Deep shale gas multiphase heat-fluid-solid three-field coupling numerical simulation method and system

Abstract

The invention relates to the technical field of unconventional oil gas numerical simulation, and provides a deep shale gas multiphase heat-fluid-solid three-field coupling numerical simulation method and system. The method comprises the steps that reservoir parameters, fracture basic parameters and liquid attribute parameters of a target deep shale gas reservoir area are obtained; the reservoir parameters, the fracture basic parameters and the liquid attribute parameters are imported into the trained deep shale gas multiphase heat-fluid-solid three-field coupling numerical simulation model, and target dynamic simulation information is generated, the deep shale gas multiphase heat-fluid-solid three-field coupling numerical simulation model is obtained through coupling solution according to a seepage field equation, a temperature field equation, a stress field equation and a three-pore medium coupling model. The three-pore medium coupling model is obtained by coupling a single-pore medium model, a dual-medium model, a nonlinear unsteady fluid channeling model and an embedded discrete fracture model. According to the method and the device, an efficient and accurate numerical calculation model can be constructed for highly complex heat-fluid-solid information of the shale gas reservoir, and accurate simulation data can be obtained through calculation.

Description

Technical Field

[0001] The present disclosure relates to the technical field of unconventional oil and gas numerical simulation, and in particular to a method and system for deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation. Background Art

[0002] As an effective supplement to conventional energy, shale gas is an important unconventional natural gas resource with the advantages of low carbon, cleanness, great development potential, and long mining life. With huge resource potential, deep shale gas reservoirs will be one of the important areas for increasing domestic natural gas reserves and production in the future. However, deep shale gas reservoirs are characterized by high temperature, high pressure, and high stress. The deformation characteristics of reservoir rocks no longer obey the law of linear elastic deformation. During the mining process, shale gas migration is a dynamic coupling process of multiple fields. The temperature field, stress field, and seepage field interact with each other, and the complex fracture network after fracturing also has an impact on it, resulting in very complex gas-water relationships, seepage mechanisms, and flow laws. Therefore, existing numerical simulation technologies face the following three major challenges:

[0003] (1) There is no model suitable for the thermal-fluid-solid coupled flow characteristics of deep shale gas under high temperature, high pressure and high stress environment.

[0004] The establishment of equivalent continuous medium models mostly adopts the semi-empirical formula method, lacking rigorous theoretical derivation; the currently commonly used dual medium model is difficult to accurately and efficiently describe the unsteady-state crossflow between low-permeability bedrock and microcracks, and the research on its thermal-fluid-solid coupling theory still needs to be further deepened, especially the characterization and simulation of the interaction between matrix rock and fracture system under the action of thermal-fluid-solid coupling; shale gas reservoirs after hydraulic fracturing contain multi-scale pore media: nano-scale intragranular pores-micron-scale intergranular pores-millimeter-scale microcracks-meter-scale artificial fractures, and a single continuous medium model or discrete fracture model has certain limitations. For fractured media, the use of discrete fracture models has not yet had a mature method and theory.

[0005] (2) There is no efficient model for dealing with discrete fracture networks.

[0006] The traditional embedded discrete fracture model embeds discrete fractures directly into the corner grid. Although it reduces the grid dependency and simplifies the difficulty of meshing complex fractures, it still has the problem of non-convergence of calculation due to the small volume of the fracture unit after cutting. Due to the complex fracture network formed after deep shale fracturing, how to improve the current discrete fracture model to achieve the purpose of controllable computational convergence and controllable grid size is a key problem that needs to be solved.

[0007] (3) There is no efficient algorithm to deal with the thermal-fluid-solid three-field coupling.

[0008] The main difficulty of the typical heat-fluid-solid three-field coupling problem in the exploitation process of deep oil and gas reservoirs lies in the solution of multi-field coupling. There are currently three main methods: one-way coupling, sequential iterative coupling and full coupling. The first two methods are simple to implement, but the convergence speed and calculation accuracy are poor. The full coupling method has good stability and convergence, but it is difficult to build mathematical models and solutions. Due to the high complexity of the thermal, fluid-solid information of shale gas reservoirs, how to construct an efficient and accurate numerical calculation model and form a corresponding numerical calculation module is also a key problem that needs to be solved. Summary of the invention

[0009] In view of this, the embodiments of the present disclosure provide a deep shale gas multiphase heat-fluid-solid three-field coupled numerical simulation method and system to solve the problem in the prior art that it is impossible to construct an efficient and accurate numerical calculation model due to the high complexity of the heat-fluid-solid information of shale gas reservoirs.

[0010] In a first aspect of the embodiments of the present disclosure, a method for numerical simulation of multiphase thermal-fluid-solid three-field coupling of deep shale gas is provided, comprising:

[0011] Obtain reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area;

[0012] The reservoir parameters, basic fracture parameters and liquid property parameters are imported into a trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling a single-pore medium model, a dual-medium model, a nonlinear unsteady-state crossflow model and an embedded discrete fracture model.

[0013] In some embodiments, the step of obtaining the trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model comprises:

[0014] Set the mean stress to a preset value;

[0015] Based on the average stress of the time, according to the finite volume method, the seepage field equation and the temperature field equation are solved by fully implicit method to obtain the seepage-temperature coupling field distribution of the time;

[0016] Based on the current seepage-temperature coupling field distribution, the stress field equation is solved based on the finite element method to obtain the current displacement-stress strain result;

[0017] If the current seepage-temperature coupling field distribution and displacement-stress-strain results do not meet the preset requirements, the next average stress is calculated based on the current displacement-stress-strain results, and the process returns to execute the step of solving the seepage field equation and the temperature field equation by fully implicit method based on the current average stress according to the finite volume method until the current seepage-temperature coupling field distribution and displacement-stress-strain results meet the preset requirements;

[0018] Based on the seepage-temperature coupling field distribution that meets the preset requirements, the seepage field equation, temperature field equation, stress field equation and three-pore medium coupling model corresponding to the displacement-stress strain results, the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model is generated.

[0019] In some embodiments, according to the single-porous medium model, the dual-media model, the nonlinear unsteady crossflow model and the embedded discrete fracture model, the step of coupling to obtain the three-porous medium coupling model includes:

[0020] If calculating the material flow outside the fracturing zone, select the single-pore medium model for processing;

[0021] If calculating the material flow in the fracturing zone, when calculating the material flow between the bedrock and the fracture, the dual medium model is selected for processing;

[0022] If calculating the material flow between the inside and outside of the fracturing zone, select the nonlinear unsteady crossflow model;

[0023] If the material flow associated with large fractures in the fracturing stimulation area is calculated, the embedded discrete fracture model is selected.

