Carbon dioxide pressure flooding oil displacement and burying numerical simulation technology system

Abstract

The invention discloses a carbon dioxide pressure flooding oil displacement and burying numerical simulation technical system, and relates to the field of CCUS numerical simulation, and the technical system comprises a geological data obtaining module which obtains the geological data of a target oil field site; an oil reservoir geologic model construction module constructs an oil reservoir geologic model in the CO2 pressure drive process of the deep shale oil reservoir according to the geological data; the pressure-drive oil displacement and burying mathematical model building module is used for building a deep shale oil reservoir CO2 pressure-drive oil displacement and burying mathematical model on the basis of the multiphase multicomponent seepage model and the mechanical deformation model in combination with the reservoir damage mechanical constitutive model; and the pressure-drive oil displacement and burying numerical simulation module is used for solving the seepage equation and the mechanical equation, carrying out iterative coupling solution on the fluid-solid two fields based on a definite stress decomposition algorithm, carrying out deep shale oil reservoir CO2 pressure-drive oil displacement and burying numerical simulation, and can better simulate the porosity and permeability change and the evolution of a damaged area in the CO2 pressure-drive oil displacement and burying process.

Description

Technical Field

[0001] The present application relates to the field of CCUS numerical simulation, and in particular to a numerical simulation technology system for carbon dioxide pressure drive oil recovery and storage. Background Art

[0002] In recent years, the proportion of deep shale oil reservoirs in the proven or developed oil reservoirs has gradually increased, and the oil and gas reserves are huge, which is an important position for increasing reserves and production. However, this type of reservoir has the characteristics of poor physical properties, low conductivity and small natural energy, which is difficult to exploit and generally requires fracturing production. Although fracturing technology can effectively increase the production of a single well, the high drilling cost, rapid production decline, unsustainable exploitation and difficulty in replenishing reservoir energy in the later stage are the disadvantages of this fracturing method. Therefore, the pressure drive process has been developed. By adopting large-displacement, high-pressure pumping equipment, a large amount of displacement agent is pumped into the formation continuously in a short period of time at a pumping pressure higher than the formation fracture pressure, to replenish the formation energy, increase the oil well production capacity and oil recovery efficiency, thereby improving the development effect of the well group.

[0003] Existing research mainly focuses on pressure-driven water injection development, and there is little research on CO2 pressure-driven production in deep shale reservoirs. Therefore, in view of the unclear understanding of the mechanism in the pressure-driven process and the lack of corresponding numerical simulation technology, a deep shale reservoir CO2 pressure-driven oil recovery and storage numerical simulation technology system is urgently needed. Summary of the invention

[0004] The purpose of this application is to provide a numerical simulation technology system for carbon dioxide pressure-driven oil recovery and storage, which can simulate the changes in porosity and permeability and the evolution of damaged areas during CO2 pressure-driven oil recovery and storage.

[0005] To achieve the above objectives, this application provides the following solutions: This application provides a carbon dioxide pressure drive oil recovery and storage numerical simulation technology system, including the following modules: The geological data acquisition module is used to: obtain geological data at the target oil field site; The reservoir geological model building module is used to: build a reservoir geological model of the CO2 pressure drive process in deep shale reservoirs according to the geological data; A module for establishing a mathematical model of pressure-driven oil displacement and storage is used to establish a mathematical model of CO2 pressure-driven oil displacement and storage in deep shale reservoirs based on a multiphase and multicomponent seepage model and a mechanical deformation model, combined with a reservoir damage mechanical constitutive model; the mathematical model of CO2 pressure-driven oil displacement and storage in deep shale reservoirs includes a multiphase and multicomponent fluid seepage equation, a stress balance equation, an effective stress equation, a matrix porosity dynamic change relationship equation, and a permeability dynamic change relationship equation; The pressure-driven oil recovery and storage numerical simulation module is used to solve the seepage equation and mechanical equation, solve the fluid-solid field iterative coupling based on the constant stress decomposition algorithm, conduct numerical simulation of CO2 pressure-driven oil recovery and storage in deep shale reservoirs, and obtain numerical simulation results.

