Method and device for analyzing permeability of weathered sandstone

Abstract

The invention relates to the technical field of geotechnical engineering, in particular to a weathered sandstone permeability analysis method and device.The method comprises the steps that sandstone samples of different weathering degrees are collected and processed into cylindrical samples, and a CT scanning technology is adopted, and sandstone three-dimensional data volumes of different weathering degrees are obtained through the cylindrical samples; based on the sandstone three-dimensional data body, extracting a pore data body of the sandstone sample; and based on the pore data volume, extracting a connected pore network to construct a pore seepage model, and outputting the weathered sandstone permeability by using the pore seepage model. Therefore, the problems of limited prediction precision, difficulty in meeting actual engineering requirements and the like caused by difficulty in comprehensively capturing complex change of the microstructure in the weathering process and influence of the complex change on the permeability due to the fact that most of related technologies are based on experimental measurement or numerical simulation are solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of geotechnical engineering, in particular to a weathered sandstone permeability analysis method and an analysis device. BACKGROUND

[0002] In the related art, sandstone is widely distributed in the natural environment, and its weathering behavior is of great significance to geological disaster prediction, rock mass stability evaluation and resource exploration. In-depth analysis of weathering behavior can reveal the change law of rock mass physical and mechanical properties, improve the scientific nature of risk warning and engineering design, and bring more accurate geological evaluation and resource development effect.

[0003] However, in the related art, most analysis methods are based on experimental measurement or numerical simulation, which has the problems of limited sample size, difficulty in completely reproducing the natural weathering environment in the experiment, and the numerical simulation model usually simplifies the microstructure of the rock, which is difficult to accurately reflect the influence of pore change and fracture development on permeability in the weathering process, resulting in large errors in the prediction results, and it is difficult to meet the actual engineering needs and other problems, which need to be solved urgently. SUMMARY

[0004] The application provides a weathered sandstone permeability analysis method and analysis device for cloud edge integration to solve the technical problem that in the related art, the analysis of weathered sandstone permeability is mostly based on experimental measurement or numerical simulation, it is difficult to fully capture the complex changes of microstructure in the weathering process and its influence on permeability, resulting in limited prediction accuracy and difficulty in meeting the actual engineering needs.

[0005] The first aspect of the application provides a weathered sandstone permeability analysis method, comprising the following steps: collecting sandstone samples of different weathering degrees, processing the sandstone samples into cylindrical samples, and using CT (Computed Tomography, computed tomography) scanning technology to obtain three-dimensional data volume of sandstone of different weathering degrees by using the cylindrical samples; based on the three-dimensional data volume of the sandstone, extracting the pore data volume of the sandstone sample; based on the pore data volume, extracting the connected pore network to construct a pore seepage model, so that the weathered sandstone permeability is output by using the pore seepage model.

[0006] Through the above technical means, CT scanning technology can be used for non-destructive testing of weathered sandstone to obtain three-dimensional pore data volume that truly reflects the internal structure of the rock, and a refined pore seepage model can be further constructed to accurately characterize the pore structure evolution process and realize quantitative prediction of the permeability of weathered sandstone.

[0007] Optionally, in an embodiment of the present application, the extracting the pore data volume of the sandstone sample comprises: determining a minimum unit data volume satisfying a preset representative volume requirement based on the sandstone three-dimensional data volume, taking porosity as a key constraint parameter; performing spatial filtering processing on the original data of the sandstone three-dimensional data volume to obtain a pretreated gray image, by optimizing the sequence slice data; performing binaryzation processing on the pretreated gray image, and distinguishing a pore phase from a mineral matrix phase based on the minimum unit data volume to determine the pore data volume.

[0008] By the above technical means, the minimum unit data volume is determined by taking porosity as a key constraint parameter, which can ensure that the selected data volume has representativeness and analysis value, improve calculation efficiency and processing accuracy, and perform pretreatment operations such as filtering and binaryzation on the original sequence, thereby improving image quality and pore boundary recognition effect, and laying a reliable foundation for subsequent extraction of three-dimensional pore data volume and establishment of a percolation model.

[0009] Optionally, in an embodiment of the present application, the constructing the pore percolation model comprises: performing Gaussian filtering smoothing processing on a pore surface of a connected pore network, and optimizing and simplifying a surface grid of the pore surface and repairing a topological problem of the surface to generate a tetrahedral grid satisfying a preset quality condition; generating training data based on the tetrahedral grid to train the pore percolation model.

