The characterization and enhanced oil recovery mechanisms of a nanosized polymeric cross-linked gel are presented herein. A negatively charged nanogel was synthesized using a typical free radical suspension polymerization process by employing 2-acrylamido 2-methyl propane sulfonic acid monomer. The synthesized nanogel showed a narrow size distribution with one peak pointing to a predominant homogeneous droplet size. The charged nanogels were also able to adsorb at the oil–water interfaces to reduce interfacial tension and stabilize oil-in-water emulsions, which ultimately improved the recovered oil from hydrocarbon reservoirs. In addition, a fixed concentration of negatively charged surfactant (sodium dodecyl sulfate or SDS) was combined with different concentrations of the nanogel. The effect of the nanogels combined with surfactant on sandstone core plugs was examined by running a series of core flooding experiments using multiple flow patterns. The results show that combining nanogel and SDS was able to reduce the interfacial tension to a value of 6 Nm/m. The core flooding experiments suggest the ability of the nanogel, both alone and combined with SDS, to improve the oil recovery by a factor of 15% after initial seawater flooding.

本文介绍了纳米级聚合物交联凝胶的表征和增强的采油机理。通过使用2-丙烯酰胺基2-甲基丙烷磺酸单体，使用典型的自由基悬浮聚合方法合成带负电荷的纳米凝胶。合成的纳米凝胶显示出狭窄的尺寸分布，其中一个峰指向主要的均匀液滴尺寸。带电的纳米凝胶还能够吸附在油水界面，以降低界面张力并稳定水包油乳液，从而最终改善了从碳氢化合物储层中回收的油。另外，将固定浓度的带负电荷的表面活性剂（十二烷基硫酸钠或SDS）与不同浓度的纳米凝胶混合。通过运行一系列使用多种流型的岩心驱油实验，研究了纳米凝胶与表面活性剂结合对砂岩岩心塞的影响。结果表明，纳米凝胶和SDS的结合能够将界面张力降低至6 Nm / m。核心驱油实验表明，单独的纳米凝胶和与SDS组合的纳米凝胶能够在初始海水驱油后将原油采收率提高15％。