability, water saturation, and well pattern of the reservoir.

[0053] In this embodiment, the reaction kinetic parameters include reaction rate constant, activation energy, and reaction specific surface area.

[0054] Example 2

[0055] A numerical simulation method for a carbon filtering gas recovery scheme, the method comprising:

[0056] According to the drilling data, logging data, seismic data and hydrogeological data of the target area, the main aquifers and mixed gas reservoirs developed in the target area and the spatial distribution of aquifers and mixed gas reservoirs are identified. The mixed gas reservoirs are CO2 and CH4.

[0057] A three-dimensional geological structure model of the target reservoir is established based on the obtained aquifer, mixed gas reservoir, and the spatial distribution of the aquifer and mixed gas reservoir, and the three-dimensional address model is used to reflect the geological structure, structural characteristics, and spatial distribution of lithological parameters of the target reservoir;

[0058] Based on the capillary pressure experiment and displacement experiment at the indoor core scale, the capillary pressure curve and water-gas two-phase relative permeability curve of the target reservoir are obtained;

[0059] Conduct indoor water chemistry testing, XRD mineral analysis and high-temperature and high-pressure reactor experiments to identify the water chemistry composition data of formation water in the target reservoir, the core mineral composition data and the reaction kinetic parameters of the CO2-water-rock interaction process;

[0060] A mathematical model for carbon-filtering gas recovery simulation is established based on a reservoir numerical simulator. The mathematical model includes a seepage equation, a phase equilibrium equation, a saturation equation and a molar compatibility equation.

[0061] Among them, for the components in the water component and the oil and gas phase, the finite difference format of the seepage equation is as follows:

[0062] Wherein, superscript n represents time n; superscript n+1 represents time n+1; subscript i represents component i; subscript j represents phase j; subscript o represents oil; subscript g represents gas; subscript w represents water; D is depth (m); n c is the total number of components, excluding water; N iis the number of moles of component i in each grid, in mol; is the number of moles of water component in each grid, its unit is mol; p is the pressure, its unit is Pa; P cog is the oil and gas capillary pressure, its unit is Pa; P cwo is the oil-water capillary pressure, in Pa; q is the source-sink term; t is the time, in s; T j is the hydraulic conductivity of phase j, and its unit is m 2 / s; V is the grid volume, its unit is m 3 ;y ij is the mole fraction of component i in phase j; γ is the gravity term; Δt is the time step, and its unit is s; in equations (1) and (2), it is assumed that there is no mass transfer between the water phase and the oil and gas phases. If the superscript m is n, the grid is calculated explicitly; if it is n+1, it is calculated implicitly, N i It is a function of molar density, saturation and component content, and is calculated as follows:

[0063] N i =v(ρ o S o y io +ρ g S g y ig ),i=1,…n c (3)

[0064]

[0065] Where φ is the porosity; ρ is j is the molar density of phase j (m 3 / mol); S j is the saturation of phase j.

[0066] In addition, based on the phase equilibrium equation, if the oil and gas system is located in the two-phase region, the molar number N of component i in the gas phase is ig and the number of moles N in the oil phase io It can be obtained by solving the following thermodynamic equilibrium equation:

[0067] lnfi ig =lnfi io ,i=1,…n c (5)

[0068] N io =N i -N ig (6)

[0069] Where: f ig is the fugacity of component i in phase j, and its unit is Pa.

[0070] Here, the degree of saturation is related to the total number of moles of substance in each phase:

[0071]

[0072] In the formula, S w , S o , S g are the saturation of water phase, oil phase and gas phase, respectively, and ρ w , ρ o , ρ g are the molar densities of water phase, oil phase and gas phase under formation conditions, N o and N g are the mole numbers of oil phase and gas phase in each grid, respectively.

[0073] In this embodiment, the molar compatibility equation, according to N i The definition of can be obtained as follows:

[0074]

[0075] Equation (10) forces the number of moles of component i in each grid to be consistent with the molar density, saturation, and porosity.

