Reservoir X-ray imaging methods and apparatus, sample preparation methods and apparatus

Abstract

This invention provides a reservoir X-ray imaging method and apparatus, and a sample preparation method and apparatus, relating to the field of geological exploration technology. The reservoir X-ray imaging method includes: acquiring first imaging data of a first-size sample; a first marker is provided on a first surface of the first-size sample, and multiple second markers are provided on a second surface of the first-size sample; the shapes of the second markers are all different; determining the position data of a second-size sample using the first imaging data, the first markers, and the multiple second markers; acquiring second imaging data of the second-size sample; obtaining the second-size sample from the first-size sample based on the position data of the second-size sample; the accuracy of the second imaging data is higher than that of the first imaging data; and using the first imaging data and the second imaging data as the reservoir X-ray imaging result. This invention can achieve accurate correspondence of sample positions under different resolutions in X-ray scanning, improving the characterization accuracy and representativeness of rock structures.

Description

Technical Field

[0001] This invention relates to the field of geological exploration technology, and in particular to a reservoir X-ray imaging method and apparatus, and a sample preparation method and apparatus. Background Technology

[0002] Currently, sample preparation in X-ray imaging studies at different resolutions has not achieved large-scale control over small-scale data. The general approach is as follows: First, a relatively low resolution is used to scan the rock sample as a whole. Then, by visual observation or using a stereomicroscope, the reservoir sample is divided into several distinct parts. Next, smaller samples are drilled using a mechanical drilling rig, and then the drilled small plunger samples are scanned using a higher resolution. Finally, by comparing the overall scan and the local scan images, the reservoir structure is determined and the effectiveness of the reservoir is evaluated.

[0003] Existing methods fail to achieve in-situ sampling and characterization: while the acquired X-ray imaging data at different resolutions appear to have a progressive magnification effect from large to small, the specific location of the high-resolution small-field image within the low-resolution large-field image cannot be determined, and the constraint effect of the large-field result on the small-field result is very weak. Features that are relatively characteristic in the large-field or locations requiring detailed study cannot be verified in the high-resolution small-field image. Summary of the Invention

[0004] This invention provides a reservoir X-ray imaging method and apparatus, and a sample preparation method and apparatus, which can achieve accurate correspondence of X-ray scanning sample positions at different resolutions. By in-situ sampling, the distribution of high-resolution fine scanning units in the whole sample can be clarified, thereby improving the characterization accuracy and representativeness of rock structures.

[0005] In a first aspect, embodiments of the present invention provide a reservoir X-ray imaging method, the method comprising: acquiring first imaging data of a first-size sample; a first marker being provided on a first surface of the first-size sample, and a plurality of second markers being provided on a second surface of the first-size sample; the second markers having different shapes; determining position data of a second-size sample using the first imaging data, the first markers, and the plurality of second markers; acquiring second imaging data of the second-size sample; obtaining the second-size sample from the first-size sample based on the position data of the second-size sample; the second imaging data having higher precision than the first imaging data; and using the first imaging data and the second imaging data as the reservoir X-ray imaging result.

[0006] Secondly, embodiments of the present invention also provide a sample preparation method, the method comprising: acquiring position data of a second-sized sample; determining the position data of the second-sized sample based on first imaging data of a first-sized sample; having a first marker on a first surface of the first-sized sample and having a plurality of second markers on a second surface of the first-sized sample; the second markers having different shapes; obtaining a second-sized sample from the first-sized sample based on the position data of the second-sized sample, so as to generate second imaging data based on the second-sized sample; the second imaging data having higher precision than the first imaging data; and using the first-sized sample and the second-sized sample as the sample preparation result.

[0007] Thirdly, embodiments of the present invention also provide a reservoir X-ray imaging apparatus, the apparatus comprising: a first acquisition module, configured to acquire first imaging data of a first-sized sample; a first marker is provided on a first surface of the first-sized sample, and a plurality of second markers are provided on a second surface of the first-sized sample; the shapes of the second markers are all different; a position module, configured to determine position data of a second-sized sample using the first imaging data, the first markers, and the plurality of second markers; a second acquisition module, configured to acquire second imaging data of the second-sized sample; the second-sized sample is obtained from the first-sized sample based on the position data of the second-sized sample; the accuracy of the second imaging data is higher than that of the first imaging data; and an imaging result module, configured to use the first imaging data and the second imaging data as reservoir X-ray imaging results.

[0008] Fourthly, embodiments of the present invention also provide a sample preparation apparatus, the apparatus comprising: a data module for acquiring position data of a second-sized sample; the position data of the second-sized sample being determined based on first imaging data of a first-sized sample; a first marker being provided on a first surface of the first-sized sample, and a plurality of second markers being provided on a second surface of the first-sized sample; the shapes of the second markers being different; a segmentation module for obtaining a second-sized sample from the first-sized sample based on the position data of the second-sized sample, so as to generate second imaging data based on the second-sized sample; the accuracy of the second imaging data being higher than that of the first imaging data; and a sample result module for using the first-sized sample and the second-sized sample as the sample preparation result.

[0009] Fifthly, embodiments of the present invention also provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described reservoir X-ray imaging method or sample preparation method.

[0010] In a sixth aspect, embodiments of the present invention also provide a computer-readable storage medium storing a computer program for performing the above-described reservoir X-ray imaging method or sample preparation method.

