A three-dimensional modeling method for equivalent lamellae fractures in continental shale oil reservoirs

Abstract

The present invention provides a three-dimensional modeling method for equivalent lamellae in continental shale oil reservoirs, which mainly solves the problem that existing technical methods are unable to independently establish a quantitative three-dimensional characterization model of lamellae and thus cannot provide data input for production research. It is characterized in that the present invention includes the following steps: Step 1: seismic acquisition and drilling coring in the target work area; Step 2: seismic data anisotropy prediction and core observation measurement; Step 3: establishing a three-dimensional model of lamellae line density; Step 4: establishing a three-dimensional model of equivalent lamellae body density; Step 5: establishing a three-dimensional model of equivalent lamellae. The three-dimensional modeling method for equivalent lamellae in continental shale oil reservoirs of the present invention uses seismic, geological and measurement and analysis information to establish a three-dimensional model of equivalent lamellae. This method can ensure that the development characteristics of the original lamellae and the porosity and permeability characteristics are reflected, and meet the needs of fracturing simulation and numerical simulation analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield exploration and development, and in particular to a three-dimensional modeling method for equivalent lamellae fractures in continental shale oil reservoirs. Background Art

[0002] Shale oil is currently a key research area in the domestic and international oil industry. Lamination fractures are important storage spaces and seepage channels for shale oil. Establishing a three-dimensional model of lamulation fractures is of great significance for implementing integrated geological and engineering research on shale oil and facilitating the efficient development of shale oil.

[0003] Currently, research on lamellar fractures primarily focuses on the microscale, with limited research on three-dimensional lamellar fracture modeling at the development zone level. Published literature and patents primarily employ phase-controlled modeling methods, which first use well information to determine the lithofacies and lamellar fracture intensity development pattern of a single well. Then, a lamellar fracture model is established under the control of the lithofacies model. These methods are primarily developed for marine shale gas reservoirs and are not applicable to continental pure shale oil reservoirs. This is primarily reflected in three aspects: First, the formation of continental lamellar fractures is related not only to lithofacies but also to organic carbon content and maturity. Second, the lithofacies distribution pattern and range of continental pure shale are difficult to predict, resulting in significant uncertainty in the prediction results. Third, continental pure shale fractures are densely developed, with hundreds to thousands often developing in a 1-meter-thick reservoir. Current modeling methods and software struggle to accurately characterize the distribution characteristics of lamellar fractures in three dimensions, severely hindering the design and implementation of shale oil development plans. Establishing a three-dimensional lamellar fracture model has become a crucial challenge that must be addressed during shale oil development.

[0004] Research has found that anisotropy prediction based on seismic information can reflect the relative development of lamellae, while core observations can accurately describe the density, morphology, and occurrence of lamellae at well points. Measurement and analysis can also reveal the microscopic porosity and permeability characteristics of lamellae. However, none of these technical methods can independently establish a quantitative 3D lamellae characterization model and thus provide data input for production research. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the problem that the existing technical methods in the background technology cannot independently establish a quantitative lamellae fracture three-dimensional characterization model and thus cannot provide data input for production research, and provide a three-dimensional modeling method for equivalent lamellae fractures in continental shale oil reservoirs. The three-dimensional modeling method for equivalent lamellae fractures in continental shale oil reservoirs adopts seismic, geological and measurement analysis information to establish a three-dimensional model of equivalent lamellae fractures. This method can ensure that the development characteristics of the original lamellae fractures and the porosity and permeability characteristics are reflected under the conditions to meet the needs of fracturing simulation and numerical simulation research.

[0006] The present invention solves the problem by the following technical solution: The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs comprises the following steps:

[0007] Step 1: Acquire seismic data in the target work area to obtain a 3D seismic data volume; drill and coring to obtain core samples of the target layer;

[0008] Step 2: Based on the acquired 3D seismic data volume, perform seismic data anisotropy prediction; based on the acquired target layer core samples, perform core observation and measurement;

[0009] Step 3: Based on the anisotropy prediction of seismic data and the core observation measurement results, a three-dimensional model of foliation density is established;

[0010] Step 4: Based on the established lamellae seam density 3D model, establish an equivalent lamellae seam density 3D model;

[0011] Step 5: Based on the established equivalent lamellae fracture density model, establish an equivalent lamellae fracture three-dimensional model.

[0012] Furthermore, the method of obtaining the three-dimensional seismic data volume in step 1 includes:

[0013] Explosives are fired in the target field seismic area, and geophones are used to collect signals to obtain three-dimensional seismic data.