[0076] The expression based on Henry's law to describe the dissolution process of CO2 in formation water during carbon extraction simulation;

[0077] The calculation formula for the residual CO2 in porous media during carbon-filter gas recovery simulation is described based on the Land model;

[0078] Based on the established three-dimensional geological model, mathematical model, expression, calculation formula, and the acquired target reservoir geological structure, structural characteristics, spatial distribution of lithological parameters, capillary pressure curve, water-gas two-phase relative permeability curve, formation water hydrochemical composition data, core mineral composition data, and reaction kinetic parameters, a reactive migration model of CO2 and CH4 mixed gas in the target reservoir under actual formation temperature and pressure is constructed;

[0079] Based on the reactive migration model, the effects of different numbers, locations and pressure differences of production wells on the CO2 dissolution storage capacity and the CH4 mass fraction in the production wells were compared and analyzed, and the scheme with the largest CO2 dissolution storage capacity and the largest CH4 mass fraction in the production wells was screened out.

[0080] Example 3

[0081] A numerical simulation method for a carbon filtering gas recovery scheme, the method comprising:

[0082] According to the drilling data, logging data, seismic data and hydrogeological data of the target area, the main aquifers and mixed gas reservoirs developed in the target area and the spatial distribution of aquifers and mixed gas reservoirs are identified. The mixed gas reservoirs are CO2 and CH4.

[0083] A three-dimensional geological structure model of the target reservoir is established based on the obtained aquifer, mixed gas reservoir, and the spatial distribution of the aquifer and mixed gas reservoir, and the three-dimensional address model is used to reflect the geological structure, structural characteristics, and spatial distribution of lithological parameters of the target reservoir;

[0084] Based on the capillary pressure experiment and displacement experiment at the indoor core scale, the capillary pressure curve and water-gas two-phase relative permeability curve of the target reservoir are obtained;

[0085] Conduct indoor water chemistry testing, XRD mineral analysis and high-temperature and high-pressure reactor experiments to identify the water chemistry composition data of formation water in the target reservoir, the core mineral composition data and the reaction kinetic parameters of the CO2-water-rock interaction process;

[0086] A mathematical model for carbon-filtering gas recovery simulation is established based on a reservoir numerical simulator. The mathematical model includes a seepage equation, a phase equilibrium equation, a saturation equation and a molar compatibility equation.

[0087] Among them, for the components in the water component and the oil and gas phase, the finite difference format of the seepage equation is as follows:

[0088] Wherein, superscript n represents time n; superscript n+1 represents time n+1; subscript i represents component i; subscript j represents phase j; subscript o represents oil; subscript g represents gas; subscript w represents water; D is depth (m); n c is the total number of components, excluding water; N i is the number of moles of component i in each grid, in mol; is the number of moles of water component in each grid, its unit is mol; p is the pressure, its unit is Pa; P cog is the oil and gas capillary pressure, its unit is Pa; P cwo is the oil-water capillary pressure, in Pa; q is the source-sink term; t is the time, in s; T j is the hydraulic conductivity of phase j, and its unit is m 2 / s; V is the grid volume, its unit is m 3 ;y ij is the mole fraction of component i in phase j; γ is the gravity term; Δt is the time step, and its unit is s;

[0089] In equations (1) and (2), it is assumed that there is no mass transfer between the water phase and the oil and gas phases. If the superscript m is n, the grid is calculated explicitly; if it is n+1, it is calculated implicitly. i It is a function of molar density, saturation and component content, and is calculated as follows:

[0090] N i =φ(ρ o S o y io +ρ g S g y ig ),i=1,…n c (3)

[0091]

[0092] Where φ is the porosity; ρ is j is the molar density of phase j (m 3 / mol); S j is the saturation of phase j.

[0093] In addition, based on the phase equilibrium equation, if the oil and gas system is located in the two-phase region, the molar number N of component i in the gas phase is ig and the number of moles N in the oil phase ii It can be obtained by solving the following thermodynamic equilibrium equation:

[0094] lnfi ii =lnfi io ,i=1,…n c (5)

[0095] N io =N i -N ig (6)

[0096] Where: f ig is the fugacity of component i in phase j, and its unit is Pa.

