Method and device for acquiring aperture distribution of rock image based on linear cutting technology, electronic equipment and storage medium

Abstract

The invention provides a method and device for obtaining rock image aperture distribution based on a linear cutting technology, electronic equipment and a storage medium, and the method comprises the steps: obtaining an imaging image of a rock, carrying out the binarization processing of the image, obtaining a binarization matrix, and enabling a non-zero value in the binarization matrix to represent a pore region; multi-direction linear cutting is conducted on the binary matrix, the pixel number and the single-pixel length of a continuous pore section in each direction are obtained, and the multiple directions at least comprise the row direction and the column direction; and according to the pixel number and the single pixel length of the continuous pore section in each direction, obtaining the pore size distribution of the rock in each direction. Thus, the pore size distribution is obtained through the multi-direction linear cutting technology, accurate depiction of the pore size distribution of the rock in all directions is achieved, and the problem that the pore size distribution of the irregular pore structure is not accurately obtained through a traditional method is effectively solved.

Description

Technical Field

[0001] The present application relates to the field of oil and gas exploration technology, and in particular to a method, device, electronic device and storage medium for obtaining pore size distribution of rock images based on wire cutting technology. Background Art

[0002] In oil and gas geological exploration, it is crucial to accurately describe the microscopic pore structure of rock reservoirs. At present, the characterization methods of the microscopic pore structure of rock reservoirs are mainly divided into fluid injection experiments and radiographic imaging methods. Although these methods have achieved certain results in pore identification and characterization, when using image processing technology to obtain the pore size distribution of rocks, there is still a problem of how to deal with the diverse pore structures.

[0003] To solve this problem, equivalent circle processing technology and inscribed circle processing technology are proposed in the prior art. The equivalent circle processing technology uses binarization of the electron microscope image to convert the pore area into a circle, and the radius of the circle represents the pore size. However, this method may not accurately reflect the true characteristics of the pores when dealing with irregular pores, resulting in deviations in the description of the pore size distribution. The inscribed circle processing technology is a method based on morphological analysis, which characterizes the "bottleneck size" of the pores by calculating the maximum inscribed circle diameter that can be accommodated inside the pores. Although this method improves the accuracy of pore characterization to a certain extent, it also has limitations. For example, for pore structures with extremely complex morphology, the inscribed circle may not accurately reflect the anisotropy of the pores, resulting in inaccurate characterization of the pore size distribution. Therefore, how to provide a method that can accurately process irregular pores and accurately characterize the pore size distribution of rocks has become an urgent problem to be solved. Summary of the invention

[0004] The embodiments of the present application provide a method, device, electronic device and storage medium for obtaining the pore size distribution of rock images based on wire cutting technology.

[0005] According to a first aspect of the present application, a method for obtaining pore size distribution of rock images based on wire cutting technology is provided, the method comprising: Acquire an image of the rock, and perform binarization processing on the image to obtain a binarization matrix, wherein non-zero values ​​in the binarization matrix represent pore areas; Perform multi-directional line cutting on the binary matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction, wherein the multi-directional directions at least include the row direction and the column direction; According to the number of pixels and single pixel length of continuous pore segments in each direction, the pore size distribution of the rock in each direction is obtained.

[0006] According to an embodiment of the present application, the step of obtaining an image of a rock and performing binarization processing on the image includes: Using imaging camera technology to obtain rock imaging images; Preprocessing the image, and performing binarization processing on the preprocessed image; Wherein, the preprocessing includes contrast enhancement and noise removal.

[0007] According to an embodiment of the present application, the multi-directional line cutting of the binary matrix to obtain the number of pixels and the single pixel length of the continuous pore segment in each direction includes: Scanning the binary matrix pixel by pixel along each direction, assigning independent increasing labels to continuous pore segments, and recording the number of pixels of each continuous pore segment; Gets the single pixel length.

[0008] According to an embodiment of the present application, the binary matrix is ​​scanned pixel by pixel along the row direction, independent increasing labels are assigned to the continuous pore segments, and the number of pixels of each continuous pore segment is recorded, including: Scan each pixel from top to bottom in each row of the binary matrix. When a non-zero pixel is encountered, check the label status of the left adjacent pixel in the same row. If the left pixel has been marked, inherit the label; if the left pixel is a non-porous area or the current pixel is the beginning of the row, assign a new independent increasing label; The number of pixels of consecutive pore segments marked by the same label in each row is recorded; where the labels differ between different rows.

