不同粘度条件下聚合物驱油微观数值模拟研究

Microscale Numerical Simulation of Polymer Flooding under Varying Viscosity Conditions

摘要: 为探讨聚合物粘度对非均质油藏中采收率的影响，本文构建了二维VOF-Navier-Stokes剪切变稀聚合物驱油模型，并结合Carreau流变模型进行了数值模拟。研究通过在具有高、低渗通道的微观物理模型中分析不同聚合物粘度下的界面演化与稳定性，揭示了粘度对驱油过程中的波前稳定性及采收率的影响。结果表明，低粘度聚合物易导致“粘性指进”现象，影响低渗通道采收率；适当提高粘度有助于稳定界面，减少不稳定现象，提高低渗通道的采收率，但过高粘度则可能增加粘滞阻力，影响高渗通道的驱替效率。研究揭示了聚合物粘度对采收率的不同影响规律，为聚合物驱油技术的粘度调控提供了微观理论依据。

Abstract: To investigate the effect of polymer viscosity on oil recovery in heterogeneous reservoirs, a two-dimensional VOF–Navier-Stokes model incorporating shear-thinning polymer flooding was developed. Numerical simulations were conducted using the Carreau rheological model. The study analyzed interfacial evolution and stability under different polymer viscosities within a micromodel featuring high- and low-permeability channels. The results reveal that viscosity plays a critical role in stabilizing the displacement front and enhancing oil recovery. Low-viscosity polymers tend to induce viscous fingering, thereby reducing recovery in low-permeability zones. Conversely, a moderate increase in viscosity enhances front stability, mitigates instabilities, and improves sweep efficiency in low-permeability channels. However, excessively high viscosity may lead to increased viscous resistance, negatively affecting displacement efficiency in high-permeability zones. This study elucidates the varying impacts of polymer viscosity on oil recovery and provides a pore-scale theoretical basis for optimizing viscosity in polymer flooding applications.