[0097] Here, the degree of saturation is related to the total number of moles of substance in each phase:

[0098]

[0099] In the formula, S w , S o , S g are the saturation of water phase, oil phase and gas phase, respectively, and ρ w , ρ o , ρ g are the molar densities of water phase, oil phase and gas phase under formation conditions, N o and N gare the mole numbers of oil phase and gas phase in each grid, respectively.

[0100] In this embodiment, the molar compatibility equation, according to N i The definition of can be obtained as follows:

[0101]

[0102] Equation (10) forces the number of moles of component i in each grid to be consistent with the molar density, saturation, and porosity.

[0103] Based on Henry's law, the expression for describing the dissolution process of CO2 in formation water during carbon extraction simulation is:

[0104]

[0105] In the formula, is the molar fraction of CO2 in the water phase; is the fugacity of CO2 in the water phase, its unit is KPa; P ref is the reference pressure, its unit is kPa; is the Henry constant for CO2 at the reference pressure, is the partial molar volume of CO2 at infinite dilution, its unit is m 3 / mol; R is the universal gas constant; T is temperature, its unit is ℃.

[0106] The calculation formula for the residual CO2 in the porous medium during the carbon-filter gas recovery simulation is described based on the Land model. The calculation formula is:

[0107]

[0108] In the formula, S gr is the residual CO2 gas saturation; S gcrit is the critical gas saturation of CO2; S g,max is the maximum gas saturation of CO2; C is the Land parameter calculated from the critical gas saturation.

[0109] Based on the established three-dimensional geological model, mathematical model, expression, calculation formula, and the acquired target reservoir geological structure, structural characteristics, spatial distribution of lithological parameters, capillary pressure curve, water-gas two-phase relative permeability curve, formation water hydrochemical composition data, core mineral composition data, and reaction kinetic parameters, a reactive migration model of CO2 and CH4 mixed gas in the target reservoir under actual formation temperature and pressure is constructed;

[0110] Based on the reactive migration model, the effects of different numbers, locations and pressure differences of production wells on the CO2 dissolution storage capacity and the CH4 mass fraction in the production wells were compared and analyzed, and the scheme with the largest CO2 dissolution storage capacity and the largest CH4 mass fraction in the production wells was screened out.

[0111] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A numerical simulation method for carbon filtering and gas production scheme, characterized in that: The method comprises: According to the drilling data, logging data, seismic data and hydrogeological data of the target area, the main aquifers and mixed gas reservoirs developed in the target area and the spatial distribution of the aquifers and the mixed gas reservoirs are identified, and the mixed gas reservoirs are CO2 and CH4; Establish a three-dimensional geological structure model of the target reservoir based on the obtained aquifer, mixed gas reservoir and the spatial distribution of the aquifer and the mixed gas reservoir, and use the three-dimensional address model to reflect the geological structure, structural characteristics and spatial distribution of lithological parameters of the target reservoir; Based on the capillary pressure experiment and displacement experiment at the indoor core scale, the capillary pressure curve and water-gas two-phase relative permeability curve of the target reservoir are obtained; Conduct indoor water chemistry testing, XRD mineral analysis and high-temperature and high-pressure reactor experiments to identify the water chemistry composition data of formation water in the target reservoir, the core mineral composition data and the reaction kinetic parameters of the CO2-water-rock interaction process; Establish a mathematical model for carbon-filtering gas recovery simulation based on a reservoir numerical simulator; The expression based on Henry's law to describe the dissolution process of CO2 in formation water during carbon extraction simulation; The calculation formula for the residual CO2 in porous media during carbon-filter gas recovery simulation is described based on the Land model; Construct a reactive migration model of a mixture of CO2 and CH4 in a target reservoir at actual formation temperature and pressure based on the established three-dimensional geological model, the mathematical model, the expression, the calculation formula, and the acquired geological structure, structural characteristics, spatial distribution of lithological parameters of the target reservoir, the capillary pressure curve, the water-gas two-phase relative permeability curve, the formation water hydrochemical component data, the core mineral component data, and the reaction kinetic parameters; Based on the reactive migration model, the effects of different numbers, locations and pressure differences of production wells on the CO2 dissolution storage capacity and the CH4 mass fraction in the production wells were compared and analyzed, and the scheme with the largest CO2 dissolution storage capacity and the largest CH4 mass fraction in the production wells was screened out.

