CN204789267U - Coal petrography permeability detection device - Google Patents

Abstract

The coal and rock permeability detection device provided by the utility model includes a gas input unit, a pressurization unit for simulating the state of ground stress, an acquisition unit for collecting pressure parameters and flow parameters, an inlet and outlet gas pipeline unit, and a unit for calculating coal and rock permeability. The measuring unit of permeability; the pressurizing unit includes a pressurizing device for placing the coal rock sample to be tested and applying pressure and a pressure regulating device for adjusting the pressure of the pressurizing device, and the pressurizing device passes through the air inlet and outlet pipe The circuit unit is respectively connected with the gas input unit and the collection unit, and the collection unit is connected with the measurement unit; the utility model has the advantages of compact structure, simple operation, flexible use, small volume and low cost.

Description

Coal rock permeability detection device

technical field

The utility model relates to the field of natural gas development, in particular to a coal rock permeability detection device.

Background technique

China is a major coal producer in the world, and the corresponding reserves of coalbed methane are huge, which are basically the same as natural gas. Its basic ingredient is methane. In addition to being a cheap chemical raw material, natural gas is mainly used as a fuel, not only as a living fuel for residents, but also as a fuel for vehicles, ships, airplanes and other means of transportation. Due to the high calorific value of coalbed methane, the combustion products cause less pollution to the environment, so it is considered as a high-quality clean fuel.

With the rapid development of China's oil and natural gas mining industry in recent years, the development and utilization of unconventional natural gas has become a long-term strategic goal of our country. The key points and difficulties of the coal industry, due to the very complex geological conditions in my country, are restricted in the field of unconventional natural gas exploitation, and the permeability of coal rocks is a sign that reflects the difficulty of fluid migration in coal rocks, so how to accurately measure The permeability of coal rock is of great significance to the utilization of coalbed methane and the design of gas drainage system. However, the coal rock permeability measurement in the prior art has the following problems: (1) The measuring device has no confining pressure and is difficult to seal and leak detection. (2) Under the condition of confining pressure, the processing of the test piece requires high precision and is difficult to process. (3) During the test, it is greatly affected by the external temperature. (4) The measurement error is large when the outlet port is directly connected to the atmosphere, and the pressure variable range is small. (5) It cannot simulate the deep penetration of coal and rock mass under the condition of three-dimensional stress. Therefore, a new method is urgently needed to realize the accurate measurement of coal rock permeability.

Utility model content

In view of this, the utility model provides a coal rock permeability detection device to solve the above problems.

The coal and rock permeability detection device provided by the utility model includes a gas input unit, a pressurization unit for simulating the state of ground stress, an acquisition unit for collecting pressure parameters and flow parameters, an inlet and outlet gas pipeline unit, and a unit for calculating coal and rock permeability. unit of measurement for permeability;

The pressurizing unit includes a pressurizing device for placing the coal rock sample to be tested and applying pressure, and a pressure regulating device for adjusting the pressure of the pressurizing device. The unit is connected to the acquisition unit, and the acquisition unit is connected to the measurement unit.

Further, the pressurizing device includes an oil pump, an oil cylinder, and a counter force device used as a carrier of the oil cylinder, the hydraulic oil cylinder is fixed to the counter force device, and the oil pump is connected to the oil cylinder.

Further, the pressure regulating device includes an outlet pressure regulator, an inlet pressure regulator and a pressure controller for controlling the outlet and inlet pressures.

Further, the collection unit includes a pressure collection module and a flow collection module, and the pressure collection module is used to collect the gas pressure at the inlet and outlet of the coal rock sample to be tested.

Further, the flow collection module includes a flow meter, a measuring tube and a volumetric bottle.

Further, the oil pump is a hydraulic oil pump, and the oil cylinder is a hydraulic oil cylinder.

Further, the pressure acquisition module is a pressure sensor.

Further, the gas input unit is a pressure gas cylinder.

Beneficial effects of the utility model: the utility model adopts a three-way pressurizing device and a closed container structure, intuitively simulates the three-dimensional ground stress, and detects the permeability of coal and rock under different triaxial stresses by adjusting the pressure value, and can measure different Adsorption state, different interstitial air pressure, and permeability changes at different temperatures provide technical data support for the development of gas and natural gas. The utility model has the advantages of compact structure, simple operation, flexible use, small volume and low cost.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described:

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a schematic structural view of the counter force device of the present invention.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and embodiments: Fig. 1 is a schematic structural view of the present invention, and Fig. 2 is a structural schematic view of the counterforce device of the present invention.

The coal-rock permeability detection device in the utility model includes a gas input unit 1, a pressurization unit for simulating the state of ground stress, an acquisition unit for collecting pressure parameters and flow parameters, an inlet and outlet gas pipeline unit, and a unit for calculating coal-rock unit of measurement for permeability;

The pressurizing unit includes a pressurizing device 4 for placing the coal rock sample to be tested and applying pressure, and a pressure regulating device for adjusting the pressure of the pressurizing device. The pressurizing device 4 is connected to the The gas input unit 1 is connected to the collection unit, and the collection unit is connected to the measurement unit. The specific structure of the pressurizing device 4 is shown in FIG. 2 .

