Deep coal reservoir gas content determination method, device, equipment, medium and product

Abstract

The invention provides a method, a device, equipment, a medium and a product for determining the gas content of a deep coal reservoir, and relates to the technical field of coal bed gas development. The method comprises the following steps: in response to a received gas content determination request triggered by a user through a terminal device, obtaining pore characteristic data of micropores, mesopores and macropores of a target coal sample, the pore characteristic data being obtained through high-pressure mercury injection and low-temperature carbon dioxide adsorption tests; calculating the adsorbed gas content based on the pore characteristic data of the micropores; performing compression correction on the pore feature data of the mesopores and the macropores by adopting a preset pore compression model to obtain in-situ underground porosity; and calculating the free gas content based on the in-situ underground porosity by adopting a preset free gas content prediction model. According to the method, the time for detecting the gas content of the coal reservoir is shortened, and the adsorbed gas content and the free gas content in the deep coal reservoir can be accurately determined.

Description

Technical Field

[0001] This application relates to the field of coalbed methane development technology, and in particular to a method, apparatus, equipment, medium and product for determining the gas content of deep coal reservoirs. Background Technology

[0002] The content of adsorbed gas and free gas is an important indicator in the exploration and development of deep coalbed methane, and it has significant theoretical and engineering value for evaluating the development potential of deep coalbed methane. The different occurrence states of adsorbed gas and free gas in coal seams determine the different extraction methods. Therefore, understanding the ratio of their contents helps in selecting appropriate extraction methods to improve coalbed methane recovery.

[0003] Current methods for determining the gas content in deep coal seams primarily involve wireline coring, drill pipe coring, and pressure-holding coring. However, wireline coring and drill pipe coring methods struggle to obtain the free gas content, while pressure-holding coring, although capable of measuring the total gas content, makes it difficult to distinguish between free and adsorbed gas content. This creates a current predicament where it is challenging to accurately determine the adsorbed and free gas content in deep coal reservoirs. Summary of the Invention

[0004] This application provides a method, apparatus, equipment, medium, and product for determining the gas content in deep coal reservoirs, in order to solve the current problem of the difficulty in accurately determining the adsorbed gas content and free gas content in deep coal reservoirs.

[0005] Firstly, this application provides a method for determining the gas content of deep coal reservoirs, including:

[0006] In response to receiving a gas content determination request triggered by a user through a terminal device, the system acquires pore characteristic data of the target coal sample, including micropores, mesopores, and macropores. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests.

[0007] Calculate the adsorbed gas content based on the pore characteristic data of micropores;

[0008] A pre-defined pore compression model was used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ subsurface porosity.

[0009] The free gas content was calculated based on in-situ underground porosity using a pre-defined free gas content prediction model.

[0010] In one possible design, the pore characteristic data of the micropores includes the micropore volume, and the adsorbed gas content is calculated based on the pore characteristic data, including:

[0011] The cumulative pore volume of each micropore in the target coal sample is calculated by summing up the pore volumes.

[0012] The adsorbed gas content is calculated based on the cumulative pore volume of the micropores.

[0013] In one possible design, the pore characteristic data of mesopores and macropores include the initial porosity of mesopores and macropores; a preset pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain the in-situ subsurface porosity, including:

[0014] The actual and simulated environmental parameters of the target coal sample were obtained. The actual environmental parameters were obtained through field well testing, and the simulated environmental parameters were obtained through test simulation.

[0015] The initial porosity of mesopores and macropores, actual environmental parameters, and simulated environmental parameters are input into the formula corresponding to the preset porosity compression model, and the in-situ subsurface porosity is calculated based on the formula corresponding to the preset porosity compression model.

[0016] In one possible design, the actual environmental parameters include the average value of the actual in-situ geostress and the actual in-situ reservoir pressure, while the simulated environmental parameters include the simulated in-situ geostress and the simulated reservoir pressure.

[0017] The formula corresponding to the preset pore compression model is: Where φ is the in-situ subsurface porosity; φ0 is the initial porosity; υ is the Poisson's ratio coefficient of coal; σ is the average value of actual in-situ in-situ in-situ stress; σ0 is the simulated in-situ in-situ in-situ in-situ stress from the initial porosity test; p is the actual in-situ reservoir pressure; p0 is the simulated reservoir pressure from the initial porosity test; R o,max This represents the maximum vitrinite reflectance of coal.

[0018] In one possible design, a pre-defined free gas content prediction model is used to calculate the free gas content based on in-situ subsurface porosity, including:

[0019] The reservoir environmental characteristic parameters and experimental test data of the target coal sample were obtained. The reservoir environmental characteristic parameters were obtained through field exploration and development, and the experimental test data were obtained through experiments based on the reservoir environmental characteristic parameters.

[0020] The reservoir environmental characteristic parameters, experimental test data, and in-situ subsurface porosity are input into the formula corresponding to the preset free gas content prediction model, and the free gas content is calculated based on the formula corresponding to the preset free gas content prediction model.

[0021] In one possible design, reservoir environmental characteristic parameters include reservoir pressure gradient, reservoir burial depth, reservoir temperature gradient and isothermal zone temperature, and experimental test data include reservoir pressure fitting line zero-point pressure, pore space water saturation, coal apparent density and gas compressibility factor.

[0022] The formula corresponding to the preset free gas content prediction model is: Among them, Vf Free gas content; M g f is the molar mass of methane; fP is the reservoir pressure gradient; H is the reservoir depth; P0 is the pressure at point 0 of the reservoir pressure fitting line; S w ρ represents the water saturation level in the pore space. c ρ represents the apparent density of coal. sc The density of methane gas under standard conditions is given by: Z, the gas compressibility factor, R, and f. T φ represents the reservoir temperature gradient; T0 represents the isothermal zone temperature; and φ represents the in-situ subsurface porosity.

[0023] Secondly, this application provides a device for determining the gas content of deep coal reservoirs, comprising:

[0024] The acquisition module is used to respond to a gas content determination request triggered by a user through a terminal device and acquire the pore characteristic data of the target coal sample, including micropores, mesopores and macropores. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests.

