In recent years, new oil reservoirs have been discovered gradually in yan8 subsection of Yanan Formation in Linzhen area, Ordos basin. It is important to understand the reservoir characteristics of yan8 subsection for further exploration and exploitation. On the basis of drill-core samples observation and study on rock thin section, the reservoir characteristics and Porosity evolution of Yan8 subsection of Yanan formation were analyzed. The results showed that:The sand body in the northeast side of the stud...