A gas adsorption displacement competition relationship measurement device and measurement method

Abstract

The present application relates to the technical field of oil and gas exploration and development, and discloses a gas adsorption displacement competitive relationship measurement device and measurement method. The device includes a gas injection system, an isothermal adsorption system, a pressure control system, a gas detection system, a vacuum system and an information acquisition system; the isothermal adsorption system includes a constant temperature box, a first PVT cylinder, a second PVT cylinder, a reference container, a sample container, a first pressure gauge and a second pressure gauge; the injection system includes an intermediate container filled with a gas to be tested, and the sample is injected through the pressure control system, and the pressure of the entire system is adjusted. When the sample is tested, or when the sample is prepared in the intermediate container, it is transmitted to the gas detection system through a pipeline for detection, and the gas detection system can detect the gas components. The present application can accurately measure the degree of methane adsorption in rocks under different pressure conditions, and explore the competitive adsorption behavior of methane and carbon dioxide on rocks under the same pressure environment.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas exploration and development, and in particular to a gas adsorption displacement competition relationship measurement device and measurement method. Background Art

[0002] Shale gas is a natural gas stored in shale reservoirs, mainly composed of methane. These natural gases can exist in a free state in natural cracks and pores, or in an adsorbed state on the surface of kerogen and clay particles. Shale gas is usually gradually formed when organic matter in the deep crust undergoes a series of biodegradation, thermal evolution, compaction and maturation. It is an important energy resource and chemical raw material with the advantages of cleanliness and efficiency. It is widely used in residential gas, urban heating, power generation, automobile fuel and chemical production.

[0003] The shale reservoir has a high adsorbed gas content, which accounts for 20% to 80% of the total gas content. Therefore, studying the adsorbed gas content is the key to evaluating the shale gas content. According to relevant data, the shale gas reservoirs in different geological regions also have great differences.

[0004] With the continuous development of shale gas reservoirs, the reservoir pressure continues to decline. Accurately evaluating the adsorbed gas content at different pressures is of great significance for understanding the remaining reserves of the reservoir.

[0005] In addition, injecting CO2 into shale reservoirs is an effective method to improve shale gas recovery. Shale's adsorption capacity for CO2 is much greater than that for CH4. Therefore, accurately evaluating the competitive adsorption capacity of CO2 / CH4 under different pressures plays an important guiding role in clarifying the potential for improving recovery and optimizing gas injection plans.

[0006] Adsorption experiments are a common method for measuring the adsorption capacity of CH4 or CO2. Isothermal adsorption measuring instruments are the most commonly used experimental devices, but their equipment is expensive, the measurement operation is complicated, and the measurement cost is high. In view of this situation, some technologies have been disclosed to optimize gas adsorption experiments.

[0007] The patent application with patent number CN116735418A discloses a test method for the adsorption replacement of shale methane by a carbon dioxide / nitrogen mixed gas, including: injecting a first preset amount of methane into a reference pool to obtain first pressure change data in the reference pool; injecting a second preset amount of carbon dioxide / nitrogen mixed gas into the reference pool in stages to obtain second pressure change data in the reference pool; based on the first pressure change data, the second pressure change data, the volume of the reference pool, and the residual volume of the sample pool, determining the adsorption amount of carbon dioxide, nitrogen, and methane by the shale at each pressure point and the desorption amount of methane in the shale at each pressure point. The potential impact of the bidirectional diffusion of the carbon dioxide / nitrogen mixed gas on the competitive adsorption of the mixed gas during the adsorption replacement of shale methane by the carbon dioxide / nitrogen mixed gas is fully considered, providing a solid foundation for improving the recovery efficiency of the adsorbed gas, thereby effectively improving the shale gas recovery rate. However, the scheme fails to fully reveal the true adsorption status of each of the two gases, that is, it fails to clearly distinguish and quantify the specific adsorption behavior of each gas in the mixed system. Therefore, there is still room for further improvement in revealing the depth of the adsorption characteristics of the mixed gas.

[0008] The patent application with patent number CN105606703A discloses an oil and gas detection device and a calculation method thereof, specifically a calculation method and a measuring device for shale adsorbed gas and free gas; the pore permeability of mud shale plug samples is measured under overburden pressure, and a calculation model of the change of mud shale pore volume with overburden pressure is obtained; the isothermal adsorption-acoustic wave joint measurement experiment is carried out on mud shale samples to obtain the law of change of acoustic wave amplitude with gas pressure; the conversion relationship between the free gas volume in the pore and the acoustic attenuation is obtained according to the acoustic wave attenuation law caused by the change of free gas. The adsorbed gas volume of methane is obtained by the relationship between gas content and acoustic attenuation and the acoustic attenuation L2 caused by adsorbed gas. This method ensures the integrity of the sample pore structure, puts the rock in an overburden state, and is more in line with the actual situation of the rock in the formation; the adsorption of shale on adsorbable gases such as methane and carbon dioxide is used to cause the acoustic wave attenuation test law, so as to determine the content of free gas and adsorbed gas in shale and their proportional relationship. It is mainly based on the sound wave attenuation test law caused by the adsorption of adsorbable gases such as methane and carbon dioxide by shale, so as to obtain the adsorption amount. The installation conditions of this device are relatively harsh. The ultrasonic flowmeter has high requirements for the location selection of on-site installation. It is necessary to ensure that the transducer (or probe) can be installed correctly and receive a good ultrasonic signal.

[0009] The patent application with patent number CN205656091U discloses a volumetric shale isothermal adsorption experimental device, which includes an adsorption and desorption unit, a gas injection unit, a constant temperature control unit, a vacuum unit and a data measurement and acquisition unit. The volumetric shale isothermal adsorption experimental device provided by the utility model can explore the adsorption capacity of shale samples for multi-component gases such as CH4 / CO2 and CH4 / N2. During the adsorption process, the kettle body can resist CO2 corrosion and the gas in the kettle body is uniform and non-stratified. At the same time, it can achieve precise control of gas extraction at each adsorption equilibrium pressure point; and the volumetric shale isothermal adsorption experimental device can also explore the methane carbon isotope fractionation effect during shale gas desorption, and reduce the dilution effect of the free space gas in the adsorption system on the isotope fractionation effect. However, the device cannot meet the measurement requirements under continuously changing pressure conditions, that is, continuously measuring the adsorption amount at different pressure values. Therefore, in order to improve the accuracy of the experiment and expand the scope of research, how to enhance its direct control ability over the adsorption pressure and realize the measurement function under continuous pressure changes is one of the technical problems that need to be solved urgently.