[0010] By the above technical means, the pore surface is subjected to Gaussian filtering smoothing processing, which can realize smoothing of the pore boundary and reduce the influence of surface noise on subsequent modeling accuracy; further optimization and simplification of the triangular grid structure of the pore surface can effectively reduce redundant patches and improve geometric modeling efficiency; and the existing surface topological defects are automatically repaired, which can ensure the closure and connectivity of the model, and provide high-quality and highly usable geometric data for subsequent percolation simulation and deep learning training based on the pore structure.

[0011] Optionally, in an embodiment of the present application, the causing the pore percolation model to output the weathered sandstone permeability comprises: determining a control equation describing the motion of a pore fluid; setting boundary conditions and parameters to obtain simulation results in combination with the control equation, wherein the weathered sandstone permeability is obtained by integral calculation on an outlet boundary.

[0012] By the above technical means, reasonable boundary conditions and parameter settings are applied, and integral calculation is performed on the outlet boundary, which can ensure that the numerical simulation process has good physical consistency and calculation accuracy, and further obtain key indicators such as fluid flow, so as to realize quantitative solution of the sandstone permeability, thereby effectively improving the credibility and engineering practicability of the model prediction results.

[0013] The second aspect of the present application provides a weathered sandstone permeability analysis device, including: an acquisition module for collecting sandstone samples with different degrees of weathering, processing the sandstone samples into cylindrical specimens, and using CT scanning technology to use the cylindrical specimens to obtain three-dimensional data bodies of sandstones with different degrees of weathering; an extraction module for extracting a pore data body of the sandstone sample based on the three-dimensional sandstone data body; and an analysis module for extracting a connected pore network based on the pore data body to construct a pore seepage model, so that the permeability of the weathered sandstone can be output using the pore seepage model.

[0014] Through the above technical means, CT scanning technology can be used to perform non-destructive testing on weathered sandstone, obtain three-dimensional pore data that truly reflects the internal structure of the rock, and further construct a refined pore seepage model, which can characterize the pore structure evolution process with high precision and realize quantitative prediction of the permeability of weathered sandstone.

[0015] Optionally, in one embodiment of the present application, the extraction module includes: a first determination unit, used to determine the minimum unit data volume that meets the preset representative volume requirements based on the sandstone three-dimensional data volume and with porosity as the key constraint parameter; an acquisition unit, used to optimize the original data of the sandstone three-dimensional data volume to perform spatial filtering on the serial slice data to obtain a preprocessed grayscale image; a second determination unit, used to binarize the preprocessed grayscale image and, based on the minimum unit data volume, distinguish between the pore phase and the mineral matrix phase to determine the pore data volume.

[0016] Through the above technical means, porosity is used as the key constraint parameter to determine the minimum unit data volume, which can ensure the representativeness and analytical value of the selected data volume, while improving the computational efficiency and processing accuracy. Preprocessing operations such as filtering and binarization of the original sequence can improve image quality and pore boundary recognition effect, laying a reliable foundation for the subsequent extraction of three-dimensional pore data volume and establishment of seepage model.

[0017] Optionally, in one embodiment of the present application, the analysis module includes: a generation unit for performing Gaussian filtering and smoothing on the pore surface of the connected pore network, and optimizing and simplifying the surface mesh of the pore surface and repairing the topological problems of the surface to generate a tetrahedral mesh that meets preset quality conditions; a training unit for generating training data based on the tetrahedral mesh to train the pore seepage model.

[0018] By means of the above technical means, the pore surface is subjected to Gaussian filtering and smoothing processing, so that the smoothing of the pore boundary can be realized, and the influence of surface noise on the subsequent modeling accuracy can be reduced. Further optimization and simplification of the triangular mesh structure of the pore surface can effectively reduce redundant patches and improve the geometric modeling efficiency. Meanwhile, the automatic repair of the existing surface topological defects can ensure the closure and connectivity of the model, and provide high-quality and highly usable geometric data for subsequent seepage simulation and deep learning training based on the pore structure.

[0019] Optionally, in an embodiment of the present application, the analysis module comprises: a third determination unit configured to determine a control equation describing fluid motion in pores; and a solving unit configured to set boundary conditions and parameters to obtain simulation results in combination with the control equation, wherein the weathered sandstone permeability is solved by integral calculation on an outlet boundary.