[0025] The calculation module is used to calculate the adsorbed gas content based on the pore characteristic data of the micropores;

[0026] The correction module is used to compress and correct the pore characteristic data of mesopores and macropores using a preset pore compression model in order to obtain in-situ underground porosity.

[0027] The calculation module is also used to calculate the free gas content based on in-situ underground porosity using a preset free gas content prediction model.

[0028] Thirdly, this application provides a device for determining the gas content of deep coal reservoirs, including: a processor and a memory communicatively connected to the processor;

[0029] The memory stores the instructions that the computer executes;

[0030] The processor executes computer-executable instructions stored in memory to implement the method as described in any of the first aspects.

[0031] Fourthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any of the first aspects.

[0032] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in the first aspect.

[0033] The method, apparatus, equipment, medium, and product for determining the gas content of deep coal reservoirs provided in this application, in response to receiving a gas content determination request triggered by a user through a terminal device, acquires pore characteristic data of micropores, mesopores, and macropores of a target coal sample. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests. The adsorbed gas content is calculated based on the pore characteristic data of micropores. A preset pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ subsurface porosity. A preset free gas content prediction model is used to calculate the free gas content based on the in-situ subsurface porosity. Since pore characteristic data of micropores, mesopores, and macropores of multiple coal samples were obtained in advance through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests and stored in the deep coal reservoir gas content determination device, the device can obtain the pore characteristic data of micropores, mesopores, and macropores of the target coal sample upon receiving a gas content determination request triggered by the user through the terminal device. Under the conditions of deep coalbed methane occurrence, micropores are the most important site for adsorbed gas occurrence; therefore, calculating the adsorbed gas content based on the pore characteristic data of micropores can accurately determine the adsorbed gas content. Then, the device... A pre-defined pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ underground porosity. This fully considers the impact of in-situ underground compressed pores on gas occurrence, making the free gas content calculated based on the compressed and corrected porosity more accurate. Finally, a pre-defined free gas content prediction model is used to calculate the free gas content based on the in-situ underground porosity. This not only shortens the time to determine the gas content but also improves the accuracy of the obtained free gas content. The pre-defined free gas content prediction model is applicable to various coal samples, thereby reducing the cost of gas content evaluation. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0035] Figure 1 An application scenario diagram of the method for determining the gas content of deep coal reservoirs provided in one embodiment of this application;

[0036] Figure 2 A flowchart illustrating a method for determining the gas content of deep coal reservoirs according to an embodiment of this application;

[0037] Figure 3 A flowchart of a method for determining the gas content of deep coal reservoirs provided in another embodiment of this application;

[0038] Figure 4 A schematic diagram of the structure of a device for determining the gas content of deep coal reservoirs provided in an embodiment of this application;

[0039] Figure 5A schematic diagram of a device for determining the gas content of deep coal reservoirs provided in an embodiment of this application.

[0040] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0042] To clearly understand the technical solution of this application, the solutions of the prior art will be described in detail first.

[0043] Currently, the main methods for studying the gas content of deep coal seams are wireline coring, drill pipe coring, and pressure-holding coring. Drill pipe coring involves sending a drill bit into the formation and retrieving a core. When the sampling location is reached, drilling is stopped, the drill pipe is secured, and a special tool is used to retrieve the core from the drill bit. Wireline coring allows core retrieval from the bottom of the borehole without removing the drill bit and drilling tools. A retrieval device connected to a thin steel wire rope is lowered into the drill pipe and used to lift the inner core tube to the surface for core retrieval. Pressure-holding coring is a technique that retrieves cores while maintaining formation pressure. This technique uses special devices and methods to ensure that the retrieved core retains its original underground state, including key parameters such as pressure, temperature, and fluid saturation, thus providing accurate geological information. However, wireline and drill pipe coring are time-consuming and difficult to obtain free gas volume, while pressure-holding coring is costly and makes it difficult to distinguish between free and adsorbed gas, resulting in the current difficulty in accurately determining the adsorbed and free gas content in deep coal reservoirs.

[0044] Therefore, when facing technical problems in existing technologies, in order to accurately determine the adsorbed gas content and free gas content in deep coal reservoirs, the influence of the multi-scale pore system of coal on gas occurrence was fully considered. Firstly, pore characteristic data of micropores, mesopores, and macropores of multiple coal samples were obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests, and these data were stored. Then, when a gas content determination request is received from a user via a terminal device, the relevant pore characteristic data of the target coal sample can be obtained. Since micropores are the most important site for adsorbed gas occurrence under deep coalbed methane conditions, the micropore-based... Using pore characteristic data to calculate the adsorbed gas content allows for precise determination of the adsorbed gas content. To further improve the accuracy of the free gas content, a pre-set pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ underground porosity. The pre-set pore compression model can quickly correct porosity, accelerating the determination of free gas content. To save costs, a pre-set free gas content prediction model is used to calculate the free gas content based on in-situ underground porosity. The pre-set free gas content prediction model not only saves time in determining the gas content but also improves the accuracy of the obtained free gas content.

[0045] Figure 1 This is an application scenario diagram of the method for determining the gas content of deep coal reservoirs provided in one embodiment of this application, such as... Figure 1 As shown in the embodiments of this application, the application scenarios corresponding to the method for determining the gas content of deep coal reservoirs include: a terminal device 101, a server 102, and a server database 103. The server database 103 pre-stores pore characteristic data of micropores, mesopores, and macropores of multiple coal samples. This data was obtained through high-pressure mercury intrusion porosimetry and low-temperature carbon dioxide adsorption tests, and is stored in the server database 103 according to the correspondence between different coal samples and the pore characteristic data of micropores, mesopores, and macropores. When a user sends a gas content determination request to the server 102 through the terminal device 101, the type of coal sample can be included in the request.

[0046] Specifically, when server 102 receives a gas content determination request, it retrieves the micropore, mesopore, and macropore pore characteristic data of the target coal sample from server database 103 according to the coal sample type in the request. Then, server 102 calculates the adsorbed gas content based on the micropore pore characteristic data and uses a preset pore compression model to compress and correct the mesopore and macropore pore characteristic data to obtain the in-situ underground porosity. Finally, server 102 uses a preset free gas content prediction model to calculate the free gas content based on the in-situ underground porosity and sends a gas content determination request response to terminal device 101 so that the user can obtain the adsorbed gas content and free gas content.

