Reservior Evaluation Of Chang2 Oil-formation In Wangjie Oil Region, Ansai Oilfield

This paper carries out an intensive and systematic analysis to Chang 2 reservoir nature and oil reservoir conditions of Wang Jie oil region based on the principles of combing field observation and laboratory study, macro visual study and microscopic study, theoretical analysis and practical work, using the latest test analysis technologies, such as petrographic thin section observing, core sample observing, chonolith thin section evaluation, SEM-EDAX, permeability & porosity determination, and capillary pressure test. This analysis takes the Wang Jie Chang 2 oil region of An Sai oil field in Ordos Basin as example, develops analysis based on the sedimentary petrology, petroleum geology, oil reservoir engineering, geophysical well logging and reservoir evaluation & modeling study. It reveals the oil reservoir conditions, oil gas concentration rules and deepens oil reservoir understanding. It presents that the main litho logical character of Chang 2 in the Wang Jie oil region is light grey, glaucescent, blocky, middle and fine grain sandstone, and then with few silt-finestones and Siltstone. The types of pores are mainly primary porosity, secondary porosity and micro porous. The types of pore canals are mainly short head coarse types and short coarse types. The reservoirs in research areas are reservoir heterogeneity, among which the non-uniformity is weak inner-layers, and moderate in inter-layers.The main oil-bearing horizon in Wang Jie oil region is Chang 2, and belongs to the type of fluvial deposit. The microfiches type of Chang 2 can be divided into the channel sandbar, channel sand and floodplain dam side. Reservoir sand type of the major causes is the channel sand bar. The Chang 2 oil sands development framework is completely controlled by sedimentary faces distribution. Reservoir sensitivity evaluation shows that Chang2 has strong alkali and other sensitive contradictions are not obvious. The paper concludes that Wangjie explorationary region has beneficial combination of reservoir and good conditions for oil and gas traps through the reservoir control factors and accumulation of oil and gas, exploration area boundary extension. The paper proposed to explorate based on the features of the main oil-bearing layer of the reservoir sand body distribution, oil distribution and dynamics of development.