Fracture simulation-based oil and gas production method, device, system, equipment and medium

Abstract

The application discloses an oil and gas exploitation method, device, system, equipment and medium based on fracture simulation. The method comprises the following steps: based on the formation type of the formation where the shale sample is located, fracture simulation is performed on the shale sample by applying external pressure, and fracture parameters of the shale sample are recorded; the fracture parameters are analyzed to obtain the fracture opening law of the shale sample; the target oil and gas recovery strategy of the formation is determined based on the fracture opening law; and the formation where the shale sample is located is exploited based on the target oil and gas recovery strategy. The problem that the existing method of planning while constructing makes the oil and gas exploitation speed slow and leads to low oil and gas exploitation efficiency due to the complex formation environment is solved.

Description

Technical Field

[0001] This application relates to the field of oil and gas extraction technology, and in particular to an oil and gas extraction method, apparatus, system, equipment and medium based on fracture simulation. Background Technology

[0002] In oil and gas drilling engineering, wellbore instability is a common and complex downhole situation. As the field of oil and gas drilling continues to expand, the formations encountered are becoming increasingly complex, and the problem of wellbore stability is becoming more prominent. Hard and brittle shale formations are prone to spalling and breaking under stress and fluid action, leading to enlargement of the wellbore. Or, due to excessive drilling fluid density, the formation may be fractured, resulting in the opening of internal cracks in the shale formation and serious well leakage of drilling fluid.

[0003] Currently, in order to improve the stability of the wellbore during oil extraction, extraction planning is generally carried out while construction is underway, based on the actual formation conditions.

[0004] However, due to the complex geological environment, the existing method of planning while constructing results in a slow oil and gas extraction speed, leading to low oil and gas extraction efficiency. Summary of the Invention

[0005] To overcome the problem that the existing method of planning while constructing is slow and the efficiency of oil and gas extraction is low due to the complex geological environment, this application provides an oil and gas extraction method, apparatus, system, equipment and medium based on fracture simulation.

[0006] Firstly, in order to solve the aforementioned technical problems, this application provides a method for oil and gas extraction based on fracture simulation, comprising:

[0007] Based on the stratigraphic type of the strata where the mudstone and shale samples are located, external pressure is applied to the mudstone and shale samples to simulate fractures, and the fracture parameters of the mudstone and shale samples are recorded.

[0008] By analyzing the crack parameters, the crack opening pattern of the mudstone and shale samples was obtained.

[0009] Determine the target oil and gas recovery strategy for the formation based on the fracture opening pattern;

[0010] Oil and gas extraction was carried out in the formation where the mudstone and shale samples were located based on the target oil and gas recovery strategy.

[0011] Secondly, this application also provides a fracture simulation device. Applying the aforementioned fracture simulation-based oil and gas extraction method, the fracture simulation device includes:

[0012] The pressurization device is equipped with a pressurization chamber for placing mudstone and shale samples;

[0013] The control device, connected to the pressurization device, is used to control the pressurization device to apply external pressure to the mudstone and shale sample based on the formation type of the strata where the mudstone and shale sample is located, to simulate cracks and record the crack parameters of the mudstone and shale sample.

[0014] Thirdly, this application also provides an oil and gas extraction system based on fracture simulation, comprising:

[0015] The fracture simulation module is used to simulate fractures by applying external pressure to the shale sample based on the formation type of the strata where the shale sample is located, and to record the fracture parameters of the shale sample.

[0016] The analysis module is used to perform regular analysis on the crack parameters to obtain the crack opening pattern of the mudstone and shale samples;

[0017] The strategy determination module is used to determine the target oil and gas recovery strategy for the formation based on the fracture opening pattern.

[0018] The strategy implementation module is used to extract oil and gas from the formation where the mudstone and shale sample is located based on the target oil and gas recovery strategy.

[0019] Fourthly, this application also provides a computing device, including a memory, a processor, and a program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps of the above-described fracture simulation-based oil and gas extraction method.

[0020] Fifthly, this application also provides a computer-readable storage medium storing instructions that, when executed on a terminal device, cause the terminal device to perform the steps of a fracture simulation-based oil and gas extraction method.

[0021] The beneficial effects of this application are as follows: First, based on the formation type of the shale sample, external pressure is applied to the shale sample to simulate fractures, and the fracture parameters of the shale sample are recorded. The fracture parameters are then analyzed to obtain the fracture opening pattern. Based on this fracture opening pattern, a targeted oil and gas recovery strategy that meets the preset requirements in terms of accuracy and feasibility can be determined. Oil and gas extraction is then carried out in the formation where the shale sample is located based on this target oil and gas recovery strategy. In this way, by planning the target oil and gas recovery strategy for the formation based on the shale sample in advance, and then directly carrying out oil and gas extraction according to this strategy, there is no need for planning during construction, thereby improving the efficiency of oil and gas extraction. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart illustrating an exemplary embodiment of an oil and gas extraction method based on fracture simulation.

