Method, device and apparatus for determining adsorbed gas and free gas content of shale gas

Abstract

The present disclosure relates to the technical field of shale gas identification, and particularly relates to a method, device and equipment for determining the content of absorbed gas and free gas of shale gas, the method comprising: obtaining an evolution correlation mapping relationship corresponding to a target shale sample, the evolution correlation mapping relationship being used to represent the temperature and pressure of the target shale sample at different time points; determining a target temperature and a target pressure corresponding to the target temperature based on the evolution correlation mapping relationship; determining the content of absorbed gas of the target shale sample based on the shale gas adsorption efficiency of the target shale sample at the target temperature and the target pressure and an absorbed gas calculation model; and determining the content of free gas of the target shale sample based on the pore volume of the target shale sample at the target temperature and the target pressure and an ideal gas state equation. The method can improve the measurement accuracy and speed of the calculation of the content of absorbed gas and free gas, and reduce the measurement cost while determining the content of absorbed gas and free gas.

Description

Technical Field

[0001] This disclosure relates to the field of shale gas identification technology, and in particular to a method, apparatus and equipment for determining the content of adsorbed gas and free gas in shale gas. Background Technology

[0002] Shale gas exists primarily in adsorbed and free states within shale formations. Adsorption and desorption rely on intermolecular interactions among different mineral components, fractures, and pores within the shale. Adsorbed gas mainly uses clay minerals and kerogen as adsorption carriers. Due to the strong heterogeneity of kerogen and clay minerals within shale, the adsorption and desorption mechanism of shale gas is not yet fully understood. Furthermore, it has been confirmed that shale gas adsorption and desorption are mainly controlled by temperature and pressure. Desorption of adsorbed gas is the most significant gas production mechanism in the later stages of shale production, and the amount of desorbed gas contributes substantially to the later-stage yield.

[0003] In related technologies, the gas content of shale is usually determined by conducting experiments on-site when the shale is unearthed. However, this method can only determine the total gas content of the shale, but cannot determine the content of adsorbed gas and free gas within the total gas content. Furthermore, the measurement process suffers from limitations in measurement accuracy, high measurement cost, and slow measurement speed. Summary of the Invention

[0004] This disclosure provides a method, apparatus, and equipment for determining the adsorbed gas and free gas content of shale gas, in order to overcome the problems existing in related technologies.

[0005] In a first aspect, this disclosure provides a method for determining the adsorbed gas and free gas content of shale gas, including:

[0006] The evolutionary correlation mapping relationship corresponding to the target shale sample is obtained, and the evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times;

[0007] Based on the evolutionary correlation mapping relationship, the target temperature and the target pressure corresponding to the target temperature are determined, wherein the target temperature is the temperature of the region where the target shale sample is located at the current moment;

[0008] Based on the shale gas adsorption efficiency and adsorbed gas calculation model of the target shale sample at the target temperature and the target pressure, the adsorbed gas content of the target shale sample is determined. The adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency.

[0009] The free gas content of the target shale sample is determined based on the pore volume and ideal gas equation of state of the target shale sample at the target temperature and the target pressure.

[0010] In some embodiments, obtaining the evolutionary correlation mapping relationship corresponding to the target shale sample includes:

[0011] Based on preset evolution modeling software, temperature evolution simulation and pressure evolution simulation are performed on the target shale sample at different times and under the same preset environment to obtain temperature evolution simulation results and pressure evolution simulation results. The preset environment is used to simulate the environment at the location where the target shale sample is exposed. The temperature evolution simulation results are used to characterize the correspondence between the temperature of the target shale sample and the formation depth, and the pressure evolution simulation results are used to characterize the correspondence between the pressure of the target shale sample and the formation depth.

[0012] Based on the temperature evolution simulation results and the pressure evolution simulation results, the evolutionary correlation mapping relationship is determined.

[0013] In some embodiments, the method further includes:

[0014] Under the target temperature and the target pressure, the adsorption capacity calculation parameters of the target shale sample are obtained; wherein, the adsorption capacity calculation parameters include a first adsorption capacity calculation parameter and a second adsorption capacity calculation parameter, the first adsorption capacity calculation parameter includes shale gas adsorption parameters, shale gas gas phase density, and the remaining adsorption vacancies on the pore surface of the target shale sample, and the second adsorption capacity calculation parameter includes shale gas conversion adsorption parameters, shale gas gas phase density, the maximum adsorption sites on the pore surface of the target shale sample, and the adsorption sites occupied by the adsorbed gas;

[0015] The shale gas adsorption efficiency is determined based on the first adsorption capacity calculation parameter and the first preset correlation relationship, or the shale gas adsorption efficiency is determined based on the second adsorption capacity calculation parameter and the second preset correlation relationship; wherein, the first preset correlation relationship is used to characterize the correlation between the shale gas adsorption efficiency and the first adsorption capacity calculation parameter, and the second preset correlation relationship is used to characterize the correlation between the shale gas adsorption efficiency and the second adsorption capacity calculation parameter.

[0016] In some embodiments, the adsorption capacity calculation parameter is a parameter obtained by measuring the separated shale sample. The separated shale sample is a shale sample obtained by separating the target shale sample and the adsorbent in the equilibrium mixture. The equilibrium mixture is a mixture obtained when the target shale sample and the adsorbent in the mixture reach an equilibrium state. The mixture is a mixture obtained after adding the adsorbent to the target shale sample. The equilibrium state refers to the state when the pressure of the mixture reaches the target pressure.

[0017] In some embodiments, determining the adsorbed gas content of the target shale sample based on the shale gas adsorption efficiency and adsorbed gas calculation model of the target shale sample at the target temperature and the target pressure includes:

[0018] Based on the shale gas adsorption efficiency, the target pressure, the maximum adsorption volume of the pore surface of the target shale sample, the adsorption pressure of the pore surface of the target shale sample, and the adsorption gas calculation model, the adsorbed gas content is determined; wherein, the adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency, the target pressure, the maximum adsorption volume of the pore surface of the target shale sample, and the adsorption pressure of the pore surface of the target shale sample.

