Analysis of Factors Affecting Polymer Flooding Based on a Response Surface Method.

Both polymer injection time and injection rate play an important role in the development of an offshore reservoir with a limited service life of the platform. To quantitatively and qualitatively investigate the influence of the formation packing sequence, injection rate, polymer injection timing, and their interaction on the performance of polymer flooding, a numerical reservoir model is simulated in this study based on the properties of offshore reservoir LD in China. Also, the polymer flooding experimental scheme is designed according to the response surface method and single-factor analysis method. Based on numerical simulation and statistical analysis, a regression model is established to predict the incremental oil recovery factor of polymer flooding. The analysis of variance (ANOVA) shows that the regression model fits well with the experimental data. The three factors' influence capacities on the increased oil recovery factor from large to small are the injection rate, formation rhythm, and injection timing. From the analysis, it is also found that the improved polymer flooding performance can be achieved under an injection rate of 0.07-0.09 PV/a and an injection timing of 30% water cut for positive rhythm formation.