基于地层条件下煤层瓦斯流动模拟研究

摘要

为了研究地层条件下瓦斯流动特点，通过建立瓦斯吸附－解吸、扩散和渗流综合流动数学模型，分析不同埋深条件下瓦斯流动机制，并模拟吸附层和滑脱效应对瓦斯流动的影响。结果表明：随煤层埋深增加，部分纳米孔隙内瓦斯流动机制由扩散过渡到渗流，这有利于瓦斯运移；在煤层深部，瓦斯吸附层和滑脱效应对瓦斯渗流作用影响不大；随埋深增加，瓦斯吸附层对瓦斯运移影响逐步增大，而滑脱效应则逐步弱化；在埋深相同时，两者对瓦斯运移的影响都随孔隙直径增大而减小。研究有助于深入了解瓦斯在深部煤层流动的机制，提高深部煤层瓦斯抽采效果。%In order to study the gas flow characteristics under geological conditions of coal seam , a comprehensive mathemati-cal model of gas flow considering the adsorption -desorption , diffusion and seepage of gas was proposed .The gas flow mech-anism under different buried depth was analyzed , and the influence of adsorption layer and slippage effect on gas flow were simulated .The results showed that with the increase of buried depth , the gas flow mechanism in partial nanometer pores tran-sits from diffusion into seepage , which is beneficial to gas migration .In deep coal seam , the influence of gas adsorption layer and slippage effect on gas seepage is slightly .With the increase of buried depth , the influence of gas adsorption layer on gas migration increases gradually , while that of slippage effect reduces gradually .With the same buried depth , both the influence of gas adsorption layer and slippage effect on gas migration decrease with the increase of pore diameter .It contributes to fur-ther understand the gas flow mechanism and improve the gas drainage effect in deep coal seam .