Sedimentary Microfacies And Reservoir Evaluation For The Second Member Of Funing Formation In Gaoji Oilfield

Gaoji oil field is located in Chenqiao and Jinbei town Jinhu county Jiangsu province and has rich oil and gas resources. It belongs to a complicated small fault block reservoir and oil layers are influenced by structure, fault, lithology, physical properties. These conditions restrict the development of fine exploration. Considering the geological characteristics and development present situation of Fu2 Member in Gaoji oil field, this paper applies all kinds of exploration and development material comprehensively, takes the theory of petroleum geology, modern sedimentology and development geology, uses computer technology, and describes Fu2 Member of Gaoji oil field finely, then provides favorable theoretical guidance for further development.Through the analysis of the data such as well logging and drilling cores, this research identified the sedimentary type of Fu2 Member in Gaoji oil field, and makes clear the sand bodies and sedimentary microfacies distribution, and thinks it mainly developed the beach and bar deposition in the period of Funing group NO.2 member. In this area the main sedimentary microfacies are beach and bar and rip channel is visible. On the basis of the research above, the plans of sand body distribution and sedimentary microfacies of each layer, and the sedimentary ideograph is established.The research shows that there is mainly carbonate reservoir in Fu2 Member E1f22, while sandstone reservoir in E1f23. Through the research of petrological characteristics, pore structure and property, reservoir sandstone type is mainly feldspar cutting quality quartz sandstone, compositional maturity is low, and reservoir physical property is general and belongs to middle porosity and low permeability reservoir.Reservoir property is influenced by sedimentary microfacies and sandstone structure obviously. According to the heterogeneity research of every sand group, the opinion is that there is mainly serious heterogeneity in the layer, heterogeneity between layers and in plan the heterogeneity is controlled by sedimentary microfacies, and the sedimentary microfacies differences in plan cause the heterogeneity change.On the basis of the distribution of sedimentary microfacies,reservoir property and sand body, the paper conducted reservoir comprehensive evaluation, determined the evaluation standard, divided reservoirs of Fu2 member in Gaoji oil field into three types: I,II,III and IV(non reservoir), and drew comprehensive evaluation maps of all layers in the plane. Result shows that the reservoir type is mainly the class II and the class I reservoir is less.