[0014] Furthermore, the method for predicting seismic data anisotropy based on the acquired three-dimensional seismic data volume in step 2 includes:

[0015] Based on the characteristics of horizontal lamellae development in shale, the acquired 3D seismic data volume is used to perform inversion prediction of VTI medium anisotropy parameters, and anisotropic 3D data volume reflecting the relative development degree of lamellae fractures is obtained.

[0016] Furthermore, the method of performing core observation and measurement based on the obtained target layer core sample in step 2 includes:

[0017] Observe the core, record the number of lamellae at different depths and the measured core length, calculate the lamellae density at different depths; connect the lamellae density values ​​at different depths in sequence to obtain a continuous distribution curve of lamellae density in the target layer;

[0018] Determine several core sections within the target layer that can represent the density distribution characteristics of different inner fractures, and sample each core section to obtain corresponding core samples. Measure the core samples to determine the minimum, maximum, and average widths of the inner fractures.

[0019] Several sections of cores that can reflect the distribution characteristics of different page fracture widths were selected for sampling to obtain core samples. The core samples were subjected to permeability analysis and testing to obtain the minimum, maximum, and average permeabilities of the page fractures.

[0020] Furthermore, the method for calculating the lamellae density value is as follows: the number of recorded lamellae fractures is divided by the measured core length to obtain the lamellae density value;

[0021] The calculation expression is: lamellae density = number of lamellae / measured core length;

[0022] Unit: strip / m.

[0023] Furthermore, the method of establishing a three-dimensional model of foliation and suture density in step 3 includes: determining the plane range size of the model according to requirements, and using modeling software to establish a three-dimensional structural model in combination with the top and bottom surface depths of the target layer, and then inputting the foliation and suture density values ​​at different depths obtained by single well core observations and the anisotropic three-dimensional data body obtained by seismic prediction into the modeling software, and using the foliation and suture density values ​​as hard data and the anisotropic three-dimensional data body as constraint data in the three-dimensional structural model, and using the random modeling method provided by the software to obtain a three-dimensional model of foliation and suture density.

[0024] Furthermore, the method of establishing an equivalent lamina fracture density three-dimensional model in step 4 includes: determining the need to equate the actual n lamina fractures to 1 lamina fracture based on actual needs, dividing the established lamina fracture line density three-dimensional model by the value n, and obtaining the equivalent lamina fracture line density three-dimensional model, and the average value of the equivalent lamina fracture width is n multiplied by the actual average width of the lamina fracture, the minimum value of the equivalent inner lamina fracture width is n multiplied by the actual minimum width of the lamina fracture, and the maximum value of the equivalent inner lamina fracture width is n multiplied by the actual maximum width of the lamina fracture; since the lamina fractures are parallel to the rock formations and are continuously distributed, it can be seen that the lamina fracture density value per unit volume is equal to the lamina fracture line density value per unit height, and the equivalent lamina fracture density model value is equal to the equivalent lamina fracture line density model value; that is, the equivalent lamina fracture line density three-dimensional model is the equivalent lamina fracture density three-dimensional model.

[0025] The lamellae fracture density = fracture area / fracture distribution area volume, unit: 1 / m.

[0026] Furthermore, the equivalent lamellae fracture three-dimensional model in step 5 includes: an equivalent lamellae fracture three-dimensional discrete model, an equivalent lamellae fracture three-dimensional porosity model and an equivalent lamellae fracture three-dimensional permeability model.

[0027] Furthermore, the method of establishing the equivalent lamellae fracture three-dimensional model in step 5 includes: inputting the equivalent lamellae fracture density three-dimensional model as input data into a modeling software, and using a built-in stochastic simulation method of the software to establish the equivalent lamellae fracture three-dimensional discrete model;

[0028] Based on the equivalent three-dimensional discrete model of lamellae fractures, the mean, minimum and maximum values ​​of the equivalent lamellae fracture width are used as fracture width parameters, and the mean, minimum and maximum values ​​of the actual lamellae fracture permeability obtained from analysis and testing are input into the modeling software as permeability parameters. The equivalent lamellae fracture three-dimensional porosity model and equivalent lamellae fracture three-dimensional permeability model are automatically simulated by the software.

[0029] Furthermore, the modeling software is mature commercial modeling software with three-dimensional fracture modeling function, such as Petrel, FracFlow, FracMan, etc.