[0009] According to an embodiment of the present application, the binary matrix is ​​scanned pixel by pixel along the column direction, independent increasing labels are assigned to the continuous pore segments, and the number of pixels of each continuous pore segment is recorded, including: Scan each pixel in each column of the binary matrix from top to bottom in turn. When a non-zero pixel is encountered, check the label status of the upper adjacent pixel in the same column. If the upper pixel has been marked, inherit the label; if the upper pixel is a non-porous area or the current pixel is the head of the column, assign a new independent incremental label; The number of pixels of consecutive pore segments marked by the same label in each column is recorded; where the labels differ between different columns.

[0010] According to an embodiment of the present application, the pore size distribution of the rock in each direction is obtained according to the number of pixels and the length of a single pixel of a continuous pore segment in each direction, including: According to the number of pixels and single pixel length of each continuous pore segment in each direction, the pore size of each continuous pore segment is calculated; According to the total number of pixels and single pixel length of the continuous pore segment under each aperture, the surface rate component of the continuous pore segment under each aperture is calculated; Taking the aperture as the abscissa and the surface porosity component under the corresponding aperture as the ordinate, the aperture distribution of the rock in each direction is obtained.

[0011] According to an embodiment of the present application, the method further includes: Anisotropy evaluation of rock is performed according to the pore size distribution in each direction to obtain anisotropy evaluation results, wherein the anisotropy evaluation results include a fluctuation anisotropy factor, a position difference factor and a comprehensive anisotropy factor; Wherein, in the case where the multiple directions include the row direction and the column direction, the anisotropy evaluation of the rock is performed according to the pore size distribution in each direction to obtain the anisotropy evaluation result, including: The number of pixels of continuous pore segments and the length of single pixel in the row and column directions were fitted with logarithmic Gaussian distribution functions to obtain the row mean, row standard deviation, column mean and column standard deviation in the row and column directions. Calculate the wave anisotropy factor:

[0012] in, is the row standard deviation, is the column standard deviation; Calculate the position difference factor:

[0013] in, is the row mean, is the column mean; Calculate the combined anisotropy factor:

[0014] in, and is the weight coefficient.

[0015] According to a second aspect of the present application, a device for obtaining pore size distribution of rock images based on wire cutting technology is provided, the device comprising: A processing module is used to obtain an image of the rock and perform binarization processing on the image to obtain a binarization matrix, wherein the non-zero values ​​in the binarization matrix represent the pore area; A cutting module, used for performing multi-directional line cutting on the binary matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction, wherein the multi-directions at least include the row direction and the column direction; The calculation module is used to obtain the pore size distribution of the rock in each direction according to the number of pixels and single pixel length of the continuous pore segment in each direction.

[0016] According to a third aspect of the present application, an electronic device is provided, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method described in the present application.

[0017] According to a fourth aspect of the present application, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to enable the computer to execute the method described in the present application.

[0018] The method, device, electronic device and storage medium for obtaining the pore size distribution of rock images based on the wire cutting technology of the embodiment of the present application obtains the imaging image of the rock, and performs binarization processing on the image to obtain a binarization matrix, wherein the non-zero values ​​in the binarization matrix represent the pore area; multi-directional wire cutting is performed on the binarization matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction, wherein the multi-direction includes at least the row direction and the column direction; the pore size distribution in each direction is obtained according to the number of pixels and single pixel length of the continuous pore segment in each direction; the anisotropy of the rock is evaluated according to the pore size distribution in each direction to obtain the anisotropy evaluation result. The pore size distribution is obtained by multi-directional wire cutting technology, which realizes the accurate characterization of the pore size distribution in each direction of the rock, and effectively solves the problem of inaccurate characterization of irregular pore structure by traditional methods.