[0006] Optionally, the geological data includes reservoir parameters, fluid physical property parameters and CO2 injection parameters.

[0007] Optionally, the reservoir geological model building module specifically includes: constructing a reservoir geological model of the CO2 pressure drive process of deep shale reservoirs based on the geological data and based on a structured network.

[0008] Optionally, the reservoir damage mechanics constitutive model is expressed as follows: ; in, is the effective stress tensor of rock, is the stress tensor, is the identity matrix, is the rock damage factor, is the elasticity tensor, is the strain tensor.

[0009] Optionally, the carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system further includes a rock damage factor determination module, which is used to: determine the rock damage factor according to the reservoir tensile damage factor and the reservoir shear damage factor; the reservoir tensile damage factor and the reservoir shear damage factor are expressed as follows: ; ; in, is the reservoir tensile damage factor, is the maximum principal stress, is the uniaxial tensile strength of rock, is the reservoir shear damage factor, is the minimum principal stress, is the internal friction angle, is the uniaxial compressive strength of rock.

[0010] Optionally, the rock damage factor determination module specifically includes: When the reservoir tensile damage factor is greater than or equal to 0, the relationship between the rock damage factor and the strain tensor is as follows: ; When the reservoir shear damage factor is greater than or equal to 0, the relationship between the rock damage factor and the strain tensor is as follows: ; in, is the change ratio of tensile strength, , is the residual tensile strength of rock, is the initial uniaxial tensile strength of rock, is the tensile damage strain threshold, is the ultimate tensile strain, is the shear damage strain threshold.

[0011] Optionally, the pressure-driven oil displacement and burial storage numerical simulation module specifically includes: Step 501: In each time step, the current geostress field is fixed, and the seepage equation is iteratively solved using the finite volume method to obtain the fluid pressure field distribution. The matrix and fracture porosity are updated in real time during the iteration process; Step 502: Based on the fluid pressure field distribution, the finite element method is used to iteratively solve the mechanical equation to obtain the ground stress field distribution, and update the matrix and fracture porosity and permeability; Step 503: Based on the distribution of the geostress field, determine whether each grid unit is damaged, and update the permeability of the damaged grid unit; Step 504: Repeat steps 501 and 502 until the coupled iteration converges and enter the next time step.

[0012] Optionally, the numerical simulation results include reservoir pressure, saturation, oil production and water content.