[0020] By means of the above technical means, reasonable boundary conditions and parameter settings are applied, and integral calculation is performed on the outlet boundary, so that the numerical simulation process can have good physical consistency and calculation accuracy, and then the key indicators such as fluid flow can be obtained, so that the quantitative solution of the sandstone permeability can be realized, thereby effectively improving the credibility and engineering practicability of the model prediction results.

[0021] The third aspect embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the weathered sandstone permeability analysis method as described in the above embodiments.

[0022] The fourth aspect embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the weathered sandstone permeability analysis method as described above.

[0023] The fifth aspect embodiment of the present application provides a computer program product comprising a computer program, which is executed to implement the weathered sandstone permeability analysis method as described above.

[0024] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings, wherein:

[0026] Figure 1 A flowchart of a weathered sandstone permeability analysis method according to an embodiment of the present application is provided.

[0027] Figure 2 An extraction diagram of a weathered sandstone pore data body according to an embodiment of the present application;

[0028] Figure 3 An establishment diagram of a weathered sandstone pore percolation model according to an embodiment of the present application;

[0029] Figure 4 A boundary condition setting diagram of a weathered sandstone pore percolation model according to an embodiment of the present application;

[0030] Figure 5 A pressure and flow line distribution cloud diagram of a weathered sandstone pore percolation model according to an embodiment of the present application;

[0031] Figure 6 A flowchart of weathered sandstone permeability calculation according to an embodiment of the present application;

[0032] Figure 7 A block diagram of a weathered sandstone permeability analysis device according to an embodiment of the present application;

[0033] Figure 8 A structural diagram of an electronic device according to an embodiment of the present application.

[0034] Reference Signs:

[0035] 10-weathered sandstone permeability analysis device; 100-acquisition module, 200-extraction module and 300-analysis module; 801-memory, 802-processor and 803-communication interface. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0037] A weathered sandstone permeability analysis method and analysis device of embodiments of the present application are described below with reference to the accompanying drawings. In view of the technical problems in the background art that the analysis of the permeability of weathered sandstone is mostly based on experimental measurement or numerical simulation, it is difficult to fully capture the complex changes of the microstructure during weathering and its influence on the permeability, resulting in limited prediction accuracy and difficulty in meeting the actual engineering needs, the present application provides a weathered sandstone permeability analysis method. In the method, sandstone samples of different weathering degrees are collected, and CT scanning technology is used to obtain a three-dimensional pore data volume of the sandstone. Based on the pore data volume, a connected pore network is extracted to construct a pore seepage model, and the permeability of the weathered sandstone is predicted. It can truly reflect the change characteristics of the internal pore structure of the sandstone during weathering, realize accurate simulation of seepage behavior under complex pore structure, can quantify the influence of different weathering degrees on permeability, improve the scientificity and accuracy of permeability evaluation, and has good adaptability and wide engineering application value. Thus, the problem that the related art is mostly based on experimental measurement or numerical simulation, it is difficult to fully capture the complex changes of the microstructure during weathering and its influence on the permeability, resulting in limited prediction accuracy and difficulty in meeting the actual engineering needs.

[0038] Specifically, Figure 1 A flowchart of a weathered sandstone permeability analysis method provided by embodiments of the present application is shown.

[0039] As Figure 1 shown, the weathered sandstone permeability analysis method includes the following steps:

[0040] In step S101, sandstone samples of different weathering degrees are collected, and the sandstone samples are processed into cylindrical samples, and CT scanning technology is used to obtain a three-dimensional data volume of the sandstone of different weathering degrees using the cylindrical samples.

[0041] The three-dimensional data volume of the sandstone can include, but is not limited to, pore, permeability, density, saturation, stress distribution, velocity (such as seismic wave velocity), resistivity, temperature, etc.

[0042] CT scanning technology is a technology that uses X-rays to scan an object from multiple angles and reconstructs the collected data using a computer to generate two-dimensional slice images or three-dimensional reconstruction images of the internal structure of the object.

[0043] In the embodiments of the present application, after collecting sandstone samples with different weathering degrees, the samples can be processed into cylindrical samples with a diameter of 8 mm and a length of 16 mm by wire cutting technology, and micron-level CT scanning technology is used to obtain three-dimensional data of sandstone with different weathering degrees, which makes preliminary preparations for subsequent three-dimensional pore data extraction and seepage simulation. The resolution of the micron-level CT scanner can be set to identify micron-level pores, and the X-ray source parameters are optimized and adjusted according to the sample density and size to ensure high-fidelity characterization of micron-level pores.

