A method and system for making a microscopic model of original coal and rock

Abstract

The present invention provides a method and system for making a microscopic model of an original coal rock. After extracting real fracture network data based on the original coal rock sample, the method controls an automated instrument to cut and obtain microscopic coal rock blocks and solidify them, and then performs precision grinding and polishing on the solidified coal rock blocks, and then performs laser etching on the microscopic coal rock blocks according to the extracted fracture network data, and adheres the preset cover sheet and the etched microscopic coal rock blocks through a cover sheet sealing operation to form a target microscopic model. The scheme of the present invention overcomes the defects of insufficient etching accuracy and the inability to restore the original gas-liquid migration process in the prior art. The model made by the present invention preserves a variety of original characteristics of coal rock to the greatest extent, and can ensure that the physical simulation experiment accurately restores the state of gas and water migration in the coal seam. At the same time, it expands the flexibility of the model research object and is suitable for various types of coalbed methane reservoirs.

Description

Technical Field

[0001] The invention relates to the technical field of coalbed methane mining, and in particular to a method and system for making an original coal rock microscopic model. Background Art

[0002] The development of coalbed methane mining technology has reached more than 10 years, and commercial development or breakthroughs have been achieved in high, medium and low coal rank basins. Although the annual output of coalbed methane can reach 8.8 billion m 3 However, objectively speaking, there is still a considerable gap between the actual mining output and the expected value. The main reason for this actual deviation is that the coalbed methane industry has the problem of low single well production, with an average single well production of less than 900m per day. 3 However, the average coalbed methane content in coal in the coalbed methane reservoir area is about 10m 3 / t, which shows that the reason for the low single well production is not the insufficient resource content, but the current understanding of the coalbed methane water migration mechanism during the mining process is still unclear, and the existing related research cannot better guide coalbed methane mining.

[0003] In the field, the constructed model is usually used to implement experiments with different parameter configurations to analyze the reaction mechanism or material migration characteristics of the research object during the experiment. The existing microscopic model technology is mainly developed for related issues in the petroleum field, and is generally divided into two categories: original sandstone microscopic model and glass simulation model. Since the original coal rock belongs to the dual medium of pores and fractures, it has extremely strong heterogeneity, and the coal rock fracture network mainly serves as a channel for gas and water migration during the development of coalbed methane. Therefore, the characteristic mechanism of gas and water migration in the fracture network is indispensable. However, the current microscopic models in the petroleum field are mainly used to study the gas-liquid or liquid-liquid flow in pores and pores, which is significantly different from the gas-liquid flow in the fractures to be studied in the coalbed methane field, and its experimental data cannot be effectively applied to the research on the mining and migration mechanism of the original coal rock. However, the glass materials that have been wet-etched and dry-etched in the prior art cannot reach the nanoscale level. In addition, for glass simulation models, when the original sandstone slices are used as raw materials to make the corresponding microscopic models, adhesives need to be added during the production process, which will change the surface properties of the core, resulting in poor observation effects, and it is impossible to effectively observe the flow, adsorption, and diffusion of fluids inside the channel. On the other hand, the methods for making microscopic models in the prior art are usually only applicable to sandstones with better pore development, which has certain limitations. It can be seen that the microscopic models previously used in the field of oil and gas exploration are not competent for the study of gas-water two-phase migration required for pore-scale original coalbed methane mining projects. Summary of the invention

[0004] To solve the above problems, the present invention provides a method for making a microscopic model of original coal rock, which can be used to make an original coal rock microscopic displacement model used for studying the pore-scale gas-liquid two-phase migration mechanism, the effective utilization of residual gas and liquid, and the improvement of coalbed methane recovery rate. The model of the present invention can be used to intuitively and in real time observe the gas-water migration state of different coal ranks under different conditions, thereby studying the residual saturation of coalbed methane, relative permeability, coalbed methane water storage state and other issues, and further guiding the production increase of low-yield wells and the stable production and optimization development of high-yield wells.