The pressurizing device 4 in this embodiment includes an oil pump, an oil cylinder and a reaction device used as a carrier of the oil cylinder, the hydraulic oil cylinder is fixed to the reaction device, and the oil pump is connected to the oil cylinder; the oil cylinder adopts three hydraulic oil cylinders. Inject pressure oil of different pressures, provide true triaxial pressure for the coal sample during the pressurization process, and then simulate the ground stress. The pressure regulating device in this embodiment includes an outlet pressure regulator, an inlet pressure regulator 5 and a A pressure controller 6 for controlling the outlet and inlet pressure. The acquisition unit includes a pressure acquisition module 2 and a flow acquisition module. The pressure acquisition module is used to acquire the gas pressure at the inlet and outlet of the coal rock sample to be tested. The flow collection module includes a flow meter 7 , a measuring tube 8 and a volumetric bottle 9 . In this embodiment, the gas flow rate is measured by the flow meter 7. Since the coal sample gas permeation flow rate varies greatly with the gas pressure, the gas volume measurement method per unit time is used when the flow rate is small. Specifically, it includes: measuring once every 5 minutes at the beginning until the flow is stable, and when the volume of permeated gas is equal to the third reading, calculate the gas flow as the volume of permeated gas. When reading, first move the balance device so that the liquid levels in the two containers of measuring tube 8 and volumetric bottle 9 are equal, then read the scale where the liquid level of the measuring tube is located, and read again after a certain period of time. The difference between the two readings is the measured volume. The detection device provided by the invention can measure the variation of permeability in different adsorption states, different gap pressures, and different temperatures, and provide technical data support for the development of gas and natural gas.

In this embodiment, the oil pump is a hydraulic oil pump, the oil cylinder is a hydraulic oil cylinder, the gas input unit 1 is a pressure gas cylinder equipped with high-pressure gas, and the pressure acquisition module 2 uses a pressure sensor to display the gas pressure value at the inlet and outlet in real time. The measurement unit in the embodiment is the HCA high-pressure adsorption device pressure collector developed by the Chongqing Research Institute of the General Academy of Coal Science Research, which can directly read the pressure value, and can also be replaced by other devices that can realize the above functions. Those skilled in the art can It is easy to obtain and will not be repeated here.

In this embodiment, the hydraulic oil cylinder is filled with liquid, the block is moved to pressurize the coal rock sample to be tested, and the coal rock sample to be tested is inflated with gas through the pressure cylinder. By obtaining the gas pressure at the inlet and outlet of the reaction device, the pressurization pressure of the true triaxial pressurization equipment and the flow rate of the seepage gas are obtained at the same time. Using the collected pressure parameters and flow values, the permeability under the pressure state is calculated.

According to the collected pressure parameters and flow values, the measurement unit calculates the permeability of the coal sample to be tested by the following formula:

$K=\frac{P_0{Q}_{0}L}{f(P_1-P_2)(P_m+b)}$ Formula 1)

Among them, K is the measured permeability of coal, Q ₀ is the gas flow rate, P ₀ —atmospheric pressure, P ₁ is the inlet pressure, P ₂ is the outlet pressure, P _m is the triaxial confining pressure, F is the permeable effective area, L is the length of the coal sample, and b is the gas Klingberg coefficient.

The utility model acquires the pressure of the gas at the inlet and outlet of the reaction device, and at the same time acquires the pressure of the true triaxial pressurization equipment and the flow rate of the seepage gas. Using the collected pressure parameters and flow values, the permeability under the pressure state is calculated. The method has the advantages of simple operation, low cost of stability test and low processing requirement.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present utility model without limitation. Although the utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the utility model can be Modifications or equivalent replacements of the technical solutions without departing from the spirit and scope of the technical solutions of the utility model shall be covered by the claims of the utility model.

Claims (8)

1. A coal-rock permeability detection device, characterized in that: comprising a gas input unit, a pressurization unit for simulating the ground stress state, a collection unit for collecting pressure parameters and flow parameters, an air inlet and outlet pipeline unit and a The measurement unit for calculating the permeability of coal rock; The pressurizing unit includes a pressurizing device for placing the coal rock sample to be tested and applying pressure, and a pressure regulating device for adjusting the pressure of the pressurizing device. The unit is connected to the acquisition unit, and the acquisition unit is connected to the measurement unit. 2. The coal-rock permeability detection device according to claim 1, characterized in that: the pressurizing device comprises an oil pump, an oil cylinder and a counter force device used as a carrier of the oil cylinder, the oil cylinder is fixed to the counter force device, and the The oil pump is connected with the oil cylinder. 3. The coal rock permeability detection device according to claim 1, characterized in that: the pressure regulating device comprises an outlet pressure regulator, an inlet pressure regulator and a pressure controller for controlling the outlet and inlet pressures. 4. The coal rock permeability detection device according to claim 1, characterized in that: the acquisition unit includes a pressure acquisition module and a flow acquisition module, and the pressure acquisition module is used to collect gas pressure at the inlet and outlet of the coal rock sample to be tested . 5. The coal rock permeability detection device according to claim 4, characterized in that: the flow acquisition module includes a flow meter, a measuring tube and a volumetric bottle. 6. The coal rock permeability detection device according to claim 2, characterized in that: the oil pump is a hydraulic oil pump, and the oil cylinder is a hydraulic oil cylinder. 7. The coal rock permeability detection device according to claim 4, characterized in that: the pressure acquisition module is a pressure sensor. 8. The coal rock permeability detection device according to claim 1, characterized in that: the gas input unit is a pressure gas cylinder.