[0044] In step S102, based on the three-dimensional data of the sandstone, the pore data of the sandstone sample is extracted.

[0045] The pore data is a data cube describing the porosity distribution inside the rock or material in three-dimensional space obtained by geological modeling, CT scanning, seismic inversion, numerical simulation and other technical means. Each voxel (volume pixel) contains porosity or other related attribute information.

[0046] Optionally, in an embodiment of the present application, the pore data of the sandstone sample is extracted, including: based on the three-dimensional data of the sandstone, determining a minimum unit data cube that meets a preset representative volume requirement with porosity as a key constraint parameter; optimizing the original data of the three-dimensional data of the sandstone to perform spatial filtering processing on the sequence slice data to obtain a preprocessed gray image; performing binaryzation processing on the preprocessed gray image, and based on the minimum unit data cube, distinguishing the pore phase from the mineral matrix phase to determine the pore data.

[0047] As a specific example, as shown in FIG. 1, based on the three-dimensional data of the weathered sandstone obtained by CT scanning, the extraction of the three-dimensional pore data is realized, and the specific steps can be as follows: Figure 2

[0048] (a) First, the weathered sandstone sample can be collected in the embodiments of the present application, and prepared into a cylinder that meets the sample size for CT scanning, and the three-dimensional original data of the weathered sandstone sample is obtained by CT scanning.

[0049] (b) Secondly, the determination of the representative voxel can be performed in the embodiments of the present application, and the minimum unit data cube that meets the representative volume requirement is determined by statistical analysis with porosity as a key constraint parameter.

[0050] The determination method of the representative voxel can be: taking porosity as a constraint, expanding the cubic volume step by step until the porosity tends to be stable, and selecting the minimum representative volume unit as an analysis unit, which can ensure the statistical effectiveness of the analysis result and reduce the consumption of computing resources.

[0051] ​(c) Then, the embodiment of the present application can optimize the original data by using digital image processing technology, and perform spatial filtering processing on the sequence slice data by using a median filtering algorithm.

[0052] (d) Finally, the embodiment of the present application can realize phase separation by using image segmentation technology, perform binaryzation processing on the preprocessed gray-scale image by using a proper threshold algorithm, accurately distinguish the pore phase and the mineral matrix phase, and thus complete extraction of the three-dimensional pore data volume.

[0053] The embodiment of the present application can effectively process the sandstone sequence slice image obtained by CT scanning by determining a representative volume, using image preprocessing methods such as median filtering and image binaryzation, effectively remove noise interference, enhance the geometric feature expression of the pore structure, effectively improve the recognition accuracy of the pore boundary and the reliability of the data, and provide high-quality basic data for subsequent pore network modeling and percolation property research.

[0054] In step S103, based on the pore data volume, a connected pore network is extracted to construct a pore percolation model, so that the weathered sandstone permeability is output by using the pore percolation model.

[0055] Optionally, in an embodiment of the present application, constructing the pore percolation model comprises: performing Gaussian filtering smoothing processing on a pore surface of the connected pore network, and optimizing and simplifying a surface mesh of the pore surface and repairing a topological problem of the surface to generate a tetrahedral mesh meeting a preset quality condition.

[0056] Specifically, as shown in FIG. 5, the weathered sandstone pore percolation model establishment can include the following steps: Figure 3

[0057] (a) Based on the three-dimensional pore data volume of the weathered sandstone obtained by CT scanning, the AxisConnectivity algorithm of the AVIZO software is used to extract the connected pore network and remove isolated pores.

[0058] (b) For the roughness problem of the pore surface caused by voxel aliasing, Gaussian filtering smoothing processing is performed.

[0059] (c) The surface mesh is optimized and simplified based on a curvature adaptive algorithm.

[0060] (d) Since the complex pore structure is prone to defect meshes, the embodiment of the present application can use a surface editing tool to repair topological problems such as intersecting surfaces, non-manifold edges and holes, and finally generate a high-quality tetrahedral mesh.