[0023] Figure 2This is a schematic diagram of the structure of a crack simulation device shown in an exemplary embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the structure of an oil and gas extraction system based on fracture simulation, which is an exemplary embodiment of this application.

[0025] The attached diagram lists the components represented by each number as follows:

[0026] 10 mudstone and shale sample, 20 pressurizing device, 21 circumferential pressurizing device, 22 vertical pressurizing device, 23 pressure gauge, 24 air valve. Detailed Implementation

[0027] The following embodiments are further explanations and supplements to this application and do not constitute any limitation on this application.

[0028] The following description, in conjunction with the accompanying drawings, describes an oil and gas extraction method, apparatus, system, equipment, and medium based on fracture simulation according to embodiments of this application.

[0029] The oil and gas extraction method based on fracture simulation provided in this application can be executed by a server. It should be noted that the server can be a standalone server or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDN), and big data and artificial intelligence platforms. No limitation is imposed here.

[0030] Please see Figure 1 , Figure 1 An exemplary embodiment of this application illustrates an oil and gas extraction method based on fracture simulation, such as... Figure 1 As shown, this application provides a method for oil and gas extraction based on fracture simulation, including:

[0031] Step S11: Based on the stratigraphic type of the strata where the shale sample is located, apply external pressure to the shale sample to simulate cracks and record the crack parameters of the shale sample.

[0032] Step S12: Analyze the crack parameters to obtain the crack opening pattern of the mudstone and shale sample.

[0033] Step S13: Determine the target oil and gas recovery strategy for the formation based on the fracture opening pattern;

[0034] Step S14: Extract oil and gas from the formation where the mudstone and shale sample is located based on the target oil and gas recovery strategy.

[0035] The fracture simulation-based oil and gas extraction method provided in this application first applies external pressure to the shale sample based on the formation type of the strata where the shale sample is located to simulate fractures, records the fracture parameters of the shale sample, and analyzes the patterns of these parameters to obtain fracture opening rules. Based on these fracture opening rules, a target oil and gas recovery strategy that meets preset requirements in terms of accuracy and feasibility can be specifically determined. Oil and gas extraction is then carried out in the strata where the shale sample is located based on this target oil and gas recovery strategy. In this way, by planning the target oil and gas recovery strategy for the formation based on the shale sample in advance, and then directly following the strategy for oil and gas extraction, there is no need for on-site planning during construction, thereby improving the efficiency of oil and gas extraction. The shale sample can be a hard and brittle shale sample.

[0036] Optionally, based on the stratigraphic type of the shale sample, external pressure is applied to the shale sample to simulate fractures, and the fracture parameters of the shale sample are recorded, including:

[0037] Based on the stratigraphic type of the strata where the shale sample is located and the rock type of the shale sample, a target pressure law for the shale sample is generated.

[0038] External pressure was applied to the mudstone and shale samples according to the target pressure law to simulate cracks, and the crack parameters of the mudstone and shale samples were recorded.

[0039] In the embodiment provided in this application, a target pressurization law is generated for the shale sample based on the stratigraphic type of the strata where the shale sample is located and the rock type of the shale sample. External pressure is applied to the shale sample according to the target pressurization law to simulate fractures, and the fracture parameters of the shale sample are recorded. This allows the stratigraphic type and rock type to be taken into account when determining the fracture opening law based on the fracture parameters in the future, thereby improving the accuracy of the determined fracture opening law and thus improving the accuracy of the target oil and gas recovery strategy determined based on the fracture opening law for oil and gas extraction.

[0040] Optionally, based on the stratigraphic type of the strata where the shale sample is located and the rock type of the shale sample, a target compressibility law corresponding to the shale sample is generated, including:

[0041] Based on the stratigraphic type of the strata where the mudstone and shale samples are located, the corresponding target pressurization rate is found in the preset pressurization rate data table;

[0042] The corresponding initial pressure value is found in the preset initial pressure data table based on the formation type.

[0043] The target pressure value is found from the preset target pressure data table based on the rock type of the mudstone and shale sample.

[0044] The target pressurization law for shale samples is formed based on the target pressurization rate, initial pressure value, and target pressure value.

