Abstract:

China's coalbed methane resources is estimated at 25-35 trillion m³,distributed in coal forming sets of 39 coal-bearing basins or 68 coal-bearing units.The exploration of coalbed methane is different either from conventional oil/gas or coal,the traps of coalbed methane can be classified into 4 types,i.e.gas pressure sealing trap,confined water sealing trap,micro-penetration sealing trap from top water-bearing bed and structural trap.According to the study of accumulation regularity for coalbed methane on regional thermodynamic metamorphism,regional compaction metamorphism and structure dynamic metamorphism,the areas of high-productivity are located in (1) gas pressure or confined water sealing area where there is thermodynamic metamorphism,(2) confined water sealing area where there is structure dynamic and thermodynamic metamorphism,and (3) confined water sealing area where there is light-compacted area and lifted lately.

Key words: coalbed methane, resources, type of gas reservoir, distribution characteristic

摘要：

预测了中国煤层气远景资源量约 25～35万亿m³,分布于 39个含煤盆地或 68个聚煤单元的八套含煤层系中;探讨了煤层气不同于常规石油天然气或固体煤的勘探特性;划分了压力封闭气藏、承压水封堵气藏、顶板水网络状微渗滤封堵气藏和构造圈闭气藏四大类煤层气气藏类型;分析了煤层气高产富集的基本条件,特别是从煤的区域热变质、区域压实变质和构造应力变质上,论述了对煤层气高产富集的控制作用,进一步指出了热变质压力封闭及承压水封堵区、应力-热变质承压水封堵区和轻压实变质、后期抬升的承压水封堵区是煤层气高产富集最有利的地区.

关键词: 煤层气, 资源, 气藏类型, 分布特征