[0010] Patent application number CN110857927A discloses a competitive adsorption detection method and device for carbon dioxide and methane in shale, a competitive adsorption detection method and device for carbon dioxide and methane in shale, the method comprising: after introducing methane with a pressure of a first pressure value into the detection chamber of a nuclear magnetic resonance (NMR) instrument, the mass of the first adsorbed methane in the shale in the detection chamber is determined. Further, after a mixed gas of carbon dioxide and methane with a pressure of a second pressure value is introduced into the detection chamber of the NMR instrument again, the mass of the second adsorbed methane in the shale in the detection chamber is determined; further, according to the mass of the first adsorbed methane and the mass of the second adsorbed methane, the competitive adsorption information of carbon dioxide on methane in shale under the same methane partial pressure can be determined, so as to reasonably guide the efficient exploitation of shale gas. It is clear to those skilled in the art that the adsorption amount of gas molecules in the core is small, and this weak NMR signal will have a greater impact on the accuracy of the experimental results. Since the signal intensity is proportional to the adsorption amount, a weak signal means that the experimental data may contain a larger error range. Therefore, how to reduce the error is one of the technical problems that urgently needs to be solved.

[0011] In summary, how to continuously measure the adsorption amount of methane gas on rock particles under different pressure conditions, obtain isothermal adsorption curves more efficiently, thereby improving experimental efficiency and significantly saving costs, and simulating the replacement capacity of CO2 for formation methane under in-situ conditions of the formation while maintaining constant temperature and pressure, and measuring the selective competitive adsorption capacity of CO2 / CH4 mixed gases in different proportions are technical problems that need to be solved urgently. Summary of the invention

[0012] The purpose of this application is to provide a gas adsorption displacement competition relationship measurement device to accurately measure the degree of methane adsorption in rocks under different pressure conditions; to explore the competitive adsorption behavior of methane and carbon dioxide on rocks under the same pressure environment; and to simulate the adsorption conditions of both carbon dioxide and methane in rocks when carbon dioxide and methane are injected simultaneously.

[0013] In order to achieve the above purpose, the technical solutions adopted are as follows:

[0014] In a first aspect, the present application provides a gas adsorption displacement competition relationship measurement device, including a gas injection system, an isothermal adsorption system, a pressure control system, a gas detection system, a vacuum system and an information acquisition system;

[0015] The isothermal adsorption system comprises a constant temperature box, a first PVT cylinder, a second PVT cylinder, a reference container, a sample container, a first pressure gauge and a second pressure gauge, wherein the first PVT cylinder and the second PVT cylinder are arranged in the constant temperature box, and the reference container and the sample container are arranged in the first PVT cylinder and the second PVT cylinder respectively; the first pressure gauge and the second pressure gauge are used to measure the pressure values ​​of the reference container and the sample container respectively;

[0016] The gas injection system injects gas into the reference container and / or the sample container under the control of the pressure control system;

[0017] The gas detection system is connected to the reference container and / or the sample container and is used to detect gas components;

[0018] The information acquisition system is connected to the thermostat, the first pressure gauge, the second pressure gauge, the pressure control system and the gas detection system signal, and is used to obtain the pressure, temperature and volume change information of the sample container and the reference container and the gas component information detected by the gas detection system.

[0019] Furthermore, it also includes a first piston, a second piston, a first observation window and a second observation window; wherein, the first piston and the second piston are respectively arranged in the reference container and the sample container, the first observation window and the second observation window are both provided with scales, and the first observation window and the second observation window are respectively arranged on the side walls of the reference container and the sample container.

[0020] Further, it also includes a switch assembly, the switch assembly includes switch 1, switch 2, switch 3, switch 4, switch 5, switch 6, switch 7, switch 8, switch 9, switch 10, switch 11, switch 12, switch 13, switch 14 and switch 15;

[0021] The gas injection system comprises a first container, a second container, a third container and a fourth container;

[0022] The pressure control system comprises a first constant pressure pump and a second constant pressure pump;

[0023] The first container, the second container and the third container are used to store helium, methane and carbon dioxide respectively, and the fourth container is used as a spare container; the first ends of the first container, the second container, the third container and the fourth container are respectively connected to the first pipeline through pipelines, and the switches 1, 2, 3 and 15 are arranged on the pipelines connected to the first pipeline at the first ends of the first container, the second container, the third container and the fourth container, and the first pipeline is connected to the reference container and the sample container through the second pipeline and the third pipeline respectively; the switch 12 and the switch 7 are arranged on the second pipeline and the third pipeline; the second ends of the first container, the second container, the third container and the fourth container are respectively connected to one end of the fourth pipeline through pipelines, and the other end of the fourth pipeline is connected to the reference container, the second ends of the first container, the second container, the third container and the fourth container are respectively arranged on the pipelines connected to the fourth pipeline, and the first constant pressure pump and the switch 14 are arranged on the fourth pipeline, and the sample container is connected to the second constant pressure pump through a pipeline and the switch 11 is arranged on the pipeline connected to the second constant pressure pump.

[0024] Further, the vacuum system includes a vacuum pump, the vacuum pump is connected to the reference container and the sample container through a pipeline, and the switch eight and the switch nine are respectively arranged on the pipelines connected to the reference container and the sample container;

[0025] The gas detection system comprises a gas chromatograph, which is connected to the reference container and the sample container via a pipeline, and the switch 10 is arranged on the pipeline connecting the gas chromatograph, the reference container and the sample container.

[0026] In a second aspect, the present application provides an adsorption amount measurement method, based on the gas adsorption displacement competition relationship measurement device as described above, the measurement method comprises:

[0027] Prepare the sample and determine the sample volume , assembling the sample in the sample container;

[0028] Passing helium into the reference container and the sample container to measure the volume of the free space;

[0029] The reference container and the sample container are evacuated, and based on the set pressure parameters and temperature parameters, methane at a preset pressure is introduced into the reference container. After stabilization, the first pressure is recorded. , open switch 12 and switch 7, connect the reference container and the sample container, and after stabilization, record the second pressure , calculating the initial adsorption amount of methane at the current pressure and the current temperature according to the first pressure and the second pressure, wherein the temperature parameter is the temperature of the reference container and the sample container; adjusting the set pressure parameter, pressurizing the reference container based on the adjusted set pressure parameter, obtaining a third pressure after stabilization, and calculating the first pressurized adsorption amount of methane according to the third pressure and the initial adsorption amount, repeatedly adjusting the set pressure parameter and temperature parameter multiple times, and obtaining the t-th pressurized adsorption amount.