[0024] In some embodiments, the meshing processing steps corresponding to the embedded discrete fracture model include:

[0025] Based on the reservoir parameters and the basic fracture parameters, a plurality of bedrock grids and a plurality of converted target fracture surface grids are generated;

[0026] Overlapping the bedrock grid and the target fracture surface grid, and determining the corresponding relationship between the center point of each fracture surface grid and the bedrock grid;

[0027] The corresponding relationship is added to a preset grid connection list to complete the grid division corresponding to the embedded discrete fracture model.

[0028] In some embodiments, the step of generating the fracture surface mesh comprises:

[0029] Performing three-dimensional crack mesh division on each of the multiple cracks corresponding to the basic crack parameters to obtain multiple basic three-dimensional crack meshes;

[0030] Performing intersection judgment on any two cracks among the plurality of cracks to obtain a plurality of intersection relationships;

[0031] The basic three-dimensional fracture mesh is processed based on the multiple intersection relationships to generate the fracture surface mesh.

[0032] In some embodiments, performing basic three-dimensional fracture meshing on each of the plurality of fractures corresponding to the fracture basic parameters to obtain a plurality of basic three-dimensional fracture meshes includes:

[0033] Obtain the three-dimensional crack surface corresponding to each crack;

[0034] Each three-dimensional crack surface is transformed to the left, ignoring the width of the crack, and converted into multiple two-dimensional crack surfaces;

[0035] Dividing the two-dimensional fracture surface into the plurality of two-dimensional fracture grids;

[0036] The coordinates of the multiple two-dimensional fracture grids are restored to obtain the multiple basic three-dimensional fracture grids.

[0037] In some embodiments, the performing intersection judgment on any two cracks among the plurality of cracks to obtain a plurality of intersection relationships includes:

[0038] Obtain any two uncompared cracks to be compared among the multiple cracks;

[0039] Determine a comparison plane where any of the to-be-compared fractures is located;

[0040] Determine whether another crack to be compared has an intersection with the comparison plane;

[0041] If there is an intersection, determine the coordinates of the intersection, and judge whether the coordinates of the intersection are within the range of the comparison plane;

[0042] Swapping the positions of the two cracks to be compared, and again performing the step of determining the comparison plane where any one of the two cracks to be compared is located, to obtain the number of intersections of the two cracks to be compared;

[0043] Determining the intersection relationship between the two cracks to be compared according to the number of intersection points;

[0044] Any two uncompared cracks among the multiple cracks are selected, and the step of determining the comparison plane where any of the cracks to be compared is located is returned to obtain the multiple intersection relationships.

[0045] In some embodiments, the step of determining whether the intersection coordinates are within the range of the comparison plane includes:

[0046] Connecting the intersection point with any two adjacent vertices of the comparison plane to form multiple angles;

[0047] If the sum of the multiple angles is 360, the intersection coordinates are within the range of the comparison plane;

[0048] Otherwise, the intersection coordinates are outside the range of the comparison plane.

[0049] In some embodiments, judging the intersection of the two cracks according to the number of intersection points includes:

[0050] If the number of intersection points is 0, it is judged that the two cracks do not intersect;

[0051] If the number of intersection points is 1, the two cracks are judged to be in contact and non-intersecting;

[0052] If the number of intersection points is 2, it means that two cracks intersect.

[0053] In some embodiments, the types of intersections between two cracks include a center intersection type and an edge intersection type, wherein the center intersection type divides the intersecting cracks into four sections, and the edge intersection type divides the intersecting cracks into two sections.

[0054] In some embodiments, determining the correspondence between the center point of each fracture surface grid and the bedrock grid includes:

[0055] If the center point of any fracture surface grid is located in one of the bedrock grids, it is determined that the fracture surface grid is completely located in the bedrock grid, and the corresponding relationship is obtained.

[0056] In some embodiments, the dual medium model is a matrix rock-microfracture dual-porosity medium non-steady-state crossflow model, wherein when the fracture unit is a square or a cube, the transition point position is 0.04L, wherein L represents the side length of the square or the cube.

[0057] A second aspect of the disclosed embodiment provides a deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation system, comprising:

[0058] An acquisition module is used to obtain reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area;

[0059] A generation module is used to import the reservoir parameters, basic fracture parameters and liquid property parameters into a trained deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling a single-pore medium model, a dual-medium model, a nonlinear unsteady-state crossflow model and an embedded discrete fracture model.

[0060] In some embodiments, according to the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, the step of coupling and solving the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model comprises:

[0061] Set the mean stress to a preset value;

[0062] Based on the average stress of the time, according to the finite volume method, the seepage field equation and the temperature field equation are solved by fully implicit method to obtain the seepage-temperature coupling field distribution of the time;

[0063] Based on the current seepage-temperature coupling field distribution, the stress field equation is solved based on the finite element method to obtain the current displacement-stress strain result;

[0064] If the current seepage-temperature coupling field distribution and displacement-stress-strain results do not meet the preset requirements, the next average stress is calculated based on the current displacement-stress-strain results, and the process returns to execute the step of solving the seepage field equation and the temperature field equation by fully implicit method based on the current average stress according to the finite volume method until the current seepage-temperature coupling field distribution and displacement-stress-strain results meet the preset requirements;

[0065] Based on the seepage-temperature coupling field distribution that meets the preset requirements, the seepage field equation, temperature field equation, stress field equation and three-pore medium coupling model corresponding to the displacement-stress strain results, the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model is generated.

[0066] In some embodiments, according to the single-porous medium model, the dual-media model, the nonlinear unsteady crossflow model and the embedded discrete fracture model, the step of coupling to obtain the three-porous medium coupling model includes:

[0067] If calculating the material flow outside the fracturing zone, select the single-pore medium model for processing;

[0068] If calculating the material flow in the fracturing zone, when calculating the material flow between the bedrock and the fracture, the dual medium model is selected for processing;

[0069] If calculating the material flow between the inside and outside of the fracturing zone, select the nonlinear unsteady crossflow model;

[0070] If the material flow associated with large fractures in the fracturing stimulation area is calculated, the embedded discrete fracture model is selected.

[0071] In some embodiments, the meshing processing steps corresponding to the embedded discrete fracture model include:

[0072] Based on the reservoir parameters and the basic fracture parameters, a plurality of bedrock grids and a plurality of converted target fracture surface grids are generated;

[0073] Overlapping the bedrock grid and the target fracture surface grid, and determining the corresponding relationship between the center point of each fracture surface grid and the bedrock grid;

[0074] The corresponding relationship is added to a preset grid connection list to complete the grid division corresponding to the embedded discrete fracture model.

