摘要
针对不同瓦斯压力作用下煤岩渗透率的差异性,利用自行研制改造的含瓦斯煤热流固耦合三轴渗流实验装置,对构造煤及硬煤两种煤样进行了不同轴压围压条件下瓦斯压力对渗流特性的试验研究。结果表明,煤样渗透率随瓦斯压力变化出现明显的Klinkenberg效应,软煤样与硬煤样的渗透率变化均符合二次多项式函数。不同围压下,两种煤样渗透率随瓦斯压力变化差异性较大,且Klinkenberg效应拐点也不一致,其主要受煤样吸附常数影响。煤样渗透率出现先减小后增大趋势的主要原因为:Klinkenberg效应与围压及轴压作用下瓦斯吸附致使煤基质膨胀从而使煤样渗透率减小,后来孔隙压力增大导致渗透率增加。研究结果为提高煤层气抽采率提供理论参考依据。
According to the response characteristics of tectonic coal to gas pressure, experimental studies about permeability of two different coal samples were carried out with self-developed experiment facility for triaxial seepage flow test of fluid-solid-thermal coupling gas filled coal. The results show that permeability variation with gas pressure of coal samples have apparent Klinkenberg effect, the permeability changes of soft coal and hard coal samples conform to quadratic polynomial function. Under different confining pressures, permeability of coal samples with gas pressure changes greatly, Klinkenberg effect and inflection is also inconsistent, which is mainly affected by the sample adsorption constant. The coal permeability decreases first then increases, permeability decrease is caused by Klinkenberg effect and gas adsorption effect of coal matrix expansion under confining pressure and axial compression in the beginning stages, and then as pore pressure rises, permeability increases.
出处
《煤炭工程》
北大核心
2016年第8期85-88,共4页
Coal Engineering
基金
国家自然科学基金资助项目(51174082)
河南省重点科技攻关资助项目(132102210485)
