CN110782729A - A simulation training system and teaching and practice method for coal shale adsorption/desorption evaluation experiment - Google Patents

Abstract

The invention relates to a simulation training system and a teaching and practice method for a coal shale adsorption/desorption evaluation experiment, belonging to the field of simulation teaching and comprising a human-computer interaction module, an experimental design module, a comprehensive evaluation module, a calculation module and an output module. According to the real scene of the coal shale adsorption/desorption characteristic evaluation experiment, and on the basis of the existing theoretical system and calculation method, the invention develops the virtual simulation training system of the present invention, that is, the simulation teaching and practice method, and realizes the analysis of coal shale. The virtual reality simulation of static adsorption/desorption characteristics and dynamic desorption-flow characteristics experiments can improve the quality of experimental teaching, reduce experimental teaching costs and potential safety hazards.

Description

A simulation training system and teaching and practice of coal shale adsorption/desorption evaluation experiment method

technical field

The invention relates to a coal shale adsorption/desorption evaluation experiment simulation training system and a teaching and practice method, belonging to the technical field of unconventional oil and gas reservoir physical property evaluation experiment simulation teaching.

Background technique

The exploration and development of unconventional oil and gas resources is of great significance to improving my country's energy structure, alleviating energy shortage, and improving the self-sufficiency of oil and gas resources. The adsorption/desorption characteristics of coal shale are the key parameters for evaluation in the exploration and development of unconventional oil and gas resources, which have a great impact on the evaluation of geological reserves and the design of efficient development plans.

Coal shale adsorption/desorption evaluation experiments include the determination of static adsorption/desorption characteristics and dynamic desorption-flow characteristics. Because the experimental equipment is expensive and the experimental gas is flammable and explosive, considering the cost and safety, in the normal teaching process, the abstract conceptual model is usually used to teach, the method is single, the students have little hands-on ability, and it is difficult to deeply understand the adsorption of coal shale. /Desorption characteristics and change characteristics.

Facing the current situation of education and teaching reform in colleges and universities and the rapid development of information technology, the use of virtual simulation methods to evaluate the adsorption/desorption characteristics of coal shale will have a very wide range of applications in teaching.

SUMMARY OF THE INVENTION

In view of the deficiencies of the existing technology, in order to meet the development needs of education and teaching, establish a new mode of knowledge acquisition and imparting under the condition of informatization, and cultivate information and practical talents in the field of unconventional oil and gas resources, the invention aims to be based on coal shale adsorption/desorption. Based on the existing theoretical system and calculation method, a virtual simulation training system was developed to realize the virtual reality simulation of the static adsorption/desorption characteristics and dynamic desorption-flow characteristics of coal shale in the real scene of the characteristic evaluation experiment. Improve the quality of experimental teaching, reduce the cost of experimental teaching and potential safety hazards.

Terminology Explanation:

Static adsorption/desorption characteristics: refers to the amount of gas adsorbed by a unit mass of coal shale sample when it reaches adsorption equilibrium under certain temperature and pressure conditions;

Dynamic desorption-flow characteristics: It refers to the change process of the amount of adsorbed gas per unit mass of coal shale samples from one adsorption equilibrium state to another adsorption equilibrium state with changes in temperature and pressure conditions.

The present invention adopts following technical scheme:

On the one hand, the present invention provides a simulation training system for coal shale adsorption/desorption evaluation experiments, including:

Human-computer interaction module, including display unit and input unit;

The experimental design module is connected to the human-computer interaction module. The virtual material library is preset in the experimental design module, which is used to freely design experimental schemes and realize two types of experiments with different evaluation methods, including coal shale static adsorption/desorption characteristics experiments and Dynamic desorption-flow characteristic evaluation experiment, and select and input experimental parameters through the human-computer interaction module;

The comprehensive evaluation module is connected with the experimental design module, and is used for different evaluation methods selected by the user in the experimental design module, as well as the self-built experimental equipment and operation procedures;

The calculation module, connected with the comprehensive evaluation module, is used for running and calculating the simulation results;

The output module is connected with the comprehensive evaluation and calculation module, and is used for outputting the calculation result and displaying it on the display unit.

Preferably, the system further includes an online evaluation module, which is used to generate a human-computer interaction experiment operation code by writing a program, compare it with the standardized operation process code, evaluate the rationality of the user operation, and give guidance and suggestions according to the difference between the two, so as to achieve Optimize teaching purpose.

Preferably, the human-computer interaction module includes an interconnected computer and a data acquisition and processing system, and the data acquisition system is respectively connected with the sensing element for sensing the pressure, temperature, etc. of the system, and the sensing element here can be connected with a pressure gauge and a pressure sensor. , temperature sensor connection, etc.

Preferably, the virtual material library in the experimental design module includes but is not limited to the following 3D animation elements:

Coal shale sample library, gas source library, pressurization device, series standard room, series sample room, temperature control system, pressure gauge, pressure sensor, manual metering pump, vacuum pump and data acquisition and processing system, etc.

The required gas source can be selected from the gas source library, and the appropriate standard chamber and sample chamber can be selected from a series of standard chambers and a series of sample chambers;

The experimental design module can also be used to add or delete virtual materials, and users can freely select the required accessories from the virtual material library. Users can configure, connect and use the 3D animation components in the virtual material to conduct experiments by themselves, and learn two different experimental procedures and operations of static adsorption/desorption characteristics and dynamic desorption-flow characteristics evaluation of coal shale through simulation to improve teaching and practice. Level.