[0013] According to the specific embodiments provided in this application, this application discloses the following technical effects: The present application provides a numerical simulation technology system for CO2 pressure-driven oil displacement and storage, which obtains geological data at the target oil field site, and constructs a reservoir geological model of the CO2 pressure-driven oil displacement and storage process in deep shale oil reservoirs according to the geological data; establishes a mathematical model of CO2 pressure-driven oil displacement and storage in deep shale oil reservoirs based on a multiphase and multicomponent seepage model and a mechanical deformation model, and in combination with a reservoir damage mechanics constitutive model; solves the seepage equation and the mechanical equation, and solves the fluid-solid two-field iterative coupling solution based on a constant stress decomposition algorithm, and performs a numerical simulation of CO2 pressure-driven oil displacement and storage in deep shale oil reservoirs to obtain numerical simulation results; establishes a mathematical model of CO2 pressure-driven oil displacement and storage in deep shale oil reservoirs through a reservoir damage mechanics constitutive model, and performs a numerical simulation of CO2 pressure-driven oil displacement and storage in deep shale oil reservoirs, which can better simulate the changes in porosity and permeability and the evolution of damaged areas during CO2 pressure-driven oil displacement and storage, and provide technical support for CO2 pressure-driven development of deep shale oil reservoirs, and can be used to guide the efficient development of oil fields and improve oil field production effects and development benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of a process flow of a carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system provided in one embodiment of the present application; Figure 2 A detailed flow chart of numerical simulation of CO2 flooding and storage in deep shale oil reservoirs provided in one embodiment of the present application; Figure 3 A schematic diagram of a numerical calculation solution process of a constant stress decomposition algorithm provided in an embodiment of the present application; Figure 4 A schematic diagram of a low permeability reservoir model and its calculation grid provided in an embodiment of the present application; Figure 5 A schematic diagram of the matrix porosity distribution of a low permeability reservoir provided in one embodiment of the present application; Figure 6 A schematic diagram of the distribution of matrix permeability of a low permeability reservoir provided in one embodiment of the present application; Figure 7 A schematic diagram of pressure-driven stress distribution provided in an embodiment of the present application; Figure 8 A schematic diagram of the evolution of damage factors after pressure driving provided in one embodiment of the present application; Fig. 9 A schematic diagram showing the comparison of the simulation results of daily oil production and water content of the Niu 6-x22 and Niu 21-x2 production wells with the historical production data provided in an embodiment of the present application; Fig. 9 (a) is the comparison between the simulation result of daily oil production of Niu 6-x22 production well and the historical production data; Fig. 9 (b) is the comparison between the water cut simulation result and the historical production data of the Niu 6-x22 production well; Fig. 9 (c) is the comparison between the simulation result of daily oil production of Niu 21-x2 production well and the historical production data; Fig. 9 (d) is the comparison between the water cut simulation result and the historical production data of the Niu 21-x2 production well; Fig.10 A schematic diagram showing the comparison of the simulation results of daily oil production and water content of the Niu 21-x3 and Niu 21-x5 production wells with the historical production data provided in an embodiment of the present application; Fig.10 (a) is the comparison between the simulation result of daily oil production of Niu 21-x3 production well and the historical production data; Fig.10(b) is the comparison between the water cut simulation result and the historical production data of the Niu 21-x3 production well; Fig.10 (c) is the comparison between the simulation result of daily oil production of Niu 21-x5 production well and the historical production data; Fig.10 (d) in the figure is the comparison between the water cut simulation results of the Niu 21-x5 production well and the historical production data. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0018] In an exemplary embodiment, Figure 1 and Figure 2 As shown, a carbon dioxide pressure drive oil recovery and storage numerical simulation technology system is provided, and the technology system includes the following modules.

[0019] The geological data acquisition module T1 is used to obtain geological data at the target oil field site.

[0020] The reservoir geological model building module T2 is used to build a reservoir geological model of the CO2 pressure drive process in deep shale reservoirs according to the geological data.

[0021] The pressure-driven oil displacement and storage mathematical model establishment module T3 is used to establish a CO2 pressure-driven oil displacement and storage mathematical model for deep shale oil reservoirs based on a multiphase and multicomponent seepage model and a mechanical deformation model, and in combination with a reservoir damage mechanical constitutive model; the CO2 pressure-driven oil displacement and storage mathematical model for deep shale oil reservoirs includes a multiphase and multicomponent fluid seepage equation, a stress balance equation, an effective stress equation, a matrix porosity dynamic change relationship equation, and a permeability dynamic change relationship equation.

[0022] The pressure-driven oil recovery and storage numerical simulation module T4 is used to solve the seepage equation and mechanical equation, solve the fluid-solid field iterative coupling based on the constant stress decomposition algorithm, conduct numerical simulation of CO2 pressure-driven oil recovery and storage in deep shale reservoirs, and obtain numerical simulation results.

[0023] Based on the above modules T1 to T4, the changes in porosity and permeability and the evolution of damaged areas during CO2 pressure-driven oil recovery and storage can be better simulated, which can provide technical support for the formulation of on-site pressure-driven water injection plans in oil fields.

[0024] In another exemplary embodiment of the present application, the geological data includes reservoir parameters, fluid physical property parameters and CO2 injection parameters.

[0025] The reservoir geological model building module T2 specifically includes: constructing a deep shale reservoir CO2 pressure drive process reservoir geological model based on the structured network according to the geological data. Specifically, the model of the target oil field site is divided into multiple grid units, and the geological data is loaded into each grid unit.

[0026] Based on the multiphase and multicomponent seepage model and mechanical deformation model, combined with the reservoir damage mechanics constitutive model, and the relationship between matrix and porosity and permeability changes, a mathematical model of CO2 pressure drive and storage in deep shale reservoirs is established.

