Abstract: Based on core observation, comprehensive laboratory analysis, combined with logging and other means, this paper studied the petrological and physical characteristics of Shahejie Formation reservoir in the study area, analyzed the characteristics and main controlling factors of reservoir development. The result shows that Feldspar lithic sandstone (49.29%) is the main rock type, followed by lithic feldspar sandstone (33.21%), which are near provenances with low compositional maturity. The porosity of the reservoir is mainly distributed in the range of 5%~25%, accounting for 83.38% of the sample, and the permeability is mainly distributed in the range of 0~10 mD, accounting for 77.45% of the sample, which belongs to the ultra-low porosity–low porosity–medium porosity, ultra–low permeability reservoir. Porosity and permeability are different in the vertical sections of the reservoirs, and the correlation is poor, and the reservoir heterogeneity is strong. Based on the above analyses, the reservoir physical property are mainly controlled by sedimentary facies, diagenesis and tectonics. Subaqueous distributary channel, underwater natural dike, mouth bar sand body in delta front, distributary channel, fissure fan sand body in delta plain and nearshore subaqueous fan are favorable reservoir distribution facies belts. Compaction and cementation lead to the deterioration of reservoir properties, micritic carbonate and chlorite cementation, dispersion cementation has a certain positive effect on the protection of the remaining intergranular pores. Morever, the dissolution and metasomatism of feldspar and debris also improved the performance of the reservoir. The tectonism is the effective supplement for reservoir development.

Key words: reservoir characteristics, controlling factor, sedimentary facies, diagenesis, Sha 3 Member, Qinan Sag