[0011] The embodiments of this invention bring the following beneficial effects: This invention provides a reservoir X-ray imaging method, which includes: acquiring first imaging data of a first-size sample; a first marker is provided on a first surface of the first-size sample, and multiple second markers are provided on a second surface of the first-size sample; the shapes of the second markers are all different; determining the position data of the second-size sample using the first imaging data, the first markers, and the multiple second markers; acquiring second imaging data of the second-size sample; obtaining the second-size sample from the first-size sample based on the position data of the second-size sample; the accuracy of the second imaging data is higher than that of the first imaging data; and using the first imaging data and the second imaging data as the reservoir X-ray imaging result. This invention can achieve accurate correspondence between the positions of X-ray scanned samples at different resolutions, strengthen the control of the large field-of-view scanning unit on the high-resolution fine scanning unit, and clarify the distribution of the high-resolution fine scanning unit in the overall sample through in-situ sampling, thereby improving the characterization accuracy and representativeness of the rock structure and providing a basic model for reservoir effectiveness evaluation and enhanced oil and gas recovery research.

[0012] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0013] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 A flowchart of a reservoir X-ray imaging method provided in an embodiment of the present invention;

[0016] Figure 2 A flowchart of the sample preparation method provided in the embodiments of the present invention;

[0017] Figure 3A schematic diagram illustrating the implementation process of the reservoir X-ray imaging method and sample preparation method provided in this embodiment of the invention;

[0018] Figure 4 This is a schematic diagram of the marking position of the marking metal sheet on the reservoir rock plunger sample provided in an embodiment of the present invention;

[0019] Figure 5 An example illustration of the position of the marking metal sheet under X-ray imaging conditions and its correspondence with the X-ray scan image provided in the embodiments of the present invention;

[0020] Figure 6 Example study effect diagrams provided for embodiments of the present invention;

[0021] Figure 7 A structural block diagram of a reservoir X-ray imaging device provided in an embodiment of the present invention;

[0022] Figure 8 Another structural block diagram of a reservoir X-ray imaging device provided in an embodiment of the present invention;

[0023] Figure 9 This is a structural block diagram of a sample preparation device provided in an embodiment of the present invention;

[0024] Figure 10 A structural block diagram of a computer device provided for an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Currently, with unconventional oil and gas becoming a hot topic in my country's oil and gas exploration industry, reservoir effectiveness evaluation has received widespread attention from both academia and industry, with accurate characterization and delineation of pore structure being a key focus (Zou et al., 2012; Jia et al., 2012). The understanding of pore networks directly impacts the estimation of oil and gas resource potential and the formulation of enhanced oil recovery (EOR) strategies. Because low-permeability tight reservoirs are dominated by micro- and nano-scale pore-throat systems with small pore sizes, traditional core displacement experiments are time-consuming and labor-intensive. As a supplement to traditional techniques, digital core analysis of reservoirs, which has emerged in recent years, has become an important means of pore structure characterization. Digital core technology simulates fluid physical properties and obtains the kinematic characteristics of single-phase or multiphase fluids through high-resolution virtual core pore network data, providing an effective method for improving oil and gas recovery. However, due to limitations in current imaging technology, balancing resolution and sample representativeness remains a major challenge. To address this issue, existing research has employed multi-view stitching techniques in scanning electron microscopy (SEM) to combine high resolution with large scale by stitching together multiple high-resolution SEM images (Zhu et al., 2013; Wu et al., 2018). However, this method primarily focuses on two-dimensional pore structures, and the images are too large, making analysis and processing difficult. In terms of three-dimensional characterization, industrial CT has too low a resolution to detect pores larger than tens of μm. While three-dimensional focused ion beam field emission scanning electron microscopy (FEM) can provide high-resolution imaging, it is destructive to the sample and produces very small images (1-10 μm), making it unable to detect pores at scales of hundreds of μm and above, often leading to questions about the representativeness of the results. Therefore, some scholars have proposed using multi-level X-ray scanning for reservoir evaluation (Bai et al., 2013; Zhu et al., 2018), utilizing different equipment to obtain rock characterization results at different resolutions and evaluating reservoir properties. Overall, published articles have only presented imaging results at different scales, but have not explained the in-situ nature of these results, leading to doubts about the accuracy and representativeness of the multi-scale results. The key to solving this problem lies in in-situ sample preparation methods for X-ray serial imaging, but this remains a gap in current understanding.

[0027] To address the bottleneck problem in X-ray imaging research of reservoir structures, this invention provides a reservoir X-ray imaging method and apparatus. By controlling the imaging positions in situ step by step, the accuracy of imaging results at different scales is ensured, and non-destructive high-resolution imaging is achieved while effectively improving the representativeness of the imaging units.

[0028] To facilitate understanding of this embodiment, a reservoir X-ray imaging method disclosed in this embodiment of the invention will first be described in detail.

[0029] This invention provides a reservoir X-ray imaging method, see [link to relevant documentation]. Figure 1The flowchart shown illustrates a reservoir X-ray imaging method, which includes the following steps:

[0030] Step S102: Obtain the first imaging data of the first-size sample.

[0031] In this embodiment of the invention, a first marker is provided on the first surface of the first-size sample, and multiple second markers are provided on the second surface of the first-size sample; the shapes of the second markers are all different. Both the first and second markers can be made of metal, for example, aluminum sheets. The first-size sample is a rock sample obtained from the reservoir of interest and can be configured into a regular three-dimensional shape, such as a cylinder. The first surface can be the upper surface of the cylinder, and the second surface can be the cylindrical surface of the cylinder. The cylindrical sample is placed in an X-ray imaging scanning device and scanned at a preset resolution to obtain three-dimensional first imaging data.

[0032] It should be noted that multiple second markers can be arranged on the second surface according to certain rules. For example, they can be arranged on the cylindrical surface of the cylinder at fixed intervals, parallel to the central axis of the cylinder. Alternatively, they can be arranged as needed; this embodiment of the invention does not impose specific limitations on this.

