利用铸体薄片鉴定、X 射线衍射、镜质体反射率、扫描电镜及阴极发光等资料，对鄂尔多斯盆地下 寺湾龙咀沟地区长2 油层组储集层的岩石学、储层物性、成岩作用、成岩阶段及储层微观结构特征进行 了分析和评价。结果表明：下寺湾龙咀沟地区长2 油层组主要发育中—细粒岩屑长石砂岩；孔隙类型主 要为粒间孔隙；喉道类型主要为点状喉道；成岩作用类型主要为压实作用、胶结作用、交代作用和溶蚀作 用；在孔隙演化过程中，压实作用对储层物性的破坏性最强，其次为胶结和交代作用，溶蚀作用对储层孔 隙的改善效果明显。结合流体包裹体及镜质体反射率等分析资料，得出龙咀沟地区长2 油层组砂岩现 今处于中成岩A 期演化阶段。

Based on analysis of cast sections, X-ray diffraction, vitrinite reflectance, scanning electronic microscope and cathodoluminescence, this paper analyzed and evaluated the characteristics of petrology, reservoir physical properties, diagenesis, diagenetic stage and reservoir microstructure of the Chang 2 oil reservoir bet in Longzuigou area of Xiasiwan in Ordos basin. The results show that the Chang 2 oil reservoir set mainly developed medium and fine-grained lithic arkose. Its pore type is mainly intergranular pore and the main throat type is dominated by punctate throat. The diagenesis types are mainly compaction, cementation, replacement and dissolution. The compaction has the most destructive effect on reservoir physical properties in the process of porosity evolution, followed by cementation and replacement, while
dissolution improves the reservoir pore significantly. Combined the analysis data of the fluid inclusion and the vitrinite reflectance, it is considered that the Chang 2 oil reservoir set in Longzuigou area is now in the middle diagenetic stage A.