[0075] In some embodiments, the step of generating the fracture surface mesh comprises:

[0076] Performing three-dimensional crack mesh division on each of the multiple cracks corresponding to the basic crack parameters to obtain multiple basic three-dimensional crack meshes;

[0077] Performing intersection judgment on any two cracks among the plurality of cracks to obtain a plurality of intersection relationships;

[0078] The basic three-dimensional fracture mesh is processed based on the multiple intersection relationships to generate the fracture surface mesh.

[0079] In some embodiments, performing basic three-dimensional fracture meshing on each of the plurality of fractures corresponding to the fracture basic parameters to obtain a plurality of basic three-dimensional fracture meshes includes:

[0080] Obtain the three-dimensional crack surface corresponding to each crack;

[0081] Each three-dimensional crack surface is transformed to the left, ignoring the width of the crack, and converted into multiple two-dimensional crack surfaces;

[0082] Dividing the two-dimensional fracture surface into the plurality of two-dimensional fracture grids;

[0083] The coordinates of the multiple two-dimensional fracture grids are restored to obtain the multiple basic three-dimensional fracture grids.

[0084] In some embodiments, the performing intersection judgment on any two cracks among the plurality of cracks to obtain a plurality of intersection relationships includes:

[0085] Obtain any two uncompared cracks to be compared among the multiple cracks;

[0086] Determine a comparison plane where any of the to-be-compared fractures is located;

[0087] Determine whether another crack to be compared has an intersection with the comparison plane;

[0088] If there is an intersection, determine the coordinates of the intersection, and judge whether the coordinates of the intersection are within the range of the comparison plane;

[0089] Swapping the positions of the two cracks to be compared, and again performing the step of determining the comparison plane where any one of the two cracks to be compared is located, to obtain the number of intersections of the two cracks to be compared;

[0090] Determining the intersection relationship between the two cracks to be compared according to the number of intersection points;

[0091] Any two uncompared cracks among the multiple cracks are selected, and the step of determining the comparison plane where any of the cracks to be compared is located is returned to obtain the multiple intersection relationships.

[0092] In some embodiments, the step of determining whether the intersection coordinates are within the range of the comparison plane includes:

[0093] Connecting the intersection point with any two adjacent vertices of the comparison plane to form multiple angles;

[0094] If the sum of the multiple angles is 360, the intersection coordinates are within the range of the comparison plane;

[0095] Otherwise, the intersection coordinates are outside the range of the comparison plane.

[0096] In some embodiments, judging the intersection of the two cracks according to the number of intersection points includes:

[0097] If the number of intersection points is 0, it is judged that the two cracks do not intersect;

[0098] If the number of intersection points is 1, the two cracks are judged to be in contact and non-intersecting;

[0099] If the number of intersection points is 2, it means that two cracks intersect.

[0100] In some embodiments, the types of intersections between two cracks include a center intersection type and an edge intersection type, wherein the center intersection type divides the intersecting cracks into four sections, and the edge intersection type divides the intersecting cracks into two sections.

[0101] In some embodiments, determining the correspondence between the center point of each fracture surface grid and the bedrock grid includes:

[0102] If the center point of any fracture surface grid is located in one of the bedrock grids, it is determined that the fracture surface grid is completely located in the bedrock grid, and the corresponding relationship is obtained.

[0103] In some embodiments, the dual medium model is a matrix rock-microfracture dual-porosity medium non-steady-state crossflow model, wherein when the fracture unit is a square or a cube, the transition point position is 0.04L, wherein L represents the side length of the square or the cube.

[0104] According to a third aspect of the embodiments of the present disclosure, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the steps implemented when the processor executes the computer program include:

[0105] In a fourth aspect of the embodiments of the present disclosure, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and the steps implemented when the computer program is executed by a processor include:

[0106] In a fifth aspect of the embodiments of the present disclosure, a computer program product is provided. The computer program product includes a computer program or an instruction. When the computer program or the instruction is executed by a processor, the steps implemented include:

[0107] By obtaining the reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area; importing the reservoir parameters, basic fracture parameters and liquid property parameters into the trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model to generate target dynamic simulation information, an efficient and accurate numerical calculation model can be constructed for the highly complex thermal-fluid-solid information of shale gas reservoirs to calculate and obtain accurate simulation data. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only for the embodiments, and ordinary technicians in this field can obtain other drawings based on these drawings without paying any creative work.

[0109] Figure 1 It is a schematic diagram of an application scenario of the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided by the embodiment of the present disclosure;

[0110] Figure 2It is a flow chart of some embodiments of a method for numerical simulation of multiphase thermal-fluid-solid three-field coupling of deep shale gas provided according to an embodiment of the present disclosure;

[0111] Figure 3 It is a schematic diagram of the mesh division of the fracture unit and the improved MINC model according to the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided by the embodiment of the present disclosure;

[0112] Figure 4 It is a schematic diagram of geometric coordinate transformation of fracture surface according to the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided by the embodiment of the present disclosure;

[0113] Figure 5 It is a schematic diagram of the steps for judging whether the intersection point is within the range of the fracture surface A according to another deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation method provided by an embodiment of the present disclosure;

[0114] Figure 6 It is a flow chart of two intersection situations of two fracture surfaces of another deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided according to an embodiment of the present disclosure;

[0115] Figure 7 It is a schematic diagram of an actual well group model of another deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided according to an embodiment of the present disclosure;

[0116] Figure 8 It is a schematic diagram of a fitted gas production curve of another deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation method provided according to an embodiment of the present disclosure;

[0117] Fig. 9 It is a schematic diagram of pressure distribution of an actual well group model according to another deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided by an embodiment of the present disclosure;

[0118] Fig.10 It is a schematic diagram of porosity distribution of an actual well group model according to another deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method provided by an embodiment of the present disclosure;

[0119] Fig.11 It is a flow chart of some other embodiments of another method for deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation provided according to the embodiments of the present disclosure;

[0120] Fig.12 It is a simplified structural schematic diagram of a deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation system provided according to an embodiment of the present disclosure;

[0121] Fig.13 is a schematic diagram of an electronic device provided according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0122] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0123] It should also be noted that, for ease of description, only the parts related to the present disclosure are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0124] It should be noted that the concepts such as "first" and "second" mentioned in this disclosure are only used to distinguish different systems, systems, modules or units, and are not used to limit the order or interdependence of the functions performed by these systems, systems, modules or units.

[0125] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0126] The names of the messages or information exchanged between multiple systems in the embodiments of the present disclosure are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0127] The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0128] Embodiment 1:

[0129] Figure 1 It is a schematic diagram of an application scenario of the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method according to the first embodiment of the present disclosure.

[0130] exist Figure 1 In the application scenario, first, the computing device 101 can obtain reservoir parameters 102, basic fracture parameters 103 and liquid property parameters 104 of the target deep shale gas reservoir area.

