为研究鄂尔多斯盆地吴起、定边地区延长组长7~长9 油层组的储层特征，利用薄片、粒度、压 汞、物性等资料，对储层的岩石学、孔隙结构、物性等特征进行了分析，并分析了沉积作用、成岩作用对储 层物性的影响。研究结果表明：吴起、定边地区上三叠统延长组长7~长9 油层组的储层主要发育岩屑 长石砂岩；孔隙以溶蚀粒间孔为主，孔隙度主要为8%～12%，渗透率主要为0.1～1 mD。压实作用使储集 层的原始孔隙空间损失；胶结作用不仅破坏了部分原生孔隙，而且使部分次生溶孔也遭到了破坏；溶解作 用使储层物性得到了改善。

In order to study the reservoir characteristics ofChang 7-Chang 9 reservoir group in Wuqi and Dingbian area of Ordos Basin, the data of thin section, grain size, mercury penetration and physical properties are used to analyze the petrology, pore configuration, physical properties of the reservoir. The effects of sedimentation and diagenesis on reservoir properties are also studied. The result shows that the reservoirs of Chang 7-Chang 9 reservoir group are mainly of lithic arkose, the pores are mainly corroded intergranular pores, the porosity ranges from8% to 12%, and the permeability ranges from 0.1mD to 1mD. Compaction makes the primary pores decrease, cementation not only damages the primary pores, but alsomakes the secondary dissolved pores suffer damage, and dissolution improves the reservoir properties.