[0030] Compared with the above-mentioned background technology, the present invention has the following beneficial effects: the three-dimensional modeling method of equivalent lamellae fractures in continental shale oil reservoirs uses seismic, geological, and test analysis results to establish a three-dimensional model of equivalent lamellae fractures in shale oil reservoirs, which equivalently reproduces the distribution density, position, scale, and spatial distribution of lamellae fractures in three-dimensional space; at the same time, the equivalent porosity and permeability model of lamellae fractures established can reflect the numerical values ​​of porosity and permeability under actual lamellae fracture development conditions, and thus can provide support for estimating the size of lamellae fracture oil and gas reserves and their distribution characteristics, and analyzing the impact of lamellae fractures on reservoir heterogeneity. This equivalent model can provide input data for a series of shale development studies such as shale oil reservoir fracturing simulation and numerical simulation, ultimately laying a solid technical foundation for the efficient development of shale oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of a three-dimensional modeling method for equivalent lamellae fractures in continental shale oil reservoirs according to the present invention;

[0032] Figure 2 This is a seismic data volume map of a shale oil development test area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0033] Figure 3a This is a diagram showing the anisotropy prediction results for a shale oil development test area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0034] Figure 3b This is a characteristic diagram of the density distribution of lamellae observed in a core well in a shale oil development pilot area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0035] Figure 4 This is a three-dimensional model diagram of the lamellae fracture density in a shale oil development test area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0036] Figure 5a This is a three-dimensional model diagram of equivalent lamellae fracture density in a shale oil development pilot area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0037] Figure 5bThis is a three-dimensional model diagram of the equivalent lamellae density of a shale oil development test area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0038] Figure 6a This is a discrete three-dimensional model of equivalent lamella fractures in a shale oil development test area in Qijia-Gulong, Daqing, according to an embodiment of the present invention;

[0039] Figure 6b This is a three-dimensional model of equivalent lamellae porosity in a shale oil development pilot area in Qijia-Gulong, Daqing, according to an embodiment of the present invention.

[0040] Figure 6c This is a three-dimensional model of equivalent lamella permeability in a shale oil development test area in Qijia-Gulong, Daqing, according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings:

[0042] As attached Figure 1 As shown, the 3D modeling method of equivalent lamella fractures of continental shale oil reservoirs includes the following steps:

[0043] Step 1: Acquire seismic data in the target work area to obtain a 3D seismic data volume; drill and coring to obtain core samples of the target layer;

[0044] The method for obtaining a three-dimensional seismic data volume comprises:

[0045] Explosives are fired in the target field seismic area, and geophones are used to collect signals to obtain three-dimensional seismic data.

[0046] Step 2: Based on the acquired 3D seismic data volume, perform seismic data anisotropy prediction; based on the acquired target layer core samples, perform core observation and measurement;

[0047] The method for predicting seismic data anisotropy based on the acquired three-dimensional seismic data volume includes:

[0048] Based on the characteristics of horizontal lamellae development in shale, the acquired 3D seismic data volume is used to perform inversion prediction of VTI medium anisotropy parameters, and anisotropic 3D data volume reflecting the relative development degree of lamellae fractures is obtained.

[0049] The method for performing core observation and measurement based on the obtained target layer core sample includes:

[0050] Observe the core, record the number of lamellae at different depths and the measured core length, calculate the lamellae density at different depths; connect the lamellae density values ​​at different depths in sequence to obtain a continuous distribution curve of lamellae density in the target layer;

[0051] Determine several core sections within the target layer that can represent the density distribution characteristics of different inner fractures, and sample each core section to obtain corresponding core samples. Measure the core samples to determine the minimum, maximum, and average widths of the inner fractures.

[0052] Several sections of cores that can reflect the distribution characteristics of different page fracture widths were selected for sampling to obtain core samples. The core samples were subjected to permeability analysis and testing to obtain the minimum, maximum, and average permeabilities of the page fractures.

[0053] The calculation method of the lamina line density value is as follows: the number of recorded lamina line fractures is divided by the measured core length to obtain the lamina line density value;

[0054] The calculation expression is: lamellae density = number of lamellae / measured core length;

[0055] Unit: strip / m.

[0056] Step 3: Based on the anisotropy prediction of seismic data and the core observation measurement results, a three-dimensional model of foliation density is established;

[0057] The method for establishing a three-dimensional model of lamellae seam density comprises:

[0058] The plane range of the model is determined according to the needs, and a three-dimensional structural model is established using modeling software in combination with the top and bottom depths of the target layer. Then, the lamellae suture density values ​​at different depths obtained from single well core observations and the anisotropic three-dimensional data volume obtained from seismic prediction are input into the modeling software. In the three-dimensional structural model, the lamellae suture density values ​​are used as hard data and the anisotropic three-dimensional data volume is used as constraint data. The random modeling method provided by the software is used to obtain a three-dimensional model of lamellae suture density.