[0019] In some embodiments, the method further includes:

[0020] The first pore volume, second pore volume, and third pore volume of a unit shale sample in the target shale sample are obtained; wherein, the first pore volume is obtained by performing a low-temperature nitrogen adsorption experiment on the target shale sample, the second pore volume is obtained by performing a low-temperature carbon dioxide adsorption experiment on the target shale sample, and the third pore volume is obtained by performing a high-pressure mercury intrusion porosimetry experiment;

[0021] The pore volume is determined based on the first pore volume, the second pore volume, and the third pore volume.

[0022] Secondly, this disclosure provides a device for determining the content of adsorbed gas and free gas in shale gas, comprising:

[0023] The mapping relationship acquisition module is configured to acquire the evolutionary correlation mapping relationship corresponding to the target shale sample, wherein the evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times;

[0024] The target parameter determination module is configured to determine the target temperature and the target pressure corresponding to the target temperature based on the evolutionary correlation mapping relationship, wherein the target temperature is the temperature of the region where the target shale sample is located at the current moment;

[0025] The adsorbed gas content determination module is configured to determine the adsorbed gas content of the target shale sample based on the shale gas adsorption efficiency and the adsorbed gas calculation model of the target shale sample at the target temperature and the target pressure. The adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency.

[0026] The free gas content determination module is configured to determine the free gas content of the target shale sample based on the pore volume and ideal gas equation of state of the target shale sample at the target temperature and the target pressure.

[0027] Thirdly, this disclosure provides a computer device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the first aspect above.

[0028] Fourthly, this disclosure provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method described in the first aspect.

[0029] Fifthly, this disclosure provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in the first aspect.

[0030] This disclosure provides a method, apparatus, and equipment for determining the adsorbed gas and free gas content of shale gas. By calculating the adsorbed gas content at target temperature and target pressure, and calculating the free gas content based on the ideal gas law when the adsorbed gas is removed, the method can improve the measurement accuracy and speed of the adsorbed gas content and free gas content calculation, while reducing the measurement cost. Attached Figure Description

[0031] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:

[0032] Figure 1 This is a schematic flowchart illustrating a method for determining the adsorbed gas and free gas content of shale gas, provided in an embodiment of this disclosure.

[0033] Figure 2 This is a schematic diagram of an evolutionary association mapping relationship provided in an embodiment of this disclosure.

[0034] Figure 3 This is a schematic diagram of a temperature evolution simulation result provided in an embodiment of this disclosure.

[0035] Figure 4 This is a schematic diagram of a pressure evolution simulation result provided in an embodiment of this disclosure.

[0036] Figure 5 This is a schematic diagram of an isothermal adsorption line provided in an embodiment of the present disclosure.

[0037] Figure 6 This is a schematic diagram of experimental data for a specific surface area-pore size release test report (1) in a low-temperature nitrogen adsorption experiment provided in this embodiment of the present disclosure.

[0038] Figure 7 This is a schematic diagram of a surface area-pore size relationship curve provided in an embodiment of the present disclosure.

[0039] Figure 8 This is a schematic diagram of experimental data for a specific surface area-pore size release test report (2) in a low-temperature nitrogen adsorption experiment provided in this embodiment of the present disclosure.

[0040] Figure 9 This is a schematic diagram of a pore volume-pore diameter-cumulative pore volume curve provided in an embodiment of this disclosure.

[0041] Figure 10 This is a schematic diagram of experimental data from a low-temperature carbon dioxide adsorption experiment provided in an embodiment of this disclosure.

[0042] Figure 11 This is a schematic diagram of an isothermal adsorption curve provided in an embodiment of this disclosure.

[0043] Figure 12 A schematic diagram of experimental data for a low-temperature carbon dioxide adsorption experiment provided in an embodiment of this disclosure;

[0044] Figure 13 This is a schematic diagram of a cumulative pore volume-pore volume-pore diameter curve provided in an embodiment of this disclosure.

[0045] Figure 14 This is a schematic diagram of a mercury intrusion porosimetry experiment to measure the mercury intrusion curve, provided as an embodiment of this disclosure.

[0046] Figure 15 This is a schematic diagram of the adsorption volume curves of shale samples of different diameters provided in an embodiment of this disclosure.

[0047] Figure 16 This is a block diagram of a device for determining the adsorbed gas and free gas content of shale gas, provided in an embodiment of this disclosure.

[0048] In the accompanying drawings, the same parts are referred to by the same reference numerals, and the drawings are not drawn to scale. Detailed Implementation

[0049] To enable those skilled in the art to better understand the technical solutions of this disclosure, and to fully understand and implement the process of how this disclosure applies technical means to solve technical problems and achieve corresponding technical effects, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. The embodiments of this disclosure and the various features within them can be combined with each other without conflict, and the resulting technical solutions are all within the protection scope of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort should fall within the protection scope of this disclosure.

[0050] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0051] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0052] The method provided in this disclosure is executed by a computer device, which may be a mobile phone, tablet computer, laptop computer, desktop computer, or other similar device. This disclosure does not limit the specific type of computer device.

[0053] Figure 1 This is a flowchart illustrating a method for determining the adsorbed gas and free gas content of shale gas according to an embodiment of this disclosure, executed by a computer device. See [link / reference]. Figure 1 The method includes the following steps:

[0054] Step S101: Obtain the evolutionary correlation mapping relationship corresponding to the target shale sample. The evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times.

[0055] Step S102: Based on the evolutionary correlation mapping relationship, determine the target temperature and the target pressure corresponding to the target temperature. The target temperature is the temperature of the area where the target shale sample is located at the current moment.

[0056] Step S103: Based on the shale gas adsorption efficiency and adsorption gas calculation model of the target shale sample under the target temperature and target pressure, determine the adsorption gas content of the target shale sample. The adsorption gas calculation model is used to characterize the correlation between the adsorption gas content and the shale gas adsorption efficiency.

[0057] Step S104: Determine the free gas content of the target shale sample based on the pore volume and ideal gas equation of state of the target shale sample at the target temperature and target pressure.

[0058] The method provided in this disclosure calculates the adsorbed gas content at target temperature and target pressure, and calculates the free gas content based on the ideal gas law when the adsorbed gas is removed. This method can improve the measurement accuracy and speed of the adsorbed gas content and free gas content calculation, while reducing the measurement cost.

