• 责任者：Bao Yuan (Key Lab. of Computational Geodynamics ; CAS ; College of Earth Science ; University of Chinese Academy of Sciences ; Beijing 100049 ; China) ; Wei Chongtao
• 刊名：Earth Science
• 出版年：2013
• 卷期：38(5)
• 关键词：生物气 ; biogenetic gas ; 煤层气 ; coalbed gas
• 页码：p.1037-1046
• 图表：5 illus., 1 table, 43 refs.
• 分类号：1003
• issnNo：ISSN1000-2383
• isbnNo：CN42-1233/P

     Based on the statistic study of 324groups of published coal type gas geochemical data from 21basins or areas from all over the world,stratigraphic distribution,stable carbon and hydrogen isotopic composition,and spatial distribution of coal type gas in various genesis are analyzed.Multiple charts for identifying the genetic types of coal type gas are established.And the feasibility of these charts is demonstrated by an example.The results show that biogenic gases that generated from coal seam are not the same as normal biogas（compared with normal gas）.The most significant difference is theδ13C（CH4）value of microbial gases lower than that of normal biogas.The stable isotopic composition of microbial gases fall within the following ranges：δ13C（CH4）＆lt;-60‰,while for thermogenic gases,δ13C（CH4）＆gt;-40‰.And for mixed gases,δ13C（CH4）ranges from-60‰to-40‰.There is a tendency that from biogenic gases to thermogenic gases,δ13C（CH4）,δ13C（CO2-CH4）,δ13C（C2 H6-CH4）,and CH4 /（C2 H6 ＋C3 H8）gradually become heavier with the increase of the maturity of organic matter.An obvious positive correlation exists among aforementioned parameters.It is concluded that the charts ofδ13 C（CH4）andδ13C（CO2-CH4）,δ13 C（CH4）andδ13 C（C2 H6-CH4）,andδ13 C（CH4）and CH4 /（C2 H6 ＋C3 H8）are the most reliable charts for classifying the genetic type of coal type gas.