Preferably, the temperature control system includes a constant temperature box, and a constant temperature water bath or oil bath or heating belt.

On the other hand, the present invention also provides a teaching and practice method using the above-mentioned coal shale adsorption/desorption evaluation experiment simulation training system, comprising the following steps:

S1: Establish a virtual material library, and use existing software to realize 3D modeling of experimental materials and equipment, including but not limited to the following 3D animation components:

Coal shale sample library, gas source library, pressurization device, series standard room, series sample room, temperature control system, pressure gauge, pressure sensor, manual metering pump and data acquisition and processing system, etc.

S2: Establish an experimental design module. The virtual material library of S1 is preset in the experimental design module. Using computer programming, two types of experiments with different evaluation methods can be realized by freely designing experimental schemes, including coal shale static adsorption/desorption characteristics experiments and dynamic experiments. Desorption-flow characteristic evaluation experiment, and select and input experimental parameters through the human-computer interaction module;

S3: Establish a comprehensive evaluation and calculation module for different evaluation methods selected by the user in the experimental design module, as well as self-built experimental equipment and operation procedures;

S4: Run the virtual simulation experimental model, conduct experimental operations based on the human-computer interaction interface, and call data through statistics and intelligent algorithms to obtain virtual experimental results;

S5: The simulation result is output through the output module and displayed on the display unit.

Preferably, it also includes S6: establishing an online evaluation system, evaluating user operations and giving guidance tasks by comparing standardized operation procedures, so as to achieve the purpose of optimizing teaching.

Preferably, each 3D animation element in step S1 is provided with a connection node, the user can assemble the device through the connection node of each 3D animation element, and the parameters of each 3D animation element are assigned values through a parameter configuration module.

Preferably, the parameter configuration module includes three parameter configuration sub-modules that affect the adsorption/desorption characteristics of coal shale, specifically: a temperature control system parameter configuration sub-module, a gas injection parameter configuration sub-module and a sample physical property parameter configuration sub-module, wherein, The temperature control system parameter configuration sub-module is used to realize temperature adjustment and control, the gas injection parameter configuration sub-module is used to realize the pressure adjustment and control, and the sample physical parameter configuration sub-module is used to configure the sample parameters: clay content, TOC, maturity and The moisture content is adjusted and controlled.

The invention is based on the real scene of the coal shale adsorption/desorption characteristic evaluation experiment, and on the basis of the existing theoretical system and calculation method, assigns values to each 3D animation element through the parameter configuration module, so that the 3D animation element has the characteristics of the real element. For specific characteristics, please refer to the prior art.

Preferably, in step S2, the experimental process of designing the static adsorption/desorption characteristics of coal shale is as follows:

(1) Select the following 3D animation components: air source, booster system (including air compressor and booster pump), standard chamber, sample chamber, temperature control system, pressure gauge, data acquisition and processing system, vacuum pump and valve valve two;

(2) Assemble the experimental device, select the required test sample type, quantity, sample chamber and standard chamber, check the air tightness of the device, use the vacuum device to vacuum the device, use helium to measure the void volume of the sample, and then again The device is evacuated; the process of using helium to measure the void volume of the sample is preferably: first, a certain amount of helium can be introduced into the standard chamber, and then the standard chamber and the sample chamber can be connected, and the void volume of the sample can be determined by the pressure and the container volume, To provide reference for future measurements, helium is a non-adsorbed gas, which can reduce the measurement error. In the actual simulation teaching, a hot key button can be set, and the user can click the hot key button to consider that the void volume of the sample has been measured.

(3) Close valve 2, disconnect the standard chamber and sample chamber, open valve 1, inject test gas into the standard chamber through the gas source, and record the pressure value of the standard chamber after the pressure is stable;

(4) Close valve 1 and open valve 2 to connect the standard chamber and the sample chamber, so that the gas is fully adsorbed in the coal shale sample, and after the pressure is stabilized, the pressure value of the sample chamber is recorded;

(5) Repeat steps (3) and (4) until the design test pressure is reached (the maximum design test pressure is 40MPa), and the adsorption experiment ends.

Preferably, the experimental device for the static adsorption/desorption characteristics of coal shale includes a gas source, a booster system (including an air compressor and a booster pump), a standard chamber, a sample chamber, a temperature control system, a pressure gauge, and a data acquisition and processing system , vacuum pump and valve one and valve two;

The air source is connected to the standard chamber through pipeline 1, the standard chamber is connected to the sample chamber through pipeline 2, the air compressor and booster pump are connected to pipeline 1, and valve 1 is set on pipeline 1 to control the air source to the sample chamber. For the on-off of the gas in the standard chamber, a valve 2 and a pressure sensor 1 are set on the pipeline 2. The valve 2 is used to control the on-off of the gas from the standard chamber to the sample chamber, and the pressure sensor 1 is used to monitor the pressure of the sample chamber;

Both the standard chamber and the series of sample chambers are set in the temperature control system to set the temperature and keep the samples at the real formation temperature conditions; a pressure gauge is set on the first line, and a pressure sensor 1, a pressure gauge and a pressure sensor are set on the second line The first is connected to the data acquisition and processing system. The vacuum pumping device of the present invention is a vacuum pump, and the vacuum pump is connected to the pipeline for vacuuming the entire device.

Preferably, the temperature control system includes a water bath/oil bath device or a heating belt device, and the sample chamber, the standard chamber, the water bath/oil bath device and the heating belt device are all placed in an incubator for setting and maintaining the real formation of the sample test piece temperature conditions.