[0033] Step S104: Determine the position data of the second-sized sample using the first imaging data, the first marker, and multiple second markers.

[0034] In this embodiment of the invention, after obtaining the first imaging data, the positional relationship between the marker, the image position and the sample position can be established, and then, based on these positional relationships, the positional data of the second-sized sample can be determined.

[0035] It should be noted that the size of the second-sized sample is smaller than that of the first-sized sample. The positional data of the second-sized sample can be used to determine which positional range of the first-sized sample should be used as the second-sized sample.

[0036] Step S106: Obtain the second imaging data of the second-sized sample.

[0037] In this embodiment of the invention, the second-sized sample is obtained from the first-sized sample based on the position data of the second-sized sample; the imaging accuracy of the second imaging data is higher than that of the first imaging data.

[0038] Step S108: Use the first imaging data and the second imaging data as the reservoir X-ray imaging results.

[0039] In this embodiment of the invention, the second-sized sample is sampled based on the position of the first-sized sample, and the imaging accuracy of the second imaging data is higher than that of the first imaging data. Therefore, it is possible to achieve accurate correspondence of X-ray scan sample positions at different resolutions.

[0040] This invention provides a reservoir X-ray imaging method, comprising: acquiring first imaging data of a first-size sample; a first marker being provided on a first surface of the first-size sample, and multiple second markers being provided on a second surface of the first-size sample; the second markers having different shapes; determining the position data of the second-size sample using the first imaging data, the first markers, and the multiple second markers; acquiring second imaging data of the second-size sample; obtaining the second-size sample from the first-size sample based on the position data of the second-size sample; the second imaging data having higher precision than the first imaging data; and using the first and second imaging data as the reservoir X-ray imaging result. This invention can achieve accurate correspondence between the positions of X-ray scanned samples at different resolutions, strengthen the control of large-field-of-view scanning units on high-resolution fine scanning units, and clarify the distribution of high-resolution fine scanning units in the overall sample through in-situ sampling, thereby improving the characterization accuracy and representativeness of rock structures and providing a basic model for reservoir effectiveness evaluation and enhanced oil and gas recovery research.

[0041] In one embodiment, the first imaging data is three-dimensional data; determining the position data of the second-sized sample using the first imaging data, a first marker, and multiple second markers can be performed according to the following steps:

[0042] Multiple two-dimensional image data are determined based on the first imaging data; the position data of the second-sized sample are determined using the multiple two-dimensional image data, the first marker, and the multiple second markers.

[0043] In this embodiment of the invention, image processing software is used to convert the scanned contrast image into a grayscale image. Based on the three-dimensional first imaging data, multiple two-dimensional image data can be obtained. Then, the position data of the second-size sample is determined according to the multiple two-dimensional image data, the first marker, and the multiple second markers.

[0044] In one embodiment, determining the location data of a second-sized sample using two-dimensional image data, a first marker, and multiple second markers can be performed according to the following steps:

[0045] The coordinate information of the first marker is determined in multiple two-dimensional image data; the first positional relationship between the multiple two-dimensional image data and the first marker is determined; the second positional relationship between the multiple two-dimensional image data and the second marker is determined; the target two-dimensional image data is determined, and the target coordinate range is determined in the target two-dimensional image data; the position data of the second-sized sample is determined according to the target coordinate range, the coordinate information of the first marker, the first positional relationship and the second positional relationship.

[0046] In one embodiment, determining the target two-dimensional image data and the target coordinate range within the target two-dimensional image data can be performed according to the following steps:

[0047] The reference position data of the second-sized sample is determined based on the target coordinate range, the coordinate information of the first marker, the first positional relationship, and the second positional relationship; the fifth imaging data of the adjusted first-sized sample is obtained; the adjusted first-sized sample includes a third marker added based on the reference position data; the setting density of the third marker is greater than the setting density of the second marker; multiple updated two-dimensional image data are determined based on the fifth imaging data; the target two-dimensional image data is determined in the updated two-dimensional image data, and the target coordinate range is determined in the target two-dimensional image data.

[0048] In one embodiment, the method may also perform the following steps:

[0049] The position data of the third-size sample is determined based on the second imaging data; the third imaging data of the third-size sample is obtained; the third-size sample is obtained from the second-size sample based on the position data of the third-size sample; the position data of the fourth-size sample is determined based on the third imaging data; the fourth imaging data of the fourth-size sample is obtained; the fourth-size sample is obtained from the third-size sample based on the position data of the fourth-size sample; the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are used as the reservoir X-ray imaging results.

[0050] In this embodiment of the invention, considering that the number of sample sizes required varies under different circumstances, the scheme can also continue to sample based on the position of the second-sized sample, and then sample again based on the obtained sample to obtain imaging data of multiple samples of different sizes.

[0051] In this embodiment of the invention, the resolutions of the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are progressively increased. Different resolutions are selected to perform X-ray imaging on the sample. By setting calibration points on the top surface and cylindrical surface of the sample, an accurate correspondence between the scanned image and the physical position of the sample is established. Sample preparation is carried out using a high-precision mechanical drill and laser sample preparation to ensure the representativeness and accuracy of the higher resolution scanning results.

[0052] In one embodiment, the method may also perform the following steps:

[0053] Determine the positional correlation between the first, second, third, and fourth imaging data; generate reservoir structure analysis results based on the positional correlation.

[0054] The implementation steps of this method are described below using a specific embodiment.

