CN105974070B - A kind of underground water influences analogue means and method to coal bed gas - Google Patents

Abstract

The invention discloses a device and method for simulating the influence of groundwater on coalbed gas. The device includes a sample chamber and a high-pressure gas bottle; The cylinder is detachably combined; the pressure tank is provided with a pressure gauge and a gas-water separator; the pressure tank communicates with a high-pressure gas bottle. The device and method of the invention are simple and effective, and can be applied to large-volume coal samples without crushing. It can also be adapted to different temperature conditions to investigate the influence of different pressure, water quality, coal quality, and coal-water ratio on coalbed methane storage.

Description

A device and method for simulating the impact of groundwater on coalbed methane

technical field

The invention relates to an experimental device and method for coalbed gas, in particular to a simulation device and method for the influence of groundwater on coalbed gas.

Background technique

CBM is mainly stored in the double-porous medium of coal in the state of adsorption. In the study of coalbed methane storage and migration, research on the impact of groundwater on coalbed methane storage has always been the focus of coalbed methane storage research.

The Chinese patent authorization number is CN100487755C, which discloses a coalbed methane accumulation simulation device, which is composed of a gas booster pump, a constant temperature cabinet, a control system and a computer processing system.

The application publication number is CN1 01799466A, which discloses a physical simulation device and simulation method for coalbed methane production. The simulation device includes a sample chamber, a constant temperature water bath system, a gas/water metering system and a pressure monitoring system. The production pipelines are connected to each other to form a simulation system. A constant temperature water bath system is set around the simulation system. The sample warehouse of the simulation system is connected to the confining pressure simulation pipeline. /water configures the connection of the simulated wellhead on the production pipeline, and the simulated wellhead is connected to the gas/water metering system.

The structure of the above simulation device is relatively complex, which cannot satisfy the simulation of large coal samples, and the maximum control temperature is 100°C. In addition, the influence of different solid-liquid ratios on CBM storage cannot be confirmed.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention aims to provide a simulation device and method for the influence of groundwater on coalbed methane. The device has a simple structure, is applicable to large-volume coal samples, and does not need to be crushed. It can also adapt to the conditions of different temperatures (the highest temperature can reach 400°C), and investigate the effects of different pressures, water quality, coal quality, and coal-water ratio on the storage of coalbed methane.

In order to achieve the above object, the present invention adopts the following technical solutions:

A device for simulating the impact of groundwater on coalbed methane, including a sample chamber and a high-pressure gas bottle; the sample chamber is mainly composed of a pressure tank, and the pressure tank is cylindrical as a whole, and is composed of two semi-cylinders that can be separated; The pressure tank is provided with a pressure gauge and a gas-water separator; the pressure tank communicates with the high-pressure gas bottle.

It should be noted that a safety valve is also provided on the pressure tank. The safety valve can improve the safety of the use of the pressure tank.

It should be noted that the high-pressure gas bottle is connected with a pressure reducing valve, and the pressure tank is provided with an air intake connection valve, and the pressure relief valve communicates with the air intake connection valve.

It should be noted that the two half cylinders are combined by screws, and a sealing gasket is provided at the joint of the two half cylinders. The two semi-cylinders can be opened or combined at will through the combination of screws, and the setting of the sealing gasket makes the combination of the two semi-cylinders have higher sealing performance.

It should be noted that an induction heating coil is wound on the outer surface of the pressure tank, and the induction heating coil is mainly composed of an induction coil and a temperature controller, and the induction coil is electrically connected to the temperature controller. By setting the induction heating coil, the temperature of the pressure tank can also be controlled, so that the influence of temperature on the coalbed gas can be studied.