[0045] In the embodiment provided in this application, firstly, a pre-established correspondence between formation types and target pressurization rates is stored in a pressurization rate data table, a pre-established correspondence between formation types and initial pressure values ​​is stored in an initial pressure data table, and a pre-established correspondence between rock types and target pressure values ​​is stored in a target pressure data table. This facilitates the direct determination of the corresponding target pressurization rate and initial pressure value from the pressurization rate data table and the initial pressure data table based on the required formation type, and the direct lookup of the corresponding target pressure value from the target pressure data table based on the required rock type. Then, a target pressurization pattern is formed for the shale sample based on the target pressurization rate, the initial pressure value, and the target pressure value: according to the target pressurization rate, the external pressure applied to the shale sample gradually increases from the initial pressure value to the target pressure value. This facilitates the consideration of the formation type and rock type corresponding to the shale sample when applying external pressure to the shale sample according to the target pressurization pattern for fracture simulation, thereby improving the accuracy of fracture simulation for the shale sample.

[0046] In this embodiment, the correspondence between formation type and pressurization rate in the pressurization rate data table is as follows: when the formation type is shale, the corresponding target pressurization rate is any value greater than or equal to 0.1 MPa and less than 0.5 MPa; when the formation type is sandstone, the corresponding target pressurization rate is any value greater than or equal to 0.5 MPa and less than 1.0 MPa; when the formation type is granite, the corresponding target pressurization rate is any value greater than or equal to 1.0 MPa and less than 2.0 MPa; when the formation type is coal seam / coal rock, the corresponding target pressurization rate is any value greater than or equal to 0.05 MPa and less than 0.3 MPa.

[0047] The correspondence between formation type and initial pressure value in the initial pressure data table is as follows: When the formation type is shale, the corresponding initial pressure value is any value greater than or equal to 0.1 MPa and less than 0.5 MPa; when the formation type is sandstone, the corresponding initial pressure value is any value greater than or equal to 0.5 MPa and less than 1.0 MPa; when the formation type is granite, the corresponding initial pressure value is any value greater than or equal to 1.0 MPa and less than 2.0 MPa; when the formation type is coal seam / coal rock, the corresponding initial pressure value is any value greater than or equal to 0.05 MPa and less than 0.3 MPa.

[0048] The correspondence between rock type and target pressure value in the target pressure data table is as follows: When the rock type is a conventional reservoir, the corresponding target pressure value is any value greater than or equal to 10 MPa and less than 50 MPa. In this way, structural stress superposition is possible, and its pore pressure is close to the hydrostatic pressure. When the rock type is an overpressured / deep reservoir, the corresponding target pressure value is any value greater than or equal to 50 MPa and less than 150 MPa. In this way, its pore pressure exceeds the hydrostatic pressure (gradient > 0.015 MPa / m). This overpressured / deep reservoir is commonly found in closed shale or subsalt reservoirs. When the rock type is a geothermal / hot dry rock, the corresponding target pressure value is any value greater than or equal to 80 MPa and less than 200 MPa. In this way, deep high temperature (>150℃) and high static rock pressure can be superimposed.

[0049] Optionally, the fracture parameters include fracture morphology, number of fractures, fracture distribution, and fracture propagation rate; by analyzing the patterns of these fracture parameters, the fracture initiation patterns of the shale sample are obtained, including:

[0050] The fracture type of the mudstone and shale sample was determined based on the fracture morphology and the corresponding fracture propagation rate.

[0051] Based on the preset crack initiation rules, the crack type, number, and distribution are analyzed to obtain the crack initiation rules of the mudstone and shale samples.

[0052] In the embodiment provided in this application, since each fracture has a unique Leifeng morphology and fracture propagation speed, the fracture type of the shale sample can be accurately determined based on the fracture morphology and corresponding fracture propagation speed. Furthermore, based on preset fracture opening rules, the fracture type, number, and distribution are analyzed to obtain the fracture opening rules of the shale sample that conform to the strata it is located in. This improves the matching degree between the fracture opening rules and the strata where the shale sample is located, thereby improving the accuracy of the determined fracture opening rules and ultimately enhancing the accuracy of the target oil and gas recovery strategy determined based on the fracture opening rules.