[0019] It should be understood that the teachings of the present application are not required to achieve all of the beneficial effects described above, but specific technical solutions can achieve specific technical effects, and other embodiments of the present application can also achieve beneficial effects not mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become readily understood. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, wherein: In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0021] Figure 1 A schematic diagram of the implementation process of the method for obtaining the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown; Figure 2 A schematic diagram of the wire cutting principle of a method for obtaining pore size distribution of rock images based on wire cutting technology provided in an embodiment of the present application is shown; Figure 3A schematic diagram of the implementation flow of the row-direction cutting operation of the method for obtaining the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown; Figure 4 A schematic diagram of the implementation flow of the column-direction cutting operation of the method for obtaining the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown; Figure 5 A schematic diagram of the implementation flow of the pore size distribution acquisition operation of the method for acquiring the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown; Figure 6 An example diagram of pore size distribution of a method for obtaining pore size distribution of rock images based on wire cutting technology provided in an embodiment of the present application is shown; Figure 7 An example diagram of Gaussian fitting of the aperture distribution of line cutting in the x-direction provided in an embodiment of the present application is shown; Figure 8 An example diagram of Gaussian fitting of the y-direction line-cut aperture distribution provided in an embodiment of the present application is shown; Fig. 9 A schematic diagram of the composition structure of a device for obtaining pore size distribution of rock images based on wire cutting technology provided in an embodiment of the present application is shown; Fig.10 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0022] In order to make the purpose, features, and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0023] Figure 1 A schematic diagram of the implementation process of the method for obtaining the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown.

[0024] refer to Figure 1 The embodiment of the present application provides a method for obtaining the pore size distribution of a rock image based on a wire cutting technique, the method comprising: Operation 101, obtaining an image of a rock, and binarizing the image to obtain a binarized matrix, wherein non-zero values ​​in the binarized matrix represent pore areas.

[0025] In one embodiment of the present application, an imaging image of a rock is obtained and the image is binarized, including: using imaging camera technology to obtain an imaging image of the rock; preprocessing the image and binarizing the preprocessed image; wherein the preprocessing includes contrast enhancement and noise removal.

[0026] First, the rock sample is photographed by high-resolution imaging camera technology to obtain a rock imaging image. Among them, photographing the rock sample by high-resolution imaging camera technology can be regarded as obtaining the rock imaging image by using optical microscope, electron microscope and other technical means.

[0027] After the image is obtained, in order to improve the quality of the image, the image is also preprocessed to ensure that the image is clearer and has richer details. The preprocessing may include contrast enhancement and noise denoising.

[0028] In one embodiment of the present application, contrast enhancement is preferably performed using fused limited contrast histogram equalization (CLAHE). Specifically, CLAHE is first used to divide the image into multiple small areas, histogram equalization is performed on each small area, and then interpolation is performed to obtain the final enhanced image.

[0029] In one embodiment of the present application, noise removal is preferably performed using non-local mean denoising (NL-means). Specifically, NL-means is used to calculate the weighted average of all pixels in the image to denoise the image, so as to reduce random noise in the image and improve the recognition ability of pore boundaries.

[0030] After the image is preprocessed, the preprocessed image can be binarized based on image processing algorithms, image processing software or neural networks, such as threshold segmentation method, converting each pixel in the pore area to a non-zero value, and taking other areas as background, converting all pixels to zero to obtain a binary image. After obtaining the binary image, in order to facilitate the extraction of pore information in the image, the binarization matrix of the binary image is also extracted, and each element in the binarization matrix corresponds to the pixel point at the corresponding position in the binary image. Among them, the non-zero value can be configured in advance based on the analysis of the image, which can be regarded as a pre-configured threshold, for example, the non-zero value can be configured as 1.

[0031] Operation 102 , performing multi-directional line cutting on the binary matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction, where the multi-directional direction at least includes the row direction and the column direction.

[0032] In one embodiment of the present application, before performing multi-directional line cutting on the binary matrix, multi-directional settings are performed so that when cutting, cutting is performed according to the set multi-directional directions, wherein the multi-directional directions at least include row directions and column directions.

[0033] Preferably, in order to ensure that the cutting operation can fully and accurately capture the characteristics of the pore structure in different directions, any angle θ other than the row and column directions is set for cutting, 0°<θ<180°. The selection of the angle θ can be determined according to actual needs. For example, if it is known that there are cracks or beddings in specific directions in the rock, the angle corresponding to these directions can be selected for cutting, which will not be repeated here.

[0034] After setting multiple directions, multi-directional line cutting is performed on the binary matrix based on the set multiple directions, wherein line cutting in one direction can be understood as traversing the binary matrix with a cutting line based on the current direction, for example, cutting each row or column of the binary matrix.

[0035] In the process of cutting the binary matrix, the number of pixels and the single pixel length of the continuous pore segments on the cutting line are recorded synchronously.

