Two-Phase Interference Well Testing Interpretation Method for Polymer Flooding Multilayer Reservoir

The current research on interference well test technology is based on water flooding reservoir, but the analysis method of interference well test in polymer flooding reservoir has not been reported, which leads to unclear understanding of the physical property changes between wells in polymer flooding reservoir. Considering the characteristics of polymer flow, a two-phase interference well test model of polymer flooding multi-layer reservoir is established. The pressure, water saturation and polymer concentration are all implicitly solved to improve the stability of the numerical solution, and the typical curve is drawn. The results show that: the water phase viscosity is greater during the polymer flooding process, the pressure fluctuation of the active well is later, which affects the observation well, and the pressure fluctuation received by the observation well is greater. The results show that the interference well test curve of polymer flooding is farther to the right than that of water flooding in the early stage and higher than that of water flooding in the middle and late stage. The application example shows that coincidence rate with commercial software well test interpretation is over 90% when the model is degenerated to conventional water flooding, which proves the accuracy of polymer flooding interference well test model, and provides technical support for the improvement of well test method of polymer flooding reservoir.