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

摘要： 借鉴国外煤层气成藏理论研究的思路和方法,开展了中国低煤阶煤层气藏的地质特征和成藏模式研究.研究表明,中国低煤阶煤层气藏具有煤储层厚度大、含气量低、渗透率易改造、吸附时间短和两个解吸峰值的特征;存在深部承压式超压成藏模式、盆缘缓坡晚期生物气成藏模式及构造高点常规圈闭水动力成藏模式3种低煤阶煤层气成藏模式.在目前技术条件下,构造高点常规圈闭水动力煤层气藏和盆缘缓坡晚期生物煤层气藏是勘探开发的首选目标.

关键词: 低煤阶煤层气, 渗透率, 含气量, 解吸, 成藏模式