Multi-scale pore imbibition numerical simulation method, system, equipment and medium

Abstract

The invention belongs to the technical field of petroleum and natural gas exploration and development, and provides a multi-scale pore imbibition numerical simulation method and system, electronic equipment and a storage medium. The method comprises the steps that a heterogeneous fracture network gas-water two-phase flow model is established, dimension reduction processing is conducted on the flow model, and the flow model comprises a control equation, boundary conditions and initial conditions; based on the boundary condition and the initial condition, solving the control equation by using a finite element method to obtain a dependent variable influencing multi-scale pore imbibition; and according to the flow model and the control equation after dimension reduction, the influence of the dependent variable on multi-scale pore imbibition is simulated. According to the method, the factors influencing the shale fracturing fracture and the multi-scale matrix pore imbibition can be quantitatively researched, and the understanding of the fracturing fracture and the multi-scale matrix pore imbibition is improved to a great extent.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration and development technology, and particularly relates to a multi-scale pore permeation numerical simulation method, system, electronic equipment and storage medium. Background Technology

[0002] During shale hydraulic fracturing, artificial fractures open and expand in the shale reservoir when the injection pressure of the fracturing fluid exceeds the minimum principal stress and tensile strength of the reservoir rock. After fracturing stops, the fractures communicate with the matrix pores. The matrix pore pressure exceeds the inter-fracture pressure, creating a self-absorption phenomenon that causes shale gas to spontaneously flow from the matrix pores to the fractures. Due to the heterogeneity of shale reservoirs, the pore throat scales of the matrix pores vary, resulting in different scales of seepage processes between the matrix pores and the fractures. This process plays a crucial role in the early stages of shale mining. This process is complex, involving not only reservoir seepage and cross-scale processes but also multiple disciplines such as fluid mechanics, rock mechanics, and geomechanics. Most current research assumes that the matrix reservoir is homogeneous and the flow between the matrix pores and fractures is unidirectional, neglecting the capillary force scale range between the matrix pores and fractures. However, this cross-scale phenomenon exists not only within the matrix but also at the matrix-fracture interface. Therefore, establishing heterogeneous fracture propagation models to study the capillary pressure between the matrix and the fracture, the matrix-fracture interface, and the seepage between matrix pores and fractures at different scales is a current research trend for heterogeneous fracture problems. Many researchers have also investigated the spontaneous water absorption phenomenon in multi-scale internal pore structures.

[0003] CN116738883A discloses a method and apparatus for predicting the recovery rate of fractured shale oil reservoirs, which can simply, quickly and efficiently predict the percolation rate, production and recovery rate of shale oil reservoirs during the fracturing and shut-in process.

[0004] Although these studies also involve the permeation of fractures and matrix pores, the heterogeneity of shale reservoirs causes cross-scale interactions between pressure fractures and matrix pores of different scales. More importantly, there is currently no mature research on the spontaneous water absorption mechanism of multi-scale matrix pores and pressure fractures, and a numerical simulation method for multi-scale pore permeation has not yet been developed. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a multi-scale pore permeation numerical simulation method, system, electronic device, and storage medium. This method can quantitatively study the factors influencing shale fractures and multi-scale matrix pore permeation, significantly increasing our understanding of fractures and multi-scale matrix pore permeation.

[0006] To address the aforementioned technical problems, the first aspect of this invention proposes a multi-scale pore permeation numerical simulation method, the method comprising:

[0007] A gas-water two-phase flow model was established in a heterogeneous fracture network, and the flow model was dimensionally reduced. The flow model includes governing equations, boundary conditions, and initial conditions.

[0008] Based on the boundary conditions and the initial conditions, the governing equations are solved using the finite element method to obtain the dependent variables affecting multi-scale pore absorption.

[0009] Based on the reduced-dimensional flow model and the governing equations, the influence of the dependent variable on multi-scale pore permeation is simulated.

[0010] According to a preferred embodiment of the present invention, establishing a gas-water two-phase flow model in a heterogeneous fracture network includes:

[0011] The flow model is established based on the heterogeneous porous medium containing cracks;

[0012] The velocity of fluid flow is described using the continuity equation. Mass and momentum are conserved, gravity is ignored, the fluid does not undergo phase change and is incompressible, and the governing equation is established.

[0013] According to a preferred embodiment of the present invention, the dimensionality reduction processing of the flow model includes:

[0014] The flow model is dimensionality reduced to simplify matrix porosity and pressure fractures;

[0015] The matrix pores are simplified into circles of different diameters, and the pressure cracks are simplified into rectangles.

