After 43 years of water drive development, the DG oilfield reached the stage of high recovery and ultrahigh watercut. At present, the efficiency of enhanced oil recovery (EOR) technologies, namely waterflooding, in the DG oilfield and the stable production are low. To develop and evaluate a new EOR mode, we have performed pilot tests comparing the waterflooding technique and the weak-alkali alkali/surfactant/polymer (ASP) flooding. Based on the laboratory tests, the formulation of the weak-alkali ASP flooding system has been developed. The objective of the new EOR method is to maintain the stability of the system under reservoir conditions. In this paper, we focus on the factors influencing the effectiveness of the proposed weak-alkali ASP system, including sodium and potassium ion concentrations, calcium and magnesium ion concentrations, water quality, and the shear viscosity of the solution. The results show that, depending on water quality and the ion concentrations, the interfacial tension of the developed weak-alkali ASP system can be maintained at an ultralow level below 10^–3 mN/m. The influence of sodium and magnesium ion concentrations is slightly higher than that of potassium and calcium ion concentrations, respectively. Considering the cost-effectiveness of the new system, it is recommended that the solution be diluted with clean water mixed with oilfield sewage, and the calcium and magnesium ions be removed from the solution before preparation. When the core permeability is 95·10^–3 μm², the pore throat size has little effect on the molecular weight and viscosity of the system after shearing.

经过43年的水驱开发，DG油田达到了高采收率和超高含水阶段。目前，DG油田注水提高采收率（EOR）技术效率和稳产效率较低。为了开发和评估新的 EOR 模式，我们进行了对比水驱技术和弱碱/表面活性剂/聚合物 (ASP) 驱油技术的中试。在实验室试验的基础上，开发了弱碱三元复合驱体系的配方。新 EOR 方法的目标是在储层条件下保持系统的稳定性。在本文中，我们关注影响所提出的弱碱 ASP 系统有效性的因素，包括钠和钾离子浓度、钙和镁离子浓度、水质和溶液的剪切粘度。结果表明，根据水质和离子浓度的不同，所开发的弱碱三元复合体系的界面张力可以维持在10以下的超低水平。^–3 mN/m。钠和镁离子浓度的影响分别略高于钾和钙离子浓度。考虑到新系统的成本效益，建议将溶液用与油田污水混合的清水稀释，并在制备前去除溶液中的钙和镁离子。当岩心渗透率为95·10 ^–3 μm ^{2 时}，孔喉尺寸对剪切后体系的分子量和粘度影响不大。