[0036] Operation 103 , obtaining the pore size distribution of the rock in each direction according to the number of pixels and single pixel length of the continuous pore segment in each direction.

[0037] After determining the number of pixels of the continuous pore segment and the length of a single pixel in each direction, the equivalent aperture can be calculated based on a suitable equivalent aperture algorithm or formula. For example, the equivalent aperture is calculated based on the number of pixels of the continuous pore segment and the length of a single pixel, and the aperture distribution in each direction is statistically calculated.

[0038] In this way, the embodiment of the present application determines the pore size distribution through multi-directional wire cutting technology, thereby achieving accurate characterization of the pore size distribution of the rock in all directions, and effectively solving the problem of inaccurate characterization of irregular pore structure by traditional methods.

[0039] In one embodiment of the present application, multi-directional line cutting is performed on the binary matrix to obtain the number of pixels and single-pixel length of the continuous pore segment in each direction, including: scanning the binary matrix pixel by pixel along each direction, assigning independent and incremental labels to the continuous pore segments, and recording the number of pixels of each continuous pore segment; obtaining the single-pixel length.

[0040] For each of the set multi-directions, a pixel-by-pixel scan is performed based on the cutting line. During the scanning process, each continuous pore segment is marked by label assignment, and the number of pixels of each continuous pore segment is recorded. Among them, the label of each continuous pore segment is the same, and the labels of different continuous pore segments are different. The labels are incremented based on the traversal order.

[0041] In one embodiment of the present application, in the process of line cutting in each direction, the continuous pore segments can be marked by combining the 8-neighborhood topological analysis method with the fast union-find algorithm, and a label is assigned to each continuous pore segment. Specifically, when traversing each pixel in each direction, the 8-neighborhood topological analysis is used to check the 8 neighborhoods of the upper, lower, left, right and diagonal lines to determine whether they belong to the same pore, and the fast union-find algorithm is used to assign labels to the pixels.

[0042] To further understand the cutting process of continuous pore segments, the following example is given. Figure 2 , Figure 2 A schematic diagram of the wire cutting principle of a method for obtaining pore size distribution of rock images based on wire cutting technology provided in an embodiment of the present application is shown. Figure 2 (a) shows an example of a binary image corresponding to a binary matrix. When a line cut is performed on the binary matrix, it can be regarded as cutting the binary image. Figure 2 (b) is an example of the wire cutting result obtained after line cutting in the row direction, and the white rectangular bars therein are the continuous pore segments obtained after wire cutting. Figure 2 (c) is an example of the wire cutting result obtained after line cutting in the column direction, and the white strips in it are the continuous pore segments obtained after wire cutting. It should be noted that Figure 2 Each binary image in the figure is a simplified schematic diagram. In order to avoid the complexity of the graphics interfering with the understanding of the core principles, it is only used to intuitively demonstrate the physical segmentation effect of wire cutting, and does not reflect the details of label allocation.

[0043] Figure 3 A schematic diagram of the implementation flow of the row-direction cutting operation of the method for obtaining the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown.

[0044] In one embodiment of the present application, a process of scanning the binary matrix pixel by pixel based on the row direction in multiple directions, that is, scanning the binary matrix pixel by pixel along the row direction, assigning independent increasing labels to continuous pore segments, and recording the number of pixels and single pixel length of each continuous pore segment, includes: Operation 201 scans each pixel in each row of the binary matrix from top to bottom. When a non-zero pixel is encountered, check the label status of the left adjacent pixel in the same row. If the left pixel has been marked, it inherits the label; if the left pixel is a non-porous area or the current pixel is the beginning of the row, assign a new independent incremental label.

[0045] Traverse the binary matrix row by row in the x direction (row direction), scan each matrix element from left to right for each row, that is, each pixel of the image, if the current pixel is a non-zero value (valid pixel), check the label of the left adjacent pixel in the same row. If the left pixel has been marked (such as the label is 2), inherit the label; if the left pixel is the background (label 0) or the current pixel is the valid pixel at the beginning of the row, assign a new label that increases independently from 1.

[0046] In the process of traversing pixels, each row is regarded as an independent space, and continuous valid pixels in the row are marked with the same label and regarded as a continuous pore segment.

[0047] In operation 202 , the number of pixels of continuous pore segments marked with the same label in each row is recorded; wherein the labels of different rows are different.