[0016] According to a preferred embodiment of the present invention, the governing equations are solved using the finite element method based on the boundary conditions and the initial conditions to obtain the dependent variables affecting multi-scale pore permeation, including:

[0017] The governing equations were solved using the finite element method and a software solver.

[0018] The dependent variable is obtained by using a fully coupled solution method for multiphysics fields.

[0019] According to a preferred embodiment of the present invention, simulating the effect of the dependent variable on multi-scale pore permeation includes:

[0020] The influence of the dependent variables on multi-scale pore permeation was simulated. The dependent variables include water injection rate, fracture spacing, grain shape, and wetting phase contact angle.

[0021] To address the aforementioned technical problems, a second aspect of this invention proposes a multi-scale pore permeation numerical simulation system, characterized in that the system comprises: a model building module, an equation solving module, and a permeation simulation module;

[0022] The model building module is used to build a gas-water two-phase flow model in a heterogeneous fracture network and to perform dimensionality reduction on the flow model. The flow model includes governing equations, boundary conditions, and initial conditions.

[0023] The equation solving module is used to solve the governing equations using the finite element method based on the boundary conditions and the initial conditions, so as to obtain the dependent variables that affect multi-scale pore permeation.

[0024] The percolation simulation module is used to simulate the influence of the dependent variable on multi-scale pore percolation based on the dimension-reduced flow model and the control equation.

[0025] According to a preferred embodiment of the present invention, it includes:

[0026] The model building module is also used to build the flow model based on the heterogeneous porous medium containing cracks;

[0027] The model building module is also used to describe the velocity of fluid flow using the continuity equation, setting up mass conservation, momentum conservation, neglecting gravity, and ensuring that the fluid does not undergo phase change and is incompressible, and then establishing the governing equation.

[0028] According to a preferred embodiment of the present invention, it includes:

[0029] The model building module is also used to reduce the dimensionality of the flow model, simplifying matrix porosity and pressure fractures;

[0030] The model building module is also used to simplify the matrix pores into circles of different diameters and the pressure cracks into rectangles.

[0031] To address the aforementioned technical problems, a third aspect of the present invention provides an electronic device, comprising:

[0032] processor;

[0033] And a memory storing computer-executable instructions, which, when executed, cause the processor to perform the method described in any of the above embodiments.

[0034] To address the aforementioned technical problems, a fourth aspect of the present invention provides a computer storage medium, wherein the computer storage medium stores one or more programs, which, when executed by a processor, implement the method described in any of the above embodiments.

[0035] Compared with the prior art, the present invention has the following advantages: The numerical simulation method for permeation provided by the present invention can quantitatively study the factors affecting the permeation of shale fractures and multi-scale matrix pores, which greatly improves the understanding of fractures and multi-scale matrix pores.

[0036] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A schematic diagram of a multi-scale pore permeation numerical simulation method according to an embodiment of the present invention is shown;

[0039] Figure 2 A second schematic diagram of a multi-scale pore permeation numerical simulation method according to an embodiment of the present invention is shown.

[0040] Figure 3 A schematic diagram of a multi-scale pore permeation numerical simulation method according to an embodiment of the present invention is shown in part three.

[0041] Figure 4 A schematic diagram of a multi-scale pore permeation numerical simulation method according to an embodiment of the present invention is shown in Figure 4.

[0042] Figure 5 A structural diagram of a multi-scale pore permeation numerical simulation system according to an embodiment of the present invention is shown;

[0043] Figure 6 A schematic diagram of an electronic device structure according to an embodiment of the present invention is shown;

[0044] Figure 7 The curves showing the change of final matrix collection rate over time under different water injection rates according to an embodiment of the present invention are illustrated.

[0045] Figure 8 The curves showing the change of final matrix recovery rate over time under different hydraulic fracture spacings according to an embodiment of the present invention are illustrated.

[0046] Figure 9The curves showing the change of final matrix collection rate over time for different wetting phase contact angles according to an embodiment of the present invention are illustrated.

[0047] Figure 10 The simulated geometry of the gas-water two-phase flow model in a heterogeneous fracture network is shown. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] The same reference numerals in the accompanying drawings denote the same or similar elements, components, or parts, and therefore, repeated descriptions of the same or similar elements, components, or parts may be omitted below. It should also be understood that although terms such as first, second, third, etc., indicating numbers may be used herein to describe various devices, elements, components, or parts, these devices, elements, components, or parts should not be limited by these terms. That is, these terms are only used to distinguish one from another. For example, a first device may also be referred to as a second device, without departing from the essential technical solution of the invention. Furthermore, the terms "and / or" and "and / or" refer to all combinations including any one or more of the listed items.