[0005] In one embodiment, the method for making the original coal rock microscopic model includes:

[0006] Fracture data extraction step, extracting real fracture network data based on original coal rock samples;

[0007] Pre-processing steps of micro coal rock blocks, cutting to obtain micro coal rock blocks and solidifying them, and precisely grinding and polishing the display surface of the solidified coal rock blocks;

[0008] A fracture etching step, performing laser etching on the microscopic coal rock block according to the extracted fracture network data;

[0009] The cover sheet sealing step is based on a transparent quartz cover sheet and adopts a specific strategy to seal the etched microscopic coal rock block to form a target original coal rock microscopic model.

[0010] Specifically, in one embodiment, in the fracture data extraction step, a columnar rock sample that can effectively identify fracture network data is drilled based on the original coal rock block as the original coal rock sample. Before extracting the fracture network data, a non-destructive cylindrical coal rock sample that meets the set size requirements is shaped by sandpaper polishing technology and is cleaned with alcohol.

[0011] Furthermore, in one embodiment, industrial micro-nano ray scanning technology is used to scan the initial image of the fracture network of the original coal rock sample, and the initial image of the fracture network is subjected to three-dimensional reconstruction processing and matrix segmentation processing according to a set strategy to obtain stereoscopic image data of naturally developed fractures of the original coal rock sample.

[0012] In an optional embodiment, after the three-dimensional reconstruction and matrix segmentation processing, the initial image of the fracture network is further sharpened and denoised, so that the fracture stereoscopic image data reaches a micron-level clarity.

[0013] In one embodiment, in the pretreatment step of the micro coal rock block, wire cutting technology is used to cut coal rock blocks of a set size with no natural cracks on the surface as micro coal rock blocks, and then they are blended and fully stirred in a ratio of curing agent: resin = 1:2 to obtain epoxy resin glue of a set mass, and the micro coal rock blocks are solidified relative to a preset mold.

[0014] Specifically, in one embodiment, the display surface of the micro coal rock block is polished using sandpapers of 3000 mesh, 1500 mesh, 800 mesh, 200 mesh, 100 mesh and 60 mesh in sequence, and the polished display surface is polished using a silk wheel and polishing liquid.

[0015] In one embodiment, in the fracture etching step, based on the extracted fracture network data, a purple laser marking machine is used to perform etching on the microscopic coal rock block according to set etching parameters to form fractures that restore the original data; wherein, before performing the etching, a trial dot operation must be performed on the microscopic coal rock block according to the set etching parameters.

[0016] Furthermore, in one embodiment, the cover sheet sealing step includes the following operations:

[0017] A transparent quartz plate of a set size is selected, holes for gas and liquid to enter and exit are punched at set positions, the transparent quartz plate is used as a cover plate for the microscopic model and is cleaned with alcohol;

[0018] After the etched microscopic coal rock block is cleaned twice with alcohol, a set amount of UV glue is evenly applied on the sealing surface of the cover sheet, and the glue is solidified by irradiating with ultraviolet light for a set time;

[0019] Based on the continuous ultraviolet light environment, pressure is applied in a direction perpendicular to the display surface of the microscopic coal rock block and maintained for a set time, so that the cover sheet is bonded to the microscopic coal rock block to form a complete original coal rock microscopic model.

[0020] Based on the method for making the original coal rock microscopic model of any one or more of the above embodiments, the present invention also provides a storage medium, which stores program codes that can implement the method described in any one or more of the above embodiments.

[0021] Based on other aspects of any one or more of the above embodiments, the present invention further provides a system for making an original coal rock microscopic model, which executes the method described in any one or more of the above embodiments.