[0061] ​It should be noted that in the embodiments of the present application, the surface smoothing treatment can include but is not limited to a noise reduction algorithm and a pore segmentation algorithm; the mesh simplification can adopt a curvature adaptive algorithm, the flat area can be sparsely meshed, and the high curvature area can be densely meshed; the mesh repair can include but is not limited to filling gaps, eliminating intersections and geometry optimization, and ensuring that the mesh quality meets the requirements of finite element simulation.

[0062] The embodiments of the present application can use AVIZO software to analyze the connectivity of the pore structure, eliminate invalid pores, reduce surface noise interference through Gaussian smoothing processing, and adopt a curvature adaptive surface simplification algorithm to sparsely mesh the flat area while ensuring the accuracy of the high curvature area. In combination with the surface mesh repair operation, topological defects are eliminated, and the physical rationality of the seepage model is ensured, so that the calculation efficiency of the three-dimensional model can be significantly improved, a high-quality calculation model meeting the numerical stability requirements is provided for subsequent pore-scale seepage simulation, and the calculation resource consumption is effectively reduced while the simulation accuracy is taken into account.

[0063] The pore seepage model of the present application is described in detail below with a specific example.

[0064] In the embodiments of the present application, the Navier-Stokes (N-S) equation can be used to describe the pore fluid motion, which can be specifically as follows:

[0065]

[0066] Wherein, V represents the flow rate, unit: m / s; μ is the viscosity coefficient of water, unit: Pa·s; P represents the pressure borne by the water, unit: Pa.

[0067] Further, the embodiments of the present application can use Darcy's law to calculate the permeability, and the formula can be as follows:

[0068]

[0069] Wherein, k is the permeability, unit: m 2 ; Q is the volume flow rate, unit: m 3 / s; ΔP represents the pressure difference of the boundaries on the inflow and outflow sides, unit: Pa; μ is the viscosity coefficient of the fluid, unit: Pa·s; L represents the length of the sandstone core, unit: m; A is the cross-sectional area of the sandstone core, unit: m 2 .

[0070] The embodiment of the present application establishes a fluid dynamics model at the microscale based on the NS equation, combines key parameters such as viscosity coefficient, water pressure and core geometry, and then calculates the permeability. This can achieve an accurate description and numerical simulation of the seepage process, fully consider the impact of actual physical conditions on fluid movement, improve the physical authenticity and adaptability of the permeability prediction results, and provide scientific and reliable technical support for the analysis of seepage behavior under complex geological conditions.

[0071] Optionally, in one embodiment of the present application, the permeability of weathered sandstone is outputted using a pore seepage model, including: determining a control equation describing the movement of pore fluid; setting boundary conditions and parameters to combine the control equation to obtain simulation results, wherein the permeability of weathered sandstone is solved by integrating the outlet boundary.

[0072] It should be noted that in the embodiments of the present application, the control equations of fluid motion can be the Navier-Stokes equations, assuming that the fluid is an incompressible Newtonian fluid and the flow state is laminar. The fluid parameters in the boundary conditions can be set according to preset physical properties to ensure that the simulation results are consistent with the actual behavior.

[0073] For example, Figure 4 As shown, the boundary conditions of the embodiment of the present application can be to maintain a constant flow rate at the inlet, set another constant flow rate (or free outflow) at the outlet, and limit the fluid to flow in a specific direction, thereby simulating the driving force and flow direction in the actual seepage process.

[0074] In some cases, such as Figure 5 As shown, based on the established pore seepage model, the embodiment of the present application can use the Navier-Stokes equation to describe the pore fluid movement, and can set room temperature pure water (density 1000g / m 3 , viscosity coefficient 0.001 Pa·s) was used as the simulated fluid, and water pressure boundary conditions of 1 kPa and 0 kPa were applied at the inlet and outlet, respectively, to achieve steady-state seepage simulation.

[0075] It can be understood that the embodiment of the present application can calculate the permeability by integrating the outlet boundary flow and comparing the numerical simulation results with the indoor seepage experimental data to ensure the reliability of the model solution, thereby providing a quantitative analysis basis for the study of the permeability characteristics of weathered sandstone.

[0076] As a possible implementation method, the permeability calculation formula can be based on the seepage law. Through the correlation calculation of volume flow rate, fluid viscosity coefficient, core length, cross-sectional area and pressure difference, cross-scale modeling can be simplified and computational efficiency can be improved.

