Abstract: Due to the strong heterogeneity,conglomerate reservoir has a complex lithological and physical property background and a large rangeability of oil layer resistivity.All the above makes the quantitative evaluation of the conglomerate reservoir water flooded layers the focus and difficulty of the second regulation and development in oilfield.Based on well logging,coring,testing data and reservoir quality index,under the guidance of petroleum migration and accumulation theory,the computational model of the initial oil saturation of conglomerate reservoir is built.The differential value between initial oil saturation and current oil saturation is defined in the computational model.And the ratio between differential value and initial oil saturation is defined as the productivity index,which is the dynamic waterflood characteristic parameter of the reservoir from the beginning of waterflood development to the current reservoir state.Compared with the traditional waterflood characteristic parameter such as water production ratio and oil saturation,the advantage of productivity index lies in that it takes the dynamic waterflood process of reservoir into account.As a result,it has successfully avoided the great variation of resistivity rangeability of conglomerate reservoir and the shortcoming of quantitative evaluation on water flooded layers only by using current oil saturation.This method is used in the evaluation of conglomerate reservoir water flooded layers in Karamay Oilfield.and the results show that productivity index is the highest sensitive to quantitative evaluation of water flooded layers by comparative study of three waterflood parameters,with the rate of recognition accuracy of 89.58%.The evaluation results provide technical support for the adjustment of well pattern and the design of development program in Karamay Oilfield.

Key words: conglomerate reservoir, original oil saturation, productivity index, water flooded layers, quantitative evaluation