准噶尔盆地低煤级煤层气成藏地质特征

Trapping Characteristics of Coalbed Methane in Low-rank Coal of Zhungaer Basin

从煤层气控制因素入手,对准噶尔盆地的煤层气成藏特征和煤层气藏的分布进行了分析,认为准噶尔盆地是西北地区主要的聚煤盆地,煤层厚度大、煤层层数多、煤级低,具有典型低煤级煤层气盆地的特征。准噶尔盆地煤层气资源量很大,南缘无论是井下还是地表,煤层气显示都很活跃。准噶尔盆地低煤级煤层气成藏模式是盆缘陡坡和缓坡模式。通过构造、水文地质特征分析对准噶尔盆地划分出乌鲁木齐河—白杨河煤层气藏、昌吉南煤层气藏、四棵树煤层气藏、小拐煤层气藏、克拉玛依煤层气藏、乌尔禾煤层气藏、彩南—大井煤层气藏,这些区域是开展煤层气勘探的有利区块。

Based on the controlling factors of coalbed methane （CBM）, the characteristics and distribution of CBM formation in Zhungaer Basin have been analyzed, and the results reveal that Zhungaer Basin is the main coal-bearing basin in northwest China, which has the characteristics of representative basin of low-rank CBM, such as big thickness, many coal seams and low-rank coal. In Zhungaer Basin, the CBM resources are very abundant, and CBM indication is very active either in well or on the surface of the southern edge. The formation models of low-rank CBM reservoir include steep slope and gentle slope in the basin edge. Based on the analysis of tectonic and hydrologic geological characteristics of Zhungaer basin, seven CBM reservoirs are divided as follows, Urumqi-Baiyanghe CBM reservoir, South Changji CBM reservoir, Sikeshu CBM reservoir, Xiaoguai CBM reservoir, Kelamayi CBM reservoir, Wuerhe CBM reservoir, and Cainan-Dajing CBM reservoir, these areas are profitable for CBM exploration.