Simulation test method and device for inhibiting methane desorption effect by coal seam water injection

Abstract

The invention discloses a simulation test method and device for inhibiting methane desorption effect by coal seam water injection. The device comprises an isothermal desorption system, a ground stress applying system, a methane gas injection system and a high-pressure water injection system, wherein the isothermal desorption system comprises a desorption unit, a vacuum degassing unit and a constant-temperature unit; the ground stress applying system, the methane gas injection system, the high-pressure water injection system, the vacuum degassing unit and the constant-temperature unit are respectively connected with the desorption unit; after an experiment coal sample is put into the desorption unit, the constant-temperature unit is used for providing a water bath constant temperature to the desorption unit; the vacuum degassing unit is used for vacuumizing the desorption unit; the high-pressure water injection system is used for injecting water into the coal sample and the methane gas injection system is used for injecting methane into the coal sample; the ground stress applying system is used for applying pressure to the coal sample; and the desorption unit is used for analyzing a desorption property of the methane gas in the coal sample to obtain data. The device is simple in structure and the testing method is simple, so that people can utilize the methane desorption inhibiting effect of the coal seam water injection to carry out coal and gas outburst prevention and treatment very well.

Description

technical field [0001] The invention belongs to the field of simulation test devices, and in particular relates to a simulation test method and device for suppressing gas desorption effect by water injection into coal seams. Background technique [0002] Coal seam high-pressure water injection, as a measure to prevent and control coal and gas outburst, has been widely used in my country. However, due to the unclear understanding of coal and gas outburst mechanism for a long time, there are still great differences in the understanding of coal seam water injection outburst prevention mechanism. [0003] Coal is a porous medium containing a large number of pores and fissures. As high-pressure water enters the coal body, it will not only change the pore characteristics and mechanical properties of the coal body, but also affect the coal gas due to the water occupying the fissures and pores of the coal body. The desorption of outburst coal seams has a significant impact on the g...

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Problems solved by technology

[0004] At present, although scholars at home and abroad have achieved certain results in the research on the mechanism of coal seam water injection outburst prevention, for example, some scholars have used different research methods to confirm that the length of the pressure relief zone after coal seam water injection is increased, which is beneficial to the prevention and control of coal and gas outburst. In terms of the influence of coal seam water injection on coal gas desorption characteristics, systematic research at home and abroad has made slow progress. For example, some scholars have found that the gas emission in the working face after water injection has decreased to varying degrees after water injection. The water in the micropores will block the gas desorption. However, since the inhibition of the desorption effect is the microcosmic effect of coal, gas and water, the field experiment can only understand the change of gas emission in the working face after water injection. , the obtained effect of suppressing gas desorption is mainly based on experience and theoretical speculation, lacking quantitative experimental data

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