Preferably, the number of standard chambers may be multiple, and multiple standard chambers form a series of standard chambers. Correspondingly, the number of sample chambers may also be multiple, and the number is the same as the number of standard chambers, and multiple sample chambers form a series of sample chambers, A standard room and a sample room form an experimental group, each experimental group is connected in parallel to the pipeline 1 through pipelines, and the sample rooms in each experimental group are of different sizes, allowing users to flexibly select suitable samples according to the type and quality of the samples In the experiment, it is preferable to conduct a separate experiment for each experimental group.

After the adsorption experiment is carried out using the devices of steps (1) to (5), the desorption experiment is carried out, and the process is as follows:

(6) Close valve 2, disconnect the standard chamber and the sample chamber, open the vent valve, so that a certain amount of gas is discharged from the standard chamber (preferably discharged into an exhaust bottle to prevent environmental pollution), close the vent valve, and wait for the standard After the chamber pressure is stable, record the pressure value of the standard chamber; preferably, the vent valve and valve 1 can share a valve with one inlet and two outlets, one outlet realizes the function of valve 1, and the other outlet realizes the purpose of venting, which does not affect the the implementation of the present invention;

(7) Close valve one, open valve two, and connect the standard chamber and the sample chamber to desorb the saturated adsorbed coal shale sample. After the desorption equilibrium pressure is stabilized, read the pressure value of the sample chamber;

(8) Repeat steps (6) and (7) until the designed minimum pressure is reached, and the desorption experiment ends.

Preferably, based on the experimental process of the static adsorption/desorption characteristics of coal shale, step S3 is further as follows:

The number of free gas molecules can be calculated from the pressure measured in the experiment according to the gas state equation. Combined with the free gas state equations in the standard chamber and the sample chamber at different stages, the total number of experimental gas adsorption molecules corresponding to the nth adsorption equilibrium pressure point can be obtained. for:

及

为压力及

对应的气体压缩系数，无因次；R为通用气体常数，8.314J·mol^-1·K^-1；T为实验温度，K；V_b为标准室体积，cm³；V_y为样品室的空隙体积，cm³。In the formula, Respectively represent the pressure at the n-1th and nth times when the standard chamber and the sample chamber system are connected, MPa; is the pressure after the nth standard chamber inflation, MPa;

and

for pressure and

Corresponding gas compressibility, dimensionless; R is the universal gas constant, 8.314J·mol ^-1 ·K ^-1 ; T is the experimental temperature, K; V _b is the standard chamber volume, cm ³ ; V _y is the sample chamber Void volume, cm ³ .

The adsorbed gas volume _Na per unit mass of coal shale sample is:

In the formula, T _sc is the temperature under standard conditions, 279.15K; R is the universal gas constant, 8.314J·mol ^-1 ·K ^-1 ; P _sc is the standard atmospheric pressure, 0.101MPa; M is the sample mass, in g.

Preferably, in step S2, the experimental process of designing the dynamic adsorption/desorption characteristics of coal shale is as follows:

(a) Select 3D animation components, including: air source, booster system, multiple manual metering pumps, series of standard chambers, series of sample chambers, temperature control system, data acquisition and processing system, vacuum pump, etc.;

(b) Set up an experimental device for dynamic adsorption/desorption evaluation of coal shale, select the required experimental sample type, quantity, sample chamber and standard chamber, check the air tightness of the device, use a vacuum device to vacuum the device, and use helium to measure The void volume of the sample, and then the device is evacuated again;

(c) Set the experimental temperature, fill the standard chamber with the experimental gas through the gas source, fill the gas into the sample chamber after the gas rises to the experimental temperature and the pressure remains stable, keep the pressure in the sample chamber at the actual formation pressure, and make the gas Fully diffuse and adsorb in the sample chamber. After the pressure of the sample chamber is stable, close the valve between the sample chamber and the standard chamber, and calculate the amount of gas charged into the sample chamber; open the vent valve of the standard chamber and slowly release the gas in the standard chamber. Make its pressure reach the predetermined diffusion boundary pressure (ie the actual bottom hole pressure), and close the vent valve after the pressure is stable;

(d) Open the valve between the sample chamber and the standard chamber, the gas diffuses and desorbs from the sample chamber into the standard chamber, adjusts the manual metering pump to keep the gas pressure in the standard chamber unchanged, records the volume and time of the pump back, and obtains the The relationship curve of pump volume V and time t;

Preferably, the coal shale dynamic adsorption/desorption evaluation experimental device includes a gas source, a booster system (including an air compressor and a booster pump), a manual metering pump, a standard chamber, a sample chamber, a temperature control system, a pressure gauge, and a data acquisition. and processing systems, vacuum pumps, etc.;

The air source is connected to the inlet of the standard chamber through pipeline 3, the air compressor and booster pump are connected to pipeline 3, the pipeline 3 is provided with valve 3, the outlet of the standard chamber and the inlet of the sample chamber are connected through pipeline 4, and the pipeline Valve No. 4 and pressure sensor No. 2 are arranged on the fourth. The standard chamber is also connected to the manual metering pump interface through pipeline five. Valve five is set on pipeline five. The standard chamber is also connected with a vent valve. Preferably, the vent valve can be connected with valve five. A valve with one inlet and two outlets is shared, one outlet realizes the function of valve 5, and the other outlet realizes the purpose of emptying, which does not affect the implementation of the present invention. The sample chamber and the standard chamber are placed in a constant temperature water bath, constant temperature water bath, manual metering The pump is placed in an incubator to set and maintain the real formation temperature conditions of the sample specimen. Temperature sensors can also be set in the sample chamber and standard chamber. The pressure gauge, pressure sensor 1 and temperature sensor can all be connected to the data acquisition and processing system .