[0077] In the embodiments of the present application, the sample for the overburden pressure seepage simulation can be a standardized cylindrical sample, and the simulated pressure gradient and temperature can be preset according to the simulation conditions to improve the test accuracy.

[0078] The numerical calculation of the permeability of weathered sandstone is described in detail below with a specific example.

[0079] As shown in Figure 6 The embodiments of the present application can include the following steps:

[0080] Step S601, sample preparation and CT scanning.

[0081] The embodiments of the present application can collect weathered sandstone samples, prepare them into sample sizes conforming to CT scanning, use CT scanning technology to obtain the three-dimensional data volume of the weathered sandstone samples, and provide data support for subsequent three-dimensional pore reconstruction and establishment of a pore seepage model.

[0082] Step S602, extraction of three-dimensional pore data of weathered sandstone.

[0083] Specifically, based on the three-dimensional data volume of weathered sandstone, first, the representative characterization volume element for subsequent modeling can be determined through porosity constraint analysis, then the slice data is subjected to median filtering processing to reduce noise generated in the CT scanning process, and finally, the three-dimensional pore data volume of the weathered sandstone is extracted through binarization processing of the slice data.

[0084] Step S603, establishment of a pore seepage model of weathered sandstone.

[0085] In the embodiments of the present application, the pore seepage model can be established based on the extracted three-dimensional pore data volume of weathered sandstone. First, the connected pores in the pore structure can be extracted through the Axis Connectivity command in AVIZO, and the isolated pores are removed, then the pore data volume surface is smoothed to reduce the roughness and complexity of the pore data volume surface, then the data volume surface is simplified to reduce the division of the number of surface meshes, and finally, the surface editor module in the AVIZO software is used to repair the details of the pore space data volume surface of the digital core.

[0086] Step S604: permeability solving analysis.

[0087] In the embodiments of this application, the permeability of weathered sandstone can be solved by setting boundary conditions based on the established pore seepage model. First, the Navier-Stokes (NS) equations are used to describe the movement of pore fluids, serving as the governing equations for the simulation process. Then, room-temperature pure water is used as the simulated fluid during the simulation process, with its basic properties set as follows: density 1000 g / m³, viscosity coefficient 0.001 Pa s. The inlet water pressure is set to 1 kPa, and the outlet water pressure is set to 0 kPa. Finally, the permeability is solved by integrating the outlet boundary.

[0088] According to the weathered sandstone permeability analysis method proposed in the embodiment of the present application, sandstone samples with different weathering degrees are collected, and CT scanning technology is used to obtain a three-dimensional pore data volume of the sandstone. Based on the pore data volume, the connected pore network is extracted to construct a pore seepage model to predict the permeability of the weathered sandstone. This method can effectively reflect the influence of key factors such as pore connectivity, pore throat size distribution and heterogeneity of sandstone at different weathering degrees on the seepage behavior, realize quantitative analysis of the seepage characteristics of complex reservoirs, improve the accuracy and reliability of permeability estimation, can adapt to changes in different geological conditions and weathering degrees, and has good generalization ability and engineering applicability.

[0089] Next, the weathered sandstone permeability analysis device proposed according to the embodiment of the present application is described with reference to the accompanying drawings.

[0090] Figure 7 Schematic diagram of a weathered sandstone permeability analysis device according to an embodiment of the present application.

[0091] like Figure 7 As shown, the weathered sandstone permeability analysis device 10 includes: an acquisition module 100 , an extraction module 200 and an analysis module 300 .

[0092] The acquisition module 100 is used to collect sandstone samples with different weathering degrees, process the sandstone samples into cylindrical specimens, and use CT scanning technology to obtain three-dimensional data bodies of sandstone with different weathering degrees using the cylindrical specimens.

[0093] The extraction module 200 is used to extract the pore data volume of the sandstone sample based on the three-dimensional sandstone data volume.

[0094] The analysis module 300 is used to extract a connected pore network based on the pore data volume to construct a pore seepage model, so as to output the permeability of weathered sandstone using the pore seepage model.

[0095] Optionally, in one embodiment of the present application, the extraction module 200 includes: a first determination unit, an acquisition unit, and a second determination unit.

[0096] The first determination unit is configured to determine a minimum unit data volume meeting a preset representative volume requirement based on the sandstone three-dimensional data volume and taking porosity as a key constraint parameter.