The method for using the above-mentioned simulation device for the influence of groundwater on coalbed methane includes the following steps:

S1 Determine pressure, coal-water ratio, water quality and coal quality as the influencing factors to be studied, then set the fixed values of the other three factors, and set different values of several influencing factors to be studied;

S2 performs the following operations for each value of the influencing factors to be studied;

Separate the two half cylinders of the pressure tank, put the coal sample and water in according to the set coal-water ratio, the water quality and coal quality must meet the set requirements; close the pressure tank, and put the induction coil of the induction heating coil wrapped around the surface of the pressure tank;

Open the pressure reducing valve and the air inlet connection valve, release gas to the pressure tank at a certain flow rate through the high-pressure gas bottle, check the pressure of the pressure tank through the pressure gauge until the set pressure value is reached; heat the pressure tank through the induction coil , and the operation of the induction coil is controlled by the temperature controller until the pressure tank is heated to the set temperature;

When the required pressure is reached, close the pressure reducing valve, then release a small amount of gas from the pressure tank and collect it through the gas-water separator, analyze the gas samples and water samples therein, and measure the gas composition and concentration in the pressure tank ;

S3 After the operation of step S2 is performed for all the set values of the influencing factors to be studied, the gas composition and concentration in the pressure tank obtained under different set values are compared to know the influence of this factor on the coalbed methane.

The beneficial effects of the present invention are:

1. The present invention can investigate the effects of different pressures, water quality, coal quality, and coal-water ratio on the storage of coalbed methane through simple and effective devices and methods, and is applicable to large-volume coal samples without crushing.

2. It can adapt to different temperature conditions and investigate the influence of different pressure, water quality, coal quality and coal-water ratio on coalbed methane storage.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the device of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution, and provides detailed implementation and specific operation process, but the protection scope of the present invention is not limited to the present invention. Example.

As shown in Figure 1, a simulation device for the influence of groundwater on coalbed methane includes a sample chamber and a high-pressure gas bottle 2; The cylinders 11 and 12 are detachably combined; the pressure tank 1 is provided with a pressure gauge 3 and a gas-water separator 4; the pressure tank 1 communicates with the high-pressure gas bottle 2 .

As a preferred solution, the pressure tank 1 is further provided with a safety valve 5 .

As a preferred solution, the two high-pressure gas bottles are connected with a pressure reducing valve 6, and the pressure tank 1 is provided with an air intake connection valve 7, and the pressure relief valve 6 is connected with the air intake connection valve 7.

As a preferred solution, the two half cylinders 11 and 12 are combined by screws, and a gasket 8 is provided at the joint of the two half cylinders.

It should be noted that an induction heating coil is wound on the outer surface of the pressure tank, and the induction heating coil is mainly composed of an induction coil 9 and a temperature controller, and the induction coil is electrically connected to the temperature controller.

The method for using the above-mentioned simulation device for the influence of groundwater on coalbed methane includes the following steps:

S1 Determine pressure, coal-water ratio, water quality and coal quality as the influencing factors to be studied, then set the fixed values of the other three factors, and set different values of several influencing factors to be studied;

S2 performs the following operations for each value of the influencing factors to be studied;

Separate the two half cylinders of the pressure tank, put the coal sample and water in according to the set coal-water ratio, the water quality and coal quality must meet the set requirements; close the pressure tank, and put the induction coil of the induction heating coil wrapped around the surface of the pressure tank;

Open the pressure reducing valve and the air inlet connection valve, release gas to the pressure tank at a certain flow rate through the high-pressure gas bottle, check the pressure of the pressure tank through the pressure gauge until the set pressure value is reached; heat the pressure tank through the induction coil , and the operation of the induction coil is controlled by the temperature controller until the pressure tank is heated to the set temperature;

When the required pressure is reached, close the pressure reducing valve, then release a small amount of gas from the pressure tank and collect it through the gas-water separator, analyze the gas samples and water samples therein, and measure the gas composition and concentration in the pressure tank ;

S3 After the operation of step S2 is performed for all the set values of the influencing factors to be studied, the gas composition and concentration in the pressure tank obtained under different set values are compared to know the influence of this factor on the coalbed methane.

Embodiment one

S1 Determine the influence of research pressure on coalbed methane, then set the coal-water mass ratio, water quality and coal quality as 20:1, total salinity 0.5g/L, lignite, and set the different values of pressure as 1MPa, 5MPa, 10MPa, 15MPa.