2. The numerical simulation method for carbon filtering and gas extraction scheme according to claim 1 is characterized in that: The mathematical model includes a seepage equation, a phase equilibrium equation, a saturation equation and a molar compatibility equation.

3. The numerical simulation method for carbon filtering and gas production according to claim 2 is characterized in that: For the components in the water component and the oil and gas phase, the finite difference format of the seepage equation is as follows: Wherein, superscript n represents time n; superscript n+1 represents time n+1; subscript i represents component i; subscript j represents phase j; subscript o represents oil; subscript g represents gas; subscript w represents water; D is depth (m); n c is the total number of components, excluding water; N i is the number of moles of component i in each grid, in mol; is the number of moles of water component in each grid, its unit is mol; p is the pressure, its unit is Pa; P cog is the oil and gas capillary pressure, its unit is Pa; P cwo is the oil-water capillary pressure, in Pa; q is the source-sink term; t is the time, in s; T j is the hydraulic conductivity of phase j, and its unit is m 2 / s; V is the grid volume, its unit is m 3 ;y ij is the mole fraction of component i in phase j; γ is the gravity term; Δt is the time step, and its unit is s; In equations (1) and (2), it is assumed that there is no mass transfer between the water phase and the oil and gas phases. If the superscript m is n, the grid is calculated explicitly; if it is n+1, it is calculated implicitly. i It is a function of molar density, saturation and component content, and is calculated as follows: N i =φ(ρ o S o y io +r g S g y ig ),i=1,…n c (3) Where φ is the porosity; ρ is j is the molar density of phase j (m 3 / mol); S j is the saturation of phase j.

4. The numerical simulation method for carbon filtering and gas recovery scheme according to claim 3 is characterized in that: Based on the phase equilibrium equation, if the oil and gas system is located in the two-phase region, the molar number N of component i in the gas phase is ig and the number of moles N in the oil phase io It can be obtained by solving the following thermodynamic equilibrium equation: lnfi ig =lnfi io ,i=1,…n c (5) N io =N i -N ig (6) Where: f ig is the fugacity of component i in phase j, and its unit is Pa.

5. The numerical simulation method for carbon filtering and gas recovery scheme according to claim 4 is characterized in that: The degree of saturation is related to the total number of moles of substance in each phase: In the formula, S w , S o , S g are the saturation of water phase, oil phase and gas phase, respectively, and ρ w , ρ o , ρ g are the molar densities of water phase, oil phase and gas phase under formation conditions, N o and N g are the mole numbers of oil phase and gas phase in each grid, respectively.

6. The numerical simulation method for carbon filtering and gas production according to claim 5 is characterized in that: Molar compatibility equation, according to N i The definition of can be obtained as follows: Equation (10) forces the number of moles of component i in each grid to be consistent with the molar density, saturation, and porosity.

7. The numerical simulation method for carbon filtering and gas recovery scheme according to any one of claims 1 to 6, characterized in that: The expression is In the formula, is the molar fraction of CO2 in the water phase; is the fugacity of CO2 in the water phase, its unit is KPa; P ref is the reference pressure, its unit is kPa; is the Henry constant for CO2 at the reference pressure, is the partial molar volume of CO2 at infinite dilution, its unit is m 3 / mol; R is the universal gas constant; T is temperature, its unit is ℃.

8. The numerical simulation method for carbon filtering and gas recovery scheme according to any one of claims 1 to 6, characterized in that: The calculation formula is: In the formula, S gr is the residual CO2 saturation; S gcrit is the critical gas saturation of CO2; S g,max is the maximum gas saturation of CO2; C is the Land parameter calculated from the critical gas saturation.

9. The numerical simulation method for carbon filtering and gas recovery scheme according to claim 1 is characterized in that: The three-dimensional geological structure model includes the description of the geological structure, structure, boundary, porosity, permeability, water saturation and well network of the reservoir.

10. The numerical simulation method for carbon filtering and gas recovery scheme according to claim 1 is characterized in that: The reaction kinetic parameters include reaction rate constant, activation energy, and reaction specific surface area.

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