鄂尔多斯盆地东北部致密砂岩气成藏机理与富集规律——以榆林气田为例

Mechanism of accumulation in tight shale gas reservoir northeastern Ordos Basin-case study of Yulin gas field

鄂尔多斯盆地东北部具有南北向构造特征及发育的裂缝,为天然气成藏提供有利条件。研究区山西组主要存在两期充注成藏:依次为早侏罗世—中侏罗世和晚侏罗世—早白垩世。气源岩有机质含量较高,提供了丰富的生气母质。研究区以石英砂岩为主,且山西组顶部发育有良好的盖层条件。

The northeastern Ordos Basin features north-south structure and developed fractures,which are favorable for gasaccumulation.There are two gas charge stages in research areas of Shanxi formation:Early Jurassic-Middle Jurassic and late Jurassicearlycretaceous.High content of organic matter in gas source rocks provides rich gas parent materials.The research area is quartzsandstone,and the top of the Shanxi formation has good caprock conditions.