[0048] In the process of traversing pixels, the number of pixels of the marked continuous pore segments is obtained.

[0049] The label numbers of different rows are completely independent. In this way, even if there are horizontally aligned pixels in adjacent rows, their labels will not be merged, thereby avoiding the problem of erroneous amplification of the equivalent aperture in the horizontal direction caused by forced cross-column merging, more truly reflecting the local pore size, and avoiding false connectivity of pores in the horizontal direction, thereby more accurately calculating the difference in pore size distribution in the horizontal and vertical directions and reducing anisotropic deviation.

[0050] Figure 4 A schematic diagram of the implementation flow of the column-wise cutting operation of the method for obtaining the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown.

[0051] In one embodiment of the present application, a process of performing pixel-by-pixel scanning on a binary matrix based on a column direction in multiple directions, that is, performing pixel-by-pixel scanning on the binary matrix along the column direction, assigning independent increasing labels to continuous pore segments, and recording the number of pixels and single pixel length of each continuous pore segment, includes: Operation 301, scanning each pixel from top to bottom in each column of the binary matrix, when encountering a non-zero pixel, checking the label status of the upper adjacent pixel in the same column, if the upper pixel has been marked, then inherit the label; if the upper pixel is a non-porous area or the current pixel is the head of the column, assigning a new independent incremental label; In operation 302 , the number of pixels of continuous pore segments marked with the same label in each column is recorded; wherein the labels of different columns are different.

[0052] The line cutting method in the column direction is similar to that in the row direction. Specifically, the binary matrix is ​​traversed column by column along the y direction (column direction), and each pixel is scanned from top to bottom for each column. If the current pixel is a non-zero value (valid pixel), the label of the upper adjacent pixel in the same column is checked. If the upper pixel has been marked (such as the label 3), the label is inherited; if the upper pixel is the background (label 0) or the current pixel is the first valid pixel in the column, a new label is assigned that increases independently starting from 1.

[0053] In the traversal process, each column is regarded as an independent space, and the continuous valid pixel areas in the column are marked with the same label to obtain continuous pore segments. The label numbers of different columns are completely independent, so that even if there are vertically aligned pixels in adjacent columns, their labels will not be merged, avoiding the problem of forced cross-column merging leading to erroneous amplification of the equivalent pore size in the vertical direction, thereby more truly reflecting the local pore size and avoiding false connectivity of pores in the vertical direction, so as to more accurately calculate the difference in pore size distribution between the horizontal and vertical directions and reduce anisotropic deviation.

[0054] Figure 5 A schematic diagram of the implementation flow of the pore size distribution acquisition operation of the method for acquiring the pore size distribution of rock images based on the wire cutting technology provided in an embodiment of the present application is shown.

[0055] refer to Figure 5 In one embodiment of the present application, the above operation 103, based on the number of pixels and single pixel length of the continuous pore segment in each direction, obtains the pore size distribution of the rock in each direction, including: Operation 401, calculating the aperture of each continuous pore segment according to the number of pixels and single pixel length of each continuous pore segment in each direction; Operation 402, calculating the surface rate component of the continuous pore segment under each aperture according to the total number of pixels and the single pixel length of the continuous pore segment under each aperture; Operation 403, using the aperture as the abscissa and the surface ratio component corresponding to the aperture as the ordinate, to obtain the aperture distribution of the rock in all directions.

[0056] The pore size distribution can be expressed in the form of an pore size distribution graph, with the pore size representing the horizontal coordinate of the pore size distribution graph and the surface area ratio component as the vertical coordinate of the pore size distribution graph, and the pore size distribution in each direction is constructed in the pore size distribution graph. Among them, the pore size is the pore size, and the surface area ratio component is the pore area.

[0057] Specifically, the aperture in each direction can be obtained based on the number of pixels and the single pixel length of the continuous aperture segment in each direction. Specifically, the aperture of each continuous aperture segment can be obtained based on the following formula:

[0058] Where N is the number of pixels in the continuous pore segment, The actual length of a single pixel.

[0059] Furthermore, the surface rate component under each aperture can be obtained based on the total number of pixels and single pixel length of all continuous aperture segments corresponding to the current aperture, that is, the product of the total number of pixels and single pixel length of the continuous aperture segments.

