煤层瓦斯围岩封盖能力的定量分析

采用瓦斯地质方法,对煤层瓦斯的封盖条件进行定量分析。提出了砂岩比、岩层厚度效应系数、顶板岩性3个瓦斯地质参数,计算了煤层瓦斯封盖层的封盖指数(SI),并对研究区二1煤层瓦斯封盖能力进行了瓦斯地质区划。结果表明:研究区封盖类型为Ⅰ—Ⅳ类,研究区东北部为强封盖区,中部个别地段为弱封盖区,其余大部分地区属于中等—较强封盖区。

Quantitative Analysis on Capped Ability of Surrounding Rock for Coal-seam Gas

The paper conducted quantitative analysis on the capped condition of surrounding rock for coal-bed gas with the gas-geology method.It put forward three gas geology parameters including sandstone ratio,the effect coefficient of rock stratum thickness and roof lithology,calculated the capped index(SI) of cap rock of coal seam gas,and zoned the gas geology units according to the capped ability of capped rock stratum of 21 coal seam in the studied region.The studied results indicated that the capping types of the studied region were classified intoⅠ-Ⅳ,the north-east part of the studied region belonged to Ⅰhigh capped region,partial section in the middle part belonged to Ⅳ lower capped region,and the most regions belonged to Ⅱ-Ⅲ capped regions having medium or more strong capped ability.