Study on the reservoir characteristics of the second and the third sub-members of the third member of Shahejie Formation in north area of Gaoshangpu oilfield

In second and the third sub- members of the third member of Shahejie formation in north area of Gaoshangpu Oilfield,the oil-bearing interval is long,with big variance on reservoir characteristics.Through the cast thin sandstone core sheet and mercury,such as data analysis,carried out reservoir lithology,physical property,Research reservoirspace types and pore structure and other aspects of the work.The results show that the reservoir lithology of the second and the third sub-members of the third member of Shahejie formation in north area of Gaoshangpu oilfield are mainly of lithic feldspathic sandstone,with lower compositional maturity and structure maturity,and mainly developed intragranular pores and dissolved pores,mainly withⅡ pore structure,namely the typical low-porosity and low-permeability reservoir.On the plane,the physical property is controlled by sedimentary facies.The vertical compaction and cementation will lead to deterioration of reservoir properties,while the secondary porosity produced by dissolution will improve reservoir properties.