[0047] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0048] Figure 2 A flowchart of a method for determining the gas content of deep coal reservoirs provided in an embodiment of this application is shown below. Figure 2 As shown, the executing entity in this embodiment is a device for determining the gas content of deep coal reservoirs. This device can be implemented through a computer program, or through a medium storing the relevant computer program, such as a USB flash drive and / or optical disc; alternatively, it can be implemented through a physical device integrating or installing the relevant computer program, such as a chip or a deep coal reservoir gas content determination device. The method for determining the gas content of deep coal reservoirs provided in this embodiment includes the following steps:

[0049] Step 201: In response to receiving a gas content determination request triggered by the user through the terminal device, obtain the pore characteristic data of the target coal sample, including micropores, mesopores, and macropores. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests.

[0050] The target coal sample refers to the coal sample for which the user wants to measure the corresponding adsorbed gas content and free gas content.

[0051] It is understandable that the deep coal reservoir gas content determination device pre-stores pore characteristic data of micropores, mesopores and macropores of multiple coal samples, and the gas content determination request triggered by the user through the terminal device may include the type name of the coal sample.

[0052] Among them, pore characteristic data refers to the characteristic data corresponding to pores of different sizes in coal samples, such as pore volume, pore specific surface area, porosity, and porosity.

[0053] Specifically, the user triggers a gas content determination request through a terminal device. After receiving the request, the deep coal reservoir gas content determination device obtains the micropore, mesopore, and macropore pore characteristic data of the target coal sample from the pore characteristic data of multiple pre-stored coal samples.

[0054] It should be noted that pore characteristic data of coal samples at the 0–10000 nm scale can be obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests. Among them, micropores refer to pores with a size of 0–2 nm; mesopores and macropores refer to pores with a size of 2–10000 nm.

[0055] Step 202: Calculate the adsorbed gas content based on the pore characteristic data of the micropores.

[0056] Specifically, after obtaining the pore characteristic data of the target coal sample, the pore characteristic data of the micropores are extracted from it, and the adsorbed gas content is calculated based on the pore characteristic data of the micropores.

[0057] Optionally, the pore volume of the micropores can be substituted into Equation (1) for calculation to obtain the adsorbed gas content.

[0058] V a =ρ l V m / ρ a (1)

[0059] In the formula: V a —Adsorbed gas content; ρ l —Density of the adsorbed phase methane; V m —Cumulative pore volume of micropores; ρ a —Density of methane under standard conditions.

[0060] It should be noted that, under the conditions of deep coalbed methane occurrence, micropores are the most important sites for adsorbed gas occurrence, so the adsorbed gas content is calculated based on the pore characteristic data of micropores.

[0061] Step 203: Use a preset pore compression model to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ underground porosity.

[0062] The preset pore compression model refers to a model pre-configured in the deep coal reservoir gas content determination device, used to compress and correct the pore characteristic data of mesopores and macropores. The preset pore compression model is derived and calculated in advance.

[0063] In-situ underground porosity refers to the porosity of a coal sample at its original underground reservoir location.

[0064] Specifically, after obtaining the pore characteristic data of the target coal sample, the pore characteristic data of mesopores and macropores are extracted from it and input into the preset pore compression model to obtain the in-situ underground porosity.

[0065] It should be noted that the porosity of mesopores and macropores in coal samples in the underground reservoir state is greatly affected by compression and will differ from the porosity after extraction. In addition, free gas is mostly contained in mesopores and macropores. Therefore, the porosity characteristic data of mesopores and macropores are compressed and corrected to obtain the in-situ underground porosity, so that the calculated free gas content is more accurate.

[0066] Step 204: Calculate the free gas content based on in-situ underground porosity using a preset free gas content prediction model.

[0067] The preset free gas content prediction model refers to a model pre-configured in the deep coal reservoir gas content determination device to calculate the free gas content. This preset free gas content prediction model is derived and calculated beforehand.

[0068] Specifically, after obtaining the in-situ underground porosity, it is input into a preset free gas content prediction model, thereby calculating the free gas content based on the in-situ underground porosity.

[0069] Optionally, after obtaining the adsorbed gas content and the free gas content, the total gas content and the proportion of free gas can also be calculated based on equations (2) and (3).

[0070] V = V a +V f (2)

[0071] Where: V is the total gas content; V is the adsorbed gas content; V f This represents the free gas content.

[0072] η = V f / V (3)

[0073] In the formula: η is the proportion of free gas.

[0074] For example, Table 1 shows the gas content results obtained using the pressure-holding coring test, and Tables 2 and 3 show the adsorbed gas content and free gas content results obtained using the deep coal reservoir gas content determination method provided in this embodiment, respectively. As can be seen from the tables, the average total gas content obtained using the pressure-holding coring test is 26.33 m³. 3 / t, the average total gas content calculated using the method provided in this embodiment is 32.28m. 3 The ratio coefficient between the two is 1.23, therefore the gas content calculated by the method for determining the gas content of deep coal reservoirs provided in this embodiment is accurate and reliable.