[0027] The phase equilibrium module is used to perform multiphase and multicomponent fluid seepage simulation calculations. The specific calculation process of the phase equilibrium module is as follows: In the process of CO2 pressure-driven oil recovery and storage in deep shale reservoirs, the seepage-stress coupling relationship has a significant impact on the rock mechanical behavior characteristics and seepage characteristics. Considering the complex phase changes involved in the development of CO2 pressure-driven oil recovery and storage in deep shale reservoirs, a multiphase and multicomponent model is used to describe the fluid seepage process. The mass conservation equation of each component in the system can be uniformly expressed in the form shown in the following equation (1). The components include hydrocarbon components and water components. The multiphase and multicomponent fluid seepage equation is shown in the following equation.

[0028] (1); (2); In the formula, subscripts o, g and w represent oil phase, gas phase and water phase respectively; represent the density of oil phase, gas phase and water phase respectively, Components The mole fraction of the component in the oil phase, Components The mole fraction of the component in the gas phase, is the total number of components, is saturation, is the porosity, For time, are the source and sink items of each component caused by injection and production, is the seepage velocity, which obeys Darcy's law of multiphase flow and can be calculated by the following formula: (3); In the formula, =o, g, w, respectively represent oil phase, gas phase or water phase, is the absolute permeability, is the relative permeability; is the viscosity, is the fluid pressure, is the depth. In order to make the mass conservation equation solvable, the following constraint equations are also required, including the saturation relationship, the component mole fraction relationship, and the capillary force relationship, which are as follows: (4); (5); (6); In the formula, For components The total mole fraction in the oil and gas phases, is the capillary force at the oil-water interface, is the capillary force at the oil-gas interface, are respectively the oil phase pressure, gas phase pressure or water phase pressure. The fluid PVT relationship involved in the above equation can be given by the state equation shown below: (7); Where R is the gas constant, V is the volume of the fluid, T is the fluid temperature, a and b is a constant.

[0029] The stress balance equation is shown below: (8); The effective stress equation is shown below: (9); The geometric equation is shown below: (10); In the formula, is the rock density, is the acceleration due to gravity, is the stress tensor, is the elasticity tensor, is the strain tensor, is the displacement, is the Biot coefficient, is the identity matrix, is the total fluid pressure.

[0030] The dynamic change relationship equations of matrix porosity and permeability are shown in the following equations respectively.

[0031] (11); (12); In the formula, represents the matrix porosity, subscript 0 represents the initial value, represents the initial value of matrix porosity, is the initial value of the total fluid pressure, is the drained bulk modulus, is the volume strain, is the initial value of volumetric strain, represents the matrix permeability, represents the initial value of matrix permeability.

[0032] Crack mechanical deformation model: For cracks, the crack normal closure amount is calculated using the following formula: (13); In the formula, is the crack normal closure amount, is the maximum normal closure allowed for the crack, is the normal stress applied to the crack, is the crack normal stiffness.

[0033] The reservoir damage mechanics constitutive model is expressed as follows: (14); in, is the effective stress tensor of rock, is the rock damage factor.

[0034] The carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system further includes a rock damage factor determination module, which is used to determine the rock damage factor according to the reservoir tensile damage factor and the reservoir shear damage factor; the reservoir tensile damage factor and the reservoir shear damage factor are expressed as follows: (15); (16); in, is the reservoir tensile damage factor, is the maximum principal stress, is the uniaxial tensile strength of rock, is the reservoir shear damage factor, is the minimum principal stress, is the internal friction angle, is the uniaxial compressive strength of rock.

[0035] Among them, the rock damage factor determination module specifically includes: according to the elastic-brittle damage judgment model, when the reservoir tensile damage factor is greater than or equal to 0, that is When tensile damage occurs, the rock damage factor The relationship with the strain tensor is as follows: (17); When the reservoir shear damage factor is greater than or equal to 0, that is, When shear damage occurs in the rock, the rock damage factor The relationship with the strain tensor is as follows: (18); in, is the change ratio of tensile strength, , is the residual tensile strength of rock, is the initial uniaxial tensile strength of rock, is the tensile damage strain threshold, is the ultimate tensile strain, is the shear damage strain threshold.