[0053] In this embodiment, the external pressure includes confining pressure σ3 and axial pressure σ1, with units of MPa. The crack initiation rules include: when the confining pressure σ3 is less than a threshold, if the crack morphology is a tension crack, the main crack extends axially, with a relatively straight shape and few branches (i.e., axial pressure σ1 dominates the failure); if the crack morphology is a brittle fracture, the crack propagation speed is fast and sudden; if the number of cracks is 1-2 main cracks and the crack distribution is concentrated, the crack propagates along the direction of the maximum principal stress (axial pressure σ1); if the axial pressure σ1 reaches the rock compressive strength, the crack propagates rapidly, with the crack propagation speed reaching the millisecond level. The crack initiation rules also include the following: when the confining pressure σ3 is greater than or equal to a threshold, if the crack morphology is shear crack, the crack forms a certain angle with the axial direction (meeting the Coulomb fracture criterion), has a complex morphology, and many branches; if the crack morphology is plastic deformation, the crack propagation rate is slow, accompanied by the displacement of rock particles; if the number of cracks is greater than a preset number, a secondary crack network may appear; if the crack distribution is uniform, the cracks are constrained and influenced by the confining pressure σ3; if the crack propagation rate is slow, ranging from seconds to minutes, the confining pressure σ3 inhibits sudden failure. The threshold can be any value greater than or equal to 15 and less than 30, and the crack initiation rules can include the rule relationships shown in Table 1.

[0054] Table 1

[0055]

[0056] Among them, 80 (UCS) refers to 80% of the uniaxial compressive strength. UCS represents the maximum compressive stress that a rock or material can withstand under uniaxial (vertical) compression without lateral restraint, and can also be called uniaxial compressive strength.

[0057] Based on the aforementioned fracture initiation rules, a systematic analysis was conducted on fracture type, number, and distribution, yielding the fracture initiation patterns of the shale samples, as shown in Table 2. The correspondence between formation type, external pressure, and fracture initiation patterns is also shown in Table 2.

[0058] Table 2

[0059]

[0060] The normal pressures of sandstone reservoirs include: 5 MPa to 15 MPa for shallow formations (<1500 meters); 15 MPa to 35 MPa for medium-deep formations (1500 to 3500 meters); and greater than 35 MPa for ultra-deep formations (>3500 meters), which may deviate from the normal pressure due to geological processes. σ'\approx 0 indicates that the low effective stress is approximately 0.

[0061] Optionally, the target oil and gas recovery strategy for the formation can be determined based on the fracture opening pattern, including:

[0062] Determining the crack defects in shale samples based on crack initiation patterns;

[0063] Obtain the pre-defined correspondence between fracture defects and oil and gas recovery strategies, and based on the fracture defects and the correspondence, obtain the target oil and gas recovery strategy for the formation corresponding to the fracture defects.

[0064] In the embodiment provided in this application, the fracture opening pattern of the shale sample can be used to directly identify the corresponding fracture defects during and after the fracture opening process. In this way, by obtaining the pre-defined correspondence between fracture defects and oil and gas recovery strategies, the target oil and gas recovery strategy for the corresponding formation can be directly obtained. This allows the target oil and gas recovery strategy to be optimized based on the fracture defects, thereby improving the recovery efficiency of subsequent oil and gas extraction based on the target oil and gas recovery strategy.

[0065] In this embodiment, the correspondence between fracture defects and oil and gas recovery strategies can be as follows: When the formation where the mudstone and shale sample is located is a shale gas layer, the corresponding fracture defect is that there are few natural fractures, indicating that artificial fracture creation is required for oil and gas extraction. Therefore, the oil and gas recovery strategy corresponding to this fracture defect is ① high-displacement slickwater fracturing: high displacement (20m³ / h) 3 (Above / min) to form a complex fracture network; ② Propionate slug injection: alternately inject proppant and cleaning fluid to avoid near-wellbore blockage; ③ Pressure limiting strategy: control the wellhead pressure of the formation drilling to be lower than the caprock fracture pressure.

[0066] The correspondence between fracture defects and oil and gas recovery strategies can also be as follows: When the formation in which the mudstone and shale sample is located is a sandstone reservoir, the corresponding fracture defect is that the fracture tends to extend along the natural weak surface, resulting in uneven distribution of proppant. The oil and gas recovery strategies corresponding to this fracture defect are: ① Low sand ratio fracturing: control the sand-to-fluid ratio at 5% to 10% to reduce the scouring of natural fractures; ② Pre-acid treatment: use acid to dissolve the blockage in the near-wellbore zone and reduce the fracture pressure; ③ Stress interference utilization: induce stress field superposition and expand the fracture range by simultaneously fracturing adjacent wells.

[0067] The correspondence between fracture defects and oil and gas recovery strategies can also be as follows: When the formation in which the mudstone and shale sample is located is a deep and tight reservoir, the corresponding fracture defect is high fracture closure pressure and easy loss of conductivity. The oil and gas recovery strategies corresponding to this fracture defect are: ① Supercritical CO2 fracturing: using the low viscosity and high diffusivity of CO2 to reduce the fracture pressure; ② High-temperature stable proppant: using resin-coated ceramic particles with a temperature resistance of >150℃ as the proppant for drilling in the formation; ③ Temporary plugging and diversion within the fracture: injecting a biodegradable temporary plugging agent to force the pressure to divert to a new formation.