[0075] Table 1. Results of coring at well X with pressure retention

[0076]

[0077]

[0078] Table 2 Calculation results of adsorbed gas content in Well X

[0079]

[0080] Table 3 Calculation results of free gas content in Well X

[0081]

[0082] The method for determining the gas content of deep coal reservoirs provided in this embodiment, in response to receiving a gas content determination request triggered by a user through a terminal device, acquires the pore characteristic data of micropores, mesopores, and macropores of the target coal sample. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests. The adsorbed gas content is calculated based on the pore characteristic data of micropores. A preset pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain the in-situ underground porosity. A preset free gas content prediction model is used to calculate the free gas content based on the in-situ underground porosity. Since pore characteristic data of micropores, mesopores, and macropores of multiple coal samples were obtained in advance through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests and stored in the deep coal reservoir gas content determination device, the device can obtain the pore characteristic data of micropores, mesopores, and macropores of the target coal sample upon receiving a gas content determination request triggered by the user through the terminal device. Under the conditions of deep coalbed methane occurrence, micropores are the most important site for adsorbed gas occurrence; therefore, calculating the adsorbed gas content based on the pore characteristic data of micropores can accurately determine the adsorbed gas content. Then, the device... A pre-defined pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ underground porosity. This fully considers the impact of in-situ underground compressed pores on gas occurrence, making the free gas content calculated based on the compressed and corrected porosity more accurate. Finally, a pre-defined free gas content prediction model is used to calculate the free gas content based on the in-situ underground porosity. This not only shortens the time to determine the gas content but also improves the accuracy of the obtained free gas content. The pre-defined free gas content prediction model is applicable to various coal samples, thereby reducing the cost of gas content evaluation.

[0083] As an optional implementation, based on the above embodiments, the pore characteristic data of the micropores includes the micropore volume, and the adsorbed gas content is calculated based on the pore characteristic data of the micropores, including:

[0084] The cumulative pore volume of each micropore in the target coal sample is calculated by summing up the pore volumes.

[0085] The adsorbed gas content is calculated based on the cumulative pore volume of the micropores.

[0086] Specifically, after obtaining the micropore pore characteristic data of the target coal sample, since there may be multiple micropores, the pore volume of each micropore is accumulated to obtain the cumulative pore volume of the micropores. Then, the cumulative pore volume of the micropores is input into equation (1) to calculate the adsorbed gas content.

[0087] It is understood that equation (1) can be pre-configured in the deep coal reservoir gas content determination device, or other formulas that can calculate the adsorbed gas content can be configured. This embodiment does not limit this.

[0088] The method for determining the gas content in deep coal seams provided in this embodiment includes micropore pore characteristic data, including micropore volume, and calculating the adsorbed gas content based on the micropore pore characteristic data. This includes: summing the pore volumes of each micropore in the target coal sample to obtain a cumulative micropore volume; and calculating the adsorbed gas content based on the cumulative micropore volume. Since micropores are the most important sites for adsorbed gas under deep coalbed methane conditions, calculating the adsorbed gas content based on the micropore volume ensures the accuracy of the adsorbed gas content result; summing the pore volumes of each micropore ensures that the calculated adsorbed gas content includes the gas content of all micropores.

[0089] As an optional implementation, based on the above embodiments, the pore characteristic data of mesopores and macropores include the initial porosity of mesopores and macropores; a preset pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ subsurface porosity, including:

[0090] The actual and simulated environmental parameters of the target coal sample were obtained. The actual environmental parameters were obtained through field well testing, and the simulated environmental parameters were obtained through test simulation.

[0091] The initial porosity of mesopores and macropores, actual environmental parameters, and simulated environmental parameters are input into the formula corresponding to the preset porosity compression model, and the in-situ subsurface porosity is calculated based on the formula corresponding to the preset porosity compression model.

[0092] Initial porosity refers to the porosity of mesopores and macropores obtained through high-pressure mercury intrusion testing.

[0093] It is understandable that the actual and simulated environmental parameters of the target coal sample are pre-stored in the deep coal reservoir gas content determination device.

[0094] Specifically, before calculating the free gas content, the pore characteristic data of mesopores and macropores need to be compressed and corrected. The initial porosity of mesopores and macropores is extracted from the pore characteristic data of mesopores and macropores. The actual environmental parameters and simulated environmental parameters of the target coal sample are obtained from the deep coal reservoir gas content determination device. Then, the initial porosity of mesopores and macropores, the actual environmental parameters and the simulated environmental parameters are input into the formula corresponding to the preset pore compression model. The in-situ underground porosity is calculated using the formula corresponding to the preset pore compression model.

[0095] The method for determining the gas content of deep coal reservoirs provided in this embodiment includes the pore characteristic data of mesopores and macropores, including the initial porosity of mesopores and macropores. A preset pore compression model is used to compress and correct the pore characteristic data of mesopores and macropores to obtain in-situ subsurface porosity. This includes: obtaining the actual environmental parameters and simulated environmental parameters of the target coal sample; the actual environmental parameters are obtained through field well testing, and the simulated environmental parameters are obtained through test simulation; inputting the initial porosity of mesopores and macropores, the actual environmental parameters, and the simulated environmental parameters into the formula corresponding to the preset pore compression model, and calculating the in-situ subsurface porosity based on the formula corresponding to the preset pore compression model. Because the porosity of mesopores and macropores in coal samples is affected by compression when they are in underground reservoirs, it will differ from the porosity after mining. Therefore, before calculating free gas, the porosity characteristic data of mesopores and macropores need to be compressed and corrected to improve the accuracy of free gas content. When performing compression correction, the actual environmental parameters and simulated environmental parameters of the target coal sample are important parameters affecting porosity. Therefore, the initial porosity of mesopores and macropores, actual environmental parameters, and simulated environmental parameters need to be input into the formula corresponding to the preset porosity compression model to ensure that the calculated free gas content is more consistent with the free gas content in the actual environment.

[0096] As an optional implementation, based on the above embodiments, the actual environmental parameters include the average value of the actual in-situ ground stress and the actual in-situ reservoir pressure, and the simulated environmental parameters include the simulated ground stress and the simulated reservoir pressure.

[0097] The formula corresponding to the preset pore compression model is: Where φ is the in-situ subsurface porosity; φ0 is the initial porosity; υ is the Poisson's ratio coefficient of coal; σ is the average value of actual in-situ in-situ in-situ stress; σ0 is the simulated in-situ in-situ in-situ in-situ stress from the initial porosity test; p is the actual in-situ reservoir pressure; p0 is the simulated reservoir pressure from the initial porosity test; R o,max This represents the maximum vitrinite reflectance of coal.

[0098] Among them, the Poisson's ratio coefficient of coal is an important parameter characterizing the lateral deformation performance of coal and rock under tension or compression. It is a constant and can be pre-configured in the preset pore compression model.

