Glutenite hydraulic fracturing analogue simulation method, equipment and medium
By constructing a sand conglomerate model and imparting cohesive units with different mechanical properties to simulate the hydraulic fracturing of conglomerate, the problem of inaccurate crack morphology prediction in the existing technology is solved, and more accurate crack simulation is achieved to support reservoir development.
Patent Information
- Application Number
- CN202510325407.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2025-07-04
AI Technical Summary
In the process of simulating the hydraulic fracturing of gravel, the prior art failed to accurately simulate the impact of gravel, resulting in inaccurate prediction of fracture morphology and difficult to effectively guide reservoir development.
A gravel model was constructed, and a cohesive unit was inserted to impart different mechanical properties to the gravel body, matrix and cementing surface. Hydraulic fracturing simulation was carried out through finite element analysis software to accurately simulate crack expansion.
The accuracy of hydraulic fracture simulation of conglomerate is improved, and more accurate fracture morphology and expansion laws are provided, providing a scientific basis for reservoir mining.
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Figure CN120257880A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of hydraulic fracturing, and in particular to a method, equipment and medium for simulating hydraulic fracturing of gravel. Background Art
[0002] Tight sandstone oil and gas reservoirs are one of the most important unconventional energy sources, which are mainly sandstone and conglomerate reservoirs. Hydraulic fracturing technology is an important technical means for the development of conglomerate reservoirs. However, during the hydraulic fracturing process, due to the clear distribution of gravel particles in conglomerate, it has strong heterogeneity, which will cause the propagation path of the cracks to change and form more complex hydraulic fractures. This makes it more difficult to predict the morphology of hydraulic fractures in conglomerate. The extension and distribution morphology of hydraulic fractures are important indicators for evaluating the effect of fracturing and are of great significance for the development of oil and gas reservoirs. Therefore, clarifying the expansion law of hydraulic fractures in conglomerate and the interaction mechanism between hydraulic fractures and gravel is of great significance for promoting the exploitation of conglomerate oil and gas reservoirs.
[0003] Although existing studies have explored the fracture propagation mechanism and laws of sandstone hydraulic fracturing from different aspects, the lack of accurate simulation of sandstone structure (e.g., setting gravel as non-crackable or ignoring the influence of cementation surface during simulation) will reduce the accuracy of hydraulic fracture geometry prediction. Summary of the invention
[0004] The purpose of this application is to provide a method, device and medium for simulating hydraulic fracturing of conglomerate, which can improve the accuracy of simulating hydraulic fractures in conglomerate.
[0005] To achieve the above objectives, this application provides the following solutions:
[0006] In a first aspect, the present application provides a sandstone hydraulic fracturing simulation method, comprising:
[0007] Constructing a sandstone conglomerate model; the sandstone conglomerate model includes a sandstone entity, a matrix and a cementation surface;
[0008] Inserting a cohesive force unit globally into the gravel rock model to apply different mechanical properties to the gravel entity, the matrix and the cementation surface, so as to obtain a simulated gravel rock model to be used; the thickness of the cohesive force unit is zero;
[0009] Assigning mechanical property parameters to the simulated conglomerate model to be used, so as to obtain a numerical conglomerate model to be used;
[0010] The standby numerical conglomerate model is used to perform hydraulic fracturing simulation in a preset hydraulic fracturing simulation environment to obtain a conglomerate hydraulic fracturing simulation result.
[0011] In a second aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the sandstone hydraulic fracturing simulation method.
[0012] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the sandstone hydraulic fracturing simulation method when executed by a processor.
[0013] According to the specific embodiments provided by the present application, the present application has the following technical effects: the present application provides a method, device and medium for simulating hydraulic fracturing of conglomerate. During the simulation process, a cohesive unit with a thickness of zero is globally inserted into the conglomerate model to apply different mechanical properties to the three items of the gravel entity, matrix and cementation surface, respectively, to obtain a simulated conglomerate model to be used. The model can realize the heterogeneity of conglomerate through the above processing, which is more in line with the actual scene and provides more accurate basic data for subsequent simulation. Then, the mechanical property parameters of the simulated conglomerate model to be used are assigned, and hydraulic fracturing simulation is performed in a preset hydraulic fracturing simulation environment to obtain more accurate simulation results of hydraulic fracturing of conglomerate, thereby improving the accuracy of the simulation of hydraulic fractures in conglomerate, and providing a basis for the effective exploitation of conglomerate reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0015] Figure 1 This is a diagram of the application environment of a sandstone hydraulic fracturing simulation method in one embodiment of the present application.