Preferably, based on the experimental process of the dynamic adsorption/desorption characteristics of coal shale, step S3 is further as follows:

The adsorption amount at any time in the dynamic desorption-flow process of coal shale is:

In the formula, P is the diffusion boundary pressure during desorption-flow, in MPa; T _sc is the temperature under standard conditions, 279.15K; V is the cumulative pump volume of the manual metering pump, cm ³ ; P _sc is the standard atmospheric pressure, 0.101MPa; Z is the compression factor of the gas under pressure P and temperature T, dimensionless; T is the experimental temperature, in K; M is the sample mass, in g.

Preferably, step S3 includes two parts, one part is to complete the assembly of the experimental equipment and the experimental operation in the virtual scene with the help of the virtual equipment and the simulation system, and obtain the experimental results; The learning and training of the evaluation experiment of coal shale adsorption/desorption characteristics is realized on the Internet, and this part of the content can be simulated by multiple people at the same time.

Preferably, the experimental gas introduced into the gas source is nitrogen, methane or carbon dioxide, etc., which can simulate the adsorption/desorption characteristics of different gases.

Preferably, the standard chamber includes four types with volumes of 1000cm ³ , 500cm ³ , 200cm ³ and 50cm ³ respectively, and the sample chamber includes five types, respectively 2.5cm core holder, 5cm core holder and powder sample Container, the volume of the powder sample container is 3 specifications, respectively 1000cm ³ , 500cm ³ , 200cm ³ ), the core sample generally adopts the core holder, and the powder sample adopts the powder sample container.

The invention establishes a virtual scene model based on an actual experimental scene; establishes a virtual experimental model for the experimental operation steps; completes the virtual experimental operation based on the human-computer interaction interface and input and output devices; and displays the virtual simulation experiment results based on the experimental data and theoretical calculation methods ;Compare standardized experimental procedures and establish a comprehensive evaluation system for students' experiments.

Where the present invention is not exhaustive, the prior art can be adopted.

The beneficial effects of the present invention are:

1) The present invention discloses a virtual simulation experiment method for evaluating the adsorption/desorption characteristics of coal shale. With the help of virtual simulation technology, the changing laws of various data in the process of coal shale adsorption/desorption experiment are designed, taught and practiced. The content of static adsorption curve and dynamic adsorption process in teaching can be effectively designed and realized virtual scene and dynamic simulation, so as to achieve the purpose of comprehensive cognition, and build a relatively complete information-based practical teaching mode.

2) Aiming at the theoretical and practical content in the experimental teaching, the present invention adopts the teaching mode of combining virtual and real to visualize the whole experimental process. In the virtual environment, students can assemble experimental equipment by themselves, complete the whole experimental process step by step, and obtain The results of the virtual simulation experiment solve the problems existing in the original experimental teaching, such as large potential safety hazards, high experimental cost, weak sense of involvement of students, and low efficiency of cognition and practice.

3) The present invention combines virtual simulation technology to realize real simulation simulation and interaction of coal shale adsorption/desorption characteristic evaluation experiments, and provides students with a real-time learning and practice platform. This new experimental teaching mode is helpful to promote students' autonomous learning, research and exploration And the cultivation of innovation ability, with strong interdisciplinary and forward-looking.

Description of drawings

Fig. 1 is a schematic diagram of an experimental device for static adsorption/desorption characteristics of coal shale according to the present invention;

Fig. 2 is a schematic diagram of an experimental device for dynamic adsorption/desorption characteristics of coal shale according to the present invention;

Fig. 3 is a kind of static adsorption characteristic curve of shale powder of the present invention;

Fig. 4 is a kind of coal shale dynamic desorption-flow characteristic curve of the present invention;

Among them, 1-air source, 2-air compressor, 3-booster pump, 4-pressure gauge, 5-standard room, 6-sample room, 7-temperature control system, 8-data acquisition and processing system, 9- Vacuum pump, 10-pipe one, 11-pipeline two, 12-valve one, 13-valve two, 14-pressure sensor one, 15-manual metering pump, 16-pipeline three, 17-valve three, 18-pipe Road four, 19- valve four, 20- pressure sensor two, 21- pipeline five, 22- valve five, 23- vent valve.

Detailed ways:

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments, but not limited to this, the present invention is not described in detail, according to the conventional technology in the art.

Example 1:

The invention introduces virtual simulation technology into the experimental teaching course of coal shale adsorption/desorption evaluation, and provides a virtual reality scene and an online learning platform for users to determine the purpose of the experiment and master the experimental process. The specific implementation steps are as follows:

Step S1: Establish a virtual experiment material library, and use Maya and 3DMax software to complete the 3D modeling of experimental materials and equipment. The modeling process is an existing relatively mature technology, which will not be repeated here, including but not limited to the following 3D animation components: Coal shale sample library, gas source library, booster device, standard room, sample room, temperature control system, pressure sensor, data acquisition and processing system, vacuum pump, etc.;

Step S2: establish an experimental design module, use Visual C++ to identify and process the 3D animation elements in step S1, and assign logical attributes and numerical parameters to each animation element, and the user can realize independent experimental process design through the logic nodes of different 3D animation elements, By configuring the parameters of each component, the design of different experimental conditions is realized, that is, the user can choose and design the experiment independently;

Step S3: establish a database of experimental data and theoretical calculation methods, according to different evaluation methods selected by the user in the experimental design module, as well as self-built experimental equipment and operation procedures, the database adopts Mysql;

Step S4: running the virtual simulation experimental model, performing experimental operations based on the virtual equipment and the human-computer interaction interface, and calling data through statistics and intelligent algorithms to obtain virtual experimental results;

Step S5: virtual experiment result output;

Step S6: establish an online evaluation system, generate a human-computer interaction experiment operation code by writing a program, compare it with the standardized operation process code, evaluate the rationality of user operation, and give guidance and suggestions according to the difference between the two to achieve the purpose of optimizing teaching.

