Abstract: In order to improve the effect of polymer flooding, different slugs were injected into the N development zone to optimize the slugs. In this paper, 25 million and 7 million molecular weight polymers of different concentrations were used to conduct indoor oil displacement test on the core, so as to determine the recovery factor, polymer consumption, water cut change and injection pressure change of each combination slug, and optimize the combination of slugs. The results show that high concentration polymer is helpful to the formation pressure holding and oil recovery, and can get lower water cut value and water cut value more quickly. High concentration polymer should be used for single polymer flooding, and at the same time, polymer can also be used for pre slug of combination slug. The same polymer with different concentration and three slug combination can get oil recovery closer to that of single slug. However, with the increase of the injection volume of the high concentration slug, the injection pressure increases obviously.In practice, it is better to consider comprehensively and choose the scheme with higher recovery, lower injection pressure and less polymer consumption.Compared with the single slug and the same polymer combination slug, different polymer combination slugs have more advantages in the comprehensive performance of recovery, polymer consumption, water cut minimum and injection pressure.

Key words: Polymer flooding, Molecule, Concentration, Slug

摘要： 为提高聚合物驱油效果，对N开发区进行不同段塞注入聚合物驱油室内实验，优选段塞。采用不同质量分数的2 500万和700万相对分子质量聚合物，对岩心进行室内驱油实验，明确各组合段塞的采收率、聚合物用量、含水率变化和注入压力变化，优选段塞组合。研究表明，高质量分数聚合物有助于地层憋压，提高采收率，可更快获得含水率低值及较低的含水率，单一聚合物驱宜采用高浓高分子聚合物，同时，高分子聚合物也可用于组合段塞的前置段塞使用；相同聚合物不同质量分数三段塞组合可获得与单段塞较接近的采收率，但随前置高质量分数段塞的注入量增大，其注压上升明显；实际中，宜综合考虑，选择采收率较高、注压较低、聚合物用量较少的方案；与单一段塞、相同聚合物组合段塞相比，不同聚合物组合段塞在采收率、聚合物用量、含水率及注压等综合性能上，更具优势。

关键词: 聚合物驱, 分子, 浓度, 段塞