[0016] Figure 2 A schematic diagram of the flow chart of a sandstone hydraulic fracturing simulation method provided in one embodiment of the present application.
[0017] Figure 3 This is a flowchart for inserting a six-node pore pressure cohesive force unit in one embodiment of the present application.
[0018] Figure 4 This is a schematic diagram of the COH2D4 principle in one embodiment of the present application.
[0019] Figure 5 Schematic diagram of the cohesion model of the sandstone reservoir in one embodiment of the present application.
[0020] Figure 6 Schematic diagram of the flow of fracturing fluid in a hydraulic fracture in one embodiment of the present application.
[0021] Figure 7 It is a schematic diagram of a hydraulic fracture image in one embodiment of the present application.
[0022] Figure 8 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION
[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0024] The present application provides a method, equipment and medium for simulating hydraulic fracturing of conglomerate, which takes into account heterogeneity, can accurately characterize the initiation and expansion mechanism of hydraulic fractures at a microscopic scale, accurately capture the macroscopic distribution morphology of hydraulic fractures, and provide a basis for the effective exploitation of conglomerate reservoirs.
[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0026] The sandstone hydraulic fracturing simulation method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the gravel model to the server 104. After receiving it, the server 104 globally inserts the cohesive force unit into the gravel model to apply different mechanical properties to the gravel entity, matrix and cementation surface to obtain a simulated gravel model to be used, and then assign mechanical property parameters to the simulated gravel model to be used, and perform hydraulic fracturing simulation in a preset hydraulic fracturing simulation environment to obtain a simulation result of hydraulic fracturing of the gravel. The server 104 can feedback the simulation result of hydraulic fracturing of the gravel to the terminal 102.
[0027] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.
[0028] In an exemplary embodiment, Figure 2 As shown, a method for simulating sandstone hydraulic fracturing is provided. The method is executed by a computer device, and can be executed by a computer device such as a terminal or a server alone, or by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used for explanation, and the steps include the following steps 201 to 204.
[0029] Step 201, constructing a gravel model; the gravel model includes a gravel entity, a matrix and a cementation surface.
[0030] In an application example, step 201 includes: in the finite element analysis software Abaqus, constructing a conglomerate model according to the conglomerate data. The construction process is as follows: in the selected simulation area, a plurality of gravel entities are randomly embedded to obtain a conglomerate model; wherein, in the simulation area, the area other than the gravel entities is the matrix; and the cementation surface is between the gravel entities and the matrix. wherein, the embedded gravel entities can be round gravels to simulate the gravel components in the conglomerate.
[0031] After the conglomerate model is constructed, the "CPE4P" grid type can be used to mesh the conglomerate model, and the meshed conglomerate model is assembled in the finite element analysis software Abaqus. Therefore, the conglomerate model includes a node set, and the nodes in the node set constitute a grid.
[0032] Step 202, globally inserting a cohesive force unit into the gravel rock model to apply different mechanical properties to the gravel entity, the matrix and the cementation surface, so as to obtain a simulated gravel rock model to be used; the thickness of the cohesive force unit is zero.
[0033] In an application example, in the coding software python, a cohesive force unit with a thickness of 0 is globally inserted into the gravel model to apply force to the gravel entity, the matrix and the cementation surface to obtain a simulated gravel model to be used. In this step, the inserted cohesive force unit is finally classified according to the matrix, gravel and cementation surface to obtain different sets. Such processing facilitates the realization of heterogeneity in subsequent hydraulic fracturing simulation. Figure 3 and Figure 4, Step 202 specifically includes the following steps (21)-(27).
[0034] (21) Based on the sandstone model, obtain the number of occurrences of each node in the node set in the grid. Among them, the sandstone model is an inp file, and the node set and grid data of the sandstone model are saved in dictionary form for quick retrieval and call in subsequent steps.
[0035] In this step, in the coding software python, the number of occurrences of each node in the node set in the grid can be read using a loop iteration method. For example Figure 4 in, the number of occurrences of node M5 is four, and it needs to be used by the four surrounding grids.
[0036] (22) For any one of the nodes, based on the corresponding number of occurrences of the node, split the node to obtain a new node set. Specifically, use a loop statement to split the nodes in the inp file. The number of times a node appears is the number of times it is split, so as to obtain the new split nodes. The new nodes can be written into a new input data file for convenient subsequent call.