[0036] Absolute permeability based on rock damage factor The evolution law of is as follows: (19); In the formula, is the damage permeability influence coefficient, is the initial permeability.

[0037] The finite volume method is fully implicit in solving the residual form of the seepage equation: (20); (twenty one); in, Represents a grid cell n Components exist +1 time step residual of the percolation equation, Indicated in +1 time step grid cell n and grid cells m The conductivity between express +1 time step grid cell m The flow potential of the oil phase, express +1 time step grid cell n The flow potential of the oil phase, express +1 time step grid cellm The flow potential of the gas phase, express +1 time step grid cell n The flow potential of the gas phase, Represents a grid cell n The water phase +1 time step residual of the percolation equation, Represents a grid cell n The set of adjacent grid cells.

[0038] The Newton-Raphson method is used to iteratively solve: (twenty two); (twenty three); In the formula, p represents the iteration step, represents the time step, l Indicates the primary variable number (such as oil phase pressure , water phase saturation and the total component mole fraction wait), Indicates that the main variable is p +1 iteration increment, +1 indicates the current time step, x is the main variable.

[0039] The residual form of the finite element method to solve the mechanical equation is: (twenty four); In the formula, represents the residual vector of the mechanical equation, ; is the differential operator matrix, is the shape function matrix; is the delta Dirac function vector, which for two-dimensional problems is defined as =[1, 1, 0] T ; For three-dimensional problems, it is defined as =[1, 1, 1, 0, 0, 0] T , is the total area where stress is applied, is the matrix boundary, is the crack boundary, is a constant load on the crack boundary.

[0040] The Newton-Raphson method is used to iteratively solve: (25); (26); According to the above process, numerical simulation of CO2 pressure drive and storage in deep shale reservoirs is carried out; numerical simulation of the reservoir is carried out through the above steps, and numerical simulation results are output. The numerical simulation results include reservoir pressure, saturation, oil production and water content, that is, simulation results such as reservoir pressure, saturation, oil production and water production curves are obtained.

[0041] The following is a further detailed description of the numerical simulation of pressure-driven oil displacement and storage. The numerical simulation of XX block is carried out using the CO2 pressure-driven oil displacement and storage numerical simulation technology in deep shale reservoirs: The geometric shape of the model is as follows: Figure 4 As shown, the initial oil saturation is 0.8, the initial water saturation is 0.2, the oil viscosity is 0.33, and the matrix porosity and permeability distribution of the low permeability reservoir are as follows: Figure 5 and Figure 6 shown.

[0042] The first step is to obtain reservoir parameters, fluid physical parameters and CO2 injection parameters, and pre-process the parameters to form an input file; The second step is to perform multiphase and multicomponent flow module calculations and mechanical module calculations on the data generated in the first step. Specifically, it includes the following steps: (1) The multi-phase and multi-component flow calculation process of deep shale oil and gas reservoirs, i.e., the process of solving the seepage equation, includes the following steps 301 to 306: Step 301: Known initial time = Distribution of reservoir pressure, temperature and saturation at time 0; Step 302: Calculate the physical property parameters of the three phases of oil, gas and water using a phase equilibrium module; Step 303: Solve the linear equations to obtain The pressure distribution law at time +1; Step 304: Substitute the water phase control equation and the saturation relationship to obtain The distribution law of saturation of each phase at time +1; Step 305: Solve the equation J δ=− R 1. Determine whether the residual of the seepage equation is less than If it is not true, return to step 303 and perform iterative calculation until the residual is less than ; Value 1e -10 . J It refers to the , δ refers to the main variable in formula (23) p +1 increment , R 1 represents the residual of the seepage equation.

[0043] Step 306: If it is established, that is, the residual of the seepage equation is less than ,but = +1, enter the next time step, repeat steps 302 to 304, and the distribution law of reservoir pressure and saturation of each phase can be obtained, and the calculation is completed.