[0055] Based on the characteristics of current reservoir X-ray imaging analysis, this invention focuses on illustrating in-situ sample preparation methods with resolutions ranging from micrometers to nanometers. Considering the performance of X-ray imaging equipment, the invention will be illustrated using resolutions of 25 μm, 5 μm, 2 μm, and 65 nm as examples, corresponding to plunger sample diameters of 25.4 mm, 5 mm, 2 mm, and 65 μm, respectively. The sample preparation equipment includes a mechanical drilling rig and a laser sample preparation machine.

[0056] The main process is as follows:

[0057] (1) A plunger sample with a diameter of 25.4 mm was drilled using a mechanical drilling rig. Calibration metal plates were placed on the top surface and cylindrical surface of the sample. The sample was placed in an X-ray imaging scanning device and scanned at a resolution of 25 μm to obtain three-dimensional imaging data, which was numbered 1.

[0058] (2) In the No. 1 imaging data, establish the correspondence between the marker metal sheet and the XY plane coordinate values ​​and the longitudinal slice number; select a region of interest with a diameter of 5 mm, determine its position on the sample, and use a mechanical drill to drill a plunger sample with a diameter of 5 mm.

[0059] (3) Place calibration metal sheets on the top and cylindrical surfaces of the plunger sample again, scan with a pixel resolution of 5μm to obtain three-dimensional imaging data No. 2, and verify its correspondence with image data No. 1.

[0060] (4) Repeat step (2) to establish a new relationship between the marked metal sheet, the image position, and the sample position. Select the region of interest in the No. 2 imaging data and use a mechanical drill to drill a plunger sample with a diameter of 2 mm. Repeat step (3) to scan at a pixel resolution of 2 μm to obtain the No. 3 three-dimensional imaging data and verify its consistency and correspondence with the No. 2 image data.

[0061] (5) Repeat step (2) again, select the region of interest in the No. 3 imaging data, and determine the physical location of the region of interest in the rock sample according to the established correspondence between the metal sheet and the image coordinates; then place additional marker metal sheets around the determined location, and rescan with the same parameters as in step (4) to obtain the No. 4 imaging data; based on the No. 4 imaging data, establish a more accurate relationship between imaging data, region of interest and physical location of the sample.

[0062] (6) Based on the relationship established in step (5), a plunger sample with a diameter of 65 μm was prepared using a laser sample preparation machine, and three-dimensional imaging data No. 4 with a pixel resolution of 65 nm was obtained, and its correspondence with image data No. 3 was verified.

[0063] (7) Using three-dimensional image processing software, image data 1, 2, 3 and 4 were processed uniformly, and the relationship between X-ray imaging results at different resolutions was studied and analyzed.

[0064] It should be noted that the most challenging step in in-situ sample preparation for X-ray imaging is preparing samples from 2 mm to 65 μm in diameter. This involves switching from mechanical drilling to laser cutting, as well as changing the scanning equipment. Currently, mechanical drilling can prepare samples with a minimum diameter of 0.5 mm to 1 mm, but the preparation is difficult and the success rate is low. Therefore, mechanical drilling is mainly used to prepare plunger samples with a diameter of 2 mm or more. Sample diameters from 2 mm to 25.4 mm can all be scanned using the same X-ray imaging equipment, such as the micron-CT equipment from Carl Zeiss, Skyscan, GE, and Sanying. However, for samples with a diameter of 65 μm, preparation methods include ion beam cutting and laser preparation equipment. Considering time and cost, laser preparation is generally used. Sample imaging requires scanning with higher resolution X-ray imaging equipment, such as nano-CT or national synchrotron radiation. The transition from micron-CT to nano-CT achieves improved scanning resolution, but the drastic reduction in sample size makes in-situ sample preparation from 2 mm to 65 μm very difficult, which is the focus of this invention. This invention details the in-situ calibration process. By installing a calibration metal plate, an accurate correspondence between the X-ray scan image and the physical position of the sample is established, making in-situ sample preparation possible during continuous X-ray imaging at different resolutions.

[0065] See Figure 3 The schematic diagram of the reservoir X-ray imaging method and sample preparation method shown is illustrated in steps S01-S07. The implementation method of the method is further described below.

[0066] (1) Use a mechanical drill bit to drill a cylindrical sample with a diameter of 2.54 cm and a length of no more than 5 cm, cut both ends flat, and polish the two end faces of the cylindrical sample with 1000-mesh diamond abrasive.

[0067] (2) Use quick-drying adhesive to attach the marking metal sheet to one end face (defined as the top face), and use quick-drying adhesive to fix the other end face (defined as the bottom face) of the plunger sample to the sample stage of the X-ray imaging equipment; the marking metal sheet is about 1mm to 2mm in size and is attached to the edge of the top face of the sample, and this position is defined as P0 (see Appendix). Figure 4 );

[0068] (3) On the cylindrical surface of the plunger sample, arrange a row of marking metal patches in a straight line from top to bottom at 5mm intervals; the size of the metal patches is the same as that used in step (2), but the shape of each metal patch is significantly different. From top to bottom, the longitudinal aluminum patches are numbered as P1, P2, P3, ..., P n (See appendix) Figure 4 It should be noted that... Figure 4 The diameter of the central plunger is 2.54 cm. The positions of the aluminum marking plates for other smaller-scale samples are basically the same, except that the spacing between the marking metal plates in the longitudinal direction is smaller.

[0069] (4) After the metal patch is completely fixed, place the sample in the X-ray imaging device, set the appropriate scanning voltage, beam current, exposure time and sample transmittance, and set the scanning resolution to 25 μm / pixel to obtain the No. 1 scan image data volume; it should be noted that the marking patch must be completely placed within the scanning range, mainly for the convenience of subsequent comparison.