[0037] (23) According to the new node set, update the node set to obtain an updated node set. Specifically, according to the new node set, use a conditional statement to update the nodes that make up the CPE4P grid, requiring that each node can only be allocated and updated once in the CPE4P grid, and then the updated node set can be written into a new input data file. And because the node set is updated, the corresponding CPE4P grid is also updated.
[0038] (24) Assemble and connect the updated nodes in the updated node set according to the assembly requirements of the cohesive unit to obtain a four-node cohesive unit; specifically, according to the updated node set, process the nodes of the CPE4P grid according to the node composition order (i.e., the assembly requirements) of the zero-thickness four-node cohesive unit to obtain the node composition of the zero-thickness four-node cohesive unit, that is, the four-node cohesive unit. For example Figure 4 in, the four-node cohesive unit composed of M10-M11(M1)-M12-M13(M5). At this time, the grid is a COH2D4 four-node grid. After inserting the cohesive unit, regions S3 and S4 are obtained. In addition, according to the cohsive unit assembly requirements, the updated nodes can be assembled and connected to obtain a 4-node cohsive unit.
[0039] (25) The nodes of the four-node cohesive force unit are split to obtain two mid-surface nodes. Specifically, two mid-surface nodes are inserted into the four-node cohesive force unit, and the nodes of the zero-thickness four-node cohesive force unit are split to obtain mid-surface nodes with the same coordinates as the parent node, such as Figure 4 In addition, corresponding to the cohsive unit in the previous step, two nodes can be added to the mid-surface of the 4-node cohsive unit obtained after assembly to generate a 6-node COH2D4P unit.
[0040] (26) Based on the two mid-surface nodes and the four-node cohesion unit, a six-node pore pressure cohesion unit is constructed; specifically, the mid-surface nodes in the previous step are used to assemble the nodes according to the node composition rule of the six-node pore pressure cohesion unit, and the six-node pore pressure cohesion unit required for hydraulic fracturing numerical simulation is obtained, such as Figure 4 The six-node void pressure cohesive force unit composed of M10-M14-M11-M12-M15-M13 in the figure is a COH2D4P six-node mesh. Figure 4 The middle part of the structure is indicated by text, and the meaning and application of other endpoints M and area S can be understood similarly.
[0041] (27) Based on the gravel entity, matrix and cementation surface in the gravel model, all the six-node pore pressure cohesion units are classified to obtain gravel six-node pore pressure cohesion units, matrix six-node pore pressure cohesion units and cementation surface six-node pore pressure cohesion units; the gravel model, the gravel six-node pore pressure cohesion units, the matrix six-node pore pressure cohesion units and the cementation surface six-node pore pressure cohesion units constitute the simulated gravel model to be used. Figure 5 FIG. 1 is a schematic diagram of the cohesive force model of the sandstone conglomerate reservoir, in which an enlarged diagram of the overall pore pressure bonding zone unit is given.
[0042] Step 203 , assigning mechanical property parameters to the simulated conglomerate model to be used, so as to obtain a numerical conglomerate model to be used.
[0043] In an application example, step 203 includes: in the finite element analysis software Abaqus, the mechanical properties of the six-node pore pressure cohesion unit of the gravel, the six-node pore pressure cohesion unit of the matrix and the six-node pore pressure cohesion unit of the cementation surface are defined respectively, and mechanical property parameters are assigned to obtain a numerical conglomerate model to be used.
[0044] More specifically, based on the six-node pore pressure cohesive element obtained by globally inserting cohesive elements in the previous step, define the mechanical properties of different solid elements for the matrix and gravel entities, and define the mechanical properties of different cohesive elements for the matrix, gravel entities, and cemented surfaces; according to the defined mechanical properties above, assign different mechanical property parameters to the solid elements of the matrix and gravel entities, and assign different mechanical property parameters to the six-node pore pressure cohesive elements of the matrix, gravel entities, and cemented surfaces.
[0045] Step 204: Use the to-be-used numerical sandstone model to perform a hydraulic fracturing simulation in a preset hydraulic fracturing simulation environment to obtain a simulation result of the hydraulic fracturing of sandstone. Among them, the preset hydraulic fracturing simulation environment includes a preset principal stress, a preset confining pressure, a preset injection rate of the fracturing fluid, and a preset viscosity of the fracturing fluid applied to the to-be-used numerical sandstone model. It should be noted that the above preset data can be determined according to the actual engineering situation. In an application example, step 204 includes steps (41)-(42).
