临汾与保德地区构造差异性特征及其对煤层含气性的控制

为研究鄂尔多斯盆地东缘煤层含气性的构造控制作用,在野外构造变形特征系统研究的基础上,结合区域构造背景分析及构造应力场恢复,揭示了鄂尔多斯盆地东缘临汾和保德区块构造发育的差异性特征及其对煤储层含气性的控制作用。结果表明:研究区主要经历了燕山期NW—SE向的构造挤压作用和喜马拉雅期NW—SE向的伸展作用;南部临汾区块燕山期NW—SE向的挤压作用强烈,发育NE—NNE向的逆冲断层和次级宽缓褶皱构造等,有利于煤层气的保存,即使后期叠加了一定的喜马拉雅期NW—SE向的伸展作用,使煤层气部分散失,但总体含量较高,且高值区与构造位置相关性很好;北部保德区块燕山期挤压构造变形作用不显著,喜马拉雅期NW—SE向的伸展作用较突出,NE向正断层较为发育,为煤层气的运移及散失提供了条件,致使煤层含气量相对较低。

Diversity structural characteristics and control action on coal bed gas content in Linfen and Baode area

In order to study the tectonic control action for the eastern edge of the Ordos Basin coal bed gas，based on system research of field structural deformation，also combined with regional tectonic analysis and tectonic stress field recovery，revealed the differences of structural development and control action on coal bed gas content in Linfen and Baode blocks，eastern edge of Ordos Basin.The results show that study area mainly experiences the Yanshan NW-SE trending tectonic compression action and Himalayan NW-SE trending extensional action.Yanshan NW-SE trending compression developed strongly in Linfen block of the southern study area.Conducive to the preservation of coal bed methane with NE-NNE trending thrust faults and secondary gentle folds，etc.Late superimposed certain Himalayan NW-SE trending extensional action making coal bed methane partial loss.But on the whole the content is higher and high values area correlates well with the structural position.Yanshan compression tectonic deformation was not significant in Baode block of the northern study area，Himalayan NW-SE trending extensional was more outstanding.NE-trending normal faults development provided favorable conditions for coal bed methane migration and loss，resulting in relatively low gas content.