关键词: 低煤阶煤层气, 渗透率, 含气量, 解吸, 成藏模式

Abstract: Development of low-rank coal-bed methane(CBM)in overseas has made enormous commercialized progress,which is mainly due to preferential national policy,advanced technology and basic theory with guiding significance.The foreign theoretical progress and the basic theoretical research ideas and methods are used for reference to research the geologic characteristics and reservoir patterns of low-rank coal-bed methane in China.The results showed that the low-rank coal-bed methane in China has characteristics of great thickness of coal bed,low-content gas,easy re-construction permeability,short adsorption time and two desorption peaks.On the base of the results,the paper has put forward three reservoir patterns for low-rank coal-bed methane in China,including deep confined overpressure reservoir pattern,late-biogenic gas reservoir pattern in gentle slope of basin margin and structural height conventional hydrodynamic reservoir pattern.The two latter patterns are considered as the preferable development target under the current technical conditions in China.

Key words: low-rank coal-bed methane, permeability, gas content, desorption, reservoir pattern