[0059] Step 4: Based on the established lamellae seam density 3D model, establish an equivalent lamellae seam density 3D model;

[0060] The method for establishing a three-dimensional model of equivalent lamellae fracture density comprises:

[0061] According to actual needs, it is determined that the actual n lamina fractures need to be equivalent to 1 lamina fracture, and the established lamina fracture line density three-dimensional model is divided by the value n to obtain the equivalent lamina fracture line density three-dimensional model, and the average width of the equivalent lamina fracture is n multiplied by the actual average width of the lamina fracture, the minimum width of the equivalent inner lamina fracture is n multiplied by the actual minimum width of the lamina fracture, and the maximum width of the equivalent inner lamina fracture is n multiplied by the actual maximum width of the lamina fracture. Since the lamina fractures are parallel to the rock strata and are continuously distributed, it can be seen that the density value of the lamina fracture body in unit volume is equal to the density value of the lamina fracture line in unit height, and the equivalent lamina fracture body density model value is equal to the equivalent lamina fracture line density model value. That is, the equivalent lamina fracture line density three-dimensional model is the equivalent lamina fracture body density three-dimensional model.

[0062] The density of lamellae is the fracture area divided by the volume of the fracture distribution area.

[0063] The calculation expression is: lamella fracture density = fracture area / fracture distribution area volume;

[0064] Unit: 1 / m.

[0065] Step 5: Based on the established equivalent lamellae fracture density model, establish an equivalent lamellae fracture three-dimensional model.

[0066] The equivalent lamellae fracture three-dimensional model includes: an equivalent lamellae fracture three-dimensional discrete model, an equivalent lamellae fracture three-dimensional porosity model and an equivalent lamellae fracture three-dimensional permeability model.

[0067] The method for establishing an equivalent lamella fracture three-dimensional model comprises:

[0068] The equivalent lamellae fracture density three-dimensional model is input as input data into the modeling software, and the software's built-in random simulation method is used to establish an equivalent lamellae fracture three-dimensional discrete model. Based on the equivalent lamellae fracture three-dimensional discrete model, the mean, minimum and maximum values ​​of the equivalent lamellae fracture width are used as fracture width parameters, and the mean, minimum and maximum values ​​of the actual lamellae fracture permeability obtained from analysis and testing are input as permeability parameters into the modeling software. The equivalent lamellae fracture three-dimensional porosity model and equivalent lamellae fracture three-dimensional permeability model are obtained through automatic simulation by the software.

[0069] The modeling software is mature commercial modeling software with three-dimensional fracture modeling function, such as Petrel, FracFlow, FracMan, etc.

[0070] Example 1:

[0071] The implementation process of the method of the present invention is illustrated by taking a shale oil development test area of ​​Qijia-Gulong in Daqing Oilfield as an example. Figure 1 As shown in Figure 2, the 3D modeling method for equivalent lamella fractures in the shale oil reservoir in the study area mainly includes the following steps:

[0072] Step 1: Seismic acquisition and drilling coring in the target work area;

[0073] Seismic data were collected in the test area to obtain a three-dimensional seismic data volume (such as Figure 2 ). Drilling was carried out in the experimental area, and the target layer section was cored to obtain the core of well 1.

[0074] The method for obtaining a three-dimensional seismic data volume comprises: performing explosive excitation in a field target seismic work area, and using a geophone to collect signals to obtain a three-dimensional seismic data volume.

[0075] Step 2: Predict anisotropy of seismic data and conduct core observation and measurement

[0076] Using seismic data to perform reservoir anisotropy inversion prediction, we can obtain anisotropic three-dimensional data reflecting the relative degree of lamellar fracture development (e.g. Figure 3a ); observe and describe the core, record the density of lamellae at different positions in the target layer (Q1-Q9), connect the density of lamellae at different positions, and obtain the lamellae distribution curve reflecting the longitudinal development characteristics of lamellae in the target layer (such as Figure 3b ); 4 locations with different degrees of lamellae development were determined, and core samples were taken at these locations. The widths of the lamellae were measured respectively, and the minimum width of the actual lamellae was 0.4μm, the maximum width was 6μm, and the average width was 3μm; the permeability test and analysis of the core samples showed that the maximum horizontal permeability of the core samples was 0.15md, the minimum horizontal permeability was 0.048md, and the average horizontal permeability was 0.095md. Since the lamellae are parallel to the rock surface and their permeability is much greater than the matrix permeability, the measured horizontal permeability of the core samples can be considered as the lamellae permeability.