S2 performs the following operations on each value of the pressure;

Separate the two half cylinders of the pressure tank, put the coal sample and water in a set ratio of 20:1, wherein the water quality needs to meet the condition of a total salinity of 0.5g/L, and close the pressure tank; and The induction coil of the induction heating coil is wound on the surface of the pressure tank;

Open the pressure reducing valve and the air inlet connection valve, release the gas to the pressure tank at a certain flow rate through the high-pressure gas bottle, check the pressure of the pressure tank through the pressure gauge until it reaches the set pressure value (1MPa, 5MPa, 10MPa, 15MPa); The induction coil heats the pressure tank, and the temperature controller controls the operation of the induction coil until the pressure tank is heated to a set temperature (set as required);

When the required pressure is reached, close the pressure reducing valve, then release a small amount of gas from the pressure tank and collect it through the gas-water separator, analyze the gas samples and water samples therein, and measure the gas composition and concentration in the pressure tank ;

S3 After the operation of step S2 is performed on all the set values of the pressure, the gas composition and concentration in the pressure tank obtained under different set The impact of coal bed gas.

Embodiment two

S1 is determined to study the influence of coal-water mass ratio on coalbed methane, and then set the pressure, water quality and coal quality as 1MPa, total salinity 0.5g/L, and lignite respectively, and set the different values of coal-water mass ratio to 20 :1, 10:1, 5:1, 1:1, 1:10, 1:20;

S2 performs the following operations for each value of the coal-water mass ratio;

Separate the two half cylinders of the pressure tank, put the coal sample and water in the set ratio (20:1, 10:1, 5:1, 1:1, 1:10, 1:20), wherein The water quality needs to meet the condition of total salinity of 0.5g/L, close the pressure tank; and the induction coil of the induction heating coil is wound on the surface of the pressure tank;

Open the pressure reducing valve and the air inlet connection valve, release the gas to the pressure tank at a certain flow rate through the high-pressure gas bottle, check the pressure of the pressure tank through the pressure gauge until it reaches the set pressure value of 1MPa; Heating, and the temperature controller controls the operation of the induction coil until the pressure tank is heated to the set temperature (you can set it as needed);

When the required pressure is reached, close the pressure reducing valve, then release a small amount of gas from the pressure tank and collect it through the gas-water separator, analyze the gas samples and water samples therein, and measure the gas composition and concentration in the pressure tank ;

After S3 all set values of coal-water mass ratio carry out the operation of step S2, different set values (20:1, 10:1, 5:1, 1:1, 1:10, 1:20) By comparing the gas composition and concentration in the pressure tank obtained below, the influence of the coal-water mass ratio on the coalbed methane can be known.

Embodiment three

S1 determines the influence of water quality on coalbed methane, and then sets the pressure, coal-water mass ratio and coal quality as 1MPa, 20:1, and lignite respectively, and sets the different values of water quality as total salinity of 0.5g/L, The total salinity is 2g/L, the total salinity is 8g/L, the total salinity is 25g/L, and the total salinity is 60g/L;

S2 performs the following operations on each value of the water quality;

Separate the two half cylinders of the pressure tank, put the coal sample and water in a set ratio of 20:1, wherein the water quality value of the water meets the set conditions (total salinity 0.5g/L, total mineralization 2g/L, total salinity 8g/L, total salinity 25g/L, total salinity 60g/L), close the pressure tank; and the induction coil of the induction heating coil is wound on the surface of the pressure tank;

Open the pressure reducing valve and the air inlet connection valve, release the gas to the pressure tank at a certain flow rate through the high-pressure gas bottle, check the pressure of the pressure tank through the pressure gauge until it reaches the set pressure value of 1MPa; Heating, and the temperature controller controls the operation of the induction coil until the pressure tank is heated to the set temperature (you can set it as needed);

When the required pressure is reached, close the pressure reducing valve, then release a small amount of gas from the pressure tank and collect it through the gas-water separator, analyze the gas samples and water samples therein, and measure the gas composition and concentration in the pressure tank ;

After S3 has all carried out the operation of step S2 to all setting values of water quality, for different setting values (total salinity 0.5g/L, total salinity 2g/L, total salinity 8g/L, total mineralization By comparing the gas composition and concentration in the pressure tank obtained under the conditions of 25g/L salinity and 60g/L total salinity, the impact of water quality on coalbed methane can be known.