[0068] In an exemplary embodiment of this application, by comparing and analyzing the fracture opening patterns of hard and brittle mudstone and shale under different formation conditions, guidance can be provided for oil and gas exploration before oil and gas extraction, as follows:

[0069] When the fracture opening pattern includes a single vertical tensile fracture (single vertical fracture), the exploration method for oil and gas exploration is: to use horizontal wells along the direction of maximum geostress σ_H, to limit pressure to prevent layer penetration, and to discharge large volume of slickwater.

[0070] When the fracture initiation pattern includes a shear fracture network (complex shear network), the exploration method for oil and gas exploration is: to use small-scale multi-stage fracturing, acid pretreatment, and support small-diameter sand.

[0071] When the fracture opening pattern includes karst caves connecting fractures, the exploration method for oil and gas exploration is: seismic target selection, self-directing acid fracturing, and temporary plugging deflection.

[0072] When the fracture opening pattern includes closed shear fractures, the exploration method for oil and gas exploration is: supercritical CO2 fracturing, circulating fluid injection, and fiber optic monitoring.

[0073] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of a crack simulation device shown in an exemplary embodiment of this application, as follows: Figure 2 As shown, this application provides a fracture simulation device. Applying the aforementioned fracture simulation-based oil and gas extraction method, the fracture simulation device includes:

[0074] The pressurizing device 20 is equipped with a pressurizing chamber for placing the mudstone and shale sample 10;

[0075] A control device, connected to a pressurizing device 20, is used to control the pressurizing device 20 to apply external pressure to the mudstone and shale sample 10 based on the stratigraphic type of the strata where the mudstone and shale sample 10 is located, to simulate cracks and record the crack parameters of the mudstone and shale sample 10.

[0076] The fracture simulation device of this embodiment places the shale sample 10 in the pressurization chamber of the pressurization device 20, and controls the pressurization device 20 to apply external pressure to the shale sample 10 based on the formation type of the stratum where the shale sample 10 is located to simulate fractures. The fracture parameters of the shale sample 10 are recorded, which facilitates the subsequent planning of the target oil and gas recovery strategy for the stratum where the shale sample 10 is located based on the fracture parameters. Oil and gas extraction can then be carried out directly according to the strategy without the need for planning during construction, thereby improving the efficiency of oil and gas extraction.

[0077] Optionally, the pressurization device 20 includes:

[0078] The circumferential pressure device 21 is circumferentially located outside the pressure chamber and abuts against the mudstone and shale sample 10.

[0079] The vertical pressure device 22 is located above the pressure chamber and comes into contact with the mudstone and shale sample 10.

[0080] In the embodiment provided in this application, a confining pressure σ3 is applied to the shale sample 10 by a circumferential pressure device 21, and a vertically downward axial pressure σ1 is applied to the shale sample 10 by a vertical pressure device 22. This achieves external pressure on the shale sample 10 to simulate fractures, so that the target oil and gas recovery strategy of the formation where the shale sample 10 is located can be planned based on the fracture parameters recorded during the fracture simulation. Then, oil and gas extraction can be carried out directly according to the strategy, without the need for planning during construction, thereby improving the efficiency of oil and gas extraction.

[0081] In one exemplary embodiment provided in this application, an oil and gas extraction method based on fracture simulation is applied using a fracture simulation device, the specific steps of which include:

[0082] ① Preparation of Shale Sample 10: Representative hard and brittle shale samples were collected from the strata where Shale Sample 10 is located. Then, the samples were cut and polished using a rock cutter to prepare standard-sized core samples, ensuring that the size, shape, and integrity of the samples met the experimental requirements. Necessary pretreatment was performed on the samples, including cleaning, drying, and polishing, to eliminate the influence of surface defects on the experimental results, thus obtaining Shale Sample 10. Representativeness is reflected in: maintaining good integrity, without obvious broken, fractured, or missing parts; being able to represent the geological characteristics of the studied strata, including lithology, structure, and mineral composition; having clear bedding and structural features; and having sufficient size and quantity (based on the size of the pressurization chamber of the pressurization device).

[0083] ② Install a circumferential pressure device 21 on the pressurizing device 20: Place the shale sample 10 in the pressurizing chamber of the pressurizing device 20, and set the circumferential pressure device 21 circumferentially outside the pressurizing chamber, abutting against the shale sample 10, to simulate the circumferential pressure (confining pressure σ3) of the formation on the rock, and ensure that the experimental conditions are consistent with the actual situation of the formation. During the installation process, it is necessary to ensure that the contact between the circumferential pressure device 21 and the shale sample 10 is tight and uniform, so as to avoid experimental errors caused by local stress concentration.