[0059] In step S101, the evolutionary correlation mapping relationship corresponding to the target shale sample is obtained. The target shale sample is the shale sample for which the adsorbed gas content and free gas content need to be measured. The target shale sample can be of any size, and this embodiment of the disclosure does not impose any limitations on this. The evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times. In the context of the region where the target shale sample is located, the temperature refers to the formation temperature of the region where the target shale sample is located, and the pressure refers to the formation pressure of the region where the target shale sample is located. In one example, see... Figure 2 The diagram illustrates the evolutionary correlation mapping relationship, with time on the horizontal axis and temperature and pressure on the vertical axis. Figure 2 This shows the temperature and pressure at different times during the evolution process.

[0060] In some embodiments, obtaining the evolutionary correlation mapping relationship corresponding to the target shale sample includes: using preset evolutionary modeling software, simulating the evolution of temperature and pressure of the target shale sample at different times and under the same preset environment, obtaining temperature evolution simulation results and pressure evolution simulation results; and determining the evolutionary correlation mapping relationship based on the temperature evolution simulation results and pressure evolution simulation results. The preset environment is used to simulate the environment at the excavation location of the target shale sample, the temperature evolution simulation results are used to characterize the correspondence between the temperature of the target shale sample and the formation depth, and the pressure evolution simulation results are used to characterize the correspondence between the pressure of the target shale sample and the formation depth.

[0061] In one example, the following procedure is used to obtain the temperature evolution simulation results and the pressure evolution simulation results:

[0062] 1. Open the preset evolutionary modeling software and load the basin model.

[0063] 2. Select a region or well in the basin model and ensure that the stratigraphic properties and lithological data have been set.

[0064] Among them, the region or well is used to characterize the location where the target shale sample was unearthed. That is, the region or well is a preset environment, and the region or well can be selected according to the actual situation.

[0065] 3. Enter the settings module of the preset evolution modeling software, where tools or options specifically for calculating formation pressure and formation temperature will be displayed.

[0066] 4. In this tool or option, set the simulation parameters, such as formation pressure gradient, formation temperature gradient, fluid density, etc.

[0067] 5. Run the simulation and wait for the calculation to complete to obtain the temperature evolution simulation results and pressure evolution simulation results.

[0068] 6. View the temperature evolution simulation results and the pressure evolution simulation results.

[0069] View the generated distribution maps or data tables of formation pressure and formation temperature in the preset evolutionary modeling software, for example, Figure 3 This is a schematic diagram of the temperature evolution simulation results. The gray filled area on the right represents lithology, the horizontal axis represents formation temperature, and the vertical axis represents formation depth. (The diagram can be viewed through...) Figure 3 This shows the relationship between formation temperature and formation depth: the greater the formation depth, the higher the formation temperature. Figure 4 This is a schematic diagram of the results of the pressure evolution simulation. Figure 4 The dashed line represents hydrostatic pressure, the solid line represents rock hydrostatic pressure, and the gray filled area on the right represents lithology. The horizontal axis represents formation pressure, and the vertical axis represents formation depth. This can be achieved by... Figure 4 This reveals the relationship between formation pressure and formation depth.

[0070] In this embodiment of the disclosure, the area to be studied (i.e., region or well) is determined based on the location of the target shale sample or the experience of the experimenters. Then, a preset evolution modeling software is used to obtain temperature evolution simulation results and pressure evolution simulation results using the above-described implementation method. The temperature and pressure of the area to be studied at different times are simulated, that is, the evolution correlation mapping relationship is obtained.

[0071] In step S102, after obtaining the evolutionary correlation mapping relationship, the temperature and pressure at the current moment are determined as the target temperature and target pressure based on the evolutionary correlation mapping relationship, so as to facilitate the subsequent determination of the adsorbed gas content and free gas content of shale gas under the target temperature and target pressure.

[0072] In step S103, in order to measure the adsorbed gas content, it is necessary to obtain the shale gas adsorption efficiency and the adsorbed gas calculation model at the target temperature and target pressure. Then, based on the shale gas adsorption efficiency and the adsorbed gas calculation model, the adsorbed gas content of the target shale sample is determined.

[0073] In some embodiments, to obtain the shale gas adsorption efficiency, under target temperature and pressure, the adsorption capacity calculation parameters of the target shale sample are obtained. These parameters include a first adsorption capacity calculation parameter and a second adsorption capacity calculation parameter. The shale gas adsorption efficiency is determined based on the first adsorption capacity calculation parameter and a first preset correlation, or based on the second adsorption capacity calculation parameter and the second preset correlation. The first adsorption capacity calculation parameter includes shale gas adsorption parameters, shale gas gas phase density, and the remaining adsorption vacancies on the pore surface of the target shale sample. The second adsorption capacity calculation parameter includes shale gas conversion adsorption parameters, shale gas gas phase density, the maximum adsorption sites on the pore surface of the target shale sample, and the adsorption sites occupied by the adsorbed gas. The first preset correlation is used to characterize the relationship between the shale gas adsorption efficiency and the first adsorption capacity calculation parameter, and the second preset correlation is used to characterize the relationship between the shale gas adsorption efficiency and the second adsorption capacity calculation parameter.

[0074] Optionally, the adsorption capacity calculation parameter is a parameter obtained by measuring the separated shale sample. The separated shale sample is the shale sample obtained after separating the target shale sample and the adsorbent in the equilibrium mixture. The equilibrium mixture is the mixture obtained when the target shale sample and the adsorbent in the mixture reach an equilibrium state. The mixture is the mixture obtained after adding the adsorbent to the target shale sample. The equilibrium state refers to the state when the pressure of the mixture reaches the target pressure.

[0075] In other words, isothermal adsorption experiments are conducted on the target shale sample at the target temperature and pressure to obtain the parameters for calculating the adsorption capacity. The process for obtaining the parameters for calculating the adsorption capacity is as follows:

[0076] 1. Add adsorbent to the target shale sample to obtain a mixture.

[0077] 2. At the target temperature, when the target shale sample and adsorbent in the mixture reach equilibrium, an equilibrium mixture is obtained.

[0078] 3. Separate the target shale sample and the adsorbent in the equilibrium mixture to obtain the separated shale sample.