[0097] The acquisition unit is configured to optimize original data of the sandstone three-dimensional data volume to perform spatial filtering processing on the sequence slice data, and obtain a pretreated gray image.

[0098] The second determination unit is configured to perform binaryzation processing on the pretreated gray image, distinguish a pore phase and a mineral matrix phase based on the minimum unit data volume, and determine a pore data volume.

[0099] Optionally, in an embodiment of the present application, the analysis module 300 comprises a generation unit and a training unit.

[0100] The generation unit is configured to perform Gaussian filtering smoothing processing on a pore surface of the connected pore network, optimize and simplify a surface mesh of the pore surface, and repair a topological problem of the surface, to generate a tetrahedral mesh meeting a preset quality condition.

[0101] The training unit is configured to generate training data based on the tetrahedral mesh, to train a pore percolation model.

[0102] Optionally, in an embodiment of the present application, the analysis module 300 comprises a third determination unit.

[0103] The third determination unit is configured to determine a control equation describing pore fluid motion, and the solving unit is configured to set a boundary condition and a parameter to obtain a simulation result in combination with the control equation, wherein the weathered sandstone permeability is solved by integral calculation on an outlet boundary.

[0104] It should be noted that the foregoing explanation and description of the embodiment of the weathered sandstone permeability analysis method also apply to the embodiment of the weathered sandstone permeability analysis device, which will not be described herein again.

[0105] The weathered sandstone permeability analysis device according to the embodiment of the present application can collect sandstone samples of different weathering degrees, acquire a sandstone three-dimensional pore data volume by using a CT scanning technology, extract a connected pore network based on the pore data volume, construct a pore percolation model, and predict the weathered sandstone permeability, which can effectively reflect the influence of key factors such as pore connectivity, pore throat size distribution, and heterogeneity of sandstone under different weathering degrees on percolation behavior, realize quantitative analysis of percolation characteristics of a complex reservoir, improve the accuracy and reliability of permeability estimation, and be suitable for changes in different geological conditions and weathering degrees, and has good generalization ability and engineering applicability.

[0106] Figure 8A structural schematic diagram of an electronic device is provided in the embodiments of the present application. The electronic device can include

[0107] The memory 801, the processor 802 and the computer program stored in the memory 801 and executable on the processor 802.

[0108] The processor 802 implements the weathered sandstone permeability analysis method provided in the above embodiments when executing the program.

[0109] Further, the electronic device further includes

[0110] The communication interface 803 is used for communication between the memory 801 and the processor 802.

[0111] The memory 801 is used for storing the computer program executable on the processor 802.

[0112] The memory 801 can include a high-speed RAM memory, and can also include a non-volatile memory, for example, at least one disk memory.

[0113] If the memory 801, the processor 802 and the communication interface 803 are independently implemented, the communication interface 803, the memory 801 and the processor 802 can be connected to each other through a bus and complete communication between each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the figure, but it does not mean that there is only one bus or only one type of bus.

[0114] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can complete communication between each other through an internal interface.

[0115] The processor 802 can be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0116] The embodiment also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the weathered sandstone permeability analysis method.

[0117] The embodiment of the present application also provides a computer program product, which comprises a computer program, and the computer program can run computer instructions, and the computer instructions are executed by a processor to implement the weathered sandstone permeability analysis method provided by the embodiment of the present application.

[0118] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0119] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one feature. In the description of the present application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0120] Any process or method descriptions in flow charts or otherwise described herein represent embodiments that can be understood as a module, segment, or portion of code that includes one or N executable instructions for implementing the specified logical function or process, and the scope of the preferred embodiments of the present application includes additional implementation in which the functions described are performed in a different order, including substantially simultaneously, or in reverse order, as will be understood by those skilled in the art of the embodiments to which the present application belongs.

[0121] The logic and / or steps represented in the flowcharts and / or described herein, for example, can be considered as a sequence of executable instructions stored in a computer readable medium, which can be executed by an instruction execution system, apparatus or device, such as a computer-based system, a processor-based system, or other system that can fetch the instructions from the instruction execution system, apparatus or device and execute the instructions, or a combination of the above. For the purposes of this specification, a "computer readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus or device. The computer readable medium can be a computer readable storage medium or a computer readable signal medium. The computer readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a propagation medium. The computer readable signal medium can include, but is not limited to, a computer readable medium that facilitates transfer of the program from one place to another. A specific example of a computer readable medium is a non-transitory computer-readable storage medium. A specific example of a computer readable signal medium is a source or destination of the computer readable medium. Another specific example of a computer readable signal medium is a computer readable signal travelling through space. Thus, a computer readable medium can take many forms of hardware to carry out the program for use by or in connection with the instruction execution system, apparatus or device.