[0050] like Figure 1 As shown, the method includes:

[0051] S11. Establish a gas-water two-phase flow model in a heterogeneous fracture network and perform dimensionality reduction on the flow model. The flow model includes governing equations, boundary conditions, and initial conditions.

[0052] In this embodiment, the heterogeneous fracture network model is constructed based on a geological model, which is also a heterogeneous geological model. Fractures are treated as discrete geometric bodies and modeled in three-dimensional space. Polygons, cylinders, and other geometric shapes can be used to approximate fractures. Based on the statistical distribution of fracture parameters, parameters such as fracture location, length, width, and orientation are randomly generated to construct a fracture network. The intersections and connections between fractures are considered to ensure the model's rationality.

[0053] In this embodiment, spatially varying parameters, such as fracture density and fracture width, are introduced into the model. Heterogeneity can be achieved by defining different regions and using different parameter distributions within each region. The influence of geological structures is considered; for example, fractures are more developed near faults, while areas farther from faults have relatively fewer fractures.

[0054] In this embodiment, since the orientation and distribution of fractures typically exhibit a certain directionality, the model needs to consider anisotropy. Anisotropy can be represented by defining parameters such as permeability and porosity in different directions. By combining geological structural information and statistical results of fracture orientation, the degree and direction of anisotropy are determined.

[0055] In this embodiment, crack development exhibits a degree of randomness; therefore, introducing random factors into the model is an important means of reflecting heterogeneity. The randomness of cracks can be simulated by randomly generating crack parameters and crack locations. Multiple random simulations are performed, and the statistical characteristics of the model results are analyzed to evaluate the impact of the heterogeneous crack network on processes such as fluid flow.

[0056] S12. Based on the boundary conditions and the initial conditions, the governing equations are solved using the finite element method to obtain the dependent variables that affect multi-scale pore permeation.

[0057] In this embodiment, the COMSOL Multiphysic software solver is used to solve the governing equations.

[0058] Specifically, the equations establishing the initial conditions are expressed as follows:

[0059]

[0060] in, Let v be the divergence of the velocity field, and v be the fluid velocity. For auxiliary parameters, n is the unit length perpendicular to the rock surface, α is the contact angle of the three-phase fluid, τ is the capillary diameter, δ is the mixing energy density, and γ is the fluid migration rate on the capillary surface. The phase field order gradient in porous media. This is the gradient operator.

[0061] In this embodiment, This indicates that the divergence of the velocity field is zero at the initial moment. This means that the fluid has no source or sink in volume at the initial state, and the inflow and outflow of the fluid are in equilibrium, providing a stable starting point for subsequent analysis of the fluid flow.

[0062] In this embodiment, v = 0 further clarifies that the fluid velocity is zero at the initial moment, confirming that the system is initially at rest. This is crucial for studying the fluid's motion changes from a resting state, providing a clear initial value for subsequent velocity change analysis.

[0063] In this embodiment, For auxiliary parameters Constraints were imposed. Because... The fourth-order equation can be reduced to a computable second-order equation; this initial condition mathematically simplifies the problem. It ensures that, at the initial moment, the equation is consistent with... The relevant physical quantities have a rate of change of zero in space, which is beneficial for subsequent use. The equation reduction and solution provide a stable initial state.

[0064] In this embodiment, The interaction between the rock surface and the fluid, as well as the properties of the three-phase fluid, are considered from the initial moment. This provides initial constraints for studying the behavior of the fluid near the rock surface and the physical phenomena at the interface of the three-phase fluid.

[0065] In this embodiment, the steps for establishing boundary conditions are as follows:

[0066] Assumption 1: Water is injected into the formation at a low and uniform speed, and the outflow pressure is 0.

[0067] Assumption 2: The rest of the model is considered to be a flow-free boundary with no backflow between fluids.

[0068] Assumption 3: The boundary condition of the grain surface is assumed to be a wetting wall with a wetting angle.

[0069] Assumption 4: The fracturing fluid and the fluid in the matrix pores are not affected by temperature and pressure.

[0070] S13. Based on the reduced-dimensional flow model and the governing equation, simulate the influence of the dependent variable on multi-scale pore permeation.

[0071] In this embodiment, the effects of different water injection rates, fracture spacing, grain shape, and wetting phase contact angle on the infiltration between fractures and multi-scale matrix pores were simulated.