[0084] ③ Install a vertical pressure device 22 on the pressurizing device 20: Install a vertical pressure device 22 above the pressurizing chamber so that the vertical pressure device 22 abuts against the mudstone and shale sample 10 to simulate the vertical pressure (axial pressure σ1) of the formation on the rock. The vertical pressure device 22 should be able to accurately control the applied pressure and remain stable. During the installation process, ensure that the vertical pressure device 22 and the mudstone and shale sample 10 are accurately aligned to avoid experimental errors caused by alignment deviation.

[0085] ④ Install pressure gauge 23 and air valve 24: Install pressure gauge 23 and air valve 24 on the circumferential pressure device 21 and vertical pressure device 22 respectively to monitor and adjust the applied pressure in real time. Pressure gauge 23 has high accuracy and stability to ensure the accuracy of experimental data, and air valve 24 can flexibly control the inlet and outlet of gas and adjust the pressure as needed during the experiment.

[0086] ⑤ Loading the shale sample 10: Load the prepared shale sample 10 into the pressurization chamber of the pressurization device 20, and ensure that the shale sample 10 is in close contact with the circumferential pressure device 21 and the vertical pressure device 22. Check that all connecting parts are firm and reliable to avoid leakage or loosening during the experiment.

[0087] ⑥ Apply external pressure to shale sample 10 to simulate fractures: Adjust the external pressure applied to shale sample 10—confining pressure σ3 and axial pressure σ1—using valve 24. Gradually increase the external pressure from the corresponding initial pressure value to the corresponding target pressure value according to the corresponding target pressurization rate to simulate the fracture opening process under formation pressure conditions. Observe and record the fracture opening process of shale sample 10 under external pressure to achieve fracture simulation. During the experiment, closely monitor the reading of pressure gauge 23 to ensure that the applied external pressure is stable and meets the experimental requirements.

[0088] ⑦ Observe and record the crack initiation process of shale sample 10: Using high-resolution imaging equipment or microscopes, observe the crack initiation process of shale sample 10 under external pressure in real time, and record the crack parameters during the crack initiation process, including the number of cracks, crack distribution, and crack propagation rate. Simultaneously, record the pressure change data during the experiment for subsequent data analysis.

[0089] ⑧ Application and Data Analysis: The fracture parameters recorded during the experiment will be organized and their patterns analyzed to reveal the fracture opening pattern of shale sample 10 under external pressure. The experimental results will be compared and analyzed with the actual formation conditions to provide a scientific basis for the establishment of a fracture simulation numerical model and for exploration methods and oil and gas recovery strategies. For example, based on the fracture opening pattern, the target oil and gas recovery strategy for the formation can be determined, and oil and gas can be extracted from the formation where the shale sample is located based on the target oil and gas recovery strategy, eliminating the need for simultaneous construction and planning, thereby improving the efficiency of oil and gas extraction.

[0090] ⑨ In addition, a numerical model can be established: by analyzing experimental data, fracture parameters and fracture initiation patterns can be obtained. Based on these parameters and patterns, a numerical model simulating fractures in the strata where shale sample 10 is located can be established, allowing for real-time observation of desired fracture conditions. Furthermore, the accuracy of the numerical model can be improved through simulation execution and result analysis, and parameter optimization can be performed.

[0091] In summary, the fracture simulation-based oil and gas extraction method of this application studies the fracture opening law of hard and brittle shale under external pressure by simulating formation pressure conditions, providing a scientific basis for the evaluation of oil and gas reservoirs. Furthermore, by comparing and analyzing the fracture opening law of hard and brittle shale under different formation conditions, it provides guidance for oil and gas exploration. Based on the fracture opening law, the oil and gas recovery control strategy during the extraction process can be optimized to improve the oil and gas recovery rate. The fracture simulation device of this application is made of transparent material, allowing the fracture opening process to be directly observed. This visualization not only helps to intuitively understand the fracture opening mechanism but also provides a verification basis for subsequent numerical simulation and theoretical analysis. Compared with field experiments, simulation methods are usually conducted under laboratory conditions, which can significantly save time and costs. This allows researchers to conduct multiple experiments in a shorter period of time, thereby obtaining reliable data and conclusions more quickly. The simulation method avoids the safety risks that may arise from field experiments. Conducting simulation experiments under laboratory conditions ensures the safety of researchers and reduces the impact on the environment. Furthermore, compared with other modeling methods, the fracture simulation-based oil and gas extraction method of this application uses reliable data and conclusions obtained from experiments to simulate fractures. Through result analysis and data optimization, it has a significant advantage in accuracy when analyzing a specific region. Therefore, the fracture simulation-based oil and gas extraction method and apparatus of this application have the advantages of strong experimental controllability, high visualization, time and cost savings, and high safety.