[0030] Furthermore, the reference container and the sample container are evacuated, and based on the set pressure parameters and temperature parameters, methane at a preset pressure is introduced into the reference container, and after stabilization, the first pressure is recorded. , open switch 12 and switch 7, connect the reference container and the sample container, and after stabilization, record the second pressure , calculating the initial adsorption amount of methane at the current pressure and the current temperature according to the first pressure and the second pressure, wherein the temperature parameter is the temperature of the reference container and the sample container; adjusting the set pressure parameter, pressurizing the reference container based on the adjusted set pressure parameter, obtaining a third pressure after stabilization, and calculating the first pressurized adsorption amount of methane according to the third pressure and the initial adsorption amount, repeatedly adjusting the set pressure parameter and temperature parameter multiple times, and obtaining the t-th pressurized adsorption amount of methane, including:

[0031] Open switch nine, switch twelve, switch seven and the vacuum pump, evacuate the reference container and the sample container, and after the vacuum pump forms a negative pressure and stabilizes, close switch nine, switch twelve, switch seven and the vacuum pump, and record the gas volume in the reference container. and the gas volume of the sample container ;

[0032] Open switch 2 and switch 12, wait for methane gas to enter the reference container, open switch 5, use the first constant pressure pump to increase or decrease the pressure, and observe that the first pressure gauge reaches the specified pressure and the pressure is stable, then record the first pressure. , turn off all switches, and turn on switch 7 and switch 12. The methane in the reference container enters the sample container. After the system is balanced, record the second pressure. , then the initial adsorption amount of methane is the total number of moles injected Subtract the number of moles after equilibrium ;

[0033] When changing a pressure, increase the pressure to observe the adsorption amount of the sample. At the first change, open switch 13 and use the second constant pressure pump to pressurize the sample container until it reaches the first pressurization pressure. Keep the pressure constant. When the pressure is stable and the system is balanced, record the change in the reference sample volume. , and close switch 13, observe the first pressure gauge, and record the third pressure , the first pressurized adsorption amount of methane is equal to the first total injection amount minus the molar amount after equilibrium;

[0034] No. When the pressure is increased for the second time, switch 13 is turned on, and the sample container is pressurized by the second constant pressure pump to reach the first t Increase the pressure for the first time and keep the pressure constant. When the pressure is stable and the system is balanced, record the t Change in the volume of the secondary reference container , and turn off switch 13, observe the first pressure gauge, and record the pressure data , methane The pressure adsorption capacity is equal to the The total injected amount minus the molar amount after equilibrium.

[0035] Furthermore, the The calculation formula of the secondary pressure adsorption capacity is as follows:

[0036] ,

[0037] In the formula, Indicates Secondary pressure adsorption capacity, P t Indicates t Secondary pressure, Indicates i The change in the volume of the reference container, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, Indicates the volume of the sample.

[0038] Furthermore, the measurement method further comprises a step of determining the competitive adsorption of methane and carbon dioxide at the same pressure, wherein the step of determining the competitive adsorption of methane and carbon dioxide at the same pressure comprises:

[0039] Open switch 2, switch 12 and switch 5, use the first constant pressure pump to pressurize to the specified pressure, and observe the first pressure gauge to obtain the first pressure value. , at this time, the empty volume of the reference container and the sample container is the same, recorded as , close switch 2, open switch 7 and switch 13, and turn on the first constant pressure pump, press the piston of the reference container to the top, so that all the gas in the reference container is input into the sample container, close all switches, and observe the first pressure gauge to obtain the second pressure value of , then the first adsorption amount Equal to the first total injection volume Subtract the first free molar amount ;

[0040] Turn on switch 12 and switch 1, introduce helium into the reference container, turn on switch 13, move the piston in the middle of the reference container to the bottom, turn off all switches, turn on switch 12 and switch 8, and run the vacuum pump to make the reference container reach a vacuum state;

[0041] Close switch 12 and switch 8, open switch 3, switch 6 and switch 12, start the first pressure pump to stabilize the pressure of the reference container at the first pressure value , turn off all switches; to maintain the same pressure and fully saturate the sample with carbon dioxide, turn on switch twelve, switch seven, switch thirteen and switch eleven, start the first constant pressure pump and the second constant pressure pump, the first constant pressure pump pumps in, the second constant pressure pump withdraws, and keep the speed of the first constant pressure pump and the second constant pressure pump at the same speed, and input 30 times of of carbon dioxide, turn off all switches, and after the system stabilizes, observe the second pressure gauge to obtain the third pressure value , then the adsorption amount of carbon dioxide is Equal to the total amount injected Subtract the molar mass after equilibrium .

[0042] Further, the first adsorption amount is calculated by the following formula: :

[0043] ,

[0044] In the formula, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, Indicates the volume of the sample;

[0045] The adsorption of carbon dioxide is calculated by the following formula: :

[0046] .

[0047] Furthermore, the measuring method further comprises a step of measuring the competitive adsorption of methane and carbon dioxide injected at different ratios at the same pressure, wherein the step of measuring the competitive adsorption of methane and carbon dioxide injected at different ratios at the same pressure comprises:

[0048] Open switch 2, switch 3 and switch 15, input carbon dioxide and methane in equal proportions into the fourth container, let it stand to allow the two gases to be fully mixed, and open switch 10 to measure with a gas chromatograph to ensure that the two gases are fully mixed in equal proportions;

[0049] First, vacuum the sample container and the reference container, turn on switch 15, switch 12, and switch 14, start the first constant pressure pump, and inject the mixed gas into the reference container. When the pressure reaches the pressure value 1, P 21 When the pressure is below 20°, turn on switch 12 and switch 10, and use the gas chromatograph to calibrate and measure the deviation factor of the mixed gas below the pressure value. , and record the volume of the reference container at this time V 21 After the system is stable, close all switches and open switch 12 and switch 7 to transfer the mixed gas from the reference container to the sample container and stir the mixed gas. After the system is stable, the volume of the sample container is V 22 , observe the second pressure gauge and get the pressure value , turn on switch 10, calibrate with gas chromatograph, and measure the current gas deviation factor , the second total adsorption amount is calculated by the following formula:

[0050] ,

[0051] In the formula, represents the second total adsorption amount, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, Indicates the volume of the sample.

[0052] The beneficial effects of this application are:

[0053] The present application can measure the adsorption characteristics of gases under different temperature and pressure conditions, and at the same time has the ability to measure the competitive adsorption between carbon dioxide and methane under constant temperature and pressure conditions. When carbon dioxide and methane are injected in different proportions, the adsorption conditions of the two can be clearly obtained by accurately analyzing the component content in the sample container with the help of a gas chromatograph. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1A schematic structural diagram of a gas adsorption displacement competition relationship measurement device according to an embodiment of the present application is shown.