[0079] 4. Measure the separated shale sample to obtain the adsorption calculation parameters of the target shale sample.

[0080] Optionally, the first preset association relationship is:

[0081] R a =K a C g S r

[0082] Among them, R a K represents the shale gas adsorption efficiency. a C represents the adsorption parameters of shale gas. g S represents the gas phase density of shale gas. r This indicates the remaining adsorption vacancies on the pore surface of the target shale sample.

[0083] The second pre-defined association relationship is:

[0084] R a =kC g (S a -S o )

[0085] Among them, R a The value of C represents the shale gas adsorption efficiency, where k represents the shale gas conversion adsorption parameter. g S represents the gas phase density of shale gas. a S represents the maximum adsorption sites on the pore surface of the target shale sample. o This indicates the adsorption sites occupied by the adsorbed gas.

[0086] It should be noted that the above-mentioned shale gas adsorption parameter K a The shale gas conversion and adsorption parameter k can be set empirically or selected under equilibrium conditions; it can be customized. Other relevant parameters, such as the shale gas phase density C, can also be customized. g The remaining adsorption vacancies S on the pore surface of the target shale sample r S represents the maximum adsorption sites S on the pore surface of the target shale sample. a The adsorption sites S occupied by the adsorbed gas o All of these can be determined through isothermal adsorption experiments.

[0087] In addition, when calculating the shale gas adsorption efficiency, either the first preset correlation relationship or the second preset correlation relationship can be used, and this disclosure does not limit the specific method used.

[0088] In one example, the detailed procedure of the isothermal adsorption experiment is as follows:

[0089] 1. Prepare samples:

[0090] Representative samples were obtained from the target shale samples and subjected to crushing, grinding, and other treatments to ensure that the particle size met the experimental requirements.

[0091] Contamination must be avoided during sample processing to ensure the accuracy of experimental results.

[0092] 2. Sample pretreatment:

[0093] The processed sample is placed in an oven to dry and remove moisture.

[0094] The purpose of sample pretreatment is to remove moisture and other impurities from the sample in order to ensure the accuracy of experimental results.

[0095] 3. Experimental setup:

[0096] Experiments were conducted using adsorption instruments (such as surface area analyzers, gas adsorption instruments, etc.).

[0097] Ensure the stability and accuracy of the experimental setup.

[0098] 4. Experimental conditions:

[0099] Set the temperature, pressure, and other conditions for the experiment.

[0100] The type and concentration of the adsorbed gas are set, including nitrogen, methane, etc.

[0101] 5. Adsorption experiment:

[0102] The pretreated sample is placed into the experimental apparatus.

[0103] Under the set isothermal conditions (i.e., the target temperature), the adsorbed gas is brought into contact with the sample to conduct an adsorption experiment.

[0104] The amount of adsorbed gas is monitored in real time and the data is recorded.

[0105] 6. Data Processing:

[0106] Based on the experimental data, adsorption isotherm diagrams were plotted to analyze the adsorption amount of the gas under different conditions.

[0107] It can calculate the specific surface area, pore volume, and other adsorption parameters of the target shale sample.

[0108] Detailed experimental data on isothermal adsorption are shown in Table 1:

[0109] Table 1

[0110]

[0111]

[0112] The data in the table above are for illustrative purposes only; the experimental parameters are for mudstone. The Langmuir equation is shown in formula (1):

[0113] V = V L *p / (p+p L )*R a

[0114] Where V represents the adsorption amount, V L p represents the maximum adsorption volume on the pore surface of the target shale sample, and p represents the pressure. L R represents the adsorption pressure at the pore surface of the target shale sample. a This indicates the shale gas adsorption efficiency.

[0115] With a fitting coefficient of 0.9997, the pressure p L At a pressure of 1.66 MPa, the isothermal adsorption curves can be obtained by calculating the data in Table 1 according to formula (1). These curves represent the adsorption amounts at different pressures under the same temperature. The isothermal adsorption curves are as follows: Figure 5 As shown, the horizontal axis represents pressure, the vertical axis represents adsorption amount, the hollow circles represent measured data, and the black line represents the fitted line.

[0116] Therefore, based on the above isothermal adsorption experiments, it can be seen that a calculation model for the adsorbed gas can be constructed based on the Langmuir equation. The calculation model for the adsorbed gas is as follows:

[0117] Va = V L *p / (p+p L )*R a

[0118] Where Va represents the adsorbed gas content, V L The Langmuir volume represents the maximum adsorption volume at the pore surface of the target shale sample, where p represents the target pressure. L R represents the adsorption pressure (Langmuir pressure) on the pore surface of the target shale sample. a This represents the shale gas adsorption efficiency. Langmuir volume represents the limiting adsorption capacity of shale, showing a clear linear positive correlation with total organic carbon (TOC). Langmuir pressure is the pressure at which half the Langmuir volume is reached, reflecting the shale's ability to adsorb gas. The formation pressure on the shale sample is then calculated based on the sampling depth.

[0119] Based on this, determining the adsorbed gas content involves: determining the adsorbed gas content based on shale gas adsorption efficiency, target pressure, maximum adsorption volume on the pore surface of the target shale sample, adsorption pressure on the pore surface of the target shale sample, and an adsorbed gas calculation model. The adsorbed gas calculation model characterizes the correlation between the adsorbed gas content and the shale gas adsorption efficiency, target pressure, maximum adsorption volume on the pore surface of the target shale sample, and adsorption pressure on the pore surface of the target shale sample. In other words, the adsorbed gas content is obtained by substituting the shale gas adsorption efficiency, target pressure, maximum adsorption volume on the pore surface of the target shale sample, and adsorption pressure on the pore surface of the target shale sample into the adsorbed gas calculation model.

[0120] In step S104, in order to measure the free gas content, it is necessary to obtain the pore volume and ideal gas equation of state of the target shale sample at the target temperature and target pressure. Then, based on the pore volume and ideal gas equation of state of the target shale sample, the free gas content of the target shale sample is determined.