Embodiment four

S1 Determine the influence of coal quality on coalbed methane, then set the pressure, coal-water mass ratio and water quality as 1MPa, 20:1, and total salinity 0.5g/L, and set the coal quality as lignite and bituminous coal respectively ,anthracite;

S2 performs the following operations on each coal quality;

Separate the two half cylinders of the pressure tank, put the coal sample and water in a set ratio of 20:1, wherein the coal quality meets the preset conditions (lignite, bituminous coal, anthracite), and the water quality value meets the total salinity of 0.5 g/L, close the pressure tank; and the induction coil of the induction heating coil is wound on the surface of the pressure tank;

Open the pressure reducing valve and the air inlet connection valve, release the gas to the pressure tank at a certain flow rate through the high-pressure gas bottle, check the pressure of the pressure tank through the pressure gauge until it reaches the set pressure value of 1MPa; Heating, and the temperature controller controls the operation of the induction coil until the pressure tank is heated to the set temperature (you can set it as needed);

When the required pressure is reached, close the pressure reducing valve, then release a small amount of gas from the pressure tank and collect it through the gas-water separator, analyze the gas samples and water samples therein, and measure the gas composition and concentration in the pressure tank ;

S3 After the operation of step S2 is performed on all types of coal quality, the gas composition and concentration in the pressure tank obtained under different coal qualities (lignite, bituminous coal, anthracite) are compared, and the influence of coal quality on coalbed methane can be known. influences.

In Examples 1 to 4, all three factors are controlled at the same level, and the impact of different levels of the fourth factor on coalbed methane storage is investigated, thereby simulating the impact of different pressures, water quality, coal quality, and coal-water quality ratio on coalbed methane storage. Impact.

For those skilled in the art, various corresponding changes and modifications can be made according to the above technical solutions and ideas, and all these changes and modifications should be included in the protection scope of the claims of the present invention.

Claims (1)

1. a kind of underground water influences the application method of analogue means on coal bed gas, it is characterised in that

The underground water influences analogue means, including sample bin and high pressure gas bottle on coal bed gas；The sample bin is mainly by pressing Power tank forms, and the pressurized tank is integrally cylindrical, is separably combined into by two semicolumns；The pressurized tank is provided with Pressure gauge and moisture trap；The pressurized tank is connected with high pressure gas bottle；The high pressure gas bottle is communicated with pressure-reducing valve, institute State pressurized tank and be provided with air inlet connection valve, the pressure-reducing valve is connected with the air inlet connection valve；The outer surface of the pressurized tank Load coil is wound with, the load coil is mainly made up of induction coil and thermostat, the induction coil electricity Property is connected to the thermostat；

The application method comprises the following steps：

S1 determines then to set other three factors as influence factor to be studied in pressure, coal-water ratio, water quality and ature of coal Fixed value, and set the different values of several influence factors to be studied；

S2 proceeds as follows to each value of influence factor to be studied；

Two semicolumns of the pressurized tank are separated, coal sample and water are put into by the coal-water ratio of setting, water quality and ature of coal are required to Meet the requirement of setting；Pressurized tank is closed, the induction coil of load coil is wrapped in the pressurized tank surface；

Pressure-reducing valve and air inlet connection valve are opened, gas is discharged to pressurized tank by certain flow rate by high pressure gas bottle, passes through pressure Table investigates the pressure of pressurized tank, until reaching the pressure value of setting；Pressurized tank is heated by the induction coil, and by Operation of the thermostat to induction coil is controlled, until pressurized tank to be heated to the temperature of setting；

Pressure-reducing valve is closed when reaching and needing pressure, a small amount of gas is then released from pressurized tank and by the moisture trap It is acquired, sample analysis is carried out to gaseous sample therein and water sample, determines gas componant and concentration in pressurized tank；

After S3 carries out step S2 operation to all setting values of influence factor to be studied, to gained under different setting values Pressurized tank in gas componant and concentration contrasted, you can know influence of the factor to coal bed gas.