[0099] Among them, the maximum vitrinite reflectance of coal is an important parameter characterizing the degree of coal metamorphism. It has a corresponding relationship with the coal sample and can be pre-configured in the deep coal reservoir gas content determination device, or input by the user when triggering the gas content determination request. This embodiment does not limit this.

[0100] The derivation process of the formula corresponding to the preset pore compression model is as follows:

[0101] The coal seam is generally a high-stress-sensitive reservoir, exhibiting high stress sensitivity in its porosity, especially under deep, high-stress conditions where pore compression characteristics are even stronger. Based on pore elasticity mechanics, under uniaxial strain conditions, the porosity of the coal seam can be expressed as:

[0102]

[0103] In the formula: φ is the porosity of coal, φ0 is the initial porosity of coal, and K is the bulk modulus of coal; K p σ is the bulk modulus of the coal pore system; σ is the average geostress; and p is the reservoir pressure.

[0104] Because the bulk modulus K of the coal pore system p Much smaller than the bulk modulus K of the coal as a whole, the bulk modulus K of the coal pore system p It can be approximated as 1% of the bulk modulus K of the coal as a whole, therefore equation (4) can be simplified to:

[0105]

[0106] Meanwhile, since the bulk modulus of coal can be expressed as K = E / 3(1-2v), the coal pore compression model can be expressed as:

[0107]

[0108] In the formula: v is the Poisson's ratio coefficient of coal, and E is the Young's modulus of coal.

[0109] As shown in the above formula, porosity is affected by the Young's modulus of the sample. To avoid the influence of fracture development on the Young's modulus test, atomic force microscopy and micro-Raman spectroscopy were used to test coal of different coal grades. It was found that when R 0,max When R < 1.0%, Young's modulus increases rapidly with increasing reflectivity; when R 0,max When the Young's modulus is >1.0%, the increase in reflectance becomes slower. For coal samples of different coal ranks, the relationship between the Young's modulus and the maximum vitrinite reflectance R... 0,max The relationship can be represented as:

[0110] E = 2.9ln(R) 0,max )+4.2 (7)

[0111] Substituting equation (7) into equation (6) yields the formula corresponding to the preset pore compression model.

[0112] Understandably, the preset pore compression model is applicable to coal samples of different coal grades.

[0113] The method for determining the gas content of deep coal reservoirs provided in this embodiment uses actual environmental parameters including the average value of actual in-situ geostress and actual in-situ reservoir pressure, and simulated environmental parameters including simulated geostress and simulated reservoir pressure. The formula corresponding to the preset pore compression model is: Where φ is the in-situ subsurface porosity; φ0 is the initial porosity; υ is the Poisson's ratio coefficient of coal; σ is the average value of actual in-situ in-situ in-situ stress; σ0 is the simulated in-situ in-situ in-situ in-situ stress from the initial porosity test; p is the actual in-situ reservoir pressure; p0 is the simulated reservoir pressure from the initial porosity test; R o,max This represents the maximum vitrinite reflectance of coal. The formula corresponding to the preset pore compression model can accurately reconstruct the porosity of coal samples in their original underground reservoir state, resulting in a more precise calculation of the free gas content.

[0114] As an optional implementation, based on the above embodiments, a preset free gas content prediction model is used to calculate the free gas content based on in-situ underground porosity, including:

[0115] The reservoir environmental characteristic parameters and experimental test data of the target coal sample were obtained. The reservoir environmental characteristic parameters were obtained through field exploration and development, and the experimental test data were obtained through experiments based on the reservoir environmental characteristic parameters.

[0116] The reservoir environmental characteristic parameters, experimental test data, and in-situ subsurface porosity are input into the formula corresponding to the preset free gas content prediction model, and the free gas content is calculated based on the formula corresponding to the preset free gas content prediction model.

[0117] Specifically, when calculating the free gas content, it is necessary to obtain the reservoir environmental characteristic parameters and experimental test data of the target coal sample that have been stored in advance from the deep coal reservoir gas content determination device. Then, the reservoir environmental characteristic parameters, experimental test data and in-situ underground porosity are input into the formula corresponding to the preset free gas content prediction model, and the free gas content is calculated using the formula corresponding to the preset free gas content prediction model.

[0118] The method for determining the gas content in deep coal reservoirs provided in this embodiment uses a preset free gas content prediction model to calculate the free gas content based on in-situ underground porosity. This includes: acquiring reservoir environmental characteristic parameters and experimental test data of the target coal sample. The reservoir environmental characteristic parameters are obtained through on-site exploration and development, and the experimental test data are obtained through experiments based on the reservoir environmental characteristic parameters; inputting the reservoir environmental characteristic parameters, experimental test data, and in-situ underground porosity into the formula corresponding to the preset free gas content prediction model, and calculating the free gas content based on the formula corresponding to the preset free gas content prediction model. Reservoir environmental characteristic parameters are directly derived from on-site exploration and development. These data can accurately reflect the actual situation of the coal seam and have a direct impact on the content of free gas. Experimental test data, obtained based on reservoir environmental characteristic parameters, can simulate or approximate gas behavior under actual geological conditions, thus providing more accurate experimental data support. Inputting these real and accurate data into the prediction model can greatly improve the accuracy and reliability of free gas content prediction. Calculations using a pre-set free gas content prediction model can significantly reduce the number of on-site drilling, sampling, and testing operations compared to traditional exploration and development methods, thereby saving a significant amount of manpower, material resources, and time costs.

[0119] As an optional implementation, based on the above embodiments, the reservoir environment characteristic parameters include reservoir pressure gradient, reservoir burial depth, reservoir temperature gradient and isothermal zone temperature, and the experimental test data include reservoir pressure fitting line zero-point pressure, pore space water saturation, coal apparent density and gas compressibility factor.

[0120] The formula corresponding to the preset free gas content prediction model is: Among them, V f Free gas content; M g f is the molar mass of methane; fP is the reservoir pressure gradient; H is the reservoir depth; P0 is the pressure at point 0 of the reservoir pressure fitting line; S w ρ represents the water saturation level in the pore space. c ρ represents the apparent density of coal. sc The density of methane gas under standard conditions is given by: Z, the gas compressibility factor, R, and f. T φ represents the reservoir temperature gradient; T0 represents the isothermal zone temperature; and φ represents the in-situ subsurface porosity.