[0072] like Figure 2 As shown, the method includes:

[0073] S21. Establish the flow model based on the heterogeneous porous medium containing cracks.

[0074] In this embodiment, the system considers the heterogeneous porous medium containing cracks and establishes a gas-water two-phase flow model of the heterogeneous crack network, including governing equations, boundary conditions and initial conditions.

[0075] S22. Using the continuity equation to describe the velocity of fluid flow, and assuming that mass and momentum are conserved, gravity is ignored, the fluid does not undergo phase change and is incompressible, the governing equation is established.

[0076] In this embodiment, governing equations are established, and the Navier-Stokes and continuity equations are used to describe the velocity of fluid flow. These equations are derived under the conditions of mass conservation and momentum conservation, and it is assumed that gravity can be ignored on a two-dimensional horizontal plane, no phase change occurs, and the fluid is incompressible.

[0077] Specifically, the governing equations can be expressed as follows:

[0078]

[0079] Where μ is the viscosity of the fluid, ρ is the density of the fluid, t is time, and G is the chemical potential. The pressure gradient in the porous medium is given by ω, which is a phase field order parameter. Let v be the divergence of the velocity field, and v be the fluid velocity. For gradient operators, For the gradient in porous media, The phase field order gradient in porous media. Let T be the divergence of the velocity field at time T.

[0080] In this embodiment, the Cahn-Hilliard phase-field method, combined with the aforementioned Navier-Stokes and continuity equations, is used to solve the interface problem of countercurrent self-absorption. The concentrations of the two different components are represented by (1+ω) / 2 and (1-ω) / 2, respectively.

[0081] Specifically, the equations for each phase attribute are as follows:

[0082]

[0083] Where τ is the diameter of the capillary, δ is the mixing energy density, and γ is the fluid migration rate on the capillary surface. Here, θ1 is the contact angle of the first wetting phase, θ2 is the contact angle of the second wetting phase, and v is the fluid velocity under the current conditions. The fourth-order equation can be reduced to a computable second-order equation.

[0084] like Figure 3 As shown, the method includes:

[0085] S31. The flow model is reduced in dimensionality to simplify matrix porosity and pressure fractures.

[0086] In this embodiment, the flow model is dimensionality reduced, and the cracks are simplified into simple linear units; the study area is mainly composed of matrix pores (Kp) and pressure cracks (Kf).

[0087] S32. The matrix pores are simplified into circles of different diameters, and the pressure cracks are simplified into rectangles.

[0088] In this embodiment, as Figure 9 As shown, a rectangle of a fixed size is constructed to simulate a three-dimensional matrix block with quantitative porosity and permeability. Circles of different diameters represent multi-scale matrix pores, and rectangles represent pressure fractures near the matrix pores.

[0089] like Figure 4 As shown, the method includes:

[0090] S41. Solve the governing equations using the finite element method and a software solver.

[0091] In this embodiment, the finite element method is used to solve the numerical simulation equations, which are solved using the COMSOL Multiphysic software solver.

[0092] S42. A fully coupled solution method is used for multiphysics fields to obtain the dependent variable.

[0093] In this embodiment, the transient phase field study in the "Multiphase Flow" module of the software investigates countercurrent flow in porous media, and uses COMSOL Multiphysic to construct the geometric structure, applying triangular meshes to subdivide the simulation model. A fully coupled solution method is provided for multiphysics, forming a unified set of coupled equations for solution, and obtaining the dependent variables of each independent field.

[0094] In this embodiment, as Figure 7 As shown, the effect of water injection rate is demonstrated. The interaction between capillary pressure and viscous force plays a decisive role in the distribution of gas and water. The capillary force provides the driving force for water to be absorbed into the matrix pores, while the viscous force provides the driving force for fluid flow in the hydraulic fracture.

[0095] During water injection, the injection rate affects the fluid migration rate on the capillary surface in the governing equation. The changes in matrix porosity over time at different injection rates show that the highest injection rate results in a moderate recovery rate, allowing for rapid recovery to the original state. However, the fluid tends to aggregate into clumps, making it difficult to find pathways to fractures within the matrix pores, thus resulting in the lowest recovery rate. As the injection rate increases, the absorption rate and final recovery rate are alleviated due to water breakthrough. The stable distribution of gas and water also differs at different injection rates. Due to higher capillary pressure, the water phase propagates relatively quickly in areas with smaller matrix pore sizes. Before the water surface velocity reaches a relatively stable state, gas escapes from these smaller pore sizes into the fracture. When the injection rate stabilizes, gas struggles to enter the fracture in areas affected by capillary fingering. It can be observed that the convection of the gas-water matrix is ​​a crucial factor in the matrix pore size at these gas-filled areas, and the injection rate significantly influences the shape of the gas-filled clumps, thus affecting the percolation efficiency.