[0055] Figure 2 A flow chart of a method for measuring adsorption amount according to an embodiment of the present application is shown.

[0056] Reference numerals:

[0057] 01, switch 1; 02, switch 2; 03, switch 3; 04, switch 4; 05, switch 5; 06, switch 6; 07, switch 7; 08, switch 8; 09, switch 9; 10, switch 10; 11, switch 11; 12, switch 12; 13, switch 13; 14, switch 14; 15, switch 15; 21, first constant pressure pump; 22, second constant pressure pump; 31, first PVT cylinder; 32, second PVT cylinder; 41, first Pressure gauge; 42, second pressure gauge; 51, vacuum pump; 61, reference container; 62, sample container; 71, first container; 72, second container; 73, third container; 74, fourth container; 81, first piston; 82, second piston; 91, first observation window; 92, second observation window; 101, first agitator; 102, second agitator; 111, computer; 121, constant temperature box; 131, gas chromatograph; 141, sample. DETAILED DESCRIPTION

[0058] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0059] The specific implementation of the present application is further described in detail below in conjunction with the drawings and examples.

[0060] Embodiment 1:

[0061] The present application embodiment provides a gas adsorption displacement competition relationship measurement device, such as Figure 1 As shown, the gas adsorption displacement competition relationship measurement device includes a gas injection system, an isothermal adsorption system, a pressure control system, a gas detection system, a vacuum system and an information acquisition system.

[0062] The isothermal adsorption system includes a constant temperature box 121, a first PVT cylinder 31, a second PVT cylinder 32, a reference container 61, a sample container 62, a first pressure gauge 41 and a second pressure gauge 42. The first PVT cylinder 31 and the second PVT cylinder 32 are arranged in the constant temperature box 121, and the reference container 61 and the sample container 62 are arranged in the first PVT cylinder 31 and the second PVT cylinder 32 respectively; the first pressure gauge and the second pressure gauge are used to measure the pressure values ​​of the reference container 61 and the sample container 62 respectively; the gas injection system injects gas into the reference container 61 and / or the sample container 62 under the control of the pressure control system; the gas detection system is connected to the reference container 61 and / or the sample container 62 for detecting gas components; the information acquisition system is connected to the constant temperature box 121, the first pressure gauge 41, the second pressure gauge 42, the pressure control system and the gas detection system signal, and is used to obtain the pressure, temperature and volume change information of the sample container 62 and the reference container 61 and the gas component information detected by the gas detection system.

[0063] In this embodiment, the isothermal adsorption system is used to provide a sample container 62 for placing samples, in which a sample 141 can be placed, and a reference container 61 for the experiment. The first pressure gauge 41 and the second pressure gauge 42 can monitor the pressure of the two containers in real time, and the constant temperature box 121 is used to increase the constant temperature. The information acquisition system can be a computer 111, and the temperature information of the constant temperature box 121 is directly transmitted to the computer 111. The injection system is composed of an intermediate container containing the gas to be tested, and the sample is injected through the pressure control system, and the pressure of the entire system is adjusted. The vacuum system performs vacuum treatment on the inside of the reference container 61 and the sample container 62. When the sample in the reference container 61 and the sample container 62 is tested, or when the sample is prepared in the intermediate container, it is transmitted to the gas detection system through a pipeline for detection, and the gas detection system can detect the gas components. During the entire experiment, the pressure, temperature and volume change information of the sample container 62 and the reference container 61, as well as the component information of the gas detection system, will all be loaded into the information acquisition system.

[0064] In some implementations, such as Figure 1 As shown, the isothermal adsorption system further includes a first piston 81, a second piston 82, a first observation window 91 and a second observation window 92; wherein the first piston 81 and the second piston 82 are respectively disposed in the reference container 61 and the sample container 62, the first observation window 91 and the second observation window 92 are both provided with scales, and the first observation window 91 and the second observation window 92 are respectively disposed on the side walls of the reference container 61 and the sample container 62. When the second piston 82 is disposed in the sample container 62, the sample 141 is placed above the second piston 82.

[0065] In this embodiment, the scales set on the first observation window 91 and the second observation window 92 can be used to observe the volumes of the reference container 61 and the sample container 62 according to the positions of the first piston 81 and the second piston 82. One end of the first piston 81 and the second piston 82 is hydraulic oil, and the other end is the sample and the gas to be tested. The pressure of the gas to be tested can be controlled by the pistons (the first piston 81 and the second piston 82).

[0066] In some implementations, such as Figure 1 As shown, the isothermal adsorption system further includes a first stirrer 101 and a second stirrer 102 disposed at the top of the reference container 61 and the sample container 62. The first stirrer 101 and the second stirrer 102 function to promote uniform stirring of the gas to be measured and mass transfer with the adjacent observation chamber.

[0067] In some implementations, such as Figure 1 As shown, the gas adsorption displacement competition relationship measurement device also includes a switch component, which includes a switch 01, a switch 02, a switch 03, a switch 04, a switch 05, a switch 06, a switch 07, a switch 08, a switch 09, a switch 10, a switch 11, a switch 12, a switch 13, a switch 14, and a switch 15; the gas injection system includes a first container 71, a second container 72, a third container 73, and a fourth container 74; the pressure control system includes a first constant pressure pump 21 and a second constant pressure pump 22; the first container 71, the second container 72, and the third container 73 are used to store helium, methane, and carbon dioxide, respectively, and the fourth container 74 is used as a spare container; the first ends of the first container 71, the second container 72, the third container 73, and the fourth container 74 are connected to the first pipeline through pipelines, respectively, and the first containers 71, the second container 72, the third container 73, and the fourth container 74 are connected to the first pipeline through pipelines. The first end of 74 is connected to the first pipeline and is provided with switch one 01, switch two 02, switch three 03 and switch fifteen 15. The first pipeline is connected to the reference container 61 and the sample container 62 through the second pipeline and the third pipeline respectively; the second pipeline and the third pipeline are provided with switch twelve 12 and switch seven 07; the second ends of the first container 71, the second container 72, the third container 73 and the fourth container 74 are respectively connected to one end of the fourth pipeline through pipelines, and the other end of the fourth pipeline is connected to the reference container 61, the second ends of the first container 71, the second container 72, the third container 73 and the fourth container 74 are respectively provided with switch four 04, switch five 05, switch six 06 and switch fourteen 14 on the pipeline connected to the fourth pipeline, the fourth pipeline is provided with a first constant pressure pump 21 and switch fourteen 14, the sample container 62 is connected to the second constant pressure pump 22 through a pipeline and a switch eleven 11 is provided on the pipeline connected to the second constant pressure pump 22.