[0131] Secondly, the computing device 101 can import the reservoir parameters 102, the basic parameters of the fractures 103 and the liquid property parameters 104 into the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model 105 to generate target dynamic simulation information 106, wherein the deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model 105 is obtained by coupling and solving the seepage field equation 107, the temperature field equation 108, the stress field equation 109 and the three-pore medium coupling model 110, and the three-pore medium coupling model 110 is obtained by coupling the single-pore medium model 111, the dual-medium model 112, the nonlinear unsteady-state crossflow model 113 and the embedded discrete fracture model 114.

[0132] It should be noted that the computing device 101 can be hardware or software. When the computing device is hardware, it can be implemented as a distributed cluster consisting of multiple servers or terminal devices, or as a single server or a single terminal device. When the computing device is embodied as software, it can be installed in the hardware devices listed above. It can be implemented as multiple software or software modules for providing distributed services, or as a single software or software module. No specific limitation is made here.

[0133] It should be understood that Figure 1 The number of computing devices in the embodiment is only illustrative. Any number of computing devices may be provided according to implementation requirements.

[0134] Embodiment 2:

[0135] Continue to refer Figure 2 , showing the process 200 of the second embodiment of the deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation method according to the present disclosure. The method can be Figure 1 The method for deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation comprises the following steps:

[0136] Step 201, obtaining reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area.

[0137] In some optional implementations, the execution body of the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation method (such as Figure 1The computing device 101 shown in the figure can be connected to the target device by wired connection or wireless connection, and then the reservoir parameters, basic fracture parameters and liquid attribute parameters of the target deep shale gas reservoir area are obtained. The reservoir parameters, basic fracture parameters and liquid attribute parameters can refer to the commonly used parameters used in shale gas measurement. As an example, the reservoir parameters, basic fracture parameters and liquid attribute parameters can include the shale gas reservoir range, SRV (Stimulated Reservoir Volume, volume fracturing) area range, initial reservoir pressure, horizontal well length, bedrock inherent permeability, bottom hole pressure, reservoir temperature, bedrock density, bedrock porosity, Langmuir volume, Langmuir pressure, fracture porosity, fracture aperture, fracture permeability, fracture height, fracture half-length, stress sensitivity coefficient of fracture, number of fracturing stages, segment interval and fluid attribute parameters and other commonly used parameters in the field for subsequent calculations, but not limited thereto.

[0138] It should be noted that the above-mentioned wireless connection methods may include but are not limited to 3G / 4G / 5G connection, WiFi connection, Bluetooth connection, WiMAX connection, Zigbee connection, UWB (ultra wideband) connection, and other wireless connection methods currently known or developed in the future.

[0139] Step 202, importing the reservoir parameters, basic fracture parameters and liquid property parameters into the trained deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling the single-pore medium model, the dual-medium model, the nonlinear unsteady-state crossflow model and the embedded discrete fracture model.

[0140] In some embodiments, the above-mentioned execution subject may import the reservoir parameters, fracture basic parameters and liquid property parameters into a trained deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model to generate target dynamic simulation information. The target dynamic simulation information may refer to the relevant information predicted by the trained deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model. As an example, the target dynamic simulation information may include reservoir pressure, temperature distribution, daily gas production, cumulative daily gas production curve, etc., but is not limited thereto.

[0141] In some optional implementations of some embodiments, the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model can be obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model based on the following steps:

[0142] The first step is to set the average stress to a preset value. The deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model includes three variables: the average stress calculated based on the stress field equation, the seepage field calculated based on the seepage field equation, and the temperature field calculated based on the temperature field equation. When the average stress is fixed, the subsequent calculation of the seepage field and temperature field can be facilitated.

[0143] The second step is to solve the seepage field equation and the temperature field equation based on the average stress of the time and according to the finite volume method, using a fully implicit method to obtain the seepage-temperature coupling field distribution of the time. Fully implicit method can refer to a method of combining the seepage field equation and the temperature field equation for calculation. The seepage-temperature coupling field can refer to the comprehensive field information distribution obtained by coupling the seepage field and the temperature field. The finite volume method and the finite element method are commonly used calculation methods in this field and will not be described in detail here.

[0144] The third step is to solve the stress field equation based on the current seepage-temperature coupling field distribution and the finite element method to obtain the current displacement-stress-strain results. The displacement-stress-strain results may refer to stress-related and displacement-related data calculated by the stress field equation.

[0145] The fourth step is to calculate the rock porosity parameters based on the displacement-stress-strain results of the current time.

[0146] The fifth step is, if the current seepage-temperature coupling field distribution and displacement-stress-strain results do not meet the preset requirements, the next average stress is calculated based on the current displacement-stress-strain results, and the step of using the finite volume method to solve the seepage field equation and the temperature field equation in a fully implicit manner based on the current average stress is returned to execute, until the current seepage-temperature coupling field distribution and displacement-stress-strain results meet the preset requirements. The preset requirements may refer to the set data range that meets the requirements for the seepage-temperature coupling field distribution and displacement-stress-strain results set according to actual conditions. The preset requirements often correspond to specific projects, and their specific values ​​are set according to needs.

[0147] The sixth step is to generate the trained deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model based on the seepage-temperature coupled field distribution and the displacement-stress-strain results corresponding to the seepage field equation, temperature field equation, stress field equation and three-porous medium coupled model that meet the preset requirements. When the seepage-temperature coupled field distribution and displacement-stress-strain results meet the requirements, it means that the relevant parameters of the current seepage field equation, temperature field equation, stress field equation and three-porous medium coupled model are optimal, and the above equations can be coupled to obtain the trained deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model.

[0148] In some optional implementations of some embodiments, according to the single-pore medium model, the dual-media model, the nonlinear unsteady-state crossflow model and the embedded discrete fracture model, the step of coupling to obtain the three-pore medium coupling model includes: if the material flow outside the fracturing transformation area is calculated, the single-pore medium model is selected for processing; if the material flow within the fracturing transformation area is calculated, when calculating the material flow between bedrock and fractures, the dual-media model is selected for processing; if the material flow between inside and outside the fracturing transformation area is calculated, the nonlinear unsteady-state crossflow model is selected; if the material flow related to large fractures in the fracturing transformation area is calculated, the embedded discrete fracture model is selected.