[0121] In some embodiments, the first pore volume, second pore volume, and third pore volume of a unit shale sample in the target shale sample are obtained; based on the first pore volume, second pore volume, and third pore volume, the pore volume is determined. The first pore volume is obtained by performing a low-temperature nitrogen adsorption experiment on the target shale sample, the second pore volume is obtained by performing a low-temperature carbon dioxide adsorption experiment on the target shale sample, and the third pore volume is obtained by performing a high-pressure mercury intrusion porosimetry experiment. Optionally, the first pore volume, second pore volume, and third pore volume are added together to obtain the pore volume.

[0122] Low-temperature nitrogen adsorption experiments are suitable for characterizing pore structures with pore sizes ranging from 0.35 nm to 500 nm. For example, the pore size of the first-sized sample is 0.35 nm to 500 nm. Low-temperature carbon dioxide adsorption experiments are suitable for characterizing pore structures with pore sizes ranging from 0.3 nm to 30 nm. For example, the pore size of the second-sized sample is 0.3 nm to 30 nm. Therefore, low-temperature nitrogen adsorption experiments show better characterization results within a larger pore size range, while low-temperature carbon dioxide adsorption experiments show better characterization results within a smaller pore size range. High-pressure mercury intrusion porosimetry (HPMI) can be used to characterize the pore structure of shale, and it is suitable for characterizing pore structures with pore sizes ranging from 3.7 nm to 1000 nm. For example, the pore size of the third-sized sample is 3.7 nm to 1000 nm. In HPMI, parameters such as pore size distribution, pore volume, and porosity can be calculated by measuring pressure changes. Therefore, HPMI shows better characterization results within a larger pore size range.

[0123] The process of obtaining the volume of the first hole is as follows:

[0124] A sample with the first pore size was prepared. After preparation, nitrogen pretreatment was performed at low temperature to obtain a sample with the first pore size after impurity removal. The sample with the first pore size after impurity removal was thoroughly mixed with the adsorbent. After thorough mixing, the mass of nitrogen on the adsorbent was measured, and a nitrogen adsorption isotherm was plotted. The first pore volume of the sample with the first pore size was obtained based on the nitrogen adsorption isotherm.

[0125] In the disclosed embodiment, the first pore size sample is crushed and screened to obtain uniform particle size. Then, at low temperature, the sample and adsorbent are pretreated with nitrogen to remove any possible moisture and other impurities, resulting in a purified first pore size sample. The pretreated purified first pore size sample is added to an appropriate amount of adsorbent and thoroughly mixed. The mass of nitrogen on the adsorbent is then measured using a specific surface area meter or similar equipment, and a nitrogen adsorption isotherm is plotted. The pore size distribution of the sample is calculated from the nitrogen adsorption isotherm using the BJH (Barrett-Joyner-Hard) equation, and the specific surface area of ​​the first pore size sample is calculated from the nitrogen adsorption isotherm using the BET (Bruno-Emmett-Taylor) equation. Finally, the pore volume and porosity of the first pore size sample are calculated by comparing the dry weight and the weight after saturation. The pore volume is the first pore volume of the first pore size sample.

[0126] In one example, the detailed procedure of the low-temperature nitrogen adsorption experiment is as follows:

[0127] 1. Prepare samples:

[0128] Prepare the sample to be tested, and ensure that its surface is smooth, clean, and free of impurities.

[0129] The sample can be shale in the form of powder, film, granules or blocks.

[0130] 2. Sample processing:

[0131] Before conducting experiments, the samples are heat-treated or otherwise treated to remove surface impurities or solvent residues.

[0132] 3. Preparation of experimental setup:

[0133] Prepare the nitrogen adsorption instrument and ensure that it is in normal working condition.

[0134] According to the experimental requirements, set the experimental parameters such as temperature and pressure.

[0135] 4. Experimental Procedure:

[0136] Place the sample into the nitrogen adsorption instrument and begin the experiment.

[0137] Under set temperature and pressure conditions, the relationship curve between the amount of adsorption and the relative pressure (i.e., the nitrogen adsorption isotherm) is measured through a nitrogen adsorption experiment.

[0138] 5. Data Processing:

[0139] The experimental data were processed, and parameters such as the specific surface area, pore volume, and pore size distribution of the sample were calculated based on the BJH equation, the BET equation, and the nitrogen adsorption isotherm.

[0140] like Figure 6 and Figure 7 As shown, Figure 6 The table in the document contains experimental data from the specific surface area-pore size detection report (1) of the low-temperature nitrogen adsorption experiment (for illustrative purposes only). Figure 7 According to Figure 6 The table shown contains experimental data yielding surface area-pore size relationship curves (i.e., nitrogen adsorption isotherms). The horizontal axis represents relative pressure, the vertical axis represents adsorption volume, hollow circles represent adsorption curves, and black rhombuses represent desorption curves. Then, based on... Figure 6 The data in the table is processed, and parameters such as the specific surface area, pore volume, and pore size distribution of the sample are calculated based on BET theory. For example... Figure 8 and Figure 9 As shown, Figure 8 The table in the table contains the experimental data from the specific surface area-pore size release test report (2) of the low-temperature nitrogen adsorption experiment. Figure 9 According to Figure 8 The table data shown yields a curve of pore volume-pore diameter-cumulative pore volume. Solid circles represent the cumulative pore volume, and hollow circles represent the pore volume per unit pore diameter. The horizontal axis represents the pore diameter. When the vertical axis represents the cumulative pore volume, the cumulative pore volume curve represented by solid circles can be obtained. When the vertical axis represents the pore volume, the pore volume curve represented by hollow circles per unit pore diameter can be obtained.

[0141] The process of obtaining the volume of the second hole is as follows:

[0142] A sample with a second pore size was prepared. After preparation, carbon dioxide pretreatment was performed at low temperature to obtain a sample with a purified second pore size. The sample with the purified second pore size was thoroughly mixed with the adsorbent. After thorough mixing, the mass of carbon dioxide on the adsorbent was measured, and a carbon dioxide adsorption isotherm was plotted. The second pore volume of the sample with the second pore size was obtained based on the carbon dioxide adsorption isotherm.

