Log Interpretation For Watered Flooded Reservoir Of Upper Ng Group In Chengdao Oilfield

After water flooding development, fluid nature, pore texture, physical and chemical properties of rock ,oil and water distribution in oil layer will change to some degree during the process of oil-water displacement, mainly in the following aspects: larger water saturation and more complex salinity change of formation water after water flood, reservoir property change is related to water flooding degrees, complex relationship between reservoir resistance and water saturation, the original oil water distribution will be broken after water flooding, moreover, water flooding degree in and between oil layers are uneven because of reservoir heterogeneous.For a long period of waterflood development,oil layers of reservoirs are waterflooded seriously,but for the injection water salinity is variable,so the electric conductivity of rock is changeable. This paper studied the changement regularits of rock resistivity in the water flooding process on the basis of the material of core analysis,it also discussed the applicability of Archie equation in calculating remaining oil saturation of water flooded reservoir. According to the result of analysis, it is important to understand the waterflooding characteristics correctly and well log interpretation of the water flooded reservoir.In the paper, in view of characteristics of the water flooded reservoir of Upper Ng Group in Chengdao oilfield, different technologies of recognition and multidisciplinary analysis of the water flooded reservoir well logging are proposed systematacially,and SP curve was used successfully to calculate the mixed liquor resistivity continuously and accurately.In the paper, We probed the calculation methods of water production rate,oil relative permeability and water relative permeability,the last two are key parameters that affect the computational accuracy,and we presented the experience equation agreed with the geologic features of Chengdao oilfield, and the well log interpretation accuracy has visible enhancement.According to the water flooding features of Chengdao oilfield and research production mentioned above, a water flooded reservoir handling program is exploited. Conventional logging data of more then 10 wells of Chengdao oilfield are handled, and the interpretation accuracy is higher than 85%, a good effect of geological application is obtained and it can guide the evaluation of the water flooded reservoirs of the other oil fileds of Shengli oil region.