[0044] The mechanical module calculation process, that is, the mechanical equation solving process includes the following steps 401 to 405: Step 401: Get the initial time according to the data in the first step = 0 distribution of rock physical parameters and stress parameters along the formation; Step 402: Give the time , the initial values ​​of the formation pressure and temperature distribution; Step 403: Calculate the plastic deformation of the matrix and cracks caused by stress using formulas (11)-(13); Step 404: Solve to determine whether the residual of the mechanical equation is less than ( Value 1e -10 ) If it is not true, return to step 403 and perform iterative calculation until the residual is less than ; Step 405: If established, then = +1, enter the next time step, repeat steps 402 to 404, and the plastic deformation under different temperatures and pressures can be obtained, and the calculation ends.

[0045] Step 3: The above-mentioned pressure drive oil displacement and buried storage numerical simulation module T4 is specifically used to implement the following steps 501 to 504: Step 501: In each time step, the current geostress field is fixed, and the seepage equation is iteratively solved using the finite volume method to obtain the fluid pressure field distribution. The matrix and fracture porosity are updated in real time during the iteration process; Step 502: Based on the fluid pressure field distribution, the finite element method is used to iteratively solve the mechanical equation to obtain the ground stress field distribution, and update the matrix and fracture porosity and permeability; Step 503: Based on the distribution of the geostress field, determine whether each grid unit is damaged, and update the permeability of the damaged grid unit; Step 504: Repeat steps 501 and 502 until the coupled iteration converges and enter the next time step.

[0046] Based on the finite volume method, the seepage equation is fully implicitly solved, the mechanical equation is solved based on the finite element method, and the fluid-solid field is iteratively coupled based on the constant stress decomposition algorithm. A numerical solution method is established to form a complete numerical simulation technology for CO2 pressure drive and storage in deep shale reservoirs. The numerical calculation solution process of the constant stress decomposition algorithm is as follows: Figure 3 shown.

[0047] The fourth step is to obtain the production data (water content, oil volume) within the specified production time and perform historical fitting with the produced data of deep shale oil reservoirs.

[0048] The pressure-driven stress distribution is as follows Figure 7 As shown in Figure 2, the evolution of damage factors after pressure driving is as follows: Figure 8 shown.

[0049] Fig. 9 and Fig.10 The historical fitting of the production wells Niu 6-x22, Niu 21-x2, Niu 21-x3 and Niu 21-x5 in the block is given. The simulation results of daily oil production and water content of the four production wells are in good agreement with the historical production data, further verifying the effectiveness and applicability of numerical simulation technology.

[0050] The present application also provides an application scenario, which applies the above-mentioned carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system. Specifically: the carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system provided in this embodiment can be applied in shale oil mining scenarios. The shale oil mining scenario includes a data acquisition link, a carbon dioxide pressure-driven oil recovery and storage numerical simulation link, and a shale oil mining link; the geological data at the target oil field site enters the carbon dioxide pressure-driven oil recovery and storage numerical simulation link from the content production link, obtains the corresponding numerical simulation results, and enters the downstream shale oil mining link. The carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system provided in this embodiment belongs to the carbon dioxide pressure-driven oil recovery and storage numerical simulation link. Specifically, in the process of numerical simulation link of CO2 pressure drive for oil recovery and storage at the target oil field site, a reservoir geological model of CO2 pressure drive process in deep shale reservoirs can be constructed according to geological data. Based on multiphase and multicomponent seepage model and mechanical deformation model, and combined with reservoir damage mechanics constitutive model, a mathematical model of CO2 pressure drive for oil recovery and storage in deep shale reservoirs is established. The seepage equation and mechanical equation are solved, and the iterative coupling of fluid and solid fields is solved based on the constant stress decomposition algorithm. The numerical simulation of CO2 pressure drive for oil recovery and storage in deep shale reservoirs is carried out to obtain numerical simulation results.