[0143] In this embodiment, the second pore size sample is crushed and screened to obtain uniform particle size. Then, at low temperature, the sample and adsorbent are pretreated with carbon dioxide to remove any possible moisture and other impurities, resulting in a purified second pore size sample. The pretreated purified second pore size sample is added to an appropriate amount of adsorbent and mixed thoroughly. The mass of carbon dioxide on the adsorbent is then measured using a surface area analyzer or similar equipment, and a carbon dioxide adsorption isotherm is plotted. Then, using the Langmuir isotherm adsorption model or other models, parameters such as adsorption capacity, pore volume, and cumulative pore volume are calculated from the carbon dioxide adsorption isotherm. Finally, by comparing the dry weight of the second pore size sample with its saturated weight, the second pore volume of the second pore size sample is calculated.

[0144] In one example, the detailed procedure of the low-temperature carbon dioxide adsorption experiment is as follows:

[0145] 1. Prepare samples:

[0146] Prepare the sample to be tested, and ensure that its surface is smooth, clean, and free of impurities.

[0147] The sample can be in the form of powder, film, granules or block.

[0148] 2. Sample processing:

[0149] Before conducting experiments, the samples are heat-treated or otherwise treated to remove surface impurities or solvent residues.

[0150] 3. Preparation of experimental setup:

[0151] Prepare the carbon dioxide adsorption instrument and ensure that it is in normal working condition.

[0152] According to the experimental requirements, set the experimental parameters such as temperature and pressure.

[0153] 3. Experimental Procedure:

[0154] Place the sample into the carbon dioxide adsorption instrument and begin the experiment.

[0155] Under set temperature and pressure conditions, the relationship curve between the amount of adsorption and the relative pressure (i.e., the carbon dioxide adsorption isotherm) is measured through a carbon dioxide adsorption experiment.

[0156] 4. Data Processing:

[0157] The experimental data were processed, and parameters such as the adsorption capacity, pore volume, and cumulative pore volume of the sample were calculated based on the Langmuir isothermal adsorption model or other models.

[0158] Note: The low-temperature nitrogen and low-temperature carbon dioxide adsorption experiments are basically similar, but because nitrogen and carbon dioxide molecules have different diameters, the pore sizes tested in the two experiments are different.

[0159] like Figure 10 and Figure 11 As shown, Figure 10 The table below contains experimental data from a low-temperature carbon dioxide adsorption experiment (for illustrative purposes only). Figure 11 According to Figure 10 The table shown contains experimental data from which isothermal adsorption curves can be obtained. The horizontal axis represents pressure, and the vertical axis represents adsorption amount. Then, based on this, [the following can be determined]... Figure 10 The data in the table is processed, and parameters such as the sample's adsorption capacity and carbon dioxide adsorption isotherm are calculated based on the Langmuir isotherm adsorption model or other models. For example... Figure 12 and Figure 13 As shown, Figure 12 The table below contains experimental data from a low-temperature carbon dioxide adsorption experiment. Figure 13 According to Figure 12 The experimental data in the table shown yielded a cumulative pore volume-pore volume-pore diameter curve. The solid black circles represent the cumulative pore volume curve, and the hollow squares represent the pore volume curve. The horizontal axis represents the pore diameter. When the vertical axis represents the cumulative pore volume, we can obtain... Figure 13 The cumulative pore volume curve in the graph, when the ordinate is pore volume, can be obtained as follows: Figure 13 The pore volume curve in the image.

[0160] The process of obtaining the volume of the third hole is as follows:

[0161] A sample with a third pore size was prepared. After preparation, the sample with the third pore size was subjected to vacuum treatment to obtain a vacuum sample. Under high pressure, mercury intrusion porosimetry was gradually injected into the vacuum sample. When the vacuum sample was completely saturated, a saturated sample was obtained. The mercury intrusion porosimetry in the saturated sample was released to obtain pressure change data. Based on the pressure change data, the volume of the third pore of the sample with the third pore size was obtained.

[0162] In this embodiment, the third-pore-size sample can be pulverized and its particle size controlled by methods such as sieving. The sieved third-pore-size sample is then placed in a vacuum chamber to remove any gas and moisture. Under high pressure, mercury intrusion porosimetry is gradually injected into the third-pore-size sample and thoroughly mixed until it is completely saturated, resulting in a saturated sample. During the mercury intrusion process, pressure changes are measured to determine the pore structure parameters of the third-pore-size sample. After mercury intrusion, the mercury intrusion porosimetry is gradually released until all the porosimetry in the saturated sample is released. Pressure change data during the mercury intrusion process and the release of the mercury intrusion porosimetry are obtained, and the pressure change data is analyzed to calculate parameters such as the pore size distribution, pore volume, and porosity of the sample. The pore volume is the third pore volume of the third-pore-size sample.

[0163] In one example, the detailed procedure of a high-pressure mercury intrusion porosimetry experiment on shale:

[0164] 1. Sample preparation:

[0165] Prepare the shale sample to be tested, and ensure that its surface is clean, dry, and free of impurities.

[0166] The sample can be in the form of powder, flakes or block.

[0167] 2. Sample processing:

[0168] The sample is subjected to heat treatment or other treatments to remove surface impurities or solvent residues.

[0169] 3. Preparation of experimental setup:

[0170] Prepare the high-pressure mercury intrusion instrument and ensure that the instrument is in normal working condition.

[0171] Set experimental parameters according to the experimental requirements, such as pressure range and temperature.

[0172] 4. Experimental Procedure:

[0173] The sample is placed in the high-pressure mercury intrusion instrument, and the experiment begins.

[0174] Within the set pressure range, mercury intrusion porosimetry curves were measured using mercury intrusion porosimetry experiments, and the pore volume under different pressures was recorded.

[0175] 5. Data Processing:

[0176] Based on the mercury intrusion porosimetry data, parameters such as pore volume and pore size distribution of the shale sample were calculated.

[0177] We can use mercury intrusion porosimetry data to fit a pore structure model and further analyze the pore structure characteristics of shale.

[0178] like Figure 14 As shown, Figure 14 Mercury intrusion porosimetry (MIP) curves were measured, with pressure on the x-axis and pore volume on the y-axis. These curves were then used to observe pore volume under different pressures. Figure 14 By calculating the data from the mercury intrusion porosimetry curves obtained in the intermediate mercury intrusion test, parameters such as pore volume and pore size distribution of the shale sample can be obtained. Furthermore, based on these parameters, [the following can be determined / adapted]: Figure 15 The graphs shown represent the adsorption volumes of shale samples of different diameters. a represents the mercury withdrawal curve, and b represents the mercury entry curve. The horizontal axis represents the diameter of the shale sample, and the vertical axis represents the adsorption volume.