[0092] Please see Figure 3 , Figure 3 An exemplary embodiment of this application illustrates an oil and gas extraction system based on fracture simulation, such as... Figure 3As shown, this application provides an oil and gas extraction system 300 based on fracture simulation, comprising:

[0093] The fracture simulation module 301 is used to simulate fractures by applying external pressure to the shale sample based on the formation type of the strata where the shale sample is located, and to record the fracture parameters of the shale sample.

[0094] Analysis module 302 is used to perform regular analysis on crack parameters to obtain the crack opening pattern of mudstone and shale samples;

[0095] Strategy determination module 303 is used to determine the target oil and gas recovery strategy of the formation based on the fracture opening law;

[0096] Strategy implementation module 304 is used to extract oil and gas from the formation where the mudstone and shale sample is located based on the target oil and gas recovery strategy.

[0097] The fracture simulation-based oil and gas extraction system 300 provided in this application first uses a fracture simulation module 301 to apply external pressure to the shale sample based on the formation type of the strata where the shale sample is located to simulate fractures, recording the fracture parameters of the shale sample. Then, an analysis module 302 analyzes the fracture parameters to obtain the fracture opening pattern. Based on this fracture opening pattern, a strategy determination module 303 can then determine a target oil and gas recovery strategy that meets preset requirements in terms of accuracy and feasibility. Finally, a strategy implementation module 303 uses this target oil and gas recovery strategy to extract oil and gas from the shale sample's formation. In this way, by planning the target oil and gas recovery strategy for the formation based on the shale sample in advance, and then directly implementing the strategy, oil and gas extraction can be carried out without the need for on-site planning during construction, thereby improving the efficiency of oil and gas extraction.

[0098] Optionally, the crack simulation module 301 is specifically used for:

[0099] Based on the stratigraphic type of the strata where the shale sample is located and the rock type of the shale sample, a target pressure law for the shale sample is generated.

[0100] External pressure was applied to the mudstone and shale samples according to the target pressure law to simulate cracks, and the crack parameters of the mudstone and shale samples were recorded.

[0101] Optionally, the crack simulation module 301 is specifically used for:

[0102] Based on the stratigraphic type of the strata where the mudstone and shale samples are located, the corresponding target pressurization rate is found in the preset pressurization rate data table;

[0103] The corresponding initial pressure value is found in the preset initial pressure data table based on the formation type.

[0104] The target pressure value is found from the preset target pressure data table based on the rock type of the mudstone and shale sample.

[0105] The target pressurization law for shale samples is formed based on the target pressurization rate, initial pressure value, and target pressure value.

[0106] Optionally, the crack parameters include crack morphology, crack number, crack distribution, and crack propagation rate; the analysis module 302 is specifically used for:

[0107] The fracture type of the mudstone and shale sample was determined based on the fracture morphology and the corresponding fracture propagation rate.

[0108] Based on the preset crack initiation rules, the crack type, number, and distribution are analyzed to obtain the crack initiation rules of the mudstone and shale samples.

[0109] Optionally, the strategy determination module 303 is specifically used for:

[0110] Determining the crack defects in shale samples based on crack initiation patterns;

[0111] Obtain the pre-defined correspondence between fracture defects and oil and gas recovery strategies, and based on the fracture defects and the correspondence, obtain the target oil and gas recovery strategy for the formation corresponding to the fracture defects.

[0112] It should be noted that the fracture simulation-based oil and gas extraction system and the fracture simulation-based oil and gas extraction method provided in the above embodiments belong to the same concept. The specific operation methods of each module and unit have been described in detail in the method embodiments and will not be repeated here. In practical applications, the fracture simulation-based oil and gas extraction system provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above. This is not a limitation here.

[0113] A computing device according to an embodiment of this application includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, it implements some or all of the steps of the above-described oil and gas extraction method based on fracture simulation.

[0114] The computing device can be a computer, and the corresponding program is computer software. The parameters and steps of the computing device described above can be referred to the parameters and steps of the embodiment of the oil and gas extraction method based on fracture simulation in the above text, and will not be repeated here.

[0115] This application provides a computer-readable storage medium storing instructions that, when executed, perform the steps of the aforementioned fracture simulation-based oil and gas extraction method.

[0116] The computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0117] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of this disclosure. The aforementioned computer-readable storage medium can be a non-transitory computer-readable storage medium, including: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, and other media capable of storing program code; it can also be a transient computer-readable storage medium.