[0077] Step 3: Build a 3D model of lamella density

[0078] With the Q1 layer as the bottom surface and the Q9 layer as the top surface, a three-dimensional structural model was established using the Petrel software. The lamellae density curve data obtained from core observation and the anisotropic three-dimensional data volume obtained from seismic prediction were input into the Petrel modeling software. Within the scope of the three-dimensional structural model, the lamellae density value was used as hard data and the anisotropic three-dimensional data volume was used as constraint data. The stochastic modeling method provided by the software was used to establish a three-dimensional model of lamellae density (such as Figure 4 ).

[0079] Step 4: Establish an equivalent lamellae density model

[0080] The actual lamellae density values ​​in the Q1-Q9 layers range from 200 / m2 to 2500 / m2, which seriously exceeds the actual computing capacity of the modeling software. It is impossible to establish the actual lamellae spatial morphology, porosity, and permeability distribution characteristic model. According to actual needs, the actual 50 lamellae are equivalent to one lamellae, that is, one lamellae is used to equivalently reflect the total morphology, porosity, and permeability characteristics of 50 lamellae. The equivalent lamellae density model can be obtained by dividing the actual lamellae density model value by 50 (e.g. Figure 5a ), and the average width of the equivalent lamellar fracture is 50×3μm=150μm, the minimum width of the equivalent lamellar fracture is 50×0.4μm=20μm, and the maximum width of the equivalent lamellar fracture is 50×6μm=300μm. Since the lamellar fractures are parallel to the rock layer and are continuously distributed, it can be seen that the lamellar fracture density value per unit volume is equal to the lamellar fracture line density value per unit height, that is, the equivalent lamellar fracture density model value is equal to the equivalent lamellar fracture line density model value, and then the equivalent lamellar fracture density model (such as Figure 5b ).

[0081] Step 5: Establish a 3D model of the equivalent lamellae

[0082] The obtained equivalent lamellae fracture density model is used as input data, the rock layer dip angle is used as the fracture dip angle input, and the built-in random simulation method of petrel software is used to obtain the equivalent lamellae fracture three-dimensional discrete model reflecting the three-dimensional spatial distribution characteristics of lamellae fractures (such as Figure 6a ). Based on the equivalent lamellae fracture three-dimensional discrete model, the equivalent lamellae fracture width mean value of 150μm, minimum value of 20μm, and maximum value of 300μm are input as crack width parameters. In order to ensure that the permeability distribution characteristics of the equivalent model are consistent with the actual permeability distribution characteristics, when inputting the permeability parameters, the measured permeability values ​​need to be input as parameters, that is, the actual lamellae fracture permeability mean value of 0.095md, minimum value of 0.048md, maximum value of 0.15md, and standard deviation of 0.036md obtained by analysis and testing are input as permeability parameters into the modeling software, and the equivalent lamellae fracture porosity three-dimensional model (such as Figure 6b ) and permeability three-dimensional models (such as Figure 6c ).

[0083] The equivalent lamellae fracture three-dimensional spatial distribution model (such as Figure 6a ), porosity three-dimensional model (such as Figure 6b ) and permeability three-dimensional models (such as Figure 6c), it can be seen that the method of the present invention can establish a model that reflects the three-dimensional spatial morphological and structural characteristics of lamellae fractures, as well as the porosity and permeability distribution characteristics. This equivalent model effectively reproduces the density, location, scale, and spatial distribution of lamellae fractures in three dimensions. It can also provide input data for a range of shale development research, such as shale oil reservoir fracturing simulation and numerical simulation, ultimately laying a solid technical foundation for the profitable development of shale oil.

[0084] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation of the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Therefore, the content of the present invention is not limited to the examples listed, and any equivalent transformations of the technical solutions of the present invention made by ordinary technicians in this field after reading the specification of the present invention are all covered by the claims of the present invention.