[0122] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented in hardware and in another embodiment, the hardware can be implemented using any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.

[0123] Those of skill in the art would understand that the steps of the methods carried out above can be carried out wholly or partly by a program instructing relevant hardware, and the program can be stored in a computer readable storage medium, and when executed, includes one or a combination of the steps of the method embodiments.

[0124] In addition, each of the functional units in the various embodiments of the present application can be integrated in one processing module, or each of the units can be physically present separately, or two or more units can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0125] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for analyzing the permeability of weathered sandstone, characterized in that: The following steps are involved: Collecting sandstone samples with different weathering degrees, processing the sandstone samples into cylindrical specimens, and using CT scanning technology to obtain three-dimensional data volumes of sandstones with different weathering degrees using the cylindrical specimens; extracting a pore data volume of the sandstone sample based on the three-dimensional sandstone data volume; Based on the pore data volume, a connected pore network is extracted to construct a pore seepage model, so that the permeability of the weathered sandstone is output using the pore seepage model.

2. The method according to claim 1, characterized in that The step of extracting the pore data volume of the sandstone sample includes: Based on the three-dimensional sandstone data volume, porosity is used as a key constraint parameter to determine the minimum unit data volume that meets the preset representative volume requirements; Optimizing the original data of the sandstone three-dimensional data volume to perform spatial domain filtering on the serial slice data to obtain a pre-processed grayscale image; The pre-processed grayscale image is binarized, and based on the minimum unit data volume, the pore phase and the mineral matrix phase are distinguished to determine the pore data volume.

3. The method according to claim 1, characterized in that The constructing of the pore seepage model includes: Performing Gaussian filtering and smoothing on the pore surfaces of the connected pore network, optimizing and simplifying the surface mesh of the pore surface and repairing the topological problems of the surface to generate a tetrahedral mesh that meets preset quality conditions; Based on the tetrahedral grid, training data is generated to train the pore seepage model.

4. The method according to claim 1, wherein The step of outputting the weathered sandstone permeability using the pore seepage model includes: Determine the governing equations describing pore fluid motion; Boundary conditions and parameters are set to combine the control equations to obtain simulation results, wherein the permeability of the weathered sandstone is solved by integrating the outlet boundary.

5. A weathered sandstone permeability analysis device, characterized in that: include: An acquisition module is used to collect sandstone samples of different weathering degrees, process the sandstone samples into cylindrical specimens, and use CT scanning technology to obtain three-dimensional data volumes of sandstones of different weathering degrees using the cylindrical specimens; an extraction module, configured to extract a pore data volume of the sandstone sample based on the three-dimensional sandstone data volume; The analysis module is used to extract a connected pore network based on the pore data volume to construct a pore seepage model, so as to output the permeability of weathered sandstone using the pore seepage model.

6. The device according to claim 5, characterized in that The extraction module comprises: A first determining unit is configured to determine, based on the three-dimensional sandstone data volume and taking porosity as a key constraint parameter, a minimum unit data volume that meets a preset representative volume requirement; An acquisition unit is used to optimize the original data of the sandstone three-dimensional data volume, perform spatial domain filtering on the serial slice data, and obtain a pre-processed grayscale image; The second determining unit is configured to perform binarization processing on the pre-processed grayscale image, and distinguish the pore phase from the mineral matrix phase based on the minimum unit data volume, so as to determine the pore data volume.

7. The device according to claim 5, characterized in that The analysis module includes: A generation unit is used to perform Gaussian filtering and smoothing on the pore surface of the connected pore network, and to optimize and simplify the surface mesh of the pore surface and repair the topological problems of the surface to generate a tetrahedral mesh that meets preset quality conditions; A training unit is used to generate training data based on the tetrahedral grid to train the pore seepage model.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the weathered sandstone permeability analysis method according to any one of claims 1 to 4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the weathered sandstone permeability analysis method according to any one of claims 1 to 4.

10. A computer program product comprising a computer program, characterized in that The computer program is executed to implement the weathered sandstone permeability analysis method according to any one of claims 1 to 4.

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