Oil recovery processes depend on many factors that can be altered in order to maximize the sweeping efficiency in porous media, and one of these is the rheology behavior of the displacing agent. Furthermore, scales in the recovery process should also be considered: from the macro- to microscale systems, in which capillary forces become predominant. It is also well-known the non-Newtonian behavior of polymer solutions used in Enhanced Oil Recovery (EOR) processes. This has been considered before, explaining how the polymer’s viscosifying properties enhance the displacing process. Recently, another property exhibit by polymer solutions started being considered: the viscoelasticity. The interaction between the (macro)molecules in the displacing phase generates a complex stress field which cannot be simply addressed by an increment in the shear viscosity. We present a 2D, multiphase simulation at macro- and microscale of a recovery process with different fluid models, showing that viscoelastic fluids increase the recovery performance due to the extra stresses generated by the polymer molecules, up to a 15.4% when compared to traditional waterflooding techniques. The viscosity of the displacing phase affects indeed the recovery efficiency, and moreover, the results also evidenced that not only the bulk viscoelasticity, but also the interfacial forces play a vital role in the microscopic sweeping efficiency in polymer EOR flooding processes. This can be used when determining the properties of future EOR agents to be synthesized.

采油过程取决于许多因素，可以改变这些因素以使在多孔介质中的清扫效率最大化，其中之一是置换剂的流变行为。此外，还应考虑回收过程中的水垢：从宏观到微观的系统，其中毛细作用力占主导地位。众所周知，增强油采收率（EOR）工艺中使用的聚合物溶液的非牛顿特性。之前已经考虑了这一点，解释了聚合物的增粘特性如何增强置换过程。最近，开始考虑聚合物溶液表现出的另一种特性：粘弹性。位移相中的（大分子）分子之间的相互作用产生了一个复杂的应力场，该应力场不能简单地通过提高剪切粘度来解决。我们使用不同的流体模型在恢复过程的宏观和微观尺度上进行了二维，多相模拟，结果表明，粘弹性流体由于聚合物分子产生的额外应力而提高了恢复性能，与传统的注水方法相比，提高了15.4％技术。驱替相的粘度确实影响了采收率，此外，结果还证明，不仅本体粘弹性，而且界面力在聚合物EOR驱油工艺的微观清扫效率中也起着至关重要的作用。在确定将来要合成的EOR剂的特性时可以使用此方法。