[0022] Compared with the closest prior art, the present invention also has the following beneficial effects:

[0023] The present invention provides a method and system for making a microscopic model of original coal rock. The method extracts real fracture network data based on the original coal rock sample and uses the data as the etching basis to perform laser etching on a microscopic coal rock block cut from the original coal rock block, thereby preserving the natural characteristics of the coal rock, such as heterogeneity, pore-fracture dual medium properties, wettability, etc., to the greatest extent. When the model is used for experimental research, it can ensure that the physical simulation experimental environment accurately restores the state of gas and water migration in the coal seam. In addition, the microscopic model making method of the present invention can restore the natural fracture network state of various coal rock samples, and its applicability is greatly improved, which is helpful to promote the optimization research on the pore-scale gas-liquid two-phase migration mechanism, the effective utilization of residual gas and liquid, and the improvement of coalbed methane recovery rate in the field of coalbed methane exploitation.

[0024] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic flow chart of a method for making an original coal rock microscopic model provided by an embodiment of the present invention;

[0027] Figure 2 is an example diagram of fracture network data of a method for making an original coal rock microscopic model in an embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of a microscopic coal rock block after solidification in a method for making a microscopic model of an original coal rock in one embodiment of the present invention;

[0029] Figure 4 is an example diagram of a complete microscopic model using a method for making an original coal rock microscopic model provided in another embodiment of the present invention;

[0030] Figure 5 It is a structural schematic diagram of a system for making an original coal rock microscopic model provided in a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will describe the implementation methods of the present invention in detail in conjunction with the accompanying drawings and embodiments, so that the implementers of the present invention can fully understand how the present invention applies technical means to solve technical problems and achieve the implementation process of technical effects and implement the present invention specifically according to the above implementation process. It should be noted that as long as there is no conflict, the various embodiments and various features of the embodiments in the present invention can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0032] Although the flowcharts describe the operations as sequential processes, many of the operations may be performed in parallel, concurrently, or simultaneously. The order of the operations may be rearranged. A process may be terminated when its operations are completed, but may also have additional steps not included in the accompanying drawings. A process may correspond to a method, function, procedure, subroutine, subprogram, etc.

[0033] Computer devices include user devices and network devices. Among them, user devices or clients include but are not limited to computers, smart phones, PDAs, etc.; network devices include but are not limited to a single network server, a server group consisting of multiple network servers, or a cloud composed of a large number of computers or network servers based on cloud computing. Computer devices can be operated alone to implement the present invention, or they can be connected to the network and implement the present invention through interactive operations with other computer devices in the network. The network where the computer device is located includes but is not limited to the Internet, wide area network, metropolitan area network, local area network, VPN network, etc.

[0034] The terms "first", "second", etc. may be used herein to describe various units, but these units should not be limited by these terms, and these terms are used only to distinguish one unit from another unit. The term "and / or" used herein includes any and all combinations of one or more of the listed associated items. When a unit is referred to as being "connected" or "coupled" to another unit, it can be directly connected or coupled to the other unit, or there can be intermediate units.

[0035] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0036] At present, with the continuous development of my country's coalbed methane industry and the continuous deepening of coalbed methane-related development theories, the gas-water two-phase migration mechanism and the improvement of the productivity of low-yield wells have become research hotspots and difficulties. Domestic coalbed methane mining technology has been developed for more than decades, and commercial development or breakthroughs have been achieved in high, medium and low coal rank basins. In 2019, my country's coalbed methane production reached 8.8 billion m3, but the objective reality is still far from the expected value. An important reason for this actual deviation is that my country's coalbed methane industry faces low single well production, with an average single well production of <900m3 / day. However, the average coalbed methane content of coal in the country is about 10m3 / t, which shows that the above problem is not due to insufficient resource content, but because the current understanding of the coalbed methane water migration mechanism during the mining process is still unclear, and the existing related research cannot better guide coalbed methane mining.