[0060] In this way, after determining each aperture and the surface ratio component corresponding to the aperture, the aperture can be used as the horizontal coordinate and the surface ratio component under each aperture as the vertical coordinate to construct an aperture distribution diagram representing the aperture distribution. The specific presentation of the aperture distribution diagram can be referred to Figure 6 , Figure 6 An example diagram of pore size distribution of a method for obtaining pore size distribution of rock images based on wire cutting technology provided in an embodiment of the present application is shown, in which triangles and circles constitute pore size distributions in the x-direction and y-direction respectively.

[0061] In one embodiment of the present application, in addition to evaluating the pore size distribution, an evaluation of reservoir anisotropy is also performed, that is, an anisotropy evaluation of the rock is performed through the pore size distribution in various directions to obtain an anisotropy evaluation result.

[0062] Specifically, in order to achieve a more accurate characterization of the pore structure, it is also necessary to understand the physical properties of the rock, such as permeability and elastic modulus. The physical properties of rocks are usually characterized based on anisotropy. Therefore, in order to fully understand the physical properties of rocks, after determining the pore size distribution, the anisotropy of the rock is evaluated based on the information of the pore structure to obtain the anisotropy evaluation results of the rock.

[0063] In this embodiment of the present application, the anisotropy evaluation result includes multiple indicators for evaluating anisotropy, and the multiple indicators may include a wave anisotropy factor (WAF), a position difference factor (CAF) and a comprehensive anisotropy factor. Therefore, when evaluating anisotropy, the discrete degree of the aperture size is reflected based on the wave anisotropy factor, the relative difference of the aperture concentration position in the X / Y direction is quantified based on the position difference factor, and the WAF and CAF are combined based on the comprehensive anisotropy factor to make up for the limitations of a single indicator.

[0064] Accordingly, in the case of multiple directions including row direction and column direction, the anisotropy of the rock is evaluated according to the pore size distribution in each direction, and the anisotropy evaluation results are obtained, including: The number of pixels of continuous pore segments and the length of single pixel in the row and column directions were fitted with logarithmic Gaussian distribution functions to obtain the row mean, row standard deviation, column mean and column standard deviation in the row and column directions. Calculate the wave anisotropy factor:

[0065] in, is the row standard deviation, is the column standard deviation, WAF≈0 means that the pore size distribution has a similar degree of dispersion in the X / Y direction (isotropy), and WAF→1 means that the pore size distribution has a large degree of dispersion in the X / Y direction (strong anisotropy); Calculate the position difference factor:

[0066] in, is the row mean, is the column mean, and the LAF value range is [0, 1); Calculate the combined anisotropy factor:

[0067] in, and is the weight coefficient, which can be adjusted based on reservoir type and engineering requirements.

[0068] Specifically, firstly, the pore size distribution in each direction is fitted based on the logarithmic Gaussian distribution function, and the expression of the logarithmic Gaussian distribution function is:

[0069] Where x is the aperture distribution in each direction, and the mean of the Gaussian distribution , standard deviation , , , It can be regarded as a fitting parameter and can be configured according to actual conditions.

[0070] The pore size distribution is fitted based on the above logarithmic Gaussian distribution function to obtain the standard deviation and mean corresponding to each direction, that is, the row mean and row standard deviation for the row direction and the column mean and column standard deviation for the column direction.

[0071] After determining the mean and standard deviation in each direction, the fluctuation anisotropy factor, position difference factor and comprehensive anisotropy factor are calculated according to their calculation formulas to obtain the final anisotropy evaluation result.

[0072] In order to further illustrate the technical solution of the present application, a specific example is given below.

[0073] This specific application example of the embodiment of the present application may include: S1. Rock sample preparation; Source of rock samples: Sandstone of Shahezi Formation in Songliao Basin, standard plunger samples with a diameter of 2.5 cm were drilled.

[0074] Pretreatment: Argon ion polishing to surface roughness <10nm.

[0075] S2, rock imaging image acquisition; Equipment: FEI Quanta 650 FEG field emission electron microscope.

[0076] Parameters: acceleration voltage 5 kV, resolution 100000 × 100000 pixels, pixel size 10 nm.

[0077] S3, multi-directional wire cutting; 1) CLAHE algorithm is used to enhance image contrast, and NL-means is used for denoising (filter kernel 7×7); 2) Generate a binary image based on the U-Net network, with the pore area marked as 1 and the matrix marked as 0.