[0070] (5) Using image processing software, convert the scanned contrast images into grayscale images, numbered S1, S2, S3, ..., S... n In the XY-direction slice image of data volume 1, the characteristics of the metal sheet used for marking the top surface are identified to determine the correspondence between the sample top surface and the two-dimensional image number, as well as the position of the metal sheet in the image (X-direction and Y-direction coordinates). Then, based on the imaging characteristics of the metal sheet used for marking in the XZ and YZ-direction images, the metal sheets with different numbers (P1, P2, P3, ..., P...) are identified. n ) and image slice numbers (S1, S2, S3, ..., S n The correspondence between )

[0071] (6) In the slice images in the XY direction, select representative regions of interest for further detailed scanning to determine the coordinates of the region of interest in the XY direction and the number of the image slices in the vertical direction; based on the correspondence between the image slice numbers determined in step (5) and the metal sheet used for marking, determine the location of the region of interest in the actual sample.

[0072] (7) Based on the position determined in step (6), use a mechanical drill to drill a plunger sample with a diameter of 5 mm and a sample height of about 1 cm. If the region of interest is located deep below the top surface of the sample, the original sample can be cut with a slicer and then mechanically drilled.

[0073] (8) Repeat steps (2) and (3) to prepare a plunger sample with a diameter of 5 mm, set the pixel resolution to 5 μm, obtain the second scan image data volume, and compare its correspondence with the first scan image data volume; if the relationship is good, continue the subsequent steps; if no good correspondence is found, terminate the operation, reselect the region of interest, and repeat steps (6) to (8).

[0074] (9) Repeat steps (5) and (6) to establish a new correspondence between the slice image, the region of interest, and the physical location of the sample. Select the region of interest for further detailed scanning. After determining the actual sample location, use a mechanical drill to drill a plunger sample with a diameter of 2 mm and a height of about 5 mm.

[0075] (10) Repeat steps (2) and (3) to adjust the distance between the metal plates of the cylindrical direction marks to 1 mm; set the pixel resolution to 2 μm, obtain the data volume of scan image No. 3, and compare its correspondence with that of scan image data volume No. 2; if the relationship is good, continue the subsequent steps; if no good correspondence is found, terminate the operation, reselect the region of interest, and repeat the operation from step (9) to step (10);

[0076] (11) Repeat steps (5) and (6) to initially determine the region of interest; based on the correspondence between the new slice image, the region of interest, and the physical position of the sample, further supplement the area around the region of interest with marker metal sheets, scan again to obtain the No. 4 scan image data volume, and on this basis, establish the correspondence between the high-precision slice image, the region of interest, and the physical position of the sample within 10μm.

[0077] (12) After determining the actual sample location, cut out a plunger sample with a diameter of 65μm and a height of about 0.1mm in the laser sample preparation equipment; set the pixel resolution to 65nm, obtain the No. 5 scan image data volume, and compare its correspondence with the No. 3 scan image data volume; if the relationship is good, continue the subsequent steps; if no good correspondence is found, terminate the operation, reselect the region of interest, and repeat the operation from step (11) to step (12);

[0078] (13) Using three-dimensional image processing software, the scan data volumes No. 1, No. 2, No. 3 and No. 5 are analyzed in a unified manner to determine the position of the high-resolution scan area in the large field of view sample, so as to ensure the in-situ nature of the subsequent results analysis and improve the accuracy.

[0079] Figure 5 This is an example demonstrating the position of a metal sheet used for marking under X-ray imaging conditions and its correspondence with the X-ray scan image. Figure 5Figure A shows the relative positions of the metal sheet marking the top surface of the sample and the region of interest to the aluminum sheet. Figure 5 Figures B, C, and D in the diagram show the location and features of the regions of interest in the slices along the XY, XZ, and YZ directions, respectively.

[0080] Figure 6 This is the result of a case study. The sample lithology is tuff. Figure 6 In the diagram, A1-A2 represent two-dimensional slices and three-dimensional rock models with a resolution of 25μm. Figure 6 In Figure A1, B1-B2 are two-dimensional slices and three-dimensional rock models with a resolution of 5μm. The location of the scanned sample in Figure B is shown by the dashed circle in Figure A1. Figure 6 C1-C2 in the figure represent two-dimensional slices and three-dimensional rock models with a resolution of 2μm. Figure 6 The location of the sample scanned in Figure C is shown in the image. Figure 6 The dashed circles in Figure B1; D1-D2 represent two-dimensional slices and three-dimensional rock models with a resolution of 65nm. Figure 6 The location of the sample scanned in the D-map is shown in the image. Figure 6 The dashed circle in Figure C1 illustrates this. The method of this invention enables continuous imaging studies of X-rays from the micrometer to the nanometer scale, improving the accuracy of research results through in-situ contrast and comprehensive evaluation at different scales.

[0081] This invention provides a reservoir X-ray imaging method and apparatus, as well as a sample preparation method and apparatus. The method establishes a correspondence between the X-ray scan image, the region of interest, and the physical location of the sample by placing a marked metal sheet. It comprehensively utilizes precise mechanical cutting and laser cutting to obtain samples, achieving accurate positioning and tracking of samples of different sizes. Through continuous scanning from the micrometer to the nanometer scale, it integrates and optimizes high-resolution and large-field-of-view characterization results. This invention effectively fills the gap in existing experimental methods that cannot perform in-situ sample preparation for X-ray scanning at different resolutions. By preparing in-situ characterized samples, it effectively improves the accuracy of reservoir heterogeneity evaluation, provides a fundamental model for the effectiveness evaluation of low-permeability to tight reservoirs and research on enhanced oil and gas recovery, and further promotes basic laboratory research.

