Capital and operating expenses of polymer injection projects are sometimes borderline to ensure profitability. Therefore, it is of interest to significantly improve the oil recovery potential with a low enough marginal cost. The addition of surfactant is very effective to enhance oil recovery, but, with traditional formulation guidelines, the high cost of chemicals and the difficulties in preparing the SP solution is major obstacles. The objective of this study is to try to adapt the concept of optimal surfactant formulation, without trying to achieve ultra-low interfacial tensions, to improve the overall efficiency of polymer injection.

Phase behaviors of conventional surfactants/crude oil/water systems have been studied to find the optimal formulation conditions at high surfactants concentration. This ultra-low tension formulation was then diluted by more than one order of magnitude compared to “traditional” surfactant designs and was successfully tested in core floods at different injected volumes in order to optimize the design and minimize the cost.

Contrary to expectations, it was found that the optimal formulation used at ultra-low concentrations can sufficiently modify the flow propagation to significantly improve polymer flood. The volume of surfactant injected was optimized to be “good enough” just to upgrade polymer flood without seeking complete desaturation. The low formulation concentration level makes it easy to handle and can considerably extend the application limits of polymer injection.

聚合物注入项目的资本和运营费用有时处于临界点，以确保盈利。因此，以足够低的边际成本显着提高采油潜力是有意义的。添加表面活性剂对提高采油率非常有效，但按照传统的配方指南，化学品的高成本和制备 SP 溶液的困难是主要障碍。本研究的目的是尝试调整最佳表面活性剂配方的概念，而不是试图实现超低界面张力，以提高聚合物注射的整体效率。

已经研究了常规表面活性剂/原油/水体系的相行为，以找到高表面活性剂浓度下的最佳配方条件。然后，与“传统”表面活性剂设计相比，这种超低张力配方被稀释了一个数量级以上，并成功地在不同注入量的岩心驱替中进行了测试，以优化设计并最大限度地降低成本。

与预期相反，发现在超低浓度下使用的最佳配方可以充分改变流动传播，从而显着改善聚合物驱。注入的表面活性剂的体积被优化为“足够好”，只是为了升级聚合物驱油而不寻求完全去饱和。低配方浓度水平使其易于处理，并且可以大大扩展聚合物注射的应用范围。