[0149] In some optional implementations of some embodiments, the dual medium model can be set as a matrix rock block-microcrack dual-porosity medium unsteady-state crossflow model. The matrix rock block-microcrack dual-porosity medium unsteady-state crossflow model can be improved based on the division method of the nested grid of the MINC (Multiple INteracting Continua) model to calculate the unsteady crossflow between the low-permeability bedrock and the cracks. The specific improvement steps are as follows:

[0150] (1) According to the distribution of cracks, determine the geometry and size of the crack unit (the main parameters are the crack spacing Lx, Ly, Lz and the crack opening Df). It can be assumed that all crack units are the same, so only one crack unit needs to be selected for study. Figure 3 The fracture unit under the condition of regular distribution of two-dimensional fractures is given (where Figure 3 a represents the crack distribution, Figure 3 b represents the crack unit, Figure 3 c represents the mesh division outside the conversion point, Figure 3 d represents the grid division within the conversion point. The conversion point may refer to the proportional point in the MINC model where the grid is divided into inner grid and outer grid according to different division shapes. The following steps are described using this regular unit as an example.

[0151] (2) According to the geometric shape and size of the crack unit, the position of the grid conversion point in the unit is calculated, such as Figure 3 (b) is shown. Which position is the conversion point is the problem that needs to be solved in the improved MINC model. Combined with the change process of the pressure field in the unit, it can be seen that the position of the conversion point is only related to the unit shape. Therefore, we determine the position of the conversion point through numerical experiments: Assuming that the distance between the conversion point and the fracture boundary is D, the cumulative production under different D conditions is calculated, and the average error between it and the reference solution is calculated. The results show that for square and cubic fracture units, when D = 0.04L, the error is the smallest, so D = 0.04L is selected to determine the corresponding parameters of this model. Therefore, the conversion point position of the improved MINC model in this paper is D = 0.04L.

[0152] (3) The MINC model is used to perform regular nested grid division between the crack and the grid transition point, and the volume Vi of each nested grid, the flow distance dij between the nested grids, and the flow area Aij (i, j are both positive integers, indicating the number, such as Figure 3 shown);

[0153] (4) Divide the isobaric nested grid inside the conversion point (with the isobars as the grid boundaries), such as Figure 3 As shown in (d), the volume Vi of each isobaric nested grid and the ratio of the flow area to the flow distance between the nested grids Aij / dij are calculated. Here, the calculation of the isobaric nested grids and unit parameters adopts the multiple sub-region method, as shown in Figure 3 .

[0154] After the above steps, the improved matrix rock-microfracture dual-porosity medium unsteady crossflow model can be obtained.

[0155] In some optional implementations of some embodiments, the processing step of meshing corresponding to the embedded discrete fracture model includes: generating multiple bedrock meshes and multiple converted target fracture surface meshes based on the reservoir parameters and the basic fracture parameters; overlapping the bedrock meshes and the target fracture surface meshes, determining the correspondence between the center point of each fracture surface mesh and the bedrock mesh; adding the correspondence to a preset mesh connection list to complete the meshing corresponding to the embedded discrete fracture model. The mesh connection list may refer to a preset data table for storing the correspondence between the center point of each fracture surface mesh and the bedrock mesh.

[0156] In some optional implementations of some embodiments, determining the correspondence between the center point of each fracture surface mesh and the bedrock mesh includes: if the center point of any fracture surface mesh is located within one of the bedrock meshes, determining that the fracture surface mesh is completely located within the bedrock mesh, and obtaining the correspondence.

[0157] In some optional implementations of some embodiments, the step of generating the fracture surface mesh includes: performing three-dimensional fracture meshing on each of the multiple fractures corresponding to the fracture basic parameters to obtain multiple basic three-dimensional fracture meshes; performing intersection judgment on any two fractures among the multiple fractures to obtain multiple intersection relationships; processing the basic three-dimensional fracture meshes based on the multiple intersection relationships to generate the fracture surface mesh, such as Figure 4 shown.

[0158] In some optional implementations of some embodiments, the basic three-dimensional crack meshing is performed on each of the multiple cracks corresponding to the basic parameters of the crack to obtain multiple basic three-dimensional crack meshes, including: obtaining the three-dimensional crack surface corresponding to each crack; performing a left-side transformation on each three-dimensional crack surface, ignoring the width of the crack, and converting it into multiple two-dimensional crack surfaces; dividing the two-dimensional crack surface into the multiple two-dimensional crack meshes; and restoring the coordinates of the multiple two-dimensional crack meshes to obtain the multiple basic three-dimensional crack meshes. The left-side transformation can also be called Park's Transformation, which is a commonly used coordinate transformation calculation formula. In the present disclosure, the transformation is performed by ignoring the width of the crack. By restoring it to a three-dimensional crack mesh again after the left-side transformation, the two-dimensional crack mesh can be unified and the processing complexity can be reduced.

[0159] In some optional implementations of some embodiments, the intersection judgment of any two cracks among the multiple cracks to obtain multiple intersection relationships includes: obtaining any two cracks to be compared that have not been compared among the multiple cracks; determining the comparison plane where any one of the cracks to be compared is located; judging whether another crack to be compared has an intersection with the comparison plane; if there is an intersection, determining the coordinates of the intersection, and judging whether the coordinates of the intersection are within the range of the comparison plane; swapping the positions of the two cracks to be compared, and again executing the step of determining the comparison plane where any one of the two cracks to be compared is located, to obtain the number of intersections of the two cracks to be compared; judging the intersection relationship of the two cracks to be compared according to the number of intersections; taking any two cracks to be compared that have not been compared among the multiple cracks, and returning to execute the step of determining the comparison plane where any one of the cracks to be compared is located, to obtain the multiple intersection relationships.

[0160] In some optional implementations of some embodiments, the step of determining whether the intersection coordinates are within the range of the comparison plane includes: connecting the intersection with any two adjacent vertices of the comparison plane to form multiple angles; if the sum of the multiple angles is 360°, the intersection coordinates are within the range of the comparison plane; otherwise, the intersection coordinates are outside the range of the comparison plane. Obviously, when the sum of the angles formed by multiple adjacent vertices is 360°, it means that the multiple points are in the same plane, otherwise, they are not in the same plane, such as Figure 5 shown.

[0161] In some optional implementations of some embodiments, determining the intersection of the two cracks based on the number of intersection points includes: if the number of intersection points is 0, determining that the two cracks do not intersect; if the number of intersection points is 1, determining that the two cracks are in point contact and do not intersect; if the number of intersection points is 2, indicating that the two cracks intersect.

[0162] In some optional implementations of some embodiments, the type of intersection of two cracks includes a center intersection type (such as Figure 6 ) and edge intersection types (such as Figure 6 ), wherein the center intersection type divides the intersecting cracks into 4 sections, and the edge intersection type divides the intersecting cracks into 2 sections.

[0163] By obtaining the reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area; importing the reservoir parameters, basic fracture parameters and liquid property parameters into the trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model to generate target dynamic simulation information, an efficient and accurate numerical calculation model can be constructed for the highly complex thermal-fluid-solid information of shale gas reservoirs to calculate and obtain accurate simulation data.