Claims

1. A three-dimensional modeling method for equivalent lamella fractures in continental shale oil reservoirs, characterized by: The following steps are involved: Step 1: Acquire seismic data in the target work area to obtain a 3D seismic data volume; Drilling and coring to obtain core samples of target layer; Step 2: Based on the acquired 3D seismic data volume, perform seismic data anisotropy prediction; Based on the obtained target layer core samples, core observation and measurement are carried out, including: Based on the characteristics of horizontal lamellae development in shale, the acquired 3D seismic data volume is used to perform inversion prediction of VTI medium anisotropy parameters, and anisotropic 3D data volume reflecting the relative development degree of lamellae fractures is obtained. Step 3: Based on the anisotropy prediction of seismic data and the core observation measurement results, a three-dimensional model of foliation density is established; Step 4: Based on the established lamellae seam density 3D model, establish an equivalent lamellae seam density 3D model; specifically, it includes: According to actual needs, it is determined that the actual n lamina fractures need to be equivalent to 1 lamina fracture, and the established lamina fracture line density three-dimensional model is divided by the value n to obtain the equivalent lamina fracture line density three-dimensional model, and the equivalent lamina fracture width average value is n multiplied by the actual lamina fracture average width, the equivalent lamina fracture width minimum value is n multiplied by the actual lamina fracture minimum width, and the equivalent lamina fracture width maximum value is n multiplied by the actual lamina fracture maximum width; since lamina fractures are parallel to the rock layer and are continuously distributed, it can be seen that the lamina fracture density value per unit volume is equal to the lamina fracture line density value per unit height, and the equivalent lamina fracture body density model value and the equivalent lamina fracture line density model value are equal in size; that is, the equivalent lamina fracture line density three-dimensional model is the equivalent lamina fracture body density three-dimensional model; Step 5: Based on the established equivalent lamellae fracture density 3D model, establish an equivalent lamellae fracture 3D model.

2. The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs according to claim 1, characterized in that: The method of obtaining the three-dimensional seismic data volume in step 1 includes: Explosives are fired in the target field seismic area, and geophones are used to collect signals to obtain three-dimensional seismic data.

3. The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs according to claim 1, characterized in that: The method for performing core observation and measurement based on the obtained target layer core sample in step 2 includes: Observe the core, record the number of lamellae at different depths and the measured core length, calculate the density of lamellae at different depths; connect the density values ​​of lamellae at different depths in sequence to obtain a continuous distribution curve of lamellae density in the target layer; Identify several core sections within the target layer that can represent the density distribution characteristics of different lamellae, and sample each section to obtain corresponding core samples. Measure the core samples to determine the minimum, maximum, and average widths of the lamellae. Several core sections that can reflect the distribution characteristics of different lamellae fracture widths were selected for sampling to obtain core samples. The core samples were subjected to permeability analysis and testing to obtain the minimum, maximum and average permeabilities of the lamellae fractures.

4. The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs according to claim 3, characterized in that: The calculation method of the lamellae density value is: the lamellae density value is obtained by dividing the recorded number of lamellae by the measured core length.

5. The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs according to claim 1, characterized in that: The method of establishing the three-dimensional model of lamellae density in step 3 includes: The planar range of the model is determined according to the requirements, and a three-dimensional structural model is established using modeling software in combination with the top and bottom depths of the target layer. Then, the lamellae and suture density values ​​at different depths obtained from single well core observations and the anisotropic three-dimensional data volume obtained from seismic prediction are input into the modeling software. Within the three-dimensional structural model, the lamellae and suture density values ​​are used as hard data, and the anisotropic three-dimensional data volume is used as constraint data. The stochastic modeling method provided by the software is used to obtain a three-dimensional model of lamellae and suture density.

6. The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs according to claim 1, characterized in that: The equivalent sheet fracture three-dimensional model in step 5 includes: Equivalent lamellae fracture 3D discrete model, equivalent lamellae fracture 3D porosity model and equivalent lamellae fracture 3D permeability model; The methods for establishing the equivalent lamella fracture 3D model include: The equivalent lamellae fracture density 3D model is input into the modeling software as input data, and the software's built-in stochastic simulation method is used to establish an equivalent lamellae fracture 3D discrete model. Based on the equivalent three-dimensional discrete model of lamellae fractures, the mean, minimum and maximum values ​​of the equivalent lamellae fracture width are used as fracture width parameters, and the mean, minimum and maximum values ​​of the actual lamellae fracture permeability obtained from analysis and testing are input into the modeling software as permeability parameters. The equivalent lamellae fracture three-dimensional porosity model and equivalent lamellae fracture three-dimensional permeability model are automatically simulated by the software.

7. The method for three-dimensional modeling of equivalent lamellae fractures in continental shale oil reservoirs according to claim 5 or 6, characterized in that: The modeling software is Petrel, FracFlow or FracMan.

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