[0082] This invention also provides a sample preparation method, see [link to relevant documentation]. Figure 2 The flowchart shown illustrates a sample preparation method that includes the following steps:

[0083] Step S202: Obtain the position data of the second-sized sample.

[0084] In this embodiment of the invention, the position data of the second-sized sample is determined based on the first imaging data of the first-sized sample; the first surface of the first-sized sample is provided with a first marker, and the second surface of the first-sized sample is provided with a plurality of second markers; the shapes of the second markers are all different.

[0085] Step S204: Obtain a second-size sample from the first-size sample based on the position data of the second-size sample, so as to generate second imaging data based on the second-size sample.

[0086] In this embodiment of the invention, the accuracy of the second imaging data is higher than that of the first imaging data.

[0087] Step S206: The first-size sample and the second-size sample are taken as the sample preparation results.

[0088] This invention also provides a reservoir X-ray imaging device, as described in the following embodiments. Since the principle by which this device solves the problem is similar to that of the reservoir X-ray imaging method, its implementation can be referred to the implementation of the reservoir X-ray imaging method; repeated details will not be elaborated further. See also Figure 7 The diagram shows a structural block diagram of a reservoir X-ray imaging device, which includes:

[0089] The first acquisition module 71 is used to acquire first imaging data of a first-sized sample; a first marker is provided on the first surface of the first-sized sample, and multiple second markers are provided on the second surface of the first-sized sample; the shapes of the second markers are different; the position module 72 is used to determine the position data of a second-sized sample using the first imaging data, the first markers, and the multiple second markers; the second acquisition module 73 is used to acquire second imaging data of the second-sized sample; the second-sized sample is obtained from the first-sized sample based on the position data of the second-sized sample; the accuracy of the second imaging data is higher than that of the first imaging data; the imaging result module 74 is used to use the first imaging data and the second imaging data as reservoir X-ray imaging results.

[0090] In one embodiment, the first imaging data is three-dimensional data; the position module includes: an image unit for determining multiple two-dimensional image data based on the first imaging data; and a position unit for determining position data of a second-sized sample using the multiple two-dimensional image data, a first marker, and multiple second markers.

[0091] In one embodiment, the positioning unit is specifically configured to: determine the coordinate information of a first marker in multiple two-dimensional image data; determine a first positional relationship between the multiple two-dimensional image data and the first marker; determine a second positional relationship between the multiple two-dimensional image data and a second marker; determine target two-dimensional image data and determine a target coordinate range in the target two-dimensional image data; and determine the position data of a second-sized sample based on the target coordinate range, the coordinate information of the first marker, the first positional relationship, and the second positional relationship.

[0092] In one embodiment, the positioning unit is specifically configured to: determine reference position data of a second-sized sample based on a target coordinate range, coordinate information of a first marker, a first positional relationship, and a second positional relationship; acquire fifth imaging data of an adjusted first-sized sample; the adjusted first-sized sample includes a third marker added based on the reference position data; the density of the third marker is greater than the density of the second marker; determine multiple updated two-dimensional image data based on the fifth imaging data; determine target two-dimensional image data in the updated two-dimensional image data, and determine a target coordinate range in the target two-dimensional image data.

[0093] See Figure 8 Another reservoir X-ray imaging device block diagram is shown. In one embodiment, the device further includes a multi-scale module 75, used for: determining the position data of a third-size sample based on the second imaging data; acquiring the third imaging data of the third-size sample; obtaining the third-size sample from the second-size sample based on the position data of the third-size sample; determining the position data of a fourth-size sample based on the third imaging data; acquiring the fourth imaging data of the fourth-size sample; obtaining the fourth-size sample from the third-size sample based on the position data of the fourth-size sample; and using the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data as the reservoir X-ray imaging result.

[0094] In one embodiment, the multi-scale module is further configured to: determine the positional correlation between the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data; and generate reservoir structure analysis results based on the positional correlation.

[0095] This invention also provides a sample preparation apparatus, as described in the following embodiments. Since the principle by which this apparatus solves the problem is similar to that of the sample preparation method, the implementation of this apparatus can be found in the implementation of the sample preparation method; repeated details will not be elaborated further. See also Figure 9 The diagram shown is a structural block diagram of a sample preparation device, which includes:

[0096] Data module 91 is used to acquire position data of the second-sized sample; the position data of the second-sized sample is determined based on the first imaging data of the first-sized sample; the first surface of the first-sized sample is provided with a first marker, and the second surface of the first-sized sample is provided with multiple second markers; the shapes of the second markers are different; segmentation module 92 is used to obtain the second-sized sample from the first-sized sample based on the position data of the second-sized sample, so as to generate second imaging data based on the second-sized sample; the accuracy of the second imaging data is higher than that of the first imaging data; sample result module 93 is used to take the first-sized sample and the second-sized sample as the sample preparation result.

[0097] In one embodiment, a segmentation module is used to obtain a second-size sample from a first-size sample using a mechanical drilling rig or a laser sample preparation machine.

[0098] In one embodiment, the segmentation module is used to: acquire a sample in the shape of a cylinder or a cube.

[0099] This invention also provides a computer device, see [link to relevant documentation]. Figure 10 The schematic block diagram of the computer device shown includes a memory 81, a processor 82, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of any of the above-mentioned reservoir X-ray imaging methods or sample preparation methods.

[0100] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the computer device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0101] This invention also provides a computer-readable storage medium storing a computer program that executes any of the above-described reservoir X-ray imaging methods or sample preparation methods.

