Study on the characteristics of sedimentary reservoirs in the sandstone tight oil reservoirs of the Permian Jingjingzigou Formation in the Satan Block

The Permian Jingzigou Formation in Satan Block of Jikang Oilfield is an important target for tight oil exploration in Jinan Depression, eastern the Junggar Basin. This paper systematically reveals the sedimentary patterns, diagenetic evolution, and oil and gas enrichment laws of sandstone reservoirs in the area through detailed stratigraphic correlation, sedimentary microfacies analysis, diagenesis, and comprehensive reservoir evaluation. The research results indicate that the Jingjingzigou Formation has developed sedimentary systems of southeast source braided river delta and northeast source fan delta, with underwater distributary channel sand bodies as the dominant reservoir. The reservoir is characterized by low porosity（porosity 8%-18.6%, average 11.6%） and low permeability （permeability 0.02-43.64 mD, average 0.94 mD）, with secondary dissolved pores and residual intergranular pores as the main storage spaces, and fractures improving permeability. The fault system divides the lithological body to form a fault block reservoir, and the dissolution phase and fracture development zone are high-yield sweet spots. The research results provide geological basis for the efficient development of tight oil in the Satan Block.