The operation process of the present invention is explained below by taking the evaluation experiment of the adsorption/desorption characteristics of shale powder to methane as an example:

(1) Select 3D animation components, and build a static adsorption/desorption evaluation experimental device according to Figure 1. The main 3D animation components include: air source 1, booster system (including air compressor 2 and booster pump 3), pressure gauge 4 , standard chamber 5, sample chamber 6, temperature control system 7, data acquisition and processing system 8, vacuum pump 9, gas source 1 is connected to standard chamber 5 through pipeline one 10, and standard chamber 5 is connected to sample chamber 6 through pipeline two 11 Connection, air compressor 2 and booster pump 3 are connected to pipeline one 10, pipeline one 10 is provided with valve one 12, valve one 12 is used to control the on-off of gas from air source 1 to standard chamber 5, pipeline two Valve two 13 and pressure sensor one 14 are set on 11. Valve two 13 is used to control the on-off of gas from standard chamber 5 to sample chamber 6, and pressure sensor one 14 is used to monitor the pressure of sample chamber 6;

Both the standard chamber 5 and the sample chamber 6 are set in the temperature control system 7, which are used to set the temperature and keep the samples at the real formation temperature conditions; the pressure gauge 4 is set on the pipeline one 10, and the pressure sensor one 14 is set on the pipeline two 11. , the pressure gauge 4 and the pressure sensor 14 are connected to the data acquisition and processing system 8, and the vacuum pump 9 is connected to the pipeline 1 for evacuating the entire device.

The temperature control system adopts water bath insulation, the sample room and the standard room are placed in a constant temperature water bath, and the sample room, the standard room and the constant temperature water bath are all placed in the constant temperature box;

(2) Enter the virtual experiment material library, select the sample room (volume 200cm ³ ) and the standard room (the powder sample container is 200cm ³ ), set the shale powder mesh number to 60-80 mesh, mass 140g, clay content 18.28%, TOC 2.81%, and water content of 0.1% and other parameters;

Enter the experimental operation module, set the experimental temperature of the constant temperature water bath and the incubator to 35°C, check the air tightness of the device, use the vacuum pump 9 to evacuate the device, use helium to measure the void volume of the sample, and then evacuate the device; wherein, Checking the air tightness of the device, vacuuming and measuring the void volume with helium gas are the hot key buttons on the experimental platform. During the virtual experiment, the user clicks the hot key button, and the system will record the operation and automatically generate a code for comparing the standardized process code. , to implement the corresponding operation.

(3) Close the valve two 13, disconnect the standard chamber and the sample chamber, open the valve one 12, inject methane into the standard chamber through the gas source, and record the pressure value of the standard chamber after the pressure is stable.

(4) Close valve one 12, open valve two 13, and connect the standard chamber and the sample chamber, so that the gas is fully adsorbed in the shale powder. After the pressure is stabilized, record the pressure value of the sample chamber, that is, the value of the pressure sensor one 14;

(5) Repeat steps (3) and (4) until the design test pressure (10MPa) is reached, and the adsorption experiment ends.

After the adsorption experiment is performed using this device, the desorption experiment can be performed. The desorption experiment process is as follows:

(6) Close the valve 2 13, disconnect the standard chamber and the sample chamber, open the open valve 23, so that a certain amount of gas is discharged from the standard chamber 5 (preferably discharged into an exhaust bottle to prevent air pollution, the exhaust bottle is attached Not shown), close the vent valve 23, and after the pressure of the standard chamber is stable, record the pressure value of the standard chamber, that is, the value of the pressure gauge.

(7) Close valve one 12, open valve two 13, and connect the standard chamber and the sample chamber to desorb the saturated adsorbed shale powder. After the desorption equilibrium pressure is stabilized, read the pressure value of the sample chamber, that is, the pressure value of the pressure sensor one. value.

(8) Repeat steps (6) and (7) until the designed minimum pressure (0.14MPa) is reached, and the desorption experiment ends.

According to the above experimental process, the number of free gas molecules can be calculated from the pressure measured in the experiment according to the gas state equation. Combined with the free gas state equations in the standard chamber and the sample chamber at different stages, the methane adsorption corresponding to the nth adsorption equilibrium pressure point can be obtained. The total number of molecules is:

分别表示第n-1次、第n次连通标准室与样品室系统平衡时的压力，MPa；

为第n次标准室充气后的压力，MPa；

及

为压力

及

对应的气体压缩系数，无因次；R为通用气体常数，8.314J·mol^-1·K^-1；T为实验温度，K；V_b为标准室体积，cm³；V_y为样品室的空隙体积，cm³。In the formula,

Respectively represent the pressure at the n-1th and nth times when the standard chamber and the sample chamber system are connected, MPa;

is the pressure after the nth standard chamber inflation, MPa;

and

for pressure

and

Corresponding gas compressibility, dimensionless; R is the universal gas constant, 8.314J·mol ^-1 ·K ^-1 ; T is the experimental temperature, K; V _b is the standard chamber volume, cm ³ ; V _y is the sample chamber Void volume, cm ³ .

