气体压力对煤体瓦斯渗透特征的影响

Effect of gas pressure on infiltration characteristics of coal gas

为了研究刚性围岩中不同瓦斯压力条件下含瓦斯煤体渗透特征,使用了自行研制的煤体瓦斯吸附-解吸试验装置,建立了煤体瓦斯渗透物理模型,分别采用N2和CO2在煤体内进行渗透试验,对瓦斯压力、总压力和渗透速度进行了监测。试验结果表明,同等温度和压力条件下N2在煤体内的渗透速度比CO2大;结果还表明,含瓦斯煤体的渗透速度随气体压力增加按照二次多项式规律增加。此项试验研究对矿井瓦斯动力灾害防治和煤层气开采技术理论研究具有重要的参考价值。

In order to study the characteristics of gas infiltration in coal body surrounded by rigid rock under conditions of different gas pressure,a self-developed coal-gas sorption/desorption simulation device is used to establish a physical coal-gas infiltration model.In the infiltration experiments of coal body,we use two types of gases（N2 CO2） respectively to monitor gas pressure,total stress and infiltration velocity.The results show that the infiltration velocity of N2 is higher than that of CO2 under the conditions of same temperature and same pressure.The results also show that the relationship between gas infiltration velocity in gas-contained coal and gas pressure is fitted by second-order polynomial.This experimental study has important reference value for the prevention of coal-gas dynamic hazard and the theory and technology of CBM exploration in coal mine.