[0164] The present disclosure is further explained below by the implementation effect of a specific embodiment:

[0165] Based on reservoir parameters, basic fracture parameters and fluid property parameters, including shale gas reservoir range, SRV (Stimulated Reservoir Volume, volume fracturing) zone range, initial reservoir pressure, horizontal well length, bedrock intrinsic permeability, bottom hole pressure, reservoir temperature, bedrock density, bedrock porosity, Langmuir volume, Langmuir pressure, fracture porosity, fracture aperture, fracture permeability, fracture height, fracture half-length, fracture stress sensitivity coefficient, number of fracturing stages, stage interval and fluid property parameters, combined with the deep shale gas reservoir thermal fluid-solid coupling numerical simulation method generated in the above steps, the dynamic simulation of horizontal well fracturing production in deep shale gas reservoirs is carried out, and the influence of different multi-field coupling parameters and fracturing parameters on production capacity is studied. Output the fluid-solid coupling numerical simulation results, including reservoir pressure, temperature distribution, daily gas production, and cumulative daily gas production curve.

[0166] Preferably, in this embodiment, the thermal-fluid-solid coupling numerical simulation method and system for deep shale gas reservoirs are applied to the XX platform in the XX block. The geological parameters of the platform are shown in Tables 1 and 2. Combined with the deployment information of the platform well group, as shown in Figure 7 Through the dynamic simulation of horizontal well fracturing, the corresponding gas production curve was drawn, and it was fitted with the actual production data on site and the subsequent production capacity prediction was carried out. The production results are as follows Figure 8As shown (the production data of Jiaoye 48-3HF is the current actual production data), the final predicted pressure distribution diagram is as follows Fig. 9 The actual well group porosity distribution is shown in Fig.10 shown.

[0167]

[0168]

[0169] Table 1 Gas reservoir model parameters

[0170] Basic parameters value Shale gas reservoir range (m) 2600×2600×380 SRV area range (m) 1600×900×40 Initial reservoir pressure (MPa) 30 Horizontal well length (m) 1500 Intrinsic permeability of bedrock (mD) 5E-5 Bottom hole pressure (MPa) 5 Reservoir temperature (Celsius) 95 Bedrock density (kg / m3) 2850 Langmuir volume (m3 / kg) 0.01241 Langmuir pressure (MPa) 10.77

[0171] Table 2 Crack foundation parameters

[0172] Embodiment three:

[0173] Continue to refer Fig.11 , showing the process 300 of the third embodiment of the method for numerical simulation of deep shale gas multiphase thermal-fluid-solid three-field coupling according to the present disclosure, the method can be Figure 1 The deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation method includes:

[0174] Step 301, obtaining reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area.

[0175] Step 302, import the reservoir parameters, basic fracture parameters and liquid property parameters into the trained deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-porous medium coupling model, and the three-porous medium coupling model is obtained by coupling the single-porous medium model, the dual-medium model, the nonlinear unsteady-state cross-flow model and the embedded discrete fracture model. The steps of obtaining the trained deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation model by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-porous medium coupling model include:

[0176] Step 303, setting the average stress to a preset value.

[0177] Step 304, based on the average stress of the time, according to the finite volume method, the seepage field equation and the temperature field equation are solved by fully implicit method to obtain the seepage-temperature coupling field distribution of the time.

[0178] Step 305, based on the current seepage-temperature coupling field distribution, the stress field equation is solved based on the finite element method to obtain the current displacement-stress strain result.

[0179] Step 306, if the current seepage-temperature coupling field distribution and displacement-stress-strain results do not meet the preset requirements, calculate the next average stress based on the current displacement-stress-strain results, and return to execute the step of solving the seepage field equation and the temperature field equation based on the current average stress according to the finite volume method using a fully implicit method until the current seepage-temperature coupling field distribution and displacement-stress-strain results meet the preset requirements.

[0180] Step 307, based on the seepage-temperature coupling field distribution that meets the preset requirements, the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model corresponding to the displacement-stress-strain results, the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model is generated.

[0181] In some optional implementations, the specific implementation of steps 301-307 and the technical effects brought about can be referred to Figure 2 The corresponding steps in the second embodiment are not described again here.

[0182] All the above optional technical solutions can be combined in any way to form optional implementation methods of the present application, and will not be described in detail here.

[0183] Embodiment 4:

[0184] The following are system embodiments of the present disclosure, which can be used to execute the method embodiments of the present disclosure. For details not disclosed in the system embodiments of the present disclosure, please refer to the method embodiments of the present disclosure.

[0185] Further references Fig.12 As an implementation of the above methods in the above figures, the present disclosure provides an embodiment of a deep shale gas multiphase thermal fluid-solid three-field coupled numerical simulation system. Figure 2 The above-mentioned embodiment 2 corresponds.

[0186] like Fig.12 As shown, the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation system 400 of this embodiment includes:

[0187] The acquisition module 401 is used to acquire reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area.

[0188] The generation module 402 is used to import the reservoir parameters, basic fracture parameters and liquid property parameters into the trained deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling the single-pore medium model, the dual-medium model, the nonlinear unsteady-state crossflow model and the embedded discrete fracture model.

[0189] In some optional implementations of some embodiments, the step of coupling and solving the trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model according to the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model includes:

[0190] Set the mean stress to a preset value;

[0191] Based on the average stress of the time, according to the finite volume method, the seepage field equation and the temperature field equation are solved by fully implicit method to obtain the seepage-temperature coupling field distribution of the time;

[0192] Based on the current seepage-temperature coupling field distribution, the stress field equation is solved based on the finite element method to obtain the current displacement-stress strain result;

[0193] If the current seepage-temperature coupling field distribution and displacement-stress-strain results do not meet the preset requirements, the next average stress is calculated based on the current displacement-stress-strain results, and the process returns to execute the step of solving the seepage field equation and the temperature field equation by fully implicit method based on the current average stress according to the finite volume method until the current seepage-temperature coupling field distribution and displacement-stress-strain results meet the preset requirements;

[0194] Based on the seepage-temperature coupling field distribution that meets the preset requirements, the seepage field equation, temperature field equation, stress field equation and three-pore medium coupling model corresponding to the displacement-stress strain results, the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model is generated.

[0195] In some optional implementations of some embodiments, according to the single-porous medium model, the dual-media model, the nonlinear unsteady crossflow model and the embedded discrete fracture model, the step of coupling to obtain the three-porous medium coupling model includes:

[0196] If calculating the material flow outside the fracturing zone, select the single-pore medium model for processing;

[0197] If calculating the material flow in the fracturing zone, when calculating the material flow between the bedrock and the fracture, the dual medium model is selected for processing;

[0198] If calculating the material flow between the inside and outside of the fracturing zone, select the nonlinear unsteady crossflow model;

[0199] If the material flow associated with large fractures in the fracturing stimulation area is calculated, the embedded discrete fracture model is selected.