[0121] It is understandable that the molar mass of methane, the density of methane gas under standard conditions, and the gas constant are all constants and can be pre-configured in the preset free gas content prediction model.

[0122] Among them, the water saturation of pore space is an important parameter describing the distribution of water in rocks or soil. It is the ratio of the volume of water in rocks or soil to the maximum volume of water that can be contained in pores.

[0123] The apparent density of coal is the ratio of the mass of coal under certain conditions (such as temperature and pressure) to the mass of an equal volume of water.

[0124] The gas compressibility factor is the ratio of the molar volume of a real gas to the molar volume of an ideal gas under the same conditions, and is used to accurately describe the behavior of real gases.

[0125] The derivation process of the formula for the pre-defined free gas content prediction model is as follows:

[0126] Free gas is mainly stored in the pores and microfractures of deep coal. The mass of free gas per unit volume of coal can be calculated by the following formula:

[0127] m f =φρ g (8)

[0128] Where: m f ρ represents the mass of free gas per unit volume of coal; φ represents the coal porosity; ρ represents the free gas mass per unit volume of coal. g Let V be the density of free methane under reservoir conditions. Then, the volume of free gas per unit mass of coal converted into V under standard conditions is... f It can be represented as:

[0129]

[0130] In the formula: ρ c ρ represents the apparent density of coal. sc This represents the density of methane gas under standard conditions.

[0131] According to the gas law, the fundamental equation for the actual methane density under reservoir conditions is:

[0132]

[0133] In the formula: ρ g P is the density of free methane; T is the absolute pressure of the system; M is the absolute temperature of the reservoir; P is the density of free methane. g Z is the molar mass of methane; Z is the gas compressibility factor; R is the gas constant.

[0134] Substituting equations (8) and (10) into equation (9), we get:

[0135]

[0136] In the above formula, the molar mass of methane, the density of methane gas under standard conditions, and the gas constant are constant values. If the change in apparent density of coal is ignored, then formula (11) can be split into two terms, A and B. Term A is a constant value. Therefore, the free gas content of the coal seam is mainly affected by the gas state-related factors (temperature, pressure, compressibility factor) and porosity in Term B. That is, the free gas content is mainly affected by the following factors: reservoir temperature, pressure, and gas compressibility factor, which control the gas state and affect the gas content; and porosity, which controls the size of the free gas storage space.

[0137] Overall, reservoir temperature and pressure gradually increase with increasing burial depth. In this embodiment, the temperature increase per 100m depth is used to represent the geothermal gradient, and the pressure increase per 100m depth is used to represent the reservoir pressure gradient.

[0138] Vertical distribution of reservoir pressure:

[0139] P = f p H+P0 (12)

[0140] In the formula: P is the reservoir pressure; f p denoted as ρ, where H is the reservoir pressure gradient; H is the reservoir depth; and P0 is the pressure at point 0 on the reservoir pressure fitting line.

[0141] Vertical temperature distribution in reservoirs:

[0142] T = f T (H-H0)+T0 (13)

[0143] In the formula: T is the absolute temperature of the reservoir; f T H0 represents the reservoir temperature gradient; H0 represents the burial depth of the isothermal zone; and T0 represents the isothermal zone temperature.

[0144] Considering the effect of water content in coal samples on pore space, porosity can be expressed as:

[0145] φ=φ0(1-S w (14)

[0146] Substituting equations (12), (13), and (14) into equation (11) yields the formula corresponding to the preset free gas content prediction model.

[0147] Understandably, the pre-defined free gas content prediction model is applicable to coal samples of different coal grades.

[0148] The method for determining the gas content of deep coal reservoirs provided in this embodiment uses reservoir environmental characteristic parameters including reservoir pressure gradient, reservoir depth, reservoir temperature gradient, and isothermal zone temperature. Experimental test data include the zero-point pressure of the reservoir pressure fitting line, pore space water saturation, apparent coal density, and gas compressibility factor. The formula corresponding to the preset free gas content prediction model is: Among them, V f Free gas content; M g f is the molar mass of methane; P S is the reservoir pressure gradient; H is the reservoir depth; P0 is the pressure at point 0 of the reservoir pressure fitting line; S w ρ represents the water saturation level in the pore space. c ρ represents the apparent density of coal. sc The density of methane gas under standard conditions is given by: Z, the gas compressibility factor, R, and f. T φ represents the reservoir temperature gradient; T0 represents the isothermal zone temperature; and φ represents the in-situ subsurface porosity. The formula corresponding to the pre-set free gas content prediction model can respond quickly and provide timely prediction results, significantly reducing the number of field drilling, sampling, and testing operations, thereby saving substantial manpower, material resources, and time costs, and also improving the accuracy of free gas content prediction.

[0149] Figure 3 A flowchart of a method for determining the gas content of deep coal reservoirs provided in another embodiment of this application is shown below. Figure 3 As shown, the method for determining the gas content of deep coal reservoirs provided in this embodiment includes a specific process for calculating the adsorbed gas content and the free gas content. Therefore, the method for determining the gas content of deep coal reservoirs provided in this embodiment includes the following steps:

[0150] Step 301: Receive a gas content determination request triggered by the user through the terminal device.

[0151] Step 302: Obtain pore characteristic data of the target coal sample, including micropores, mesopores, and macropores. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests.

[0152] Step 303: The pore volumes of each micropore in the target coal sample are summed to obtain the cumulative pore volume of the micropores.

[0153] Step 304: Calculate the adsorbed gas content based on the cumulative pore volume of the micropores.

[0154] Step 305: Obtain the actual environmental parameters and simulated environmental parameters of the target coal sample. The actual environmental parameters are obtained through on-site well testing, and the simulated environmental parameters are obtained through test simulation.

[0155] Step 306: Input the initial porosity of mesopores and macropores, actual environmental parameters, and simulated environmental parameters into the formula corresponding to the preset pore compression model.

