煤层气吸附时间计算及其影响因素分析

CALCULATION OF COAL BED GAS DESORPTION TIME AND ANALYSIS OF ITS INFLUENTIAL FACTORS

煤层气吸附时间是煤层气生产的一个重要参数 ,它直接影响煤层气井的产气速度和产气高峰到来的早晚。通过对影响吸附时间的因素的分析 ,作者认为 :煤阶、灰分、温度、显微煤岩类型、割理发育程度及煤样粒度等参数是影响吸附时间长短的最重要的因素。我国主要煤层气盆地的吸附时间一般为 0 .17～ 2 7.42d。吸附时间对产量的敏感性表明 ,中国的煤层气吸附时间对煤层气单井产量影响不大。

The desorption time of coal bed gas is a n important parameter in the production of coal bed gas. It directly affects the g as production rate of coal bed gas wells and determines if the gas production pe ak comes early or late. By analysis on the factors which affect desorption time, the authors considered that coal rank, ash content, temperature, microlithotype s, the developed degree of cleat and the grain size of coal samples are the most important factors to affect desorption time. The desorption time of major coal bed gas basins in China is generally 0.17～27.42 day. The sensibility of desorpt ion time to gas production shows that the desorption time of coal bed gas in Chi na has little influence over the monowell production of coal bed gas.