[0200] In some optional implementations of some embodiments, the processing step of meshing corresponding to the embedded discrete fracture model includes:

[0201] Based on the reservoir parameters and the basic fracture parameters, a plurality of bedrock grids and a plurality of converted target fracture surface grids are generated;

[0202] Overlapping the bedrock grid and the target fracture surface grid, and determining the corresponding relationship between the center point of each fracture surface grid and the bedrock grid;

[0203] The corresponding relationship is added to a preset grid connection list to complete the grid division corresponding to the embedded discrete fracture model.

[0204] In some optional implementations of some embodiments, the step of generating the fracture surface mesh includes:

[0205] Performing three-dimensional crack mesh division on each of the multiple cracks corresponding to the basic crack parameters to obtain multiple basic three-dimensional crack meshes;

[0206] Performing intersection judgment on any two cracks among the plurality of cracks to obtain a plurality of intersection relationships;

[0207] The basic three-dimensional fracture mesh is processed based on the multiple intersection relationships to generate the fracture surface mesh.

[0208] In some optional implementations of some embodiments, performing basic three-dimensional fracture meshing on each of the multiple fractures corresponding to the basic fracture parameters to obtain multiple basic three-dimensional fracture meshes includes:

[0209] Obtain the three-dimensional crack surface corresponding to each crack;

[0210] Each three-dimensional crack surface is transformed to the left, ignoring the width of the crack, and converted into multiple two-dimensional crack surfaces;

[0211] Dividing the two-dimensional fracture surface into the plurality of two-dimensional fracture grids;

[0212] The coordinates of the multiple two-dimensional fracture grids are restored to obtain the multiple basic three-dimensional fracture grids.

[0213] In some optional implementations of some embodiments, the performing intersection judgment on any two cracks among the multiple cracks to obtain multiple intersection relationships includes:

[0214] Obtain any two uncompared cracks to be compared among the multiple cracks;

[0215] Determine a comparison plane where any of the to-be-compared fractures is located;

[0216] Determine whether another crack to be compared has an intersection with the comparison plane;

[0217] If there is an intersection, determine the coordinates of the intersection, and judge whether the coordinates of the intersection are within the range of the comparison plane;

[0218] Swapping the positions of the two cracks to be compared, and again performing the step of determining the comparison plane where any one of the two cracks to be compared is located, to obtain the number of intersections of the two cracks to be compared;

[0219] Determining the intersection relationship between the two cracks to be compared according to the number of intersection points;

[0220] Any two uncompared cracks among the multiple cracks are selected, and the step of determining the comparison plane where any of the cracks to be compared is located is returned to obtain the multiple intersection relationships.

[0221] In some optional implementations of some embodiments, the step of determining whether the intersection coordinates are within the range of the comparison plane includes:

[0222] Connecting the intersection point with any two adjacent vertices of the comparison plane to form multiple angles;

[0223] If the sum of the multiple angles is 360, the intersection coordinates are within the range of the comparison plane;

[0224] Otherwise, the intersection coordinates are outside the range of the comparison plane.

[0225] In some optional implementations of some embodiments, judging the intersection of the two cracks according to the number of intersection points includes:

[0226] If the number of intersection points is 0, it is judged that the two cracks do not intersect;

[0227] If the number of intersection points is 1, the two cracks are judged to be in contact and non-intersecting;

[0228] If the number of intersection points is 2, it means that two cracks intersect.

[0229] In some optional implementations of some embodiments, the type of intersection of two cracks includes a center intersection type and an edge intersection type, wherein the center intersection type divides the intersecting cracks into 4 sections, and the edge intersection type divides the intersecting cracks into 2 sections.

[0230] In some optional implementations of some embodiments, determining the correspondence between the center point of each fracture surface grid and the bedrock grid includes:

[0231] If the center point of any fracture surface grid is located in one of the bedrock grids, it is determined that the fracture surface grid is completely located in the bedrock grid, and the corresponding relationship is obtained.

[0232] In some optional implementations of some embodiments, the dual medium model is a matrix rock-microfracture dual-porosity medium non-steady-state crossflow model, wherein, when the fracture unit is a square or a cube, the transition point position is 0.04L, wherein L represents the side length of the square or the cube.

[0233] It is understood that the modules described in the system 400 are similar to those described in the reference Figure 2 Therefore, the operations, features and beneficial effects described above for the method are also applicable to the system 400 and the modules included therein, and will not be described in detail here.

[0234] Embodiment five:

[0235] like Fig.13 As shown, the electronic device 500 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage device 508 into a random access memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the electronic device 500 are also stored. The processing device 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0236] Typically, the following devices may be connected to the I / O interface 505: an input device 506 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 507 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 508 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 509. The communication device 509 may allow the electronic device 500 to communicate with other devices wirelessly or by wire to exchange data. Although Fig.13 The electronic device 500 is shown with various devices, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead. Fig.13 Each block shown in the figure may represent one device, or may represent multiple devices as required.

[0237] In particular, according to the present embodiment, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the present embodiment includes a computer program product, which includes a computer program or instruction carried on a computer readable medium, and the computer program or instruction contains a program code for executing the method shown in the flowchart. In the present embodiment, the computer program can be downloaded and installed from the network through the communication device 509, or installed from the storage device 508, or installed from the ROM 502. When the computer program is executed by the processing device 501, the following steps can be performed: obtaining reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area; importing the reservoir parameters, basic fracture parameters and liquid property parameters into a trained deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling a single-pore medium model, a dual-medium model, a nonlinear unsteady-state crossflow model and an embedded discrete fracture model.

[0238] It should be noted that the computer-readable medium in the present embodiment may be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device. In the present embodiment, the computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer readable signal medium may also be any computer readable medium other than a computer readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0239] In some embodiments, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (HyperText Transfer Protocol), and may be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an ad hoc peer-to-peer network), as well as any currently known or future developed network.

[0240] The computer-readable medium may be included in the device; or it may exist independently without being assembled into the electronic device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device performs the following steps: obtaining reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area; importing the reservoir parameters, basic fracture parameters and liquid property parameters into the trained deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling the single-pore medium model, the dual medium model, the nonlinear unsteady crossflow model and the embedded discrete fracture model.

[0241] The computer program code for performing the operation of the present embodiment can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., using an Internet service provider to connect through the Internet).

[0242] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0243] The modules described in this embodiment may be implemented by software or hardware. The modules described may also be set in a processor, for example, may be described as:

[0244] Acquisition module and generation module. For example, the acquisition module can also be described as "a module for acquiring reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area".

[0245] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0246] The above descriptions are only some preferred embodiments of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the embodiments of the present disclosure (but not limited to) and the technical solutions formed.