[0156] Step 307: Calculate the in-situ underground porosity using the formula corresponding to the preset pore compression model.

[0157] Step 308: Obtain reservoir environmental characteristic parameters and experimental test data of the target coal sample. The reservoir environmental characteristic parameters are obtained through on-site exploration and development, and the experimental test data are obtained through experiments based on the reservoir environmental characteristic parameters.

[0158] Step 309: Input the reservoir environment characteristic parameters, experimental test data, and in-situ subsurface porosity into the formula corresponding to the preset free gas content prediction model.

[0159] Step 310: Calculate the free gas content using the formula corresponding to the preset free gas content prediction model.

[0160] In this embodiment, the implementation method and technical effect of steps 301-310 are similar to those of the corresponding solutions in the above embodiments, and will not be repeated here.

[0161] Figure 4 A schematic diagram of the structure of a deep coal reservoir gas content determination device provided in an embodiment of this application is shown below. Figure 4 As shown, the deep coal reservoir gas content determination device provided in this embodiment is located within the deep coal reservoir gas content determination equipment. The deep coal reservoir gas content determination device 40 provided in this embodiment includes: an acquisition module 41, a calculation module 42, and a correction module 43.

[0162] The acquisition module 41 is used to acquire the pore characteristic data of micropores, mesopores and macropores of the target coal sample in response to a gas content determination request triggered by the user through the terminal device. The pore characteristic data is obtained through high pressure mercury intrusion and low temperature carbon dioxide adsorption tests. The calculation module 42 is used to calculate the adsorbed gas content based on the pore characteristic data of micropores. The correction module 43 is used to compress and correct the pore characteristic data of mesopores and macropores using a preset pore compression model to obtain the in-situ underground porosity. The calculation module 42 is also used to calculate the free gas content based on the in-situ underground porosity using a preset free gas content prediction model.

[0163] The device for determining the gas content of deep coal reservoirs provided in this embodiment can perform... Figure 2 The implementation principles and technical effects of the methods shown are similar, and will not be repeated here.

[0164] Optionally, the calculation module 42, when calculating the adsorbed gas content based on the pore characteristic data of the micropores, including the micropore volume, is specifically used to: accumulate the pore volumes of each micropore in the target coal sample to obtain the cumulative pore volume of the micropores; and calculate the adsorbed gas content based on the cumulative pore volume of the micropores.

[0165] Optionally, the correction module 43, when compressing and correcting the pore characteristic data of mesopores and macropores, including the initial porosity of mesopores and macropores, using a preset pore compression model to obtain in-situ subsurface porosity, is specifically used for: obtaining the actual environmental parameters and simulated environmental parameters of the target coal sample, where the actual environmental parameters are obtained through field well testing and the simulated environmental parameters are obtained through test simulation; inputting the initial porosity of mesopores and macropores, the actual environmental parameters, and the simulated environmental parameters into the formula corresponding to the preset pore compression model, and calculating the in-situ subsurface porosity based on the formula corresponding to the preset pore compression model.

[0166] The actual environmental parameters include the average value of the actual in-situ ground stress and the actual in-situ reservoir pressure, while the simulated environmental parameters include the simulated ground stress and the simulated reservoir pressure. The formula corresponding to the preset pore compression model is: Where φ is the in-situ subsurface porosity; φ0 is the initial porosity; υ is the Poisson's ratio coefficient of coal; σ is the average value of actual in-situ in-situ in-situ stress; σ0 is the simulated in-situ in-situ in-situ in-situ stress from the initial porosity test; p is the actual in-situ reservoir pressure; p0 is the simulated reservoir pressure from the initial porosity test; R o,max This represents the maximum vitrinite reflectance of coal.

[0167] Optionally, the calculation module 42, when calculating the free gas content based on in-situ subsurface porosity using a preset free gas content prediction model, is specifically used to: obtain reservoir environmental characteristic parameters and experimental test data of the target coal sample, wherein the reservoir environmental characteristic parameters are obtained through on-site exploration and development, and the experimental test data are obtained through experiments based on the reservoir environmental characteristic parameters; input the reservoir environmental characteristic parameters, experimental test data, and in-situ subsurface porosity into the formula corresponding to the preset free gas content prediction model, and calculate the free gas content based on the formula corresponding to the preset free gas content prediction model.

[0168] The reservoir environmental characteristic parameters include reservoir pressure gradient, reservoir depth, reservoir temperature gradient, and isothermal zone temperature. Experimental test data include the zero-point pressure of the reservoir pressure fitting line, pore space water saturation, apparent coal density, and gas compressibility factor. The formula corresponding to the preset free gas content prediction model is: Among them, V f Free gas content; M g f is the molar mass of methane; fP is the reservoir pressure gradient; H is the reservoir depth; P0 is the pressure at point 0 of the reservoir pressure fitting line; S w ρ represents the water saturation level in the pore space. c ρ represents the apparent density of coal. sc The density of methane gas under standard conditions is given by: Z, the gas compressibility factor, R, and f. T φ represents the reservoir temperature gradient; T0 represents the isothermal zone temperature; and φ represents the in-situ subsurface porosity.

[0169] Figure 5 A schematic diagram of a deep coal reservoir gas content determination device provided in an embodiment of this application is shown below. Figure 5 As shown, the deep coal reservoir gas content determination device 50 provided in this embodiment includes: a processor 51 and a memory 52 that is communicatively connected to the processor.

[0170] The memory 52 stores computer-executable instructions; the processor 51 executes the computer-executable instructions stored in the memory 52 to implement the method for determining the gas content of deep coal reservoirs provided in any of the above embodiments. Related explanations can be understood by referring to the relevant descriptions and effects corresponding to the steps in the accompanying drawings, and will not be elaborated upon here.

[0171] The program may include program code, which includes computer-executable instructions. Memory 52 may include high-speed RAM, and may also include non-volatile memory, such as at least one disk storage device.

[0172] In this embodiment, the memory 52 and the processor 51 are connected via a bus. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 5 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0173] This application also provides a computer-readable storage medium storing computer-executable instructions. When executed by a processor, these instructions are used to implement the method for determining the gas content of deep coal reservoirs provided in any of the above embodiments. For example, the computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, or optical data storage device.