[0068] In some implementations, such as Figure 1As shown, the vacuum system includes a vacuum pump 51, which is connected to a reference container 61 and a sample container 62 through a pipeline, and a switch eight 08 and a switch nine 09 are respectively arranged on the pipelines connecting the reference container 61 and the sample container 62; the gas detection system includes a gas chromatograph 131, which is connected to a reference container 61 and a sample container 62 through a pipeline, and a switch ten 10 is arranged on the pipeline connecting the gas chromatograph 131 to the reference container 61 and the sample container 62.

[0069] The gas adsorption displacement competition relationship measurement device can achieve the following functions: accurately measure the adsorption degree of methane in rocks under different pressure conditions; explore the competitive adsorption behavior of methane and carbon dioxide on rocks under the same pressure environment; and simulate the adsorption conditions of carbon dioxide and methane in rocks when they are injected simultaneously.

[0070] To further prove that the gas adsorption displacement competition relationship measurement device can achieve the above functions, this embodiment provides a method for using the gas adsorption displacement competition relationship measurement device, which specifically includes the following steps:

[0071] S1. Sample preparation: For the rock samples that have been extracted, washed and dried, they are carefully crushed with a rubber hammer and sieved using a vibrating screen device to achieve effective separation of rock particles. In order to determine the volume of the crushed rock samples, the wax sealing method is used. Before the experiment, these processed samples 141 are properly placed in a dedicated sample container 62.

[0072] S2. By introducing helium gas, the free space volume of the reference container 61 and the sample container 62 is calibrated using the gas, in order to accurately determine the residual volume of the interconnecting pipe and the switch part between the reference container 61 and the sample container 62.

[0073] S3. Evacuate the reference container 61 and the sample container 62.

[0074] S4. Perform the adsorption of methane under different pressures. A certain amount of methane at a preset pressure is introduced into the reference container 61. After the system is stable, the first pressure is recorded as , open switch twelve 12, switch seven 07, connect the reference container 61 and the sample container 62, wait for the system to stabilize, and record the second pressure .

[0075] S5. Measure the adsorption amount of methane at this pressure. The total molar amount is That is, in the reference container 61 The molar amount under the same pressure is equal to the molar amount in the reference container 61 after the connected pressure is stabilized. and the molar amount in the sample container 62 .

[0076] S6, the adsorption amount at this pressure is the adsorption amount in the reference container 61 The molar amount in the reference container 61 after equilibrium is subtracted from the molar amount in the reference container 61 Subtract the molar amount in sample container 62 .

[0077] S7. According to the real gas state equation, , we can get , the adsorption amount of methane .

[0078] S8. The next pressure value determination only requires pressurizing the reference container 61 to reach the second preset pressure. After the system is stable, the third pressure is recorded as .

[0079] S9, the adsorption amount at the second preset pressure is the adsorption amount in the reference container 61 Subtract the molar amount below The molar amount in the reference container 61 after equilibrium Subtract the molar amount in sample container 62 According to the real gas state equilibrium equation, the adsorption amount of methane is Following this step, the pressure can be increased to obtain the adsorption amount of methane at different pressures.

[0080] S10. According to the above experimental steps, the methane adsorption amount under different pressures can be obtained. Similarly, the constant temperature box can be opened to obtain the methane adsorption amount under different temperatures.

[0081] S11. When investigating the competitive adsorption phenomenon between carbon dioxide and methane under the same pressure conditions, firstly, the two containers need to be evacuated to ensure that there is no residual gas inside. Subsequently, methane gas of a preset first pressure value is filled into the reference container 61. Record the equilibrium pressure value at this time. It is worth noting that at this stage, the volumes of the reference container 61 and the sample container 62 are equal. Transfer all the gas in the reference container 61 to the sample container 62. After the gas is completely transferred, quickly close the switch connecting the two containers. After the pressure is balanced, record the pressure value of the sample container 62 at this time.

[0082] S12. Turn on the vacuum pump 51 to make the reference container 61 into a vacuum state. When the carbon dioxide pressure in the reference container 61 reaches the equilibrium pressure value, connect the reference container 61 and the sample container 62. The reference container 61 is pumped in at a constant speed, and the sample container 62 is pumped out at a constant speed. To ensure better competitive adsorption, under the same pressure conditions, inject carbon dioxide with a volume thirty times the existing methane volume in the sample container 62 into the sample container 62, and turn on the stirring switch at the same time. Turn on the first stirrer 101 and the second stirrer 102 to mix them fully. After the pressure stabilizes, record the pressure and measure the gas components with a gas chromatograph 131.

[0083] S13. Based on the relationship between pressure and volume in the above sample, the adsorption amount of the final sample can be obtained. Finally, the competitive adsorption of carbon dioxide and methane by the sample under the same pressure can be obtained.

[0084] S14. When testing the adsorption effect of a mixture of carbon dioxide and methane in different proportions on shale, adjust the temperature of the thermostat 121 to a specific temperature, inject a certain ratio of carbon dioxide gas and methane gas into the reference container 61, and after the pressure is balanced, record the pressure and measure it with a chromatograph. Turn on switch twelve 12 and switch seven 07, and after the pressure is balanced, record the pressure and measure it with a gas chromatograph 131 to obtain the adsorption amount of each carbon dioxide and methane.

[0085] Embodiment 2:

[0086] The present application embodiment provides a method for measuring adsorption amount, based on the gas adsorption displacement competition relationship measurement device as described in Example 1, such as Figure 2 As shown, the determination method includes the following steps S100 to S300.

[0087] S100: Determination of the adsorption of methane at different pressures.

[0088] S200: Determination of the competitive adsorption of methane and carbon dioxide at the same pressure.

[0089] S300: Determination of competitive adsorption of methane and carbon dioxide injected in different ratios at the same pressure.

[0090] It should be noted that the above steps S100 to S300 are three independent steps, which do not necessarily have any correlation with each other, and each step can be implemented separately.

[0091] In some embodiments, the step of determining the adsorption of methane at different pressures comprises:

[0092] S101. After extracting, cleaning and drying the cores retrieved on site, the cores are broken with a rubber hammer, sieved with a vibrating screen, and 800-mesh shale particles are selected.

