Experimental Study on Inhibitory Effect of Gas Desorption by Injecting Water into Coal-sample

Abstract

Abstract In order to further study inhibitory effect of gas desorption in coal seam water infusion, the laboratory test method is used in this paper, which experiments on coal sample that is fully adsorbed methane before being injected water into. By the experiments, gas desorption isotherms, gas desorption rate and residual gas content after water injection are obtained. And also, the following test results are got: the first, with water being injected, coal gas desorption isotherms moves upward, that is, gas content in coal sample increases under a certain balance pressure; the second, with water being injected, it can lower both the initial desorption rate and the attenuation speed of gas adsorption in coal sample, that is, coal gas desorption rate curve becomes more smooth; the third, with water being injected, it increases residual gas content in coal, and residual gas content increases with injection pressure and water content. Through these experiments, the following conclusions can be drawn: with high pressure water being injected into pores of coal, residual water in coal has inhibitory effect to adsorption methane, ultimately, reducing gas desorption rate and desorption volume; so that, water injection is benefit for gas outburst, and the inhibitory effect is an important role in mechanism of water injection to prevent coal and gas outburst.