[0078] 3) Set the scanning direction to the X / Y direction, perform line cutting on the binary image or matrix based on the scanning direction, count the lengths of continuous pore segments in each direction, calculate the equivalent aperture and surface frequency components, and obtain the aperture distribution in each direction.

[0079] 4) Perform Gaussian fitting on the pore size distribution and calculate the mean and standard deviation. For specific fitting methods, please refer to Figure 7 and Figure 8 , Figure 7 An example diagram of Gaussian fitting of the aperture distribution of line cutting in the x-direction provided in an embodiment of the present application is shown. Figure 8 An example diagram of Gaussian fitting of the y-direction line-cut aperture distribution provided in an embodiment of the present application is shown.

[0080] S4. Anisotropy quantification analysis.

[0081] Calculate the fluctuation anisotropy factor, position difference factor and comprehensive anisotropy factor.

[0082] Thus, the specific application example of the embodiment of the present application, through an innovative multi-directional wire cutting method, abandons the traditional steps of distinguishing between connected pores and isolated pores, and directly uses the cutting line length to objectively characterize the pore size, which significantly simplifies the analysis process and improves the reliability of the results; it processes pores of different morphologies through statistical differentiation of line length, overcoming the scientific defect of the traditional equivalent circle method that causes loss of morphological information; it realizes the quantification of anisotropic pore size distribution based on directional wire cutting, filling the gap that the existing technology cannot distinguish multi-directional pore characteristics.

[0083] Fig. 9A schematic diagram of the composition structure of a device for obtaining the pore size distribution of rock images based on wire cutting technology provided in an embodiment of the present application is shown.

[0084] refer to Fig. 9 Based on the above-mentioned method for obtaining the pore size distribution of rock images based on wire cutting technology, an embodiment of the present application also provides a device for obtaining the pore size distribution of rock images based on wire cutting technology, and the device includes: a processing module 501, used to obtain an imaging image of the rock, and binarize the image to obtain a binary matrix, and the non-zero values ​​in the binary matrix represent the pore area; a cutting module 502, used to perform multi-directional wire cutting on the binary matrix to obtain the number of pixels and single pixel length of continuous pore segments in each direction, and the multi-direction includes at least row direction and column direction; a calculation module 503, used to obtain the pore size distribution of the rock in each direction according to the number of pixels and single pixel length of continuous pore segments in each direction.

[0085] It should be noted that the description of the device in the embodiment of the present application is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment, so it will not be repeated. Figures 1 to 8 The present invention can be understood by referring to the description of any one of the accompanying drawings.

[0086] According to an embodiment of the present application, the present application also provides an electronic device and a non-transitory computer-readable storage medium.

[0087] Fig.10 A schematic block diagram of an example electronic device 600 that can be used to implement an embodiment of the present application is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present application described and / or required herein.

[0088] like Fig.10As shown, the electronic device 600 includes a computing unit 601, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 602 or a computer program loaded from a storage unit 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the electronic device 600 can also be stored. The computing unit 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0089] Multiple components in the electronic device 600 are connected to the I / O interface 605, including: an input unit 606, such as a keyboard, a mouse, etc.; an output unit 607, such as various types of displays, speakers, etc.; a storage unit 608, such as a disk, an optical disk, etc.; and a communication unit 609, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 609 allows the electronic device 600 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0090] The computing unit 601 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 601 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The computing unit 601 performs the various methods and processes described above, such as a method for obtaining the pore size distribution of a rock image based on a wire cutting technique. For example, in some embodiments, the method for obtaining the pore size distribution of a rock image based on a wire cutting technique may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 608. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 600 via the ROM 602 and / or the communication unit 609. When the computer program is loaded into the RAM 603 and executed by the computing unit 601, one or more steps of the method for obtaining the pore size distribution of a rock image based on a wire cutting technique described above may be performed. Alternatively, in other embodiments, the computing unit 601 may be configured in any other appropriate manner (eg, by means of firmware) to execute the method for acquiring the pore size distribution of rock images based on the wire cutting technology.