[0046] (41) In the preset hydraulic fracturing simulation environment, perform a hydraulic fracturing simulation and monitoring on the to-be-used numerical sandstone model to obtain a hydraulic fracture image, and at the same time calculate the fracture initiation criterion and damage evolution criterion of the cohesive elements inserted into the sandstone model, the fluid mass conservation equation of the fracturing fluid flowing between the hydraulic fractures, and the tangential flow and normal filtration in the hydraulic fractures, so as to obtain a simulation result; the hydraulic fracture image is used to display the propagation morphology and propagation path of the hydraulic fractures.
[0047] Specifically, for the preset principal stress, a preset maximum horizontal principal stress and a preset minimum horizontal principal stress can be set; for the preset injection rate of the fracturing fluid, it can be set that the fracturing fluid is injected at a constant rate; for the preset confining pressure, it is a boundary condition. As Figure 6 shown, it is a schematic diagram of the flow of the fracturing fluid in the hydraulic fracture. Since the heterogeneity of the sandstone is considered and different gravel properties are assigned to the matrix, gravel (gravel entity), and cemented surface, when performing a numerical simulation of hydraulic fracturing, the obtained hydraulic fractures will show various different propagation morphologies and propagation paths. In practical applications, the hydraulic fracture image can be monitored in real time, as Figure 7 shown, to judge whether microfractures or hydraulic fractures have occurred.
[0048] (42) When the propagation morphology or the propagation path reaches a preset condition, stop the hydraulic fracturing simulation, and all the simulation results constitute the simulation result of the hydraulic fracturing of sandstone. In an actual application, continue the simulation until the hydraulic fracture penetrates or the entire hydraulic fracturing process ends. At this time, the simulation result of the hydraulic fracturing of sandstone can be exported and saved.
[0049] Among them, the numerical calculation of the opening and failure of cohesive units during the hydraulic fracturing process includes the fracture initiation criterion and the damage evolution criterion. The calculation formula of the fracture initiation criterion is:
[0050]
[0051] where σ n is the normal stress component of the cohesive unit, with the unit of Pa, and σ s is the first tangential stress component of the cohesive unit, with the unit of Pa, and σ t is the second tangential stress component of the cohesive unit, with the unit of Pa, is the peak damage of the normal stress component of the cohesive unit, with the unit of Pa, is the peak damage of the first tangential stress component of the cohesive unit, with the unit of Pa, is the peak damage of the second tangential stress component of the cohesive unit, with the unit of Pa.
[0052] The calculation formula of the damage evolution criterion is:
[0053]
[0054] where is the critical strain energy release rate of fracture in the normal direction, is the critical strain energy release rate of fracture in the first tangential direction, G S is the critical strain energy release rate of fracture in the shear direction, G T is the critical strain energy release rate of fracture in the tensile direction, G C is the critical strain energy release rate of fracture, and the units of the above formats are all J / m 2 , and η is the non-linear adjustment parameter of the damage variable.
[0055] The flow of the fracturing fluid in the hydraulic fracture mainly exhibits two flow modes: tangential flow and normal flow. The fluid mass conservation equation for the flow of the fracturing fluid between hydraulic fractures is shown in the following formula:
[0056]
[0057] where q f is the local flow rate of the fracturing fluid, with the unit of m 2 / s, q t is the loss of the fracturing fluid on the top surface of the hydraulic fracture, with the unit of m / s, q b is the loss of the fracturing fluid on the bottom surface of the hydraulic fracture, with the unit of m / s, w is the width of the hydraulic fracture, with the unit of m, x is the length of the hydraulic fracture, with the unit of m, and t is the time.
[0058] The tangential flow formula of the local flow rate of the fracturing fluid is:
[0059]
[0060] Among them, μ is the preset viscosity of the fracturing fluid, with the unit of Pa·s, is the pressure gradient of the fracturing fluid in the hydraulic fracture, with the unit of Pa / m.
[0061] The normal filtration loss formula of the fracturing fluid loss is:
[0062]
[0063] where p t is the pressure on the top surface of the hydraulic fracture, with the unit of Pa, p b is the pressure on the bottom surface of the hydraulic fracture, with the unit of Pa, p f is the pressure of the fracturing fluid in the hydraulic fracture, with the unit of Pa, c t is the pressure-related filtration coefficient on the top surface of the hydraulic fracture, c b is the pressure-related filtration coefficient on the bottom surface of the hydraulic fracture.
