Well Logging Interpretation Method Of Water Flooded Reservoir And Its Application

The daqing oilfield is the terrestrial uneven multi-zone sandstone which gives priority towith river-delta facies sediment. Because of the reservoir heterogeneity serious, the thin andpoor reservoir develops. At the same time, as a result of the long-term water flooding,reservoir properties and fluid properties change considerably, and it aggravates the unevenagree of reservoir and fluid so that the accordance rates of the thin and poor layerinterpretation is lower. It has great influence on the oil field water flooding and layersadjusting and remaining oil describing. Thus, it is necessary to develop the investigation.Aiming at the complex situations of oil flooded in the late-mid period of the oil fieldwater flooding, using the normal logging to interpret the flooded grade will cause some errors.Therefore, establishing a kind of model identification technology that can aim at the floodedgrade of the thin and poor lays in Daqing, it will be helpful to correctly judge the floodedgrade of the reservoir. In the base of the changing law of the reservoir nature and the loggingresponse characteristics of the flooded, firstly, calculate the fractal dimension of loggingcurves. Then, through the research of key wells in study area, choose the logging curves andthe fractal dimension of thin-poor lay water flooded feature sensitively as distinguishingcomponent, and establish the standard sample set and the standard model database of thethin-poor water flooded. The last, using Fisher distinguishing method realizes the automaticpartition of thin-poor water flooded grade. The method will apply to the practical dataprocessing in two wells. And the explanation results will contrast with the core analysisresults. As a result, its accordance rates of explanation reach to74.8%. The method has thegood adaptability to resolve the automatic identification problem of the flooded grade, andcan improve the logging judging precision of the flooded grade.