Adsorbed gas volume per unit mass of coal shale sample:

In the formula, T _sc is the temperature under standard conditions, 279.15K; R is the universal gas constant, 8.314J·mol ^-1 ·K ^-1 ; P _sc is the standard atmospheric pressure, 0.101MPa; M is the mass of the shale sample, in g .

The adsorption amount of methane can be obtained through this Example 1. By collecting the adsorption amount of methane under different pressures, the adsorption amount of methane under different pressures can be obtained, as shown in Figure 3. With the help of the curve in Figure 3, the geological reserves of coal shale can be evaluated. Significant.

Example 2:

The experimental process of dynamic desorption-flow characteristics of shale powder is as follows:

(a) Select 3D animation components, and build a dynamic desorption-flow evaluation experimental device according to Figure 2. The main components include: air source 1, booster system (including air compressor 2 and booster pump 3), manual metering pump 15, Standard chamber 5, sample chamber 6, temperature control system 7, data acquisition and processing system 8, vacuum pump 9, various pipelines and valves, etc. Air source 1 is connected to the inlet of standard chamber 5 through pipeline 3 16, air compressor 2 and The booster pump 3 is connected to the pipeline three 16, the pipeline three 16 is provided with the valve three 17, the standard chamber 5 outlet and the sample chamber 6 inlet are connected through the pipeline four 18, the pipeline four 18 is provided with the valve four 19 and the Pressure sensor two 20, standard chamber 5 is also connected to the interface of manual metering pump 15 through pipeline five 21, pipeline five 21 is provided with valve five 22, standard chamber 5 is also connected with vent valve 23, the sample chamber and standard chamber are placed in In the constant temperature water bath, the constant temperature water bath and the manual metering pump are placed in the constant temperature box to set and maintain the real formation temperature conditions of the sample specimen.

(b) Enter the virtual experiment material library, select the shale sample and the sample room (50cm ³ ) and the standard room (50cm ³ ), configure the basic physical property parameters of the sample, set the shale powder sample mesh number 60-80 mesh, mass 63g, clay Content 18.28%, TOC 2.81% and water content 1%; by changing the parameter configuration of the sample, the influence of different factors on the adsorption/desorption characteristics can be studied;

Enter the experimental operation module, check the air tightness of the device, use the vacuum device to vacuum the device, use helium to measure the void volume of the sample, and then vacuum the device. Among them, check the air tightness of the device, evacuate and measure the gap with helium The volume is the hot key button on the experimental platform. During the virtual experiment, the user clicks the hot key button, and the system will record the operation and automatically generate the code for comparing the standardized process code.

(c) Set the temperature of the constant temperature water bath and the constant temperature box to 35°C, open the valve three 17 and fill the standard chamber 5 with methane through the gas source 1. After the methane rises to the experimental temperature of 35°C and the pressure remains stable, open the valve four 19, Fill the sample chamber 6 with methane, open the valve five 22, adjust the manual metering pump 15 to keep the pressure in the sample chamber as the experimental pressure 10MPa, that is, the actual formation pressure, so that the gas is fully diffused and adsorbed in the sample chamber 6, and the sample chamber 6 After the pressure is stabilized, close the valve four 19 between the sample chamber 6 and the standard chamber 5; open the vent valve 23, slowly release the gas in the standard chamber 5, so that the pressure reaches the predetermined diffusion boundary pressure of 6MPa, and close the vent valve 23 after the pressure stabilizes. ;

(d) Open the valve four 19 between the sample chamber 6 and the standard chamber 5, methane diffuses and desorbs from the sample chamber 6 into the standard chamber 5, and the gas enters the standard chamber 5 to increase the gas pressure. If the pressure of the standard chamber 5 is greater than 6MPa, Adjust the manual metering pump 15 to keep the gas pressure in the standard chamber 5 unchanged at 6MPa, record the volume and time of the pump back, and obtain the relationship curve between the volume V of the back pump and the time t;

(e) After obtaining the dynamic desorption-flow curve of shale under 10MPa-6MPa, continue to reduce the boundary pressure, repeat step (d), and obtain the dynamic-desorption flow curve of shale powder under 6-2MPa and 2-0.14MPa, As shown in Figure 4, the dynamic-desorption flow curve can not only describe the gas adsorption under a certain pressure, but also describe the dynamic production characteristics of methane under a certain pressure difference.

The adsorption amount at any time in the dynamic desorption-flow process of coal shale is:

In the formula, P is the diffusion boundary pressure during desorption-flow, in MPa; T _sc is the temperature under standard conditions, 279.15K; V is the cumulative pump volume of the manual metering pump, cm ³ ; P _sc is the standard atmospheric pressure, 0.101MPa; Z is the compression factor of the gas under pressure P and temperature T, dimensionless; T is the experimental temperature, in K; M is the sample mass, in g.