[0037] The existing microscopic model technology is mainly developed for related problems in the oil field, and is mainly divided into two categories: original sandstone microscopic model and glass simulation model. Coal rock, as a dual medium of pores and fractures, has extremely strong heterogeneity, and the coal rock fracture network is mainly used as a channel for gas and water migration during the development of coalbed methane. However, the current microscopic model in the oil field is mainly used to study the gas-liquid or liquid-liquid flow in pores and pores, which is different from the gas-liquid flow in the fractures to be studied in the coalbed methane field. In addition, glass materials cannot reach the nanoscale level through existing wet etching and dry etching; the microscopic model made of original sandstone slices as raw materials needs to add adhesives during the production process to change the surface properties of the core, and the observation effect is poor, and the purpose of observing the flow, adsorption and diffusion of fluids inside the channel cannot be achieved. On the other hand, when making microscopic models, sandstone with better pore development is often selected, which has certain limitations. Therefore, the microscopic models previously used in the oil industry are not competent for the study of gas-water two-phase migration in pore-scale coalbed methane extraction technology.

[0038] To solve the above problems, the present invention provides a method and system for making a microscopic model of original coal rock. By using the model made by the present invention, the gas and water migration state of coal rocks of different coal ranks under different conditions can be observed intuitively and in real time, thereby studying the mechanisms such as coalbed methane residual saturation, relative permeability, and coalbed methane water occurrence state, and further guiding the production increase of low-yield wells and the stable production of high-yield wells.

[0039] The present invention aims to use original coal rock as raw material, and through further processing with high-precision automated instruments, a microscopic model with the properties of the original coal rock can be obtained. The model is used to study the migration state of gas and water in the original coal rock fracture network, and can also accurately study the gas and water migration conditions in different types of fractures. Compared with the microscopic model of simulation materials, the model preserves the heterogeneity of coal, the dual medium properties of pores and fractures, wettability and other properties, which can ensure that the physical simulation experiment can restore the state of gas and water migration in the coal seam to the greatest extent.

[0040] Next, the detailed process of the method of the embodiment of the present invention is described in detail based on the accompanying drawings. The steps shown in the flowchart of the accompanying drawings can be executed in a computer system including a set of computer executable instructions. Although the logical order of each step is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0041] Embodiment 1

[0042] Figure 1 The schematic diagram of the process of making the original coal rock microscopic model provided by the first embodiment of the present invention is shown. Figure 1 It can be seen that the method includes the following steps.

[0043] Fracture data extraction step S110, extracting real fracture network data based on the original coal rock sample;

[0044] Micro coal block pretreatment step S120, cutting to obtain micro coal blocks and solidifying them, and precisely grinding and polishing the display surface of the solidified coal blocks;

[0045] Fracture etching step S130, laser etching the microscopic coal rock block according to the extracted fracture network data;

[0046] Cover sheet sealing step S140: using a transparent quartz cover sheet to seal the etched microscopic coal rock block according to a specific strategy to form a target original coal rock microscopic model.

[0047] Specifically, in one embodiment, a columnar rock sample that can effectively identify fracture network data is drilled based on the original coal rock block and used as the original coal rock sample. Before extracting the fracture network data, a sandpaper polishing technology is used to shape a non-destructive cylindrical coal rock sample that meets the set size requirements, and the sample is cleaned with alcohol.

[0048] In the fracture data extraction step S110, the initial fracture network image of the original coal rock sample is scanned by industrial micro-nano ray scanning technology, and the initial fracture network image is subjected to three-dimensional reconstruction processing and matrix segmentation processing according to the set strategy to obtain the naturally developed fracture stereo image data of the original coal rock sample. After the three-dimensional reconstruction processing and matrix segmentation processing, the initial fracture network image is also subjected to sharpening and noise reduction processing to make the fracture stereo image data reach the micron level of clarity.

[0049] In practical applications, fracture data is often extracted based on coal and rock samples through the following operations:

[0050] The first step is to drill a columnar coal rock sample with a diameter of about 2.5 cm from the block sample, and then use sandpaper to grind the columnar sample into a cylindrical sample of 2.5*5 cm. The drilled coal rock column can be used to identify the development of internal cracks through the surface. In this operation, the technician should understand that the drilling size of the columnar coal rock sample is not a limitation of the technical features of the technical solution. In the process of model making, the user can flexibly design according to the specific size requirements of the model making.