[0096] In this embodiment, as Figure 8 As shown, the influence of fracture spacing on the pressure in the governing equation is evident. Models with narrower fractures exhibit higher early recovery rates but lower final recovery rates. As fractures narrower, early recovery rates increase, while maintaining the same final recovery rate. This also demonstrates a relatively stable gas-water distribution, with the water drive surface continuously advancing in a manner proportional to capillary force. It can be observed that decreasing fracture spacing leads to higher early gas recovery, but the decrease in final recovery rate is not significant.

[0097] In this embodiment, as Figure 7-9 As shown, the influence of grain shape on the pressure gradient in the porous medium is illustrated in the governing equations. Different grain shapes at different scales result in varying permeation rates in the matrix pores. Changes in grain shape affect key parameters such as permeability and porosity. Higher permeability and porosity increase the water absorption of the matrix pores, leading to increased recovery rate and ultimately affecting the final recovery rate. In the model, the gas-water distribution, including the crystalline particles, shows that the multi-scale matrix pores are initially saturated with gas, while the fractures are saturated with water. After stabilization, the different grain sizes result in different pressure and velocity fields. The velocity profile mainly shows the distribution of water streamlines and gas flow lines. The water flow within the capillary generates a pressure gradient relative to the flow direction, which is the capillary force. When the capillary force decreases to its minimum value, gas can be expelled from the matrix pores into the fractures.

[0098] In this embodiment, as Figure 9 As shown, the influence of the wetting phase contact angle is evident. Quantitatively studying the wetting phase requires converting the study to the wetting angle, which is crucial for simulating different contact angles. Figure 5As described above, viscous forces are generated by water flow in the fractures, while capillary forces are generated by capillary action in the matrix pores. When the contact angle is small, capillary forces cause injected water to penetrate into the matrix pores, and air bubbles are injected one by one. Due to the high degree of capillary force, small-scale matrix pores are occupied by water. Air bubbles exiting the matrix pores gradually increase in size and connect with the fractures, accumulating into larger air bubbles that are then washed away by the injected water. As the contact angle increases, wettability changes from acute wettability to neutral wettability, and water absorption also decreases. The limiting recovery rate increases as the contact angle decreases, while the final recovery rate remains unchanged.

[0099] like Figure 5 As shown, the system includes: a model building module, an equation solving module, and an absorption simulation module.

[0100] In this embodiment, the model building module is specifically used to build a gas-water two-phase flow model in a heterogeneous fracture network and to perform dimensionality reduction processing on the flow model. The flow model includes governing equations, boundary conditions, and initial conditions.

[0101] In this embodiment, the equation solving module is specifically used to solve the governing equations using the finite element method based on the boundary conditions and the initial conditions, thereby obtaining the dependent variables that affect multi-scale pore permeation.

[0102] In this embodiment, the percolation simulation module is specifically used to simulate the influence of the dependent variable on multi-scale pore percolation based on the dimension-reduced flow model and the control equation.

[0103] In this embodiment, the model building module is specifically used to build the flow model based on the heterogeneous porous medium containing cracks.

[0104] In this embodiment, the model building module is specifically used to describe the velocity of fluid flow using the continuity equation, setting mass conservation, momentum conservation, neglecting gravity, and ensuring that the fluid does not undergo phase change and is incompressible, and then establishing the governing equation.

[0105] In this embodiment, the model building module is specifically used to reduce the dimensionality of the flow model, simplifying matrix porosity and pressure fractures.

[0106] In this embodiment, the model building module is specifically used to simplify the matrix pores into circles of different diameters and the pressure cracks into rectangles.

[0107] like Figure 6 As shown, this embodiment of the invention provides an electronic device, including a processor 1110, a communication interface 1120, a memory 1130, and a communication bus 1140, wherein the processor 1110, the communication interface 1120, and the memory 1130 communicate with each other through the communication bus 1140.

[0108] Memory 1130 is used to store computer programs;

[0109] When the processor 1110 executes the program stored in the memory 1130, it implements any of the above-described determination methods.