[0102] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0103] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0104] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0105] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0106] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A reservoir X-ray imaging method, characterized in that, include: Acquire first imaging data of a sample of the first size; The first surface of the first-sized sample is provided with a first marker, and the second surface of the first-sized sample is provided with a plurality of second markers; The second markers have different shapes; the first-sized sample is a rock sample obtained from the reservoir of interest and is set as a cylinder; the first surface is the upper surface of the cylinder, and the second surface is the cylindrical surface of the cylinder; multiple second markers are set at fixed intervals parallel to the central axis of the cylinder on the cylindrical surface of the cylinder; The location data of the second-sized sample is determined using the first imaging data, the first marker, and the plurality of second markers; The second-size sample is smaller than the first-size sample. Determining the position data of a second-size sample using the first imaging data, the first marker, and the plurality of second markers includes: establishing positional relationships between markers, image positions, and sample positions, and determining the position data of the second-size sample based on these positional relationships; Acquire second imaging data of the second-sized sample; the second-sized sample is obtained from the first-sized sample based on the position data of the second-sized sample; the imaging accuracy of the second imaging data is higher than that of the first imaging data; The first imaging data and the second imaging data are used as reservoir X-ray imaging results; The position data of the third-sized sample are determined based on the second imaging data; Acquire third imaging data of the third-size sample; the third-size sample is obtained from the second-size sample based on the position data of the third-size sample; The position data of the fourth-sized sample are determined based on the third imaging data; Acquire fourth imaging data of the fourth-size sample; the fourth-size sample is obtained from the third-size sample based on the position data of the fourth-size sample; The first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are used as reservoir X-ray imaging results. The resolution of the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are increased one by one. Different resolutions are selected to perform X-ray imaging on the sample. By setting markers on the top surface and cylindrical surface of the sample, the correspondence between the scanned image and the physical position of the sample is established. Sample preparation is carried out using a high-precision mechanical drilling rig and laser sample preparation.

2. The method according to claim 1, characterized in that, Determining the position data of the second-size sample using the first imaging data, the first marker, and the plurality of second markers includes: Multiple two-dimensional image data are determined based on the first imaging data; The location data of the second-size sample are determined using the multiple two-dimensional image data, the first marker, and the multiple second markers.

3. The method according to claim 2, characterized in that, Determining the position data of the second-size sample using the two-dimensional image data, the first marker, and the plurality of second markers includes: The coordinate information of the first marker is determined from the plurality of two-dimensional image data respectively; Determine the first positional relationship between the plurality of two-dimensional image data and the first marker; The second positional relationship between the plurality of two-dimensional image data and the second marker is determined respectively; Determine the target two-dimensional image data, and determine the target coordinate range within the target two-dimensional image data; The position data of the second-sized sample are determined based on the target coordinate range, the coordinate information of the first marker, the first positional relationship, and the second positional relationship.

4. The method according to claim 3, characterized in that, Determining the target two-dimensional image data, and determining the target coordinate range within the target two-dimensional image data, includes: The reference position data of the second-size sample is determined based on the target coordinate range, the coordinate information of the first marker, the first positional relationship, and the second positional relationship; Acquire fifth imaging data of the adjusted first-size sample; the adjusted first-size sample includes a third marker added based on the reference position data; the density of the third marker is greater than the density of the second marker; Multiple updated two-dimensional image data are determined based on the fifth imaging data; The target two-dimensional image data is determined from the updated two-dimensional image data, and the target coordinate range is determined from the target two-dimensional image data.

5. The method according to claim 1, characterized in that, Also includes: Determine the positional relationship between the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data; Reservoir structure analysis results are generated based on the location correlation.

6. A sample preparation method, characterized in that, include: Acquire the position data of the second-sized sample; The positional data of the second-sized sample is determined based on the first imaging data of the first-sized sample; the first surface of the first-sized sample is provided with a first marker, and the second surface of the first-sized sample is provided with multiple second markers; the shapes of the second markers are different; the first-sized sample is a rock sample obtained from the reservoir of interest and is set as a cylinder; the first surface is the upper surface of the cylinder, and the second surface is the cylindrical surface of the cylinder; multiple second markers are set at fixed intervals parallel to the central axis of the cylinder on the cylindrical surface; the positional relationship between the markers, image positions, and sample positions is established, and the positional data of the second-sized sample is determined based on these positional relationships; A second-sized sample is obtained from the first-sized sample based on the position data of the second-sized sample, so as to generate second imaging data based on the second-sized sample; The second imaging data has higher precision than the first imaging data; The second-size sample is smaller than the first-size sample. The position data of the third-sized sample are determined based on the second imaging data; Acquire the third imaging data of the third-sized sample; The third-size sample is obtained from the second-size sample based on the position data of the third-size sample; The position data of the fourth-sized sample are determined based on the third imaging data; Acquire the fourth imaging data of the fourth-sized sample; The fourth-size sample is obtained from the third-size sample based on the position data of the fourth-size sample; The first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are used as reservoir X-ray imaging results. The resolutions of the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are progressively increased. Different resolutions are selected for X-ray imaging of the sample. By setting markers on the top surface and cylindrical surface of the sample, a correspondence between the scanned image and the physical position of the sample is established. Sample preparation is carried out using a high-precision mechanical drilling rig and laser sample preparation. The first-sized sample, the second-sized sample, the third-sized sample, and the fourth-sized sample are used as sample preparation results.

7. The method according to claim 6, characterized in that, A second-size sample is obtained from a first-size sample using a mechanical drilling rig or a laser sample preparation machine.