[0051] In the second step, the cylindrical coal sample is cleaned with alcohol and then placed in a CT scanning room for scanning to obtain a photo of the fracture network developed inside the sample. The specific use of CT scanning technology requires obtaining images through X-ray scanning, and then VG technology is used to reconstruct the three-dimensional model. Finally, threshold analysis is performed through Avizo to segment the fractures and matrix.

[0052] The obtained fracture stereo image data is then sharpened and denoised to obtain a higher quality fracture network image, so as to present clearer micron-level coal sample fractures, such as Figure 2 shown.

[0053] In one embodiment, in the subsequent pretreatment step of the micro coal rock block, wire cutting technology is used to cut coal rock blocks of set size with no developed natural cracks on the surface, which are used as micro coal rock blocks for constituting the target micro model, and then the coal rock blocks are blended and stirred in a ratio of curing agent: resin = 1:2 to obtain epoxy resin glue of a set mass, and the micro coal rock blocks are solidified relative to a preset mold.

[0054] In practical applications, the cut coal sample can be placed in a 8*8*2cm silicone mold, and then the epoxy resin glue is poured into the silicone mold along the side gap and left to stand for more than 24 hours. After the curing is completed, the microscopic coal rock block is as follows: Figure 3 shown.

[0055] After the curing is completed, the display surface of the micro coal rock block is polished using sandpapers of 3000 mesh, 1500 mesh, 800 mesh, 200 mesh, 100 mesh and 60 mesh in sequence, and the polished display surface is polished using a silk wheel and polishing liquid.

[0056] In practical applications, the following operations are usually used to pre-treat microscopic coal blocks:

[0057] The first step is to select a coal rock block of approximately 20*20*20 cm, and use a wire cutting machine to cut out a micro coal rock block of 7.2*7.2*1.5 cm in size. It should be noted that this step requires that natural cracks on the surface of the micro coal rock block are not developed in order to fully and accurately accommodate the crack network to be etched.

[0058] In the second step, the cut 7.2*7.2*1.5cm micro coal rock blocks are placed in a silicone mold, and then mixed and stirred in a ratio of curing agent: resin = 1:2 to obtain about 45g of epoxy resin glue, which is then poured into the mold and cured for 24 hours.

[0059] In the second step, the surface of the solidified microscopic coal rock block used for microscopic display (or display surface), which is generally the bottom surface of the coal rock block placed in the silicone mold, is polished with 3000 mesh, 1500 mesh, 800 mesh, 200 mesh, 100 mesh and 60 mesh sandpaper in turn, and then the polished surface is polished with a silk wheel and polishing liquid.

[0060] Furthermore, in one embodiment, in the fracture etching step, based on the extracted fracture network data, a purple laser marking machine is used to perform etching on the microscopic coal rock block according to set etching parameters to form fractures that restore the original data; wherein, before performing the etching, a trial dot operation must be performed on the microscopic coal rock block according to the set etching parameters.

[0061] In a specific embodiment, the operation of etching using a purple laser marking machine includes:

[0062] The first step is to input the extracted natural fracture stereo image data into the computer of the laser marking machine according to the 1:1 standard;

[0063] The second step is to place the coal block with the polished surface facing up on the operating table, and enter the laser etching parameter information in the operation interface, such as frequency (50Hz), pulse width (1), speed (50mm / s), etc. Then, perform a trial point, and move the laser transmitter up and down to find the focus of the laser, make sure the focus remains on the surface of the coal sample, and then click to start laser etching;

[0064] In an embodiment of practical application, the user can also simplify and adjust the extracted fracture stereo image data according to the actual test requirements, for example, only retain the fracture network that needs to be studied in the test, and then input the simplified and adjusted natural fracture stereo image data into the computer of the laser marking machine according to the 1:1 standard;

[0065] Then, place the coal block with the polished surface facing up on the operating table, enter the laser etching parameter information in the operating interface, perform trial points, and move the laser transmitter up and down to find the focus of the laser. Make sure the focus remains on the surface of the coal sample, and then click to start laser etching. This can reduce the time required for etching cracks while ensuring that the needs of experimental research are met, and control the time utilization rate within a reasonable range.

