煤炭工程 ›› 2016, Vol. 48 ›› Issue (8): 85-88.doi: 10.11799/ce201608026

• 研究探讨 • 上一篇    下一篇

瓦斯压力对两种煤样渗流特性影响的试验研究

孙光中,郭兵兵,王公忠,等   

  1. 河南工程学院
  • 收稿日期:2016-01-01 修回日期:2016-04-20 出版日期:2016-08-10 发布日期:2016-08-19
  • 通讯作者: 孙光中 E-mail:sgz228165@csu.edu.cn

Experimental study of gas pressure to seepage characteristics of two different coal samples

  • Received:2016-01-01 Revised:2016-04-20 Online:2016-08-10 Published:2016-08-19

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。

关键词: 瓦斯压力, 渗透率, Klinkenberg效应, 构造煤, 硬煤

Abstract: Abstract:According to the response characteristics of tectonic coal to gas pressure, experimental studies about permeability of Two kinds of different coal samples were carried out with indigenously developed and improved experiment facility for triaxial seepage flow test to fluid-solid-thermal coupling gas filled coal. The results shows 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, the permeability of two kinds of coal sample with gas pressure changes greatly, Klinkenberg effect and inflection is also inconsistent, which is mainly affected by the sample adsorption constant. The reason for decreased first then increased of coal permeability: resulting in a reduced permeability of Klinkenberg effect and gas adsorption effect of coal matrix expansion under confining pressure and axial compression in the beginning stages, later pore pressure increase leads to increase the permeability of the coal plays a dominant role, those co-produced the effect. The research results provide a theoretical basis to improve coal-bed methane extraction rate.

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