The above are the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. The utility model provides a real standard system of coal shale absorption/desorption evaluation experiment simulation which characterized in that includes:

the human-computer interaction module comprises a display unit and an input unit;

the experiment design module is connected with the human-computer interaction module, a virtual material library is preset in the experiment design module and is used for freely designing an experiment scheme, two types of experiments with different evaluation methods are realized, the experiments comprise a coal shale static adsorption/desorption characteristic experiment and a dynamic desorption-flow characteristic evaluation experiment, and experiment parameters are selected and input through the human-computer interaction module;

the comprehensive evaluation module is connected with the experimental design module and is used for evaluating different evaluation methods selected by a user in the experimental design module, and automatically constructed experimental equipment and an operation flow;

the calculation module is connected with the comprehensive evaluation module and used for operating and calculating a simulation result;

the output module is connected with the comprehensive evaluation and calculation module, is used for outputting the calculation result and displaying the calculation result on the display unit;

preferably, the system also comprises an online evaluation module for comparing with the standardized operation flow codes and evaluating the rationality of the user operation;

preferably, the virtual materials library within the experimental design module includes, but is not limited to, the following 3D animation elements:

the system comprises a coal shale sample library, a gas source library, a supercharging device, a series of standard chambers, a series of sample chambers, a temperature control system, a pressure gauge, a pressure sensor, a manual metering pump, a vacuum pump and a data acquisition and processing system.

2. A teaching and practice method of the coal shale adsorption/desorption evaluation experiment simulation practical training system, which comprises the following steps:

s1: establishing a virtual material library, and realizing 3D modeling of experimental materials and equipment by adopting the existing software, wherein the virtual material library comprises the following 3D animation elements:

the system comprises a coal shale sample library, a gas source library, a supercharging device, a series of standard chambers, a series of sample chambers, a temperature control system, a pressure gauge, a pressure sensor, a manual metering pump and a data acquisition and processing system;

s2: establishing an experiment design module, presetting a virtual material library of S1 in the experiment design module, adopting computer programming, realizing two types of experiments with different evaluation methods through a free design experiment scheme, including a coal shale static adsorption/desorption characteristic experiment and a dynamic desorption-flow characteristic evaluation experiment, and selecting and inputting experiment parameters through a man-machine interaction module;

s3: establishing a comprehensive evaluation and calculation module for different evaluation methods selected by a user in an experimental design module, and self-built experimental equipment and an operation flow;

s4: running a virtual simulation experiment model, carrying out experiment operation based on a human-computer interaction interface, and calling data through statistics and an intelligent algorithm to obtain a virtual experiment result;

s5: the simulation result is output through the output module and displayed on the display unit.

3. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method according to claim 2, further comprising S6: an online evaluation system is established, user operation is evaluated and a guidance task is given by comparing standardized operation flows, and the purpose of optimizing teaching is achieved;

preferably, each 3D animation element in step S1 is provided with a connection node, a user realizes device assembly through the connection node of each 3D animation element, and the parameter of each 3D animation element realizes assignment through the parameter configuration module;

preferably, the parameter configuration module comprises 3 parameter configuration sub-modules affecting the coal shale adsorption/desorption characteristics, specifically: the temperature control system comprises a temperature control system parameter configuration submodule, a gas injection parameter configuration submodule and a sample physical property parameter configuration submodule, wherein the temperature control system parameter configuration submodule is used for realizing temperature adjustment and control, the gas injection parameter configuration submodule is used for realizing pressure adjustment and control, and the sample physical property parameter configuration submodule is used for configuring sample parameters: the clay content, TOC, maturity and water content are regulated and controlled.

4. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method according to claim 3, wherein in step S2, the experimental process for designing the coal shale static adsorption/desorption characteristics is as follows:

(1) the following 3D animation elements were selected: the system comprises a gas source, a pressurization system, a standard chamber, a sample chamber, a temperature control system, a pressure gauge, a data acquisition and processing system, a vacuum pump, a first valve and a second valve;

(2) assembling an experimental device, selecting the type and the quantity of required test samples, a sample chamber and a standard chamber, checking the air tightness of the device, vacuumizing the device by using a vacuumizing device, measuring the void volume of the samples by using helium gas, and vacuumizing the device again;

(3) closing the second valve, disconnecting the standard chamber and the sample chamber, opening the first valve, injecting test gas into the standard chamber through a gas source, and recording the pressure value of the standard chamber after the pressure is stable;

(4) closing the first valve, opening the second valve, communicating the standard chamber and the sample chamber to enable gas to be fully adsorbed in the coal shale sample, and recording the pressure value of the sample chamber after the pressure is stable;

(5) and (5) repeating the steps (3) and (4) until the design test pressure is reached and the adsorption experiment is finished.

5. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method as claimed in claim 4, wherein the experimental device for coal shale static adsorption/desorption characteristics comprises an air source, a pressurization system, a standard chamber, a sample chamber, a temperature control system, a pressure gauge, a data acquisition and processing system, a vacuum pump, a first valve and a second valve, wherein the pressurization system comprises an air compressor and a booster pump;

the air source is connected with the standard chamber through a first pipeline, the standard chamber is connected with the sample chamber through a second pipeline, the air compressor and the booster pump are connected to the first pipeline, a first valve is arranged on the first pipeline and used for controlling the on-off of air from the air source to the standard chamber, a second valve and a first pressure sensor are arranged on the second pipeline and used for controlling the on-off of air from the standard chamber to the sample chamber, and the first pressure sensor is used for monitoring the pressure of the sample chamber;

the standard chamber and the series sample chamber are arranged in the temperature control system and are used for setting the temperature and keeping the sample at the real formation temperature condition; the first pipeline is provided with a pressure gauge, the second pipeline is provided with a first pressure sensor, and the pressure gauge and the first pressure sensor are both connected to a data acquisition and processing system.

6. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method according to claim 5, characterized in that after adsorption experiments are performed by the devices of the steps (1) to (5), desorption experiments are performed, and the process is as follows:

(6) closing the second valve, disconnecting the standard chamber and the sample chamber, opening the vent valve to enable a certain amount of gas to be discharged from the standard chamber, closing the vent valve, and recording the pressure value of the standard chamber after the pressure of the standard chamber is stable;

(7) closing the first valve, opening the second valve, communicating the standard chamber and the sample chamber to desorb the saturated and adsorbed coal shale sample, and reading the pressure value of the sample chamber after the desorption balance pressure is stable;

(8) and (5) repeating the steps (6) and (7) until the designed lowest pressure is reached, and finishing the desorption experiment.

7. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method according to claim 6, wherein based on the coal shale static adsorption/desorption characteristic experiment process, the step S3 is further:

the number of the gas free molecules is calculated according to the pressure measured in the experiment by a gas state equation, and the total number of the experimental gas adsorption molecules corresponding to the n-th adsorption equilibrium pressure point is obtained by combining free gas state equations in a standard chamber and a sample chamber in different stages:

in the formula (I), the compound is shown in the specification,

respectively representing the pressure, MPa, when the communication standard chamber and the sample chamber system are balanced for the (n-1) th time and the (n) th time;

the pressure of the n-th standard chamber after inflation is MPa;

and

is pressure

And

the corresponding gas compression coefficient has no dimension; r is general gas constant, 8.314 J.mol ^-1·K ^-1(ii) a T is the experimental temperature, K; v _bIs standard cell volume, cm ³；V _yIs the void volume of the sample chamber, cm ³；

The unit mass of the coal shale sample has the following adsorbed gas volume Na:

in the formula, T _scTemperature under standard conditions, 279.15K; r is general gas constant, 8.314 J.mol ^-1·K ^-1；P _scIs standard atmospheric pressure, 0.101 MPa; m is the sample mass in g.

8. The teaching and practice method for the coal shale adsorption/desorption evaluation experiment simulation practical training system according to claim 7, wherein in the step S2, the experiment process for designing the coal shale dynamic adsorption/desorption characteristics is as follows:

(a) selecting a 3D animation element, comprising: the system comprises an air source, a pressurization system, a plurality of manual metering pumps, a series of standard chambers, a series of sample chambers, a temperature control system, a data acquisition and processing system and a vacuum pump;

(b) building a coal shale dynamic adsorption/desorption evaluation experiment device, selecting the type and the quantity of required experiment samples, a sample chamber and a standard chamber, checking the air tightness of the device, vacuumizing the device by using a vacuumizing device, measuring the void volume of the samples by using helium, and vacuumizing the device again;

(c) setting an experiment temperature, filling experiment gas into a standard chamber through a gas source, filling the gas into a sample chamber after the gas is raised to the experiment temperature and the pressure is kept stable, keeping the pressure in the sample chamber as the actual formation pressure, fully diffusing and adsorbing the gas in the sample chamber, closing a valve between the sample chamber and the standard chamber after the pressure of the sample chamber is stable, and calculating the gas amount filled in the sample chamber; opening an emptying valve of the standard chamber, slowly releasing gas in the standard chamber to enable the pressure of the gas to reach the preset diffusion boundary pressure, namely the actual bottom hole pressure, and closing the emptying valve after the pressure is stable;

(d) and opening a valve between the sample chamber and the standard chamber, diffusing and desorbing gas from the sample chamber into the standard chamber, adjusting the manual metering pump to keep the gas pressure in the standard chamber unchanged, and recording the pump withdrawal degree and time to obtain a relation curve of the pump withdrawal volume V and the time t.

9. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method as claimed in claim 8, wherein the coal shale dynamic adsorption/desorption evaluation experiment device comprises an air source, a pressurization system, a manual metering pump, a standard chamber, a sample chamber, a temperature control system, a pressure gauge, a data acquisition and processing system and a vacuum pump, and the pressurization system comprises an air compressor and a booster pump;

the air source is connected with a standard chamber inlet through a third pipeline, the air compressor and the booster pump are connected to a third pipeline, a third valve is arranged on the third pipeline, a third standard chamber outlet is connected with a fourth sample chamber inlet through a fourth pipeline, a fourth valve and a second pressure sensor are arranged on the fourth pipeline, the standard chamber is further connected with a manual metering pump interface through a fifth pipeline, a fifth valve is arranged on the fifth pipeline, the standard chamber is further connected with an emptying valve, the sample chamber and the standard chamber are placed in a thermostatic water bath, the thermostatic water bath and the manual metering pump are placed in a thermostat and used for setting and keeping the real stratum temperature condition of the sample test piece, temperature sensors are further arranged in the sample chamber and the standard chamber, and a pressure gauge, a first pressure sensor and a first temperature.

10. The coal shale adsorption/desorption evaluation experiment simulation practical training system teaching and practice method according to claim 9, wherein based on the coal shale dynamic adsorption/desorption characteristic experiment process, the step S3 is further:

the adsorption capacity at any moment in the dynamic desorption-flowing process of the coal shale is as follows:

wherein P is the diffusion boundary pressure at desorption-flow in MPa; t is _scStandard condition temperature, 279.15K; v is the accumulated pump withdrawing volume of the manual metering pump in cm ³；P _scIs standard atmospheric pressure, 0.101 MPa; z is a compression factor of the gas under the pressure P and the temperature T, and has no dimension; t is the experimental temperature in K; m is sample mass in g;

preferably, the test gas introduced from the gas source is nitrogen, methane or carbon dioxide.

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