新型pH敏感性聚合物调驱研究综述

An overview of the pH-sensitive polymer for novel conformance control and polymer-flood

pH敏感性聚合物是一种新型的聚合物调驱体系,其重要特点是聚合物分子结构对溶液pH的敏感性。在酸性条件下,聚合物分子卷曲,溶液黏度低,注入性能好;当酸进入地层与储层岩石发生反应后,pH值升高,聚合物溶液黏度增加,有效封堵高渗层,达到流度控制的目的。在调研国外pH敏感性聚合物调驱研究现状的基础上,介绍了聚合物的pH敏感特性,总结了矿化度、聚合物质量浓度等因素对pH敏感性聚合物流变特征的影响,并分析了低pH聚合物体系在多孔介质中的运移性能,证实pH敏感性聚合物能够提高注入能力,在油藏深部调剖和流度控制中效果良好,有广阔的应用前景。

The pH-sensitive polymer is a new type of profile-control and polymer-flood system. Its key fea- ture is the sensitivity of the polymer molecular structure to solution pH value, The acidic condition makes the polymer molecules coil tightly,resulting in a low viscosity. This allows the polymer solution to be in- jected easily. Once injected, the acid reacts with the formation mineral to increase the pH, stretching the polymer chains and causing a large increase in solution viscosity, which is effective for blocking high per- meability zones and mobility control. Through extensive literature research about the applications of pH- sensitive polymers, introduced polymer＇ s pH sensitive features, including a summary of the effect of fac- tors such as salinity, polymer concentration on the pH-triggered rheological properties. Then the transpor- tation of low pH polymer systems in porous media was analyzed. All of those indicate that the pH-sensitive polymer can improve the injectivity and achieve good treatment deep in the reservoir. It shows a broad prospect in oilfield application.