[0118] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0119] Those skilled in the art will recognize that this application can be implemented as a system, method, or computer program product. Therefore, this disclosure can be implemented in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "module" or "system." Furthermore, in some embodiments, this application can also be implemented as a computer program product contained in one or more computer-readable media, which contains computer-readable program code. Computer-readable storage media can be, for example, but not limited to—electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof.

[0120] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0121] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for oil and gas extraction based on fracture simulation, characterized in that, include: Based on the stratigraphic type of the strata where the mudstone and shale samples are located, the corresponding target pressurization rate is found in the preset pressurization rate data table; Based on the formation type, the corresponding initial pressure value is found in the preset initial pressure data table; The target pressure value is retrieved from the preset target pressure data table based on the rock type of the mudstone and shale sample. A target pressurization pattern for the mudstone and shale sample is formed based on the target pressurization rate, the initial pressure value, and the target pressure value. According to the target pressurization law, external pressure was applied to the mudstone and shale sample to simulate cracks, and the crack parameters of the mudstone and shale sample were recorded. By analyzing the crack parameters, the crack opening pattern of the mudstone and shale sample was obtained. The crack defects of the mudstone and shale sample are determined based on the crack opening pattern. Obtain the pre-defined correspondence between fracture defects and oil and gas recovery strategies, and obtain the target oil and gas recovery strategy for the formation corresponding to the fracture defects based on the fracture defects and the correspondence. Oil and gas extraction is carried out in the formation where the mudstone and shale sample is located based on the target oil and gas recovery strategy.

2. The method according to claim 1, characterized in that, The fracture parameters include fracture morphology, number of fractures, fracture distribution, and fracture propagation rate; the analysis of the fracture parameters to obtain the fracture initiation pattern of the shale sample includes: The fracture type of the mudstone and shale sample is determined based on the fracture morphology and the corresponding fracture propagation rate. Based on the preset crack opening rules, the crack type, the number of cracks, and the distribution of cracks are analyzed to obtain the crack opening rules of the mudstone and shale sample.

3. A fracture simulation device, employing an oil and gas extraction method based on fracture simulation as described in claim 1 or 2, characterized in that, The crack simulation device includes: The pressurization device is equipped with a pressurization chamber for placing mudstone and shale samples; A control device, connected to the pressurizing device, is used to control the pressurizing device to: find the corresponding target pressurization rate in a preset pressurization rate data table based on the formation type of the strata where the shale sample is located; find the corresponding initial pressure value in a preset initial pressure data table based on the formation type; find the corresponding target pressure value in a preset target pressure data table based on the rock type of the shale sample; form a target pressurization rule for the shale sample based on the target pressurization rate, the initial pressure value, and the target pressure value; apply external pressure to the shale sample according to the target pressurization rule to simulate cracks, and record the crack parameters of the shale sample.

4. The crack simulation device according to claim 3, characterized in that, The pressurizing device includes: A circumferential pressure device is circumferentially positioned outside the pressurization chamber and abuts against the mudstone and shale sample. A vertical pressure device is positioned above the pressure chamber and comes into contact with the mudstone and shale sample.

5. An oil and gas extraction system based on fracture simulation, characterized in that, include: The fracture simulation module is used to find the corresponding target pressurization rate from a preset pressurization rate data table based on the formation type of the shale sample. Based on the formation type, the corresponding initial pressure value is found in the preset initial pressure data table; Based on the rock type of the shale sample, the corresponding target pressure value is found from the preset target pressure data table; based on the target pressurization rate, the initial pressure value, and the target pressure value, a target pressurization law is formed for the shale sample; according to the target pressurization law, external pressure is applied to the shale sample to simulate cracks, and the crack parameters of the shale sample are recorded. The analysis module is used to perform regular analysis on the crack parameters to obtain the crack opening pattern of the mudstone and shale sample; The strategy determination module is used to determine the fracture defects of the mudstone and shale sample based on the fracture opening law; obtain the preset correspondence between fracture defects and oil and gas recovery strategies; and obtain the target oil and gas recovery strategy of the formation corresponding to the fracture defects based on the fracture defects and the correspondence. The strategy implementation module is used to extract oil and gas from the formation where the mudstone and shale sample is located based on the target oil and gas recovery strategy.

6. A computing device, comprising a memory, a processor, and a program stored in the memory and running on the processor, characterized in that, When the processor executes the program, it implements the steps of an oil and gas extraction method based on fracture simulation as described in claim 1 or 2.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a terminal device, cause the terminal device to perform the steps of a fracture simulation-based oil and gas extraction method as described in claim 1 or 2.

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