[0179] In some embodiments, determining the free gas content of a target shale sample based on its pore volume and ideal gas law includes: calculating the free gas content using the following ideal gas law:

[0180] PV = nZRT

[0181] Where P represents the experimental pressure of the target shale sample, V represents the pore volume of the target shale sample, n represents the amount of gas, Z represents the compressibility factor, Z is a constant, R represents the gas constant, and T represents the Kelvin temperature.

[0182] In this embodiment of the disclosure, during data analysis, the free gas content in the pore structure of the target shale sample is determined based on the formation pressure and temperature (target temperature and target pressure) of the target shale sample and the required pore volume.

[0183] Figure 16 A block diagram of a device for determining the adsorbed gas and free gas content of shale gas, provided in an embodiment of this disclosure, is configured on a computer device. See also... Figure 16 The device includes:

[0184] The mapping relationship acquisition module 1601 is configured to acquire the evolutionary correlation mapping relationship corresponding to the target shale sample. The evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times.

[0185] The target parameter determination module 1602 is configured to determine the target temperature and the target pressure corresponding to the target temperature based on the evolutionary correlation mapping relationship. The target temperature is the temperature of the region where the target shale sample is located at the current moment.

[0186] The adsorbed gas content determination module 1603 is configured to determine the adsorbed gas content of the target shale sample based on the shale gas adsorption efficiency and adsorbed gas calculation model of the target shale sample at the target temperature and target pressure. The adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency.

[0187] The free gas content determination module 1604 is configured to determine the free gas content of the target shale sample based on the pore volume and ideal gas equation of state of the target shale sample at the target temperature and target pressure.

[0188] In some embodiments, the mapping relationship acquisition module 1601 is configured to:

[0189] Based on the preset evolution modeling software, the temperature evolution and pressure evolution simulation of the target shale sample were carried out at different times and under the same preset environment, and the temperature evolution simulation results and pressure evolution simulation results were obtained. Among them, the preset environment is used to simulate the environment of the target shale sample's excavation location, the temperature evolution simulation results are used to characterize the correspondence between the temperature of the target shale sample and the formation depth, and the pressure evolution simulation results are used to characterize the correspondence between the pressure of the target shale sample and the formation depth.

[0190] Based on the simulation results of temperature evolution and pressure evolution, the evolutionary correlation mapping relationship is determined.

[0191] In some embodiments, the apparatus further includes:

[0192] The adsorption capacity calculation parameter acquisition module is configured to acquire the adsorption capacity calculation parameters of the target shale sample under target temperature and target pressure. The adsorption capacity calculation parameters include a first adsorption capacity calculation parameter and a second adsorption capacity calculation parameter. The first adsorption capacity calculation parameter includes shale gas adsorption parameters, shale gas phase density, and the remaining adsorption vacancies on the pore surface of the target shale sample. The second adsorption capacity calculation parameter includes shale gas conversion adsorption parameters, shale gas phase density, the maximum adsorption sites on the pore surface of the target shale sample, and the adsorption sites occupied by the adsorbed gas.

[0193] The adsorption efficiency determination module is configured to determine the shale gas adsorption efficiency based on a first adsorption amount calculation parameter and a first preset correlation relationship, or to determine the shale gas adsorption efficiency based on a second adsorption amount calculation parameter and a second preset correlation relationship; wherein, the first preset correlation relationship is used to characterize the correlation between the shale gas adsorption efficiency and the first adsorption amount calculation parameter, and the second preset correlation relationship is used to characterize the correlation between the shale gas adsorption efficiency and the second adsorption amount calculation parameter.

[0194] In some embodiments, the adsorption capacity calculation parameter is a parameter obtained by measuring the separated shale sample. The separated shale sample is the shale sample obtained after separating the target shale sample and the adsorbent in the equilibrium mixture. The equilibrium mixture is the mixture obtained when the target shale sample and the adsorbent in the mixture reach an equilibrium state. The mixture is the mixture obtained after adding the adsorbent to the target shale sample. The equilibrium state refers to the state when the pressure of the mixture reaches the target pressure.

[0195] In some embodiments, the adsorbed gas content determination module 1603 is configured to:

[0196] Based on shale gas adsorption efficiency, target pressure, maximum adsorption volume of the pore surface of the target shale sample, adsorption pressure of the pore surface of the target shale sample, and an adsorption gas calculation model, the adsorbed gas content is determined. The adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and shale gas adsorption efficiency, target pressure, maximum adsorption volume of the pore surface of the target shale sample, and adsorption pressure of the pore surface of the target shale sample.

[0197] In some embodiments, the apparatus further includes:

[0198] The pore volume acquisition module is configured to acquire the first pore volume, the second pore volume, and the third pore volume of a unit shale sample in the target shale sample; wherein, the first pore volume is obtained by performing a low-temperature nitrogen adsorption experiment on the target shale sample, the second pore volume is obtained by performing a low-temperature carbon dioxide adsorption experiment on the target shale sample, and the third pore volume is obtained by performing a high-pressure mercury intrusion porosimetry experiment.

[0199] The pore volume acquisition module is configured to determine the pore volume based on the first pore volume, the second pore volume, and the third pore volume.

[0200] Based on the above embodiments, this embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method for determining the adsorbed gas and free gas content of shale gas described in the above embodiments.

[0201] In some embodiments of this example, a computer-readable storage medium is provided, on which a computer program is stored, characterized in that, when executed by a processor, the computer program implements the steps of the method for determining the adsorbed gas and free gas content of shale gas described in the above embodiments.

[0202] In some embodiments of this example, a computer program product is provided, including a computer program, characterized in that, when executed by a processor, the computer program implements the steps of the method for determining the adsorbed gas and free gas content of shale gas described in the above embodiments.

[0203] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic component, for executing the methods described in the above embodiments.

[0204] Computer-readable storage media can be implemented by any type of volatile or non-volatile storage device or a combination thereof. Computer-readable storage media may include, but are not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, and computer storage media (e.g., hard disks, floppy disks, solid-state drives, removable disks, CD-ROMs, DVD-ROMs, Blu-ray discs, etc.).