[0093] S102. Use the wax sealing method to measure the sample volume. Specifically, let the mass of the sample in the air be m 1. Place the sample in melted paraffin to mix the sample with the paraffin. The mass of the sample mixed with the paraffin in the air is m 2. The mass of the sample mixed with paraffin in water is m 3. Get the volume of the sample .

[0094] The volume of the sample The calculation formula is:

[0095] ,

[0096] In the formula, Indicates the density of water; Indicates the density of paraffin wax.

[0097] S103. Place the sample in the sample container 62. After installing the equipment, first check the air tightness of the system to prevent gas leakage from causing errors in the experiment.

[0098] S104, firstly, the reference container 61 and the sample container 62 are subjected to vacuum treatment, and the two containers are heated to the experimental temperature by the constant temperature box 121, and helium is introduced into the reference container 61 and the sample container 62 to measure the volume of the free space. In this way, the volume of the reference container 61 and the sample container 62 can be determined more accurately.

[0099] Exemplarily, the reference container 61 and the sample container 62 are preheated to 100 degrees Celsius in a thermostat, and the vacuum pump 51 is turned on for vacuum treatment. The vacuum treatment time can be 100 minutes. After the vacuuming is completed, the temperature of the two containers is directly adjusted. The test temperature can be adjusted according to demand. When the temperature of the sample container 62 and the reference container 61 drops to the preset test value and remains constant, the helium gas can be started to calibrate the free space volume. After the calibration process is completed, the system will automatically provide the volume data of the reference container 61 and the remaining volume information of the sample container 62.

[0100] S105, turn on switch 909, switch 1212, switch 707 and vacuum pump 51, evacuate reference container 61 and sample container 62, after vacuum pump 51 forms negative pressure and stabilizes, turn off switch 909, switch 1212, switch 707 and vacuum pump 51, and record the gas volume of reference container 61 and the gas volume of the sample container 62 ; Open switch 202 and switch 12, wait for methane gas to enter the reference container 61, open switch 505, use the first constant pressure pump 21 to pressurize or reduce the pressure and observe the first pressure gauge 41 reaches the specified pressure and the pressure is stable, record the first pressure , close all switches, and open switch 707 and switch 1212, the methane in the reference container 61 enters the sample container 62, and after the system is balanced, record the second pressure , then the initial adsorption amount of methane is the total number of moles injected Subtract the number of moles after equilibrium .

[0101] Exemplarily, the vacuum pump 51 is turned on to evacuate the reference container 61 and the sample container 62, and the evacuation time is set to one hundred minutes. If the vacuum pump 51 forms a negative pressure and stabilizes, it proves that the reference container 61 and the sample container 62 have been evacuated.

[0102] Initial adsorption of methane The calculation process is as follows:

[0103] According to the real gas state equation:

[0104] ,

[0105] In the formula, Indicates the pressure of the gas, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, represents the volume of the sample, Indicates the number of moles of gas.

[0106] Get the equation for the number of moles:

[0107] ,

[0108] The total number of moles injected is:

[0109] ,

[0110] The molar mass after equilibrium is:

[0111] ,

[0112] Then the initial adsorption amount of methane is for:

[0113] ,

[0114] S106, when changing a pressure, increase the pressure to observe the adsorption amount of the sample, open the switch 13 at the first change, use the second constant pressure pump 22 to pressurize the sample container 62, reach the first pressurization pressure, and keep the pressure constant. When the pressure is stable and the system is balanced, record the change in the reference sample volume , and close switch 13, observe the first pressure gauge, and record the third pressure The first pressurized adsorption amount of methane is equal to the first total injection amount minus the molar amount after equilibrium.

[0115] Specifically, the first pressurized adsorption amount of methane is:

[0116] ,

[0117] in, n 3 is the molar amount after the first equilibrium.

[0118] According to the real gas state equation, the calculation formula for the first pressurized adsorption amount of methane is:

[0119] ,

[0120] It can be understood that the second pressurization pressure is kept constant, and when the pressure stabilizes and the system is balanced, the change in the reference sample volume is recorded. , and close the switch 13, observe the first pressure gauge 41, and record the data , the second pressurized adsorption amount of methane is The second pressurized adsorption amount is equal to the total injection amount minus the molar amount after equilibrium.

[0121] Similarly, the second pressurized adsorption capacity of methane is:

[0122] ,

[0123] in, n 4 is the molar amount after the first equilibrium.

[0124] According to the real gas state equation, the calculation formula for the second pressurized adsorption of methane is:

[0125] ,

[0126] S107, No. t When the pressure is increased for the first time, the switch 13 is turned on, and the sample container 62 is pressurized by the second constant pressure pump 22 to reach the first pressure. t Increase the pressure for the first time and keep the pressure constant. When the pressure is stable and the system is balanced, record the t Change in volume of secondary reference container 61 , and close the switch 13, observe the first pressure gauge 41, and record the pressure data , methane t The pressure adsorption amount is equal to the total injection amount for the tth time minus the molar amount after equilibrium.

[0127] Specifically, the methane t The pressure adsorption capacity is:

[0128] ,

[0129] in, n t For the t The molar amount after the second equilibrium.

[0130] According to the real gas state equation, the t The calculation formula of the secondary pressure adsorption capacity is:

[0131] ,

[0132] According to the above steps S101 to S107, the adsorption amount of methane by the sample can be measured at the same temperature and different pressures.

[0133] In some embodiments, the step of determining the competitive adsorption of methane and carbon dioxide at the same pressure comprises:

[0134] S201, competitive adsorption of methane and carbon dioxide at the same pressure, open switch 2 02, switch 12, switch 5 05, use the first constant pressure pump 21 to pressurize to the specified pressure, and observe the first pressure gauge 41, record the pressure as the first pressure value , then the empty volumes of the reference container 61 and the sample container 62 are the same, and the volumes are recorded as , and close switch 2 02, open switch 7 07, switch 13 13, and turn on the first constant pressure pump 21, press the first piston 81 of the reference container 61 to the top, so that the gas in the reference container 61 will be completely pumped into the sample container 62, and close all switches, and observe the second pressure gauge 42, recording the pressure as the second pressure value At this time, the first adsorption amount is equal to the total first injection volume Subtract the first molar amount released after adsorption .

[0135] That is, the first adsorption amount is:

[0136] ,

[0137] The first adsorption amount is obtained according to the real gas state equation:

[0138] ,

[0139] S202, turn on switch twelve 12 and switch one 01, and introduce helium into the reference container 61, so that there will be pressure above the first piston 81, turn on switch thirteen 13, and make the first piston 81 in the middle of the reference container 61 move to the bottom, close all switches, and turn on switch twelve 12 and switch eight 08 and run the vacuum pump 51 to make the reference container 61 reach a vacuum state, that is, the first pressure gauge 41 displays a negative pressure.

