中国部分煤储层解吸特性及甲烷采收率  

DESORPTION PROPERTIES OF SOME COAL RESERVOIRS AND METHANE RECOVERY RECOVERY RATE IN CHINA

作　　者：傅雪海[1] 秦勇[1] 叶建平[2] 唐书恒[2] 章云根 

机构地区：[1]中国矿业大学资源与环境学院,徐州221008 [2]中国煤田地质总局第一勘探局,邯郸05600 [3]安徽煤田地质局第一勘探队,淮南232035

出　　处：《煤田地质与勘探》2000年第2期19-21,共3页Coal Geology & Exploration

基　　金：国家自然科学基金! (编号 :49772 13 1)

摘　　要：根据常压下的解吸实验和煤层气参数井实测数据分析 ,我国煤的解吸特性变化较大 ,解吸率主要受煤层埋深及煤级的影响。最佳解吸深度一般在 40 0～ 60 0 m之间 ,镜质体反射率小于3%时 ,随煤级的升高而增大 ;大于 3%时 ,则相反。我国煤储层的吸附时间长短与煤级没有特定关系 ,但在某些地区与煤层的含气量高低有关 ,甲烷含量低则吸附时间长 ,尤其是小于 8m3 /t时急剧增长。从现有资料看 ,我国煤储层的吸附时间一般不超达 9d。煤层甲烷采收率不仅取决于煤层的含气性、煤的吸附—解吸特性以及煤层所处的原始压力系统 ,而且还受控于钻井技术及开采工艺。根据美国的经验和我国部分测试结果 ,估算我国煤层甲烷的平均理论采收率为 2 7%Based on desorption experiments under normal pressure and the data obtained from coalbed methane(CBM) well tests,it is suggested that the desorption properties of coal reservoirs in China are very different from each other and the desorption rates are controlled primarily by buried depths and coal ranks The optimum desorption depth ranges from 400 to 600m However,it increases with coal rank if the vitrinite reflectance(R o,max )is less than 3%,and decreases with coal rank if R o,max larger than 3% In China there is no apparent correlation between adsorption time and coal ranks,however,in some places of China the adsorption time is related to gas content If the gas content is low,the adsorption time must be long,especially when the gas content is less than 8m 3/t The existing data show that the adsorption time of coal reservoirs in China is generally less than 9 d.The coalbed gas recovery rate is not only controlled by gas content,adsorption and desorption properties of coal,and by in place pressure system,but also by drilling techniques and mining technology According to experiences in the U S and measurement in China,the average theoretical recovery rate of CBM in China is estimated as 27%

关 键 词：煤层甲烷 解吸量 吸附时间 饱和度 采收率 

分 类 号：P618.11[天文地球—矿床学] TE377[天文地球—地质学]