在千米深度下赋存煤层气的煤层是致密的多孔介质,煤层的渗透率低,对于致密的多孔介质渗流,滑脱效应十分显著,而滑脱效应又可以增加煤储层的渗透性能。采用试验研究的方法对吉林和阜新两地的低渗煤样进行滑脱试验,研究围压和孔隙对煤层气滑脱效应的影响,分析不同围压和孔隙水压力下滑脱渗透率对气体渗透率的影响,找到滑脱效应对不同低渗储层气测渗透率的有利影响的围压范围,验证低渗煤样中气体滑脱效应存在的普遍性。对弄清煤体内部结构特性和煤层气在煤层中的滑脱流动机制,实现低渗储层煤层气工业化开采具有一定的理论价值。
Under the depth of about 1 000 m in the deep mining, the pressure of the coal-bed is considerably high and the permeability of the coal-bed is low, in which the porous media are regarded to be highly compacted. Considering the percolation in this pre-pressing porous media, the slippage effects are remarkable, which will increase coal reservoir penetration function. So the experimental methodology is adopted to study the coal samples in Jilin and Fuxin City in order to explore the influence of slippage effects considering confining and pore water pressure, and to analyze the influence of slippage on the gas permeability under different confining and pore water pressures, and to find the range of confining pressure of beneficial influence of slippage on the gas log permeability of different hypotonic reservoirs. It verifies the universal existence of low permeability coal gas slippage effect. The experimental results establish the foundation of understanding the internal structure of coal and coal-bed methane slippage flow in coal seams and present significant theoretical value for carrying out coal-bed methane industrialization in hypotonic reservoirs.