[0140] S203, close switch twelve 12, switch eight 08, then open switch three 03, switch six 06, switch twelve 12, start the first constant pressure pump 21 to stabilize the pressure of the reference container 61 at . Close all switches. In order to maintain the same pressure and fully saturate the sample with carbon dioxide, open switch twelve 12, switch seven 07, switch thirteen 13, switch eleven 11, start the first constant pressure pump 21 and the second constant pressure pump 22, the first constant pressure pump 21 pumps in, the second constant pressure pump 22 pumps out, and keep the speed of the two pressure pumps at the same speed, and inject 30 times of In this case, the amount of methane can be ignored, and all switches are closed. After the system is stable, observe the second pressure gauge 42 and record the pressure as The amount of carbon dioxide adsorbed at this time is is equal to the total amount injected Subtract the amount after balance .

[0141] The amount of carbon dioxide adsorbed:

[0142] ,

[0143] The adsorption amount is obtained according to the real gas state equation:

[0144] ,

[0145] In some embodiments, taking two gases in the same ratio as an example, the steps of measuring the competitive adsorption of methane and carbon dioxide injected in different ratios at the same pressure include:

[0146] S301. Open switch two 02, switch three 03, and switch fifteen 15 respectively, input carbon dioxide and methane into the fourth container 74 in equal proportions, let it stand for four hours to allow the two gases to be fully mixed, and open switch ten 10, and use gas chromatograph 131 for measurement to ensure that the two gases are fully mixed in equal proportions.

[0147] S302, firstly, the sample container 62 and the reference container 61 are subjected to vacuum treatment, and the switch 15, the switch 12, and the switch 14 are turned on, and the first constant pressure pump 21 is started to inject the mixed gas into the reference container 61, and the pressure reaches the specified pressure as the pressure value 1. , and open switch twelve 12, switch ten 10, and calibrate with gas chromatograph 131, and measure the deviation factor of the mixed gas at this pressure as follows: , and record the volume of reference container 61 as After the system is stable, all switches are closed and switch 12 and switch 7 are opened, so that the mixed gas is transferred from the reference container 61 to the sample container 62, and the first stirrer 101 and the second stirrer 102 are opened. After the system is stable, the volume of the sample container 62 is Observe the first pressure gauge 41 and record the pressure as pressure value 2 , turn on switch + 10, calibrate with gas chromatograph 131, and measure the current gas deviation factor as , which is the second total adsorption amount Equal to the number of moles injected Subtract the number of moles after equilibrium .

[0148] Total adsorption capacity:

[0149] ,

[0150] The adsorption amount is obtained according to the real gas state equation:

[0151] ,

[0152] S303, turn on switch + 10, and use gas chromatograph 131 to calibrate the gas, so as to obtain the molar ratio of carbon dioxide to methane in the free mixed gas, and the molar ratio of the adsorption amount.

[0153] Since the amounts of the two gases input are equal, the molar ratio of carbon dioxide to methane in the free state is the reciprocal of the molar ratio of carbon dioxide to methane in the adsorbed amount.

[0154] The above implementation modes are only used to illustrate the present application, and are not intended to limit the present application. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions also belong to the scope of the present application, and the scope of patent protection of the present application shall be limited by the claims.

Claims

1. A gas adsorption displacement competition relationship measurement device, characterized in that: Including gas injection system, isothermal adsorption system, pressure control system, gas detection system, vacuum system and information acquisition system; The isothermal adsorption system comprises a constant temperature box, a first PVT cylinder, a second PVT cylinder, a reference container, a sample container, a first pressure gauge and a second pressure gauge, wherein the first PVT cylinder and the second PVT cylinder are arranged in the constant temperature box, and the reference container and the sample container are arranged in the first PVT cylinder and the second PVT cylinder respectively; the first pressure gauge and the second pressure gauge are used to measure the pressure values ​​of the reference container and the sample container respectively; The gas injection system injects gas into the reference container and / or the sample container under the control of the pressure control system; The gas detection system is connected to the reference container and / or the sample container and is used to detect gas components; The information acquisition system is connected to the thermostat, the first pressure gauge, the second pressure gauge, the pressure control system and the gas detection system for obtaining information on the pressure and temperature of the sample container and the reference container, as well as the change in volume of the internal sample and the gas component information detected by the gas detection system; Also included is a switch assembly, the switch assembly including switch 1, switch 2, switch 3, switch 4, switch 5, switch 6, switch 7, switch 8, switch 9, switch 10, switch 11, switch 12, switch 13, switch 14 and switch 15; The gas injection system comprises a first container, a second container, a third container and a fourth container; The pressure control system comprises a first constant pressure pump and a second constant pressure pump; The first container, the second container and the third container are used to store helium, methane and carbon dioxide respectively, and the fourth container is used as a spare container; the first ends of the first container, the second container, the third container and the fourth container are respectively connected to the first pipeline through pipelines, and the switches 1, 2, 3 and 15 are arranged on the pipelines connected to the first pipeline at the first ends of the first container, the second container, the third container and the fourth container, and the first pipeline is connected to the reference container and the sample container through the second pipeline and the third pipeline respectively; the switch 12 and the switch 7 are arranged on the second pipeline and the third pipeline; the second ends of the first container, the second container, the third container and the fourth container are respectively connected to one end of the fourth pipeline through pipelines, and the other end of the fourth pipeline is connected to the reference container, the second ends of the first container, the second container, the third container and the fourth container are respectively arranged on the pipelines connected to the fourth pipeline, and the first constant pressure pump and the switch 13 are arranged on the fourth pipeline, and the sample container is connected to the second constant pressure pump through a pipeline and the switch 11 is arranged on the pipeline connected to the second constant pressure pump; It also includes a first piston, a second piston, a first observation window and a second observation window; wherein the first piston and the second piston are respectively arranged in the reference container and the sample container, the first observation window and the second observation window are both provided with scales, and the first observation window and the second observation window are respectively arranged on the side walls of the reference container and the sample container.

2. The gas adsorption displacement competition relationship measuring device according to claim 1, characterized in that: The vacuum system comprises a vacuum pump, the vacuum pump is connected to the reference container and the sample container through a pipeline, and the switch eight and the switch nine are respectively arranged on the pipelines connected to the reference container and the sample container; The gas detection system comprises a gas chromatograph, which is connected to the reference container and the sample container via a pipeline, and the switch 10 is arranged on the pipeline connecting the gas chromatograph, the reference container and the sample container.