[0066] For the microscopic coal rock block with the fracture network etched, it is necessary to use professional techniques to seal it. In order to facilitate the real-time observation of the gas and water migration state and data of the fracture network of the coal rock block during the experiment, the present application uses a transparent quartz cover for sealing. Specifically, in one embodiment, the cover sealing step includes the following operations:

[0067] Select a transparent quartz plate of set size, punch two holes with a diameter of 2 mm at the two set corners to allow gas and liquid to enter and exit, use the transparent quartz plate as the cover of the microscopic model and clean it with alcohol;

[0068] After the etched microscopic coal rock block is cleaned twice with alcohol, a set amount of UV glue is evenly applied on the sealing surface of the cover sheet, and the glue is solidified by irradiating with ultraviolet light for a set time;

[0069] Based on an effective ultraviolet light environment, pressure is applied in a direction perpendicular to the display surface of the microscopic coal rock block and maintained for a set time, so that the cover sheet is bonded to the microscopic coal rock block to form a complete original coal rock microscopic model.

[0070] Taking the microscopic coal rock blocks cut in the above application as an example, a transparent quartz cover sheet of corresponding size is bonded based on the following operation:

[0071] In the first step, a quartz glass sheet with a size of 7.2*7.2*0.15 cm was selected, and two holes with a diameter of 2 mm were drilled at the two corners at a distance of 9.17 cm from each other as gas and liquid inlet and outlet holes, as a transparent quartz cover sheet for sealing the microscopic model, and then sprayed with alcohol for cleaning;

[0072] The second step is to spray alcohol on the etched micro coal sample display surface for cleaning. After the alcohol on the transparent quartz glass sheet and the micro coal rock block evaporates and becomes dry, use a brush to evenly apply a layer of UV glue on one side of the quartz glass sheet and pre-solidify it under ultraviolet light for 10 minutes.

[0073] The third step is to bond the quartz glass sheet to the surface of the coal sample with etched cracks, and apply a certain pressure to the quartz glass sheet under a continuous ultraviolet light environment for 1-2 hours, so that the bonding is completed and a complete original coal rock microscopic model is formed, such as Figure 4 As shown; in this step, it is ensured as much as possible that the quartz glass sheet is subjected to pressure perpendicular to its own plane or the display surface of the coal rock block, so that the adhesive can evenly bond the cover sheet and the coal rock block to improve stability.

[0074] The microscopic model making method provided in the above embodiment of the present invention is adopted, and the industrial micro-nano CT scanning technology is used to obtain the fracture network developed in the original coal rock, thereby maintaining the heterogeneity of the coal rock and the originality of the fractures. With the assistance of a purple laser marking machine, the original network fractures or simplified fractures can be etched on the surface of the microscopic coal rock more accurately and controllably. Compared with the microscopic model of the simulation material, the model accurately preserves the original properties of the coal rock, such as the heterogeneity, pore-fracture dual medium properties and wettability, and does not require the addition of any other non-natural agents. It can ensure that the physical simulation experiment restores the state of gas and water migration in the coal seam to the greatest extent. Furthermore, UV glue is used to bond the microscopic coal rock and the transparent quartz glass sheet to achieve sealing, so that users can intuitively study and observe the coalbed gas-liquid seepage mechanism at the pore scale, filling the gap in the existing technology and providing reliable support for the study of gas-water two-phase migration conditions and the design of displacement schemes in coalbed methane mining projects.

[0075] For the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0076] It should be pointed out that, in other embodiments of the present invention, the method can also obtain a new micro-model making method by combining one or several of the above embodiments.

[0077] It should be noted that, based on the method in any one or more of the above-mentioned embodiments of the present invention, the present invention also provides a storage medium, on which is stored a program code that can implement the method as described in any one or more of the above-mentioned embodiments, and when the code is executed by the operating system, the method for making the original coal rock microscopic model as described above can be implemented.