8. The method according to any one of claims 6-7, characterized in that, The sample is set to a cylindrical shape.

9. A reservoir X-ray imaging device, characterized in that, include: The first acquisition module is used to acquire first imaging data of a sample of the first size. The first surface of the first-sized sample is provided with a first marker, and the second surface of the first-sized sample is provided with a plurality of second markers; the shapes of the second markers are all different; the first-sized sample is a rock sample obtained from the reservoir of interest and is set as a cylinder; the first surface is the upper surface of the cylinder, and the second surface is the cylindrical surface of the cylinder; the plurality of second markers are set at fixed intervals and parallel to the central axis of the cylinder on the cylindrical surface of the cylinder; A location module is used to determine the location data of a second-sized sample using the first imaging data, the first marker, and the plurality of second markers; The second-size sample is smaller than the first-size sample. The position module is specifically used to: establish the positional relationship between the marker, image position, and sample position, and determine the positional data of the second-size sample based on these positional relationships; The second acquisition module is used to acquire the second imaging data of the sample of the second size. The second-sized sample is obtained from the first-sized sample based on the position data of the second-sized sample; the accuracy of the second imaging data is higher than that of the first imaging data; An imaging result module is used to use the first imaging data and the second imaging data as reservoir X-ray imaging results; Multi-scale module, used for: The position data of the third-sized sample are determined based on the second imaging data; Acquire third imaging data of the third-size sample; the third-size sample is obtained from the second-size sample based on the position data of the third-size sample; The position data of the fourth-sized sample are determined based on the third imaging data; Acquire the fourth imaging data of the fourth-sized sample; The fourth-size sample is obtained from the third-size sample based on the position data of the fourth-size sample; The first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are used as reservoir X-ray imaging results. The resolution of the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are increased one by one. Different resolutions are selected to perform X-ray imaging on the sample. By setting markers on the top surface and cylindrical surface of the sample, the correspondence between the scanned image and the physical position of the sample is established. Sample preparation is carried out using a high-precision mechanical drilling rig and laser sample preparation.

10. The apparatus according to claim 9, characterized in that, The location module includes: An image unit is used to determine multiple two-dimensional image data based on the first imaging data; A location unit is used to determine the location data of a second-size sample using the plurality of two-dimensional image data, the first marker, and the plurality of second markers.

11. The apparatus according to claim 10, characterized in that, The position unit is specifically used for: The coordinate information of the first marker is determined from the plurality of two-dimensional image data respectively; Determine the first positional relationship between the plurality of two-dimensional image data and the first marker; The second positional relationship between the plurality of two-dimensional image data and the second marker is determined respectively; Determine the target two-dimensional image data, and determine the target coordinate range within the target two-dimensional image data; The position data of the second-sized sample are determined based on the target coordinate range, the coordinate information of the first marker, the first positional relationship, and the second positional relationship.

12. The apparatus according to claim 11, characterized in that, The position unit is specifically used for: The reference position data of the second-size sample is determined based on the target coordinate range, the coordinate information of the first marker, the first positional relationship, and the second positional relationship; Acquire the fifth imaging data of the adjusted first-size sample; The adjusted first-size sample includes a third marker added based on the reference position data; the density of the third marker is greater than the density of the second marker. Multiple updated two-dimensional image data are determined based on the fifth imaging data; The target two-dimensional image data is determined from the updated two-dimensional image data, and the target coordinate range is determined from the target two-dimensional image data.

13. The apparatus according to claim 9, characterized in that, The multi-scale module is also used for: Determine the positional relationship between the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data; Reservoir structure analysis results are generated based on the location correlation.

14. A sample preparation apparatus, characterized in that, include: The data module is used to acquire the position data of the second-sized sample; The positional data of the second-sized sample is determined based on the first imaging data of the first-sized sample; the first surface of the first-sized sample is provided with a first marker, and the second surface of the first-sized sample is provided with multiple second markers; the shapes of the second markers are different; the first-sized sample is a rock sample obtained from the reservoir of interest and is set as a cylinder; the first surface is the upper surface of the cylinder, and the second surface is the cylindrical surface of the cylinder; multiple second markers are set at fixed intervals parallel to the central axis of the cylinder on the cylindrical surface; the positional relationship between the markers, image positions, and sample positions is established, and the positional data of the second-sized sample is determined based on these positional relationships; A segmentation module is used to obtain a second-sized sample from a first-sized sample based on the position data of the second-sized sample, so as to generate second imaging data based on the second-sized sample; the accuracy of the second imaging data is higher than that of the first imaging data; The second-size sample is smaller than the first-size sample. The position data of the third-size sample is determined based on the second imaging data; the third imaging data of the third-size sample is acquired; the third-size sample is obtained from the second-size sample based on the position data of the third-size sample; the position data of the fourth-size sample is determined based on the third imaging data; Acquire the fourth imaging data of the fourth-sized sample; The fourth-size sample is obtained from the third-size sample based on the position data of the fourth-size sample; the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are used as reservoir X-ray imaging results; the resolution of the first imaging data, the second imaging data, the third imaging data, and the fourth imaging data are increased one by one, and different resolutions are selected to perform X-ray imaging on the sample; by setting markers on the top surface and cylindrical surface of the sample, the correspondence between the scanned image and the physical position of the sample is established; and sample preparation is carried out using a high-precision mechanical drilling rig and laser sample preparation. The sample result module is used to take the first-size sample, the second-size sample, the third-size sample, and the fourth-size sample as the sample preparation results.

15. The apparatus according to claim 14, characterized in that, The segmentation module is used to obtain a second-size sample from a first-size sample using a mechanical drilling rig or a laser sample preparation machine.

16. The apparatus according to any one of claims 14-15, characterized in that, The segmentation module is used to: obtain cylindrical samples.

17. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 8.

18. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 8.

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