[0051] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0052] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the system and its core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A carbon dioxide pressure drive oil recovery and storage numerical simulation technology system, characterized in that: The carbon dioxide pressure drive oil recovery and storage numerical simulation technology system includes: The geological data acquisition module is used to: obtain geological data at the target oil field site; The reservoir geological model building module is used to: build a reservoir geological model of the CO2 pressure drive process in deep shale reservoirs according to the geological data; A module for establishing a mathematical model of pressure-driven oil displacement and storage is used to establish a mathematical model of CO2 pressure-driven oil displacement and storage in deep shale oil reservoirs based on a multiphase and multicomponent seepage model and a mechanical deformation model, combined with a reservoir damage mechanical constitutive model; the mathematical model of CO2 pressure-driven oil displacement and storage in deep shale oil reservoirs includes a multiphase and multicomponent fluid seepage equation, a stress balance equation, an effective stress equation, a matrix porosity dynamic change relationship equation, and a permeability dynamic change relationship equation; The pressure-driven oil recovery and storage numerical simulation module is used to solve the seepage equation and mechanical equation, solve the fluid-solid field iterative coupling based on the constant stress decomposition algorithm, conduct numerical simulation of CO2 pressure-driven oil recovery and storage in deep shale reservoirs, and obtain numerical simulation results.

2. The carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system according to claim 1 is characterized in that: The geological data include reservoir parameters, fluid physical property parameters and CO2 injection parameters.

3. The carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system according to claim 1 is characterized in that: The reservoir geological model construction module specifically includes: According to the geological data, a reservoir geological model of the CO2 pressure drive process in deep shale reservoirs is constructed based on a structured network.

4. The carbon dioxide pressure drive oil recovery and storage numerical simulation technology system according to claim 1 is characterized in that: The reservoir damage mechanics constitutive model is expressed as follows: ； in, is the effective stress tensor of rock, is the stress tensor, is the identity matrix, is the rock damage factor, is the elasticity tensor, is the strain tensor.

5. The carbon dioxide pressure drive oil recovery and storage numerical simulation technology system according to claim 4 is characterized in that: The carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system also includes a rock damage factor determination module, which is used to: determine the rock damage factor according to the reservoir tensile damage factor and the reservoir shear damage factor; the reservoir tensile damage factor and the reservoir shear damage factor are expressed as follows: ； ； in, is the reservoir tensile damage factor, is the maximum principal stress, is the uniaxial tensile strength of rock, is the reservoir shear damage factor, is the minimum principal stress, is the internal friction angle, is the uniaxial compressive strength of rock.

6. The carbon dioxide pressure drive oil recovery and storage numerical simulation technology system according to claim 5 is characterized in that: The rock damage factor determination module specifically includes: When the reservoir tensile damage factor is greater than or equal to 0, the relationship between the rock damage factor and the strain tensor is as follows: ； When the reservoir shear damage factor is greater than or equal to 0, the relationship between the rock damage factor and the strain tensor is as follows: ； in, is the change ratio of tensile strength, , is the residual tensile strength of rock, is the initial uniaxial tensile strength of rock, is the tensile damage strain threshold, is the ultimate tensile strain, is the shear damage strain threshold.

7. The carbon dioxide pressure-driven oil recovery and storage numerical simulation technology system according to claim 1 is characterized in that: The pressure drive oil displacement and burial storage numerical simulation module specifically includes: Step 501: In each time step, the current geostress field is fixed, and the seepage equation is iteratively solved using the finite volume method to obtain the fluid pressure field distribution. The matrix and fracture porosity are updated in real time during the iteration process; Step 502: Based on the fluid pressure field distribution, the finite element method is used to iteratively solve the mechanical equation to obtain the ground stress field distribution, and update the matrix and fracture porosity and permeability; Step 503: Based on the distribution of the geostress field, determine whether each grid unit is damaged, and update the permeability of the damaged grid unit; Step 504: Repeat steps 501 and 502 until the coupled iteration converges and enter the next time step.

8. The carbon dioxide pressure drive oil recovery and storage numerical simulation technology system according to claim 1 is characterized in that: The numerical simulation results include reservoir pressure, saturation, oil production and water content.

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