[0064] In summary, this application considers heterogeneity, establishes a glutenite model according to the engineering situation, obtains the final geological model of inserting six-node pore pressure cohesive elements through python, and divides the cohesive elements into three sets: matrix, gravel, and cementation surface; then assigns different mechanical property parameters of the cohesive elements to the matrix, gravel, and cementation surface, applies the horizontal principal stress, sets the viscosity and injection rate of the fracturing fluid, simulates and calculates the fluid-solid coupling process of hydraulic fracturing, and finally exports and saves the simulation results. The above settings of this application improve the accuracy of the hydraulic fracture propagation in glutenite.
[0065] The present invention combines the finite element analysis software Abaqus and the coding software python, inserts cohesive elements that can simulate the opening and propagation of fractures into the glutenite model, and divides the cohesive elements into matrix, gravel, and cementation surface to achieve the heterogeneity of glutenite. And explore the fracture propagation mechanism from the microscale, accurately simulate the propagation morphology of the hydraulic fractures in glutenite, explore the propagation law of the hydraulic fractures, and provide a scientific basis for the optimization of the hydraulic fracturing engineering in glutenite reservoirs
[0066] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 8As shown in the figure. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it realizes the method for simulating the hydraulic fracturing of glutenite.
[0067] Those skilled in the art can understand that Figure 8 the structure shown in the figure is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have a different component layout.
[0068] In an exemplary embodiment, a computer device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. The processor executes the computer program to implement the method for simulating the hydraulic fracturing of glutenite.
[0069] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, which realizes the steps in the above method embodiments when executed by a processor.
[0070] In an exemplary embodiment, a computer program product is provided, including a computer program, which realizes the steps in the above method embodiments when executed by a processor.
[0071] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.
[0072] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the various embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAMs), magnetoresistive random access memories (MRAMs), ferroelectric random access memories (FRAMs), phase change memories (PCMs), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.
[0073] The databases involved in the various embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the various embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logics, data processing logics based on quantum computing, etc., without limitation.
[0074] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.
[0075] In this article, specific examples are used to elaborate on the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A simulation method for hydraulic fracturing of glutenite, characterized in that, The method for simulating hydraulic fracturing of glutenite includes: Constructing a glutenite model; the glutenite model includes glutenite entities, matrix, and cementation surfaces; Globally inserting cohesive elements into the glutenite model to apply different mechanical properties to the glutenite entities, the matrix, and the cementation surfaces, obtaining a simulated glutenite model to be used; the thickness of the cohesive element is zero; Assigning mechanical property parameters to the simulated glutenite model to be used to obtain a numerical glutenite model to be used; Using the numerical glutenite model to be used to perform hydraulic fracturing simulation in a preset hydraulic fracturing simulation environment to obtain the simulation result of hydraulic fracturing of glutenite.
2. The method for simulating hydraulic fracturing of glutenite according to claim 1, wherein Constructing a glutenite model includes: in the finite element analysis software Abaqus, randomly embedding a plurality of glutenite entities in a selected simulation area to obtain a glutenite model; wherein, in the simulation area, the area other than the glutenite entities is the matrix; the interface between the glutenite entities and the matrix is the cementation surface.
3. The simulation method of hydraulic fracturing of glutenite according to claim 1, wherein The glutenite model includes a node set, and the nodes in the node set form a mesh; Globally inserting cohesive elements into the glutenite model to apply different mechanical properties to the glutenite entities, the matrix, and the cementation surfaces, obtaining a simulated glutenite model to be used, including: Based on the glutenite model, obtaining the occurrence times of each node in the node set in the mesh; For any one of the nodes, splitting the node based on the occurrence times corresponding to the node to obtain a new node set; Updating the node set according to the new node set to obtain an updated node set; Assembling and connecting the updated nodes in the updated node set according to the assembly requirements of the cohesive elements to obtain four-node cohesive elements; Splitting the nodes of the four-node cohesive elements to obtain two mid-plane nodes; Based on the two mid-plane nodes and the four-node cohesive elements, constructing six-node pore pressure cohesive elements; Classifying all the six-node pore pressure cohesive elements based on the glutenite entities, matrix, and cementation surfaces in the glutenite model to obtain glutenite six-node pore pressure cohesive elements, matrix six-node pore pressure cohesive elements, and cementation surface six-node pore pressure cohesive elements; the glutenite model, the glutenite six-node pore pressure cohesive elements, the matrix six-node pore pressure cohesive elements, and the cementation surface six-node pore pressure cohesive elements constitute the simulated glutenite model to be used.
