鄂尔多斯盆地东南部延长组长7段泥页岩储层特征

The Characteristics of Shale Reservoir of the No.7Members in Yanchang Formation of Southeast Ordos Basin

通过孔隙度、脉冲渗透率、全岩X-射线衍射、扫描电镜等实验手段,对延长组长7段陆相泥页岩储层特征进行了研究。实验分析表明,陆相泥页岩储层具有低孔低渗特征,有机质丰度高,但有机质演化程度低,有机质孔隙不发育。黏土矿物含量高,以伊/蒙混层为主,伊/蒙混层间层比为15%。储集空间以微孔隙和微裂缝为主。储集物性与石英含量正相关。泥页岩储层中高的黏土矿物是造成储层物性差的重要原因,因此石英含量尤为重要,不仅有利于增加储集空间,也有利于储层压裂改造。

Based on the experimental analysis of porosity, pulse permeability, X-ray diffraction of rock min- erals, scanning electron microscopy,the characteristics of terrestrial mud shale reservoir of the No. 7 mem- bers of Yanchang Formation was researched in Ordos Basin. The results show that shale in Yanchang For- mation contains rich organic matter with the characteristic of low porosity, permeability and thermal matu- rity. Organic matter pores are rarely seen. The illite-smectite mixed layer is the main part of clay minerals with smectite-illite ratio of 15 %. Macro pores and macro-fissures are the main reservoir spaces. Reservoir physical property has positive correlation with the amount of quartz. High content of clay minerals is the main cause for the low porosity of shale reservoir. Therefore, quartz is important for reservoir space broade- ning and reservoir fracturing.