3. A method for measuring adsorption amount, based on the gas adsorption displacement competition relationship measurement device according to any one of claims 1 to 2, characterized in that: The measuring method comprises: preparing a sample, determining the sample volume, and placing the sample in the sample container; Passing helium into the reference container and the sample container to measure the volume of the free space; The reference container and the sample container are evacuated, and based on the set pressure parameters and temperature parameters, methane at a preset pressure is introduced into the reference container. After stabilization, the first pressure is recorded. , open switch 12 and switch 7, connect the reference container and the sample container, and after stabilization, record the second pressure , calculating the initial adsorption amount of methane at the current pressure and the current temperature according to the first pressure and the second pressure, wherein the temperature parameter is the temperature of the reference container and the sample container; adjusting the set pressure parameter, pressurizing the reference container based on the adjusted set pressure parameter, obtaining a third pressure after stabilization, and calculating the first pressurized adsorption amount of methane according to the third pressure and the initial adsorption amount, repeatedly adjusting the set pressure parameter and temperature parameter multiple times, and obtaining the t-th pressurized adsorption amount of methane, including: Open switch nine, switch twelve, switch seven and the vacuum pump, evacuate the reference container and the sample container, and after the vacuum pump forms a negative pressure and stabilizes, close switch nine, switch twelve, switch seven and the vacuum pump, and record the gas volume in the reference container. and the gas volume of the sample container ; Open switch 2 and switch 12, wait for methane gas to enter the reference container, open switch 5, use the first constant pressure pump to increase or decrease the pressure, and observe that the first pressure gauge reaches the specified pressure and the pressure is stable, then record the first pressure. , turn off all switches, and turn on switch 7 and switch 12. The methane in the reference container enters the sample container. After the system is balanced, record the second pressure. , then the initial adsorption amount of methane is the total number of moles injected Subtract the number of moles after equilibrium ; When changing a pressure, increase the pressure to observe the adsorption amount of the sample. At the first change, open switch 13, use the first constant pressure pump to pressurize the reference container to reach the first pressurization pressure, and keep the pressure constant. When the pressure is stable and the system is balanced, record the change in the volume of the reference container for the first time. , and close switch 13, observe the first pressure gauge, and record the third pressure , the first pressurized adsorption amount of methane is equal to the first total injection amount minus the molar amount after equilibrium; No. When the pressure is increased for the first time, switch 13 is turned on, and the reference container is pressurized by the first constant pressure pump to reach the first t Increase the pressure for the first time and keep the pressure constant. When the pressure is stable and the system is balanced, record the t Change in the volume of the secondary reference container , and turn off switch 13, observe the first pressure gauge, and record the pressure data , methane The pressure adsorption capacity is equal to the The total injected amount minus the molar amount after equilibrium; The methane The calculation formula of the secondary pressure adsorption capacity is as follows: ， In the formula, Indicates Secondary pressure adsorption capacity, P t Indicates t Secondary pressure, Indicates i The change in the volume of the reference container, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, Indicates the volume of the sample.

4. The method for measuring adsorption amount according to claim 3, characterized in that: The measuring method further comprises a step of determining the competitive adsorption of methane and carbon dioxide at the same pressure, wherein the step of determining the competitive adsorption of methane and carbon dioxide at the same pressure comprises: Open switch 2, switch 12 and switch 5, use the first constant pressure pump to pressurize to the specified pressure, and observe the first pressure gauge to obtain the first pressure value. , at this time, the empty volume of the reference container and the sample container is the same, recorded as , close switch 2, open switch 7 and switch 13, and turn on the first constant pressure pump, press the piston of the reference container to the top, so that all the gas in the reference container is input into the sample container, close all switches, and observe the first pressure gauge to obtain the second pressure value of , then the first adsorption amount Equal to the first total injection volume Subtract the first free molar amount ; Turn on switch 12 and switch 1, introduce helium into the reference container, turn on switch 13, move the piston in the middle of the reference container to the bottom, turn off all switches, turn on switch 12 and switch 8, and run the vacuum pump to make the reference container reach a vacuum state; Close switch 12 and switch 8, open switch 3, switch 6 and switch 12, start the first pressure pump to stabilize the pressure of the reference container at the first pressure value , turn off all switches; to maintain the same pressure and fully saturate the sample with carbon dioxide, turn on switch twelve, switch seven, switch thirteen and switch eleven, start the first constant pressure pump and the second constant pressure pump, the first constant pressure pump pumps in, the second constant pressure pump withdraws, and keep the speed of the first constant pressure pump and the second constant pressure pump at the same speed, and input 30 times of of carbon dioxide, turn off all switches, and after the system stabilizes, observe the second pressure gauge to obtain the third pressure value , then the adsorption amount of carbon dioxide is Equal to the total amount injected Subtract the molar mass after equilibrium ; The first adsorption amount is calculated by the following formula : ， In the formula, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, Indicates the volume of the sample; The adsorption of carbon dioxide is calculated by the following formula: : 。 5. The method for measuring adsorption amount according to claim 3, characterized in that: The measuring method further comprises a step of determining the competitive adsorption of methane and carbon dioxide injected at different ratios at the same pressure, wherein the step of determining the competitive adsorption of methane and carbon dioxide injected at different ratios at the same pressure comprises: Open switch 2, switch 3 and switch 15, input carbon dioxide and methane in equal proportions into the fourth container, let it stand to allow the two gases to be fully mixed, and open switch 10 to measure with a gas chromatograph to ensure that the two gases are fully mixed in equal proportions; First, vacuum the sample container and the reference container, turn on switch 15, switch 12, and switch 14, start the first constant pressure pump, and inject the mixed gas into the reference container. When the pressure reaches the pressure value 1, P 21 When the pressure is below 20°, turn on switch 12 and switch 10, and use the gas chromatograph to calibrate and measure the deviation factor of the mixed gas below the pressure value. , and record the volume of the reference container at this time V 21 After the system is stable, close all switches and open switch 12 and switch 7 to transfer the mixed gas from the reference container to the sample container and stir the mixed gas. After the system is stable, the volume of the sample container is V 22 , observe the second pressure gauge and get the pressure value , turn on switch 10, calibrate with gas chromatograph, and measure the current gas deviation factor , the second total adsorption amount is calculated by the following formula: ， In the formula, represents the second total adsorption amount, represents the deviation factor of the gas, is the universal gas constant, represents the absolute temperature of the experiment, Indicates the volume of the sample.

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