Experimental and Statistical Investigation of Reservoir Properties with the Effect of Waterflooding Treatment

An oilfield reservoir over long-term operation may have different petrophysical information, which has a significant impact on oilfield maintenance and finance. Successful oilfield enhanced oil recovery benefits a lot from identifying and analyzing the variations of the critical properties after long-term water-flooding treatments. Since the inspection wells drilled within different development periods contain the core samples that have the petrophysical information at that period, it is necessary to collect and test the samples from different periods to investigate the overall tendency of the petrophysical properties. The samples from four inspection wells, which were drilled in four stages since the very beginning of development, were subjected to in-laboratory core analysis methods to illustrate the variation of some critical parameters in the reservoir. The permeability and porosity variation are revealed clearly by the experimental results. The migration and dissolution of clay minerals play a crucial role in the variation of petrophysical information and pore structure. To quantify the variations above, we applied the multiple linear regression model into our investigation. The dependent variable and all of the predictors in the model come from the experimental results. The quantitative results show the closed correlation between different parameters in the formation. With the development stage moving forward, the weight coefficients for different predictors have multiple trends. The experimental and statistical approach provides a novel understanding of the reservoir properties with the effect of waterflooding treatment.