[0078] Embodiment 2

[0079] The above embodiments disclosed in the present invention describe the method in detail. The method of the present invention can be implemented by various devices or systems. Therefore, based on other aspects of the method described in any one or more embodiments, the present invention also provides a system for making an original coal rock micromodel, which is used to execute the method for making an original coal rock micromodel described in any one or more embodiments. Specific embodiments are given below for detailed description.

[0080] Specifically, Figure 5 FIG. 4 shows a schematic diagram of the structure of the system for making the original coal rock microscopic model provided in an embodiment of the present invention. Figure 5 As shown, the system includes:

[0081] A fracture data extraction module 51, which is used to extract real fracture network data based on the original coal rock sample;

[0082] A micro coal rock block pre-processing module 53, which is used to cut and obtain micro coal rock blocks and solidify them, and to precisely grind and polish the display surface of the solidified coal rock blocks;

[0083] A fracture etching module 55, which is used to perform laser etching on the microscopic coal rock block according to the extracted fracture network data;

[0084] The cover sheet sealing module 57 is used to seal the etched microscopic coal rock blocks using a transparent quartz cover sheet according to a specific strategy to form a microscopic model.

[0085] Specifically, in one embodiment, the fracture data extraction module is configured as follows: based on the original coal rock block, a columnar rock sample that can effectively identify fracture network data is drilled as the original coal rock sample. Before extracting the fracture network data, a sandpaper polishing technology is used to shape a non-destructive cylindrical coal rock sample that meets the set size requirements, and the sample is cleaned with alcohol.

[0086] In actual application, in one embodiment, the fracture data extraction module uses industrial micro-nano ray scanning technology to scan the initial image of the fracture network of the original coal rock sample, and performs three-dimensional reconstruction and matrix segmentation processing on the initial image of the fracture network according to the set strategy to obtain the naturally developed fracture stereoscopic image data of the original coal rock sample.

[0087] After the three-dimensional reconstruction and matrix segmentation processing, the initial image of the fracture network is sharpened and denoised to make the fracture stereoscopic image data reach a micron-level clarity.

[0088] Furthermore, in one embodiment, the micro coal rock block pretreatment module uses wire cutting technology to cut coal rock blocks of set size with no natural cracks on the surface as micro coal rock blocks, and then mixes and stirs them in a ratio of curing agent: resin = 1:2 to obtain epoxy resin glue of set quality, and solidifies the micro coal rock blocks relative to a preset mold.

[0089] Next, the display surface of the micro coal rock block is polished using sandpapers of 3000 mesh, 1500 mesh, 800 mesh, 200 mesh, 100 mesh and 60 mesh in sequence, and the polished display surface is polished using a silk wheel and polishing liquid.

[0090] The fracture etching module is used to perform fracture etching on the micro coal rock block after grinding and polishing. Specifically, in one embodiment, the fracture etching module uses a purple laser marking machine to perform etching on the micro coal rock block according to the set etching parameters based on the extracted fracture network data, so as to form fractures that restore the original data; wherein, before etching is performed, a trial dot operation must be performed on the micro coal rock block according to the set etching parameters.

[0091] In practical applications, the cover sheet sealing module bonds the microscopic coal rock block to the transparent quartz cover sheet by performing the following operations to form a complete original coal rock microscopic model:

[0092] Select a transparent quartz plate of set size, punch two holes with a diameter of 2 mm at the two set corners to allow gas and liquid to enter and exit, use the transparent quartz plate as the cover of the microscopic model and clean it with alcohol;

[0093] After the etched microscopic coal rock block is cleaned twice with alcohol, a set amount of UV glue is evenly applied on the sealing surface of the cover sheet, and the glue is solidified by irradiating with ultraviolet light for a set time;

[0094] Based on an effective ultraviolet light environment, pressure is applied in a direction perpendicular to the display surface of the microscopic coal rock block and maintained for a set time, so that the cover sheet is bonded to the microscopic coal rock block to form a complete original coal rock microscopic model.