[0110] The electronic device provided in this embodiment of the invention includes a processor 1110 that executes a program stored in a memory 1130 to obtain the fluid flow rate of each branch under different switching states and determines the initial volumetric flow rate of each branch; it corrects the initial volumetric flow rate based on the pipe parameters and fluid parameters of each branch when it is in operating condition and standard condition to obtain the standard condition volumetric flow rate of each branch; it obtains multiple total standard condition volumetric flow rates based on the standard condition volumetric flow rates of each branch under different switching states, and determines the optimal switching state of each branch by using the switching state of each branch when the total standard condition volumetric flow rate reaches a preset target.

[0111] The communication bus 1140 mentioned in the above electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus 1140 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, it is shown in the figure with only one thick line, but this does not indicate that there is only one bus or one type of bus.

[0112] The communication interface 1120 is used for communication between the above-mentioned electronic device and other devices.

[0113] The memory 1130 may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory 1130 may also be at least one storage device located remotely from the aforementioned processor 1110.

[0114] The processor 1110 mentioned above can be a general-purpose processor 1110, including a central processing unit (CPU), a network processor (NP), etc.; it can 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 gate or transistor logic devices, or discrete hardware components.

[0115] This invention provides a computer-readable storage medium storing one or more programs that can be executed by one or more processors 1110 to implement the determination method of any of the above embodiments.

[0116] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of the present invention is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0117] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-scale pore permeation numerical simulation method, characterized in that, The method includes: A gas-water two-phase flow model was established in a heterogeneous fracture network, and the flow model was dimensionally reduced. The flow model includes governing equations, boundary conditions, and initial conditions. Based on the boundary conditions and the initial conditions, the governing equations are solved using the finite element method to obtain the dependent variables affecting multi-scale pore absorption. Based on the reduced-dimensional flow model and the governing equations, the influence of the dependent variable on multi-scale pore permeation is simulated.

2. The simulation method according to claim 1, characterized in that, The establishment of the gas-water two-phase flow model in the heterogeneous fracture network includes: The flow model is established based on the heterogeneous porous medium containing cracks; The velocity of fluid flow is described using the continuity equation. Mass and momentum are conserved, gravity is ignored, the fluid does not undergo phase change and is incompressible, and the governing equation is established.

3. The simulation method according to claim 1, characterized in that, The dimensionality reduction process for the flow model includes: The flow model is dimensionality reduced to simplify matrix porosity and pressure fractures; The matrix pores are simplified into circles of different diameters, and the pressure cracks are simplified into rectangles.

4. The simulation method according to claim 1, characterized in that, Based on the boundary conditions and the initial conditions, the governing equations are solved using the finite element method to obtain the dependent variables affecting multi-scale pore absorption, including: The governing equations were solved using the finite element method and a software solver. The dependent variable is obtained by using a fully coupled solution method for multiphysics fields.

5. The simulation method according to claim 1, characterized in that, The simulation of the dependent variable's effect on multi-scale pore permeation includes: The influence of the dependent variables on multi-scale pore permeation was simulated. The dependent variables include water injection rate, fracture spacing, grain shape, and wetting phase contact angle.

6. A multi-scale pore permeation numerical simulation system, characterized in that, The system includes: a model building module, an equation solving module, and an absorption simulation module; The model building module is used to build a gas-water two-phase flow model in a heterogeneous fracture network and to perform dimensionality reduction on the flow model. The flow model includes governing equations, boundary conditions, and initial conditions. The equation solving module is used to solve the governing equations using the finite element method based on the boundary conditions and the initial conditions, so as to obtain the dependent variables that affect multi-scale pore permeation. The percolation simulation module is used to simulate the influence of the dependent variable on multi-scale pore percolation based on the dimension-reduced flow model and the control equation.

7. The simulation system according to claim 6, characterized in that, include: The model building module is also used to build the flow model based on the heterogeneous porous medium containing cracks; The model building module is also used to describe the velocity of fluid flow using the continuity equation, setting up mass conservation, momentum conservation, neglecting gravity, and ensuring that the fluid does not undergo phase change and is incompressible, and then establishing the governing equation.

8. The simulation system according to claim 6, characterized in that, include: The model building module is also used to reduce the dimensionality of the flow model, simplifying matrix porosity and pressure fractures; The model building module is also used to simplify the matrix pores into circles of different diameters and the pressure cracks into rectangles.

9. An electronic device, characterized in that, include: processor; And a memory storing computer-executable instructions, which, when executed, cause the processor to perform the method according to any one of claims 1-5.

10. A computer storage medium, characterized in that, in, The computer storage medium stores one or more programs, which, when executed by a processor, implement the method of any one of claims 1-5.

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