[0091] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0092] The program code for implementing the method of the present application can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, implements the functions / operations specified in the flow chart and / or block diagram. The program code can be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0093] In the context of the present application, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0094] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0095] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0096] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0097] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0098] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for obtaining pore size distribution of rock images based on wire cutting technology, characterized in that: The method comprises: Acquire an image of the rock, and perform binarization processing on the image to obtain a binarization matrix, wherein non-zero values ​​in the binarization matrix represent pore areas; Perform multi-directional line cutting on the binary matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction, wherein the multi-directional directions at least include the row direction and the column direction; According to the number of pixels and single pixel length of continuous pore segments in each direction, the pore size distribution of the rock in each direction is obtained.

2. The method according to claim 1, characterized in that The step of obtaining an image of the rock and performing binarization processing on the image includes: Using imaging camera technology to obtain rock imaging images; Preprocessing the image, and performing binarization processing on the preprocessed image; Wherein, the preprocessing includes contrast enhancement and noise removal.

3. The method according to claim 1, characterized in that The performing multi-directional line cutting on the binary matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction includes: Scanning the binary matrix pixel by pixel along each direction, assigning independent increasing labels to continuous pore segments, and recording the number of pixels of each continuous pore segment; Gets the single pixel length.

4. The method according to claim 3, characterized in that The binary matrix is ​​scanned pixel by pixel along the row direction, independent increasing labels are assigned to the continuous pore segments, and the number of pixels of each continuous pore segment is recorded, including: Scan each pixel from top to bottom in each row of the binary matrix. When a non-zero pixel is encountered, check the label status of the left adjacent pixel in the same row. If the left pixel has been marked, inherit the label; if the left pixel is a non-porous area or the current pixel is the beginning of the row, assign a new independent increasing label; The number of pixels of consecutive pore segments marked by the same label in each row is recorded; where the labels differ between different rows.

5. The method according to claim 3, characterized in that: The binary matrix is ​​scanned pixel by pixel along the column direction, independent increasing labels are assigned to the continuous pore segments, and the number of pixels of each continuous pore segment is recorded, including: Scan each pixel in each column of the binary matrix from top to bottom in turn. When a non-zero pixel is encountered, check the label status of the upper adjacent pixel in the same column. If the upper pixel has been marked, inherit the label; if the upper pixel is a non-porous area or the current pixel is the head of the column, assign a new independent incremental label; The number of pixels of consecutive pore segments marked by the same label in each column is recorded; where the labels differ between different columns.

6. The method according to claim 1, characterized in that The method of obtaining the pore size distribution of the rock in each direction according to the number of pixels and the length of a single pixel of the continuous pore segment in each direction includes: According to the number of pixels and single pixel length of each continuous pore segment in each direction, the pore size of each continuous pore segment is calculated; According to the total number of pixels and single pixel length of the continuous pore segment under each aperture, the surface rate component of the continuous pore segment under each aperture is calculated; Taking the aperture as the abscissa and the surface porosity component under the corresponding aperture as the ordinate, the aperture distribution of the rock in each direction is obtained.

7. The method according to claim 1, characterized in that The method further comprises: Anisotropy evaluation of rock is performed according to the pore size distribution in each direction to obtain anisotropy evaluation results, wherein the anisotropy evaluation results include a fluctuation anisotropy factor, a position difference factor and a comprehensive anisotropy factor; Wherein, in the case where the multiple directions include the row direction and the column direction, the anisotropy evaluation of the rock is performed according to the pore size distribution in each direction to obtain the anisotropy evaluation result, including: The number of pixels of continuous pore segments and the length of single pixel in the row and column directions were fitted with logarithmic Gaussian distribution functions to obtain the row mean, row standard deviation, column mean and column standard deviation in the row and column directions. Calculate the wave anisotropy factor: in, is the row standard deviation, is the column standard deviation; Calculate the position difference factor: in, is the row mean, is the column mean; Calculate the combined anisotropy factor: in, and is the weight coefficient.

8. A device for obtaining the pore size distribution of rock images based on wire cutting technology, characterized in that: The device comprises: A processing module is used to obtain an image of the rock and perform binarization processing on the image to obtain a binarization matrix, wherein the non-zero values ​​in the binarization matrix represent the pore area; A cutting module, used for performing multi-directional line cutting on the binary matrix to obtain the number of pixels and single pixel length of the continuous pore segment in each direction, wherein the multi-directions at least include the row direction and the column direction; The calculation module is used to obtain the pore size distribution of the rock in each direction according to the number of pixels and single pixel length of the continuous pore segment in each direction.

9. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to make a computer execute the method according to any one of claims 1 to 7.

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