引言煤层气系指腐植型有机物在成煤过程中所形成的天然气的总和,其主要成份是甲烷,是天然气的一个重要类型。在现行煤矿规范用词中称之为瓦斯,是一种有害气体。据计算,1kg纤维素在变成烟煤的过程中能生成69.1kg甲烷气体,生成1t无烟煤可产生360~400m3瓦斯,据测定,现今煤层中含瓦斯量,一般不超过60m3/t。也就是说,成煤过程生成的瓦斯,大部分都已转移到围岩(可能形成气床)或大气中去了。我国煤炭储量丰富,煤层瓦斯储量也 Introduction CBM refers to the sum of natural gas formed by humic organic matters during coal formation. The main component of methane is methane, which is an important type of natural gas. In the current code of coal mines called gas, is a harmful gas. It is calculated that 1kg of cellulose can generate 69.1kg of methane gas when it turns into bituminous coal and generate 1t of anthracite to produce 360 ​​~ 400m3 of methane. It is determined that the amount of methane in coal seams nowadays is generally not more than 60m3 / t. In other words, most of the gas generated during the coal formation has been transferred to the surrounding rock (which may form a gas bed) or to the atmosphere. China is rich in coal reserves, coal reserves also