[0174] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the method for determining the gas content of deep coal reservoirs provided in any of the above embodiments.

[0175] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0176] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0177] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.

[0178] Furthermore, unless otherwise specified, the functional units / modules in the various embodiments of this application can be integrated into one unit / module, or each unit / module can exist physically separately, or two or more units / modules can be integrated together. The integrated units / modules described above can be implemented in hardware or as software program modules.

[0179] When integrated units / modules are implemented in hardware, the hardware can be digital circuits, analog circuits, etc. The physical implementation of the hardware structure includes, but is not limited to, transistors, memristors, etc. Unless otherwise specified, the processor can be any suitable hardware processor, such as a CPU, GPU, FPGA, DSP, and ASIC, etc. Unless otherwise specified, the storage unit can be any suitable magnetic or magneto-optical storage medium, such as Resistive Random Access Memory (RRAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Enhanced Dynamic Random Access Memory (EDRAM), High-Bandwidth Memory (HBM), Hybrid Memory Cube (HMC), etc.

[0180] If the integrated unit / module is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0181] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not described in detail in a particular embodiment can be referred to in the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as these combinations of technical features do not contradict each other, they should be considered within the scope of this specification. Those skilled in the art, upon considering the specification and practicing the invention disclosed herein, will readily conceive of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary technical means in the art not disclosed in this application. The specification and embodiments are considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0182] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for determining the gas content of deep coal reservoirs, characterized in that, The method includes: In response to receiving a gas content determination request triggered by a user through a terminal device, the system acquires pore characteristic data of the target coal sample, including micropores, mesopores, and macropores. The pore characteristic data is obtained through high-pressure mercury intrusion and low-temperature carbon dioxide adsorption tests. The adsorbed gas content is calculated based on the pore characteristic data of the micropores; A preset pore compression model is used to compress and correct the pore characteristic data of the mesopores and macropores to obtain the in-situ underground porosity. The free gas content is calculated based on the in-situ underground porosity using a preset free gas content prediction model.

2. The method according to claim 1, characterized in that, The pore characteristic data of the micropores includes the micropore volume, and the calculation of the adsorbed gas content based on the pore characteristic data of the micropores includes: The cumulative pore volume of each micropore in the target coal sample is calculated by summing the pore volumes of the micropores. The adsorbed gas content is calculated based on the cumulative pore volume of the micropores.

3. The method according to claim 1, characterized in that, The pore characteristic data of mesopores and macropores includes the initial porosity of mesopores and macropores. The step of compressing and correcting the pore characteristic data of mesopores and macropores using a preset pore compression model to obtain in-situ subsurface porosity includes: The actual environmental parameters and simulated environmental parameters of the target coal sample are obtained. The actual environmental parameters are obtained through field well testing, and the simulated environmental parameters are obtained through test simulation. The initial porosity of the mesopores and macropores, the actual environmental parameters, and the simulated environmental parameters are input into the formula corresponding to the preset porosity compression model, and the in-situ subsurface porosity is calculated based on the formula corresponding to the preset porosity compression model.

4. The method according to claim 3, characterized in that, The actual environmental parameters include the average value of the actual in-situ geostress and the actual in-situ reservoir pressure, and the simulated environmental parameters include the simulated geostress and the simulated reservoir pressure. The formula corresponding to the preset pore compression model is: Where φ is the in-situ subsurface porosity; φ0 is the initial porosity; υ is the Poisson's ratio coefficient of coal; σ is the average value of actual in-situ in-situ in-situ stress; σ0 is the simulated in-situ in-situ in-situ in-situ stress from the initial porosity test; p is the actual in-situ reservoir pressure; p0 is the simulated reservoir pressure from the initial porosity test; R o,max This represents the maximum vitrinite reflectance of coal.

5. The method according to claim 1, characterized in that, The calculation of free gas content based on the in-situ underground porosity using a preset free gas content prediction model includes: The reservoir environmental characteristic parameters and experimental test data of the target coal sample are obtained. The reservoir environmental characteristic parameters are obtained through field exploration and development, and the experimental test data are obtained through experiments based on the reservoir environmental characteristic parameters. The reservoir environment characteristic parameters, the experimental test data, and the in-situ subsurface porosity are input into the formula corresponding to the preset free gas content prediction model, and the free gas content is calculated based on the formula corresponding to the preset free gas content prediction model.

6. The method according to claim 5, characterized in that, The reservoir environmental characteristic parameters include reservoir pressure gradient, reservoir burial depth, reservoir temperature gradient and isothermal zone temperature. The experimental test data include reservoir pressure fitting line zero-point pressure, pore space water saturation, apparent density of coal and gas compressibility factor. The formula corresponding to the preset free gas content prediction model is: Among them, V f Free gas content; M g f is the molar mass of methane; P S is the reservoir pressure gradient; H is the reservoir depth; P0 is the pressure at point 0 of the reservoir pressure fitting line; S w ρ represents the water saturation level in the pore space. c ρ represents the apparent density of coal. sc The density of methane gas under standard conditions is given by: Z, the gas compressibility factor, R, and f. T φ represents the reservoir temperature gradient; T0 represents the isothermal zone temperature; and φ represents the in-situ subsurface porosity.

7. A device for determining the gas content of deep coal reservoirs, characterized in that, include: The acquisition module is used to acquire the pore characteristic data of the target coal sample’s micropores, mesopores and macropores in response to receiving a gas content determination request triggered by the user through a terminal device. The pore characteristic data is obtained by high pressure mercury intrusion and low temperature carbon dioxide adsorption tests. The calculation module is used to calculate the adsorbed gas content based on the pore characteristic data of the micropores; The correction module is used to compress and correct the pore characteristic data of the mesopores and macropores using a preset pore compression model in order to obtain in-situ underground porosity. The calculation module is also used to calculate the free gas content based on the in-situ underground porosity using a preset free gas content prediction model.

8. A device for determining the gas content of deep coal reservoirs, characterized in that, include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in any one of claims 1 to 6.

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