4. The simulation method of hydraulic fracturing of glutenite according to claim 1, wherein In the coding software python, globally inserting cohesive elements into the glutenite model to apply forces to the glutenite entities, the matrix, and the cementation surfaces, obtaining a simulated glutenite model to be used.
5. The simulation method of hydraulic fracturing of glutenite according to claim 3, characterized in that Assigning mechanical property parameters to the simulated glutenite model to be used to obtain a numerical glutenite model to be used, including: In the finite element analysis software Abaqus, defining the mechanical properties of the glutenite six-node pore pressure cohesive elements, the matrix six-node pore pressure cohesive elements, and the cementation surface six-node pore pressure cohesive elements respectively, and assigning mechanical property parameters to obtain a numerical glutenite model to be used.
6. The simulation method of hydraulic fracturing of glutenite according to claim 1, wherein, The preset hydraulic fracturing simulation environment includes a preset principal stress, a preset confining pressure, a preset fracturing fluid injection rate, and a preset fracturing fluid viscosity applied to the to-be-used numerical sandstone model; Using the to-be-used numerical sandstone model, hydraulic fracturing simulation is carried out in the preset hydraulic fracturing simulation environment to obtain the sandstone hydraulic fracturing simulation results, including: In the preset hydraulic fracturing simulation environment, hydraulic fracturing simulation and monitoring are performed on the to-be-used numerical sandstone model to obtain a hydraulic fracture image. At the same time, the fracture initiation criterion and damage evolution criterion of the cohesion unit inserted into the sandstone model, the fluid mass conservation equation of the fracturing fluid flowing between the hydraulic fractures, the tangential flow and normal filtration in the hydraulic fractures are calculated, so as to obtain a simulation result; the hydraulic fracture image is used to display the propagation morphology and propagation path of the hydraulic fractures; When the propagation morphology or the propagation path reaches the preset conditions, the hydraulic fracturing simulation is stopped, and all the simulation results constitute the sandstone hydraulic fracturing simulation results.
7. The method for simulating hydraulic fracturing of glutenite according to claim 6, characterized in that, The calculation formula of the fracture initiation criterion is: where σ n is the normal stress component of the cohesive element, σ s is the first tangential stress component of the cohesive element, σ t is the second tangential stress component of the cohesive element, is the peak value of the damage of the normal stress component of the cohesive element, is the peak value of the damage of the first tangential stress component of the cohesive element, is the peak value of the damage of the second tangential stress component of the cohesive element; The calculation formula of the damage evolution criterion is: Among them, is the critical strain energy release rate in the normal direction, is the critical strain energy release rate in the first tangential direction, G S is the critical strain energy release rate in the shear direction, G T is the critical strain energy release rate in the tensile direction, G C is the critical strain energy release rate, and η is the nonlinear adjustment parameter of the damage variable.
8. The simulation method of hydraulic fracturing of glutenite according to claim 6, wherein The fluid mass conservation equation of the fracturing fluid flowing between the hydraulic fractures is shown as the following formula: where q f is the local flow rate of the fracturing fluid, q t is the loss of the fracturing fluid on the top surface of the hydraulic fracture, q b is the loss of the fracturing fluid on the bottom surface of the hydraulic fracture, w is the width of the hydraulic fracture, x is the length of the hydraulic fracture, and t is the time; The tangential flow formula of the local flow rate of the fracturing fluid is: where μ is the preset viscosity of the fracturing fluid, is the pressure gradient of the fracturing fluid in the hydraulic fracture; The normal filtration formula of the fracturing fluid loss is: where p t is the pressure on the top surface of the hydraulic fracture, p b is the pressure on the bottom surface of the hydraulic fracture, p f is the pressure of the fracturing fluid in the hydraulic fracture, c t is the pressure-related filtrate loss coefficient on the top surface of the hydraulic fracture, c b is the pressure-related filtrate loss coefficient on the bottom surface of the hydraulic fracture.
9. A computer device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the sandstone hydraulic fracturing simulation method according to any one of claims 1-8.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the sandstone hydraulic fracturing simulation method according to any one of claims 1-8.