Experimental method for raising gas desorption property

Abstract

The invention discloses an experimental method for raising gas desorption property, characterized by based on the experimental study of gas absorption, desorption and permeability by existing non-mechanical method, using an experimental device which comprises a gas bottle, a pressure-tolerant gas pipe, a valve, a gas storage tank, a drying agent, a pressure sensor, a desorption pot, a positive electrode, a constant temperature water tank, a guide wire, a high-voltage variable-frequency power source, a vacuum pump, a data collection card, a computer, a rubber pipe, a measuring tube, and an Erlenmeyer flask, putting an experimental coal sample in the desorption pot, using the high-voltage variable-frequency electric field to change the physicochemical properties of the coal and allow the moisture in the coal and different charged ions dissolved in the water molecules to directionally move, thus free and adsorbed gas is increased, and the desorption property is raised. According to the invention, compared with the gas desorption property obtained by using a natural coal sample, when the high-voltage variable-frequency power source output voltage is 2kV and the frequency is 40Hz, the desorption is averagely raised by 11.42%.

Description

technical field [0001] The invention belongs to the technical field of gas drainage experiments in coal measure formations, and in particular relates to an experimental method for improving the desorption performance of coal gas gas under the action of a high-voltage variable-frequency electric field. Background technique [0002] There are many high gas and outburst mines in Shanxi. The coal seams of these mines have poor permeability, and the air permeability coefficient is mostly less than 0.1m 2 / MPa 2 · d, for the low-permeability coal seam which is difficult to extract. [0003] Based on the mechanism of coal seam gas generation, storage and migration, the downhole permeability enhancement of low-permeability coal seams needs to be considered in two aspects: 1) to promote the desorption of coal seam gas, so that the gas adsorbed on the inner surface of coal matrix pores and fractures can be released as much as possible The adsorption state is transformed into a free ...

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Problems solved by technology

One is mechanical methods, specifically water injection and gas injection displacement, high-pressure hydraulic slotting, blasting fracturing, coal seam roof drainage, mining protection layer, pressure relief mining drainage and drilling drainage, etc. The desorption and permeability of the coal seam are very effective, and the pressure relief is used to deform the low-permeability coal body, relieve the stress barrier, and increase the desorption and permeability of the coal seam gas, thereby playing the role of increasing the permeability of the low-permeability coal seam underground; the other type It is a non-mechanical method, specifically the external electromagnetic field, electric field, temperature field, sound field and electrochemistry, etc. These methods are all laboratory research at this stage, and the external electromagnetic field and electrochemistry are both experimental researches on the adsorption and desorption of coal seam gas. The applied electric field is all experimental research on the permeability of coal seam gas, and there is no related research on the experimental study of gas desorption by external electric field

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