[0095] In the system for making the original coal and rock microscopic model provided by the embodiment of the present invention, each module or unit structure can be operated independently or in combination according to actual test and research requirements to achieve corresponding technical effects.

[0096] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0097] The "one embodiment" mentioned in the specification means that a particular feature, structure or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. Therefore, the phrase "one embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0098] Although the embodiments disclosed in the present invention are as above, the above contents are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for making an original coal rock microscopic model, characterized in that: The method comprises: Fracture data extraction step, extracting real fracture network data based on original coal rock samples; Pre-processing steps of micro coal rock blocks, cutting to obtain micro coal rock blocks and solidifying them, and precisely grinding and polishing the display surface of the solidified coal rock blocks; A fracture etching step, performing laser etching on the microscopic coal rock block according to the extracted fracture network data; The cover sheet sealing step includes setting holes for gas supply liquid in and out on the transparent quartz cover sheet, using UV adhesive to bond the transparent quartz cover sheet to the microscopic coal rock block, and sealing the etched microscopic coal rock block to form a target original coal rock microscopic model; In the fracture data extraction step, the initial image of the fracture network of the original coal rock sample is scanned by using industrial micro-nano ray scanning technology, and the initial image of the fracture network is subjected to three-dimensional reconstruction processing and matrix segmentation processing according to a set strategy to obtain the naturally developed fracture stereoscopic image data of the original coal rock sample; In the pretreatment step of the micro coal rock block, wire cutting technology is used to cut coal rock blocks of set size with no natural cracks on the surface as micro coal rock blocks, and then they are blended and fully stirred in a ratio of curing agent: resin = 1:2 to obtain epoxy resin glue of a set quality, and the micro coal rock blocks are cured relative to a preset mold.

2. The method according to claim 1, characterized in that In the fracture data extraction step, a columnar rock sample that can effectively identify fracture network data is drilled based on the original coal rock block as the original coal rock sample. Before extracting the fracture network data, a non-destructive cylindrical coal rock sample that meets the set size requirements is shaped by sandpaper polishing technology and is cleaned with alcohol.

3. The method according to claim 1, characterized in that After the three-dimensional reconstruction and matrix segmentation processing, the initial image of the fracture network is sharpened and denoised to make the fracture stereoscopic image data reach a micron-level clarity.

4. The method according to claim 1, characterized in that The display surface of the micro coal rock block is polished using sandpapers of 3000 mesh, 1500 mesh, 800 mesh, 200 mesh, 100 mesh and 60 mesh in sequence, and the polished display surface is polished using a silk wheel and polishing liquid.

5. The method according to claim 1, characterized in that In the fracture etching step, based on the extracted fracture network data, a purple laser marking machine is used to perform etching on the microscopic coal rock block according to the set etching parameters to form fractures that restore the original data; wherein, before etching is performed, a trial dot operation must be performed on the microscopic coal rock block according to the set etching parameters.

6. The method according to claim 1, characterized in that The cover sheet sealing step includes the following operations: A transparent quartz plate of a set size is selected, holes for gas and liquid to enter and exit are punched at set positions, the transparent quartz plate is used as a cover plate for the microscopic model and is cleaned with alcohol; After the etched microscopic coal rock block is cleaned twice with alcohol, a set amount of UV glue is evenly applied on the sealing surface of the cover sheet, and the glue is solidified by irradiating with ultraviolet light for a set time; Based on the continuous ultraviolet light environment, pressure is applied in a direction perpendicular to the display surface of the microscopic coal rock block and maintained for a set time, so that the cover sheet is bonded to the microscopic coal rock block to form a complete original coal rock microscopic model.

7. A storage medium, characterized in that: The storage medium stores program codes that can implement the method as claimed in any one of claims 1 to 6.

8. A system for making a microscopic model of an original coal rock, characterized in that: The system executes the method according to any one of claims 1 to 6.

Images