Abstract A significant amount of oil (i.e. 60–70%) remains trapped in reservoirs after the conventional primary and secondary methods of oil recovery. Enhanced oil recovery (EOR) methods are therefore necessary to recover the major fraction of unrecovered trapped oil from reservoirs to meet the present-day energy demands. The chemical EOR method is one of the promising methods where various chemical additives, such as alkalis, surfactants, polymer, and the combination of all alkali–surfactant–polymer (ASP) or surfactant–polymer (SP) solutions, are injected into the reservoir to improve the displacement and sweep efficiency. Every oil field has different conditions, which imposes new challenges toward alternative but more effective EOR techniques. Among such attractive alternative additives are polymeric surfactants, natural surfactants, nanoparticles, and self-assembled polymer systems for EOR. In this paper, water-soluble chemical additives such as alkalis, surfactants, polymer, and ASP or SP solution for chemical EOR are highlighted. This review also discusses the concepts and techniques related to the chemical methods of EOR, and highlights the rheological properties of the chemicals involved in the efficiency of EOR methods.

中文翻译：

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化学添加剂及其流变特性在提高采收率中的作用

摘要 在采用常规的主要和次要采油方法后，大量石油（即60-70%）仍被困在储层中。因此，提高石油采收率 (EOR) 方法对于从油藏中回收大部分未回收的圈闭石油以满足当今的能源需求是必要的。化学 EOR 方法是一种很有前景的方法，其中将各种化学添加剂，如碱、表面活性剂、聚合物以及所有碱 - 表面活性剂 - 聚合物（ASP）或表面活性剂 - 聚合物（SP）溶液的组合注入储层以提高位移和波及效率。每个油田都有不同的条件，这对替代但更有效的 EOR 技术提出了新的挑战。这些有吸引力的替代添加剂包括聚合物表面活性剂、天然表面活性剂、纳米粒子和用于 EOR 的自组装聚合物系统。本文重点介绍了用于化学 EOR 的水溶性化学添加剂，如碱、表面活性剂、聚合物和 ASP 或 SP 溶液。本综述还讨论了与 EOR 化学方法相关的概念和技术，并重点介绍了与 EOR 方法效率相关的化学品的流变特性。