中外低煤阶盆地煤层气成藏及资源开发潜力对比分析——以中国吐哈盆地和保德河盆地为例

Analogy on CBM reservoir formation and its exploration potential in low-rank coal bearing basins in China and other parts of world: An example of Tuha Basin in China and Powder River Basin in USA

从吐哈盆地和保德河盆地的沉积、地层、成煤、构造等背景出发 ,结合两盆地煤层气勘探所取得的煤储层资料 ,对比分析了低煤阶盆地煤层气成藏及资源开发潜力。分析表明 ,吐哈盆地和保德河盆地虽然分属于不同的大地构造单元 ,盆地演化不同 ,但其含煤性相似 ,特别是同属低变质的褐煤—亚烟煤类 ,含煤性较好 ,沉积、水文地质条件近似 ,因而盆地煤层气成藏具有一定的可比性。美国保德河等低变质煤盆地煤层气商业性开发成功的事实说明 ,对于低变质煤盆地 ,即使气含量较低 ,但只要成藏条件合适 。

Based on the coalbed methane background,such as sedimentary,strata,coal formation and structure in both Tuha Basin and Powder River Basin,and combined with the CBM data obtained from coal reservoir exploration,CBM deposition and their exploitation potential are analyzed by contrast in this paper.The research result indicates that although both Tuha Basin and Powder River Basin respectively belong to defferent geo tectonics units with different basin evolution,but coal bearing characteristics are similar in some aspects like coalification with the feature of low rank coal,good coal bearing characteristics,sedimentary and geolydrologic conditions.Therefore,both basins could be drawn an analogy in CBM reservoir formation.The fact of lots of CBM industrial development conducted successfully in Powder River Basin indicates that even if the gas content is lower in low rank coal basin,it also has the large potential in CBM resources exploitation as long as various reservoir conditions are suitable for CBM storage.