[0205] Computer-readable storage media may also store at least one computer-executable program, such as computer-readable instructions. Computer-readable storage media include, but are not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Computer-readable storage media may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0206] In addition, the computer device may include (but is not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (e.g., keyboard, mouse, speakers, etc.).

[0207] The processor can communicate with external devices via the I / O bus through wired or wireless networks.

[0208] In one embodiment, the at least one computer-executable instruction may also be compiled into or comprise a software product / computer program product, wherein one or more computer-executable instructions are executed by a processor to perform the steps of the various functions and / or methods in the embodiments described herein.

[0209] In the embodiments provided in this disclosure, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0210] It should be noted that, in this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element limited by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0211] While the embodiments disclosed herein are as described above, the foregoing content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art to which this disclosure pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope of this disclosure; however, the scope of patent protection of this disclosure shall still be determined by the scope defined in the appended claims.

Claims

1. A method for determining the content of adsorbed gas and free gas in shale gas, characterized in that, include: The evolutionary correlation mapping relationship corresponding to the target shale sample is obtained, and the evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times; Based on the evolutionary correlation mapping relationship, the target temperature and the target pressure corresponding to the target temperature are determined, wherein the target temperature is the temperature of the region where the target shale sample is located at the current moment; Based on the shale gas adsorption efficiency and adsorbed gas calculation model of the target shale sample at the target temperature and the target pressure, the adsorbed gas content of the target shale sample is determined. The adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency. The free gas content of the target shale sample is determined based on the pore volume and ideal gas equation of state of the target shale sample at the target temperature and the target pressure.

2. The method according to claim 1, characterized in that, The acquisition of the evolutionary correlation mapping relationship corresponding to the target shale sample includes: Based on preset evolution modeling software, temperature evolution simulation and pressure evolution simulation are performed on the target shale sample at different times and under the same preset environment to obtain temperature evolution simulation results and pressure evolution simulation results. The preset environment is used to simulate the environment at the location where the target shale sample is exposed. The temperature evolution simulation results are used to characterize the correspondence between the temperature of the target shale sample and the formation depth, and the pressure evolution simulation results are used to characterize the correspondence between the pressure of the target shale sample and the formation depth. Based on the temperature evolution simulation results and the pressure evolution simulation results, the evolutionary correlation mapping relationship is determined.

3. The method according to claim 1, characterized in that, The method further includes: Under the target temperature and the target pressure, the adsorption capacity calculation parameters of the target shale sample are obtained; wherein, the adsorption capacity calculation parameters include a first adsorption capacity calculation parameter and a second adsorption capacity calculation parameter, the first adsorption capacity calculation parameter includes shale gas adsorption parameters, shale gas gas phase density, and the remaining adsorption vacancies on the pore surface of the target shale sample, and the second adsorption capacity calculation parameter includes shale gas conversion adsorption parameters, shale gas gas phase density, the maximum adsorption sites on the pore surface of the target shale sample, and the adsorption sites occupied by the adsorbed gas; The shale gas adsorption efficiency is determined based on the first adsorption capacity calculation parameter and the first preset correlation relationship, or the shale gas adsorption efficiency is determined based on the second adsorption capacity calculation parameter and the second preset correlation relationship; wherein, the first preset correlation relationship is used to characterize the correlation between the shale gas adsorption efficiency and the first adsorption capacity calculation parameter, and the second preset correlation relationship is used to characterize the correlation between the shale gas adsorption efficiency and the second adsorption capacity calculation parameter.

4. The method according to claim 3, characterized in that, The adsorption capacity calculation parameter is a parameter obtained by measuring the separated shale sample. The separated shale sample is the shale sample obtained after separating the target shale sample and the adsorbent in the equilibrium mixture. The equilibrium mixture is the mixture obtained when the target shale sample and the adsorbent in the mixture reach an equilibrium state. The mixture is the mixture obtained after adding the adsorbent to the target shale sample. The equilibrium state refers to the state when the pressure of the mixture reaches the target pressure.

5. The method according to claim 1, characterized in that, The determination of the adsorbed gas content of the target shale sample based on the shale gas adsorption efficiency and adsorbed gas calculation model at the target temperature and target pressure includes: Based on the shale gas adsorption efficiency, the target pressure, the maximum adsorption volume of the pore surface of the target shale sample, the adsorption pressure of the pore surface of the target shale sample, and the adsorption gas calculation model, the adsorbed gas content is determined; wherein, the adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency, the target pressure, the maximum adsorption volume of the pore surface of the target shale sample, and the adsorption pressure of the pore surface of the target shale sample.

6. The method according to claim 1, characterized in that, The method further includes: The first pore volume, second pore volume, and third pore volume of a unit shale sample in the target shale sample are obtained; wherein, the first pore volume is obtained by performing a low-temperature nitrogen adsorption experiment on the target shale sample, the second pore volume is obtained by performing a low-temperature carbon dioxide adsorption experiment on the target shale sample, and the third pore volume is obtained by performing a high-pressure mercury intrusion porosimetry experiment; The pore volume is determined based on the first pore volume, the second pore volume, and the third pore volume.

7. A device for determining the content of adsorbed gas and free gas in shale gas, characterized in that, include: The mapping relationship acquisition module is configured to acquire the evolutionary correlation mapping relationship corresponding to the target shale sample, wherein the evolutionary correlation mapping relationship is used to characterize the temperature and pressure of the target shale sample at different times; The target parameter determination module is configured to determine the target temperature and the target pressure corresponding to the target temperature based on the evolutionary correlation mapping relationship, wherein the target temperature is the temperature of the region where the target shale sample is located at the current moment; The adsorbed gas content determination module is configured to determine the adsorbed gas content of the target shale sample based on the shale gas adsorption efficiency and the adsorbed gas calculation model of the target shale sample at the target temperature and the target pressure. The adsorbed gas calculation model is used to characterize the correlation between the adsorbed gas content and the shale gas adsorption efficiency. The free gas content determination module is configured to determine the free gas content of the target shale sample based on the pore volume and ideal gas equation of state of the target shale sample at the target temperature and the target pressure.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 6.

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