Claims

1. A method for numerical simulation of multiphase thermal-fluid-solid three-field coupling of deep shale gas, characterized in that: include: Obtain reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area; The reservoir parameters, basic fracture parameters and liquid property parameters are imported into a trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling a single-pore medium model, a dual-medium model, a nonlinear unsteady-state crossflow model and an embedded discrete fracture model.

2. The method according to claim 1, characterized in that The steps of obtaining the trained deep shale gas multiphase thermal-fluid-solid three-field coupled numerical simulation model by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model include: Set the mean stress to a preset value; Based on the average stress of the time, according to the finite volume method, the seepage field equation and the temperature field equation are solved by fully implicit method to obtain the seepage-temperature coupling field distribution of the time; Based on the current seepage-temperature coupling field distribution, the stress field equation is solved based on the finite element method to obtain the current displacement-stress strain result; If the current seepage-temperature coupling field distribution and displacement-stress-strain results do not meet the preset requirements, the next average stress is calculated based on the current displacement-stress-strain results, and the process returns to execute the step of solving the seepage field equation and the temperature field equation by fully implicit method based on the current average stress according to the finite volume method until the current seepage-temperature coupling field distribution and displacement-stress-strain results meet the preset requirements; Based on the seepage-temperature coupling field distribution that meets the preset requirements, the seepage field equation, temperature field equation, stress field equation and three-pore medium coupling model corresponding to the displacement-stress strain results, the trained deep shale gas multiphase thermal-fluid-solid three-field coupling numerical simulation model is generated.

3. The method according to claim 1, characterized in that According to the single-pore medium model, the dual-pore medium model, the nonlinear unsteady-state crossflow model and the embedded discrete fracture model, the step of coupling to obtain the three-pore medium coupling model includes: If calculating the material flow outside the fracturing zone, select the single-pore medium model for processing; If calculating the material flow in the fracturing zone, when calculating the material flow between the bedrock and the fracture, the dual medium model is selected for processing; If calculating the material flow between the inside and outside of the fracturing zone, select the nonlinear unsteady crossflow model; If the material flow associated with large fractures in the fracturing stimulation area is calculated, the embedded discrete fracture model is selected.

4. The method according to claim 3, characterized in that The processing steps of meshing corresponding to the embedded discrete fracture model include: Based on the reservoir parameters and the basic fracture parameters, a plurality of bedrock grids and a plurality of converted target fracture surface grids are generated; Overlapping the bedrock grid and the target fracture surface grid, and determining the corresponding relationship between the center point of each fracture surface grid and the bedrock grid; The corresponding relationship is added to a preset grid connection list to complete the grid division corresponding to the embedded discrete fracture model.

5. The method according to claim 4, characterized in that The step of generating the fracture surface mesh comprises: Performing three-dimensional crack mesh division on each of the multiple cracks corresponding to the basic crack parameters to obtain multiple basic three-dimensional crack meshes; Performing intersection judgment on any two cracks among the plurality of cracks to obtain a plurality of intersection relationships; The basic three-dimensional fracture mesh is processed based on the multiple intersection relationships to generate the fracture surface mesh.

6. The method according to claim 5, characterized in that The step of performing basic three-dimensional crack meshing on each of the multiple cracks corresponding to the basic crack parameters to obtain multiple basic three-dimensional crack meshes includes: Obtain the three-dimensional crack surface corresponding to each crack; Each three-dimensional crack surface is transformed to the left, ignoring the width of the crack, and converted into multiple two-dimensional crack surfaces; Dividing the two-dimensional fracture surface into the plurality of two-dimensional fracture grids; The coordinates of the multiple two-dimensional fracture grids are restored to obtain the multiple basic three-dimensional fracture grids.

7. The method according to claim 5, characterized in that The step of determining the intersection of any two cracks among the plurality of cracks to obtain a plurality of intersection relationships includes: Obtain any two uncompared cracks to be compared among the multiple cracks; Determine a comparison plane where any of the to-be-compared fractures is located; Determine whether another crack to be compared has an intersection with the comparison plane; If there is an intersection, determine the coordinates of the intersection, and judge whether the coordinates of the intersection are within the range of the comparison plane; Swapping the positions of the two cracks to be compared, and again performing the step of determining the comparison plane where any one of the two cracks to be compared is located, to obtain the number of intersections of the two cracks to be compared; Determining the intersection relationship between the two cracks to be compared according to the number of intersection points; Any two uncompared cracks among the multiple cracks are selected, and the step of determining the comparison plane where any of the cracks to be compared is located is returned to obtain the multiple intersection relationships.

8. The method according to claim 7, characterized in that The step of judging whether the intersection coordinates are within the range of the comparison plane comprises: Connecting the intersection point with any two adjacent vertices of the comparison plane to form multiple angles; If the sum of the multiple angles is 360, the intersection coordinates are within the range of the comparison plane; Otherwise, the intersection coordinates are outside the range of the comparison plane.

9. The method according to claim 7, characterized in that: The step of judging the intersection of the two cracks according to the number of intersection points includes: If the number of intersection points is 0, it is judged that the two cracks do not intersect; If the number of intersection points is 1, the two cracks are judged to be in contact and non-intersecting; If the number of intersection points is 2, it means that two cracks intersect.

10. The method according to claim 9, characterized in that The types of intersections between two cracks include a center intersection type and an edge intersection type, wherein the center intersection type divides the intersecting cracks into four sections, and the edge intersection type divides the intersecting cracks into two sections.

11. The method according to claim 4, characterized in that The determining of the correspondence between the center point of each fracture surface grid and the bedrock grid includes: If the center point of any fracture surface grid is located in one of the bedrock grids, it is determined that the fracture surface grid is completely located in the bedrock grid, and the corresponding relationship is obtained.

12. The method according to claim 4, characterized in that The dual medium model is a matrix rock-microfracture dual-porosity medium unsteady-state crossflow model, wherein when the fracture unit is a square or a cube, the switching point position is 0.04L, wherein L represents the side length of the square or the cube.

13. A deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation system, characterized in that: include: An acquisition module is used to obtain reservoir parameters, basic fracture parameters and liquid property parameters of the target deep shale gas reservoir area; A generation module is used to import the reservoir parameters, basic fracture parameters and liquid property parameters into a trained deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model to generate target dynamic simulation information, wherein the deep shale gas multiphase thermal fluid-solid three-field coupling numerical simulation model is obtained by coupling and solving the seepage field equation, the temperature field equation, the stress field equation and the three-pore medium coupling model, and the three-pore medium coupling model is obtained by coupling a single-pore medium model, a dual-medium model, a nonlinear unsteady-state crossflow model and an embedded discrete fracture model.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 11 are implemented.

15. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 11 are implemented.

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