Department of Geosciences and Geological and Petroleum Engineering, Missouri University of Science and Technology, Rolla, Missouri65409, United States.
Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri65409, United States.
ACS Appl Mater Interfaces. 2023 Jan 25;15(3):4419-4429. doi: 10.1021/acsami.2c17390. Epub 2023 Jan 10.
Acrylamide-based polymer gels have been applied to control the preferential flow in the subsurface for decades. However, some commonly used crosslinkers, such as Cr (III) and phenol-formaldehyde, are highly toxic and are being phased out because of stringent environmental regulations. This work uses l-lysine as the green crosslinker to produce acrylamide-based polymer gels. This article systematically studied the effect of lysine and polymer concentration, salinity, pH, and temperature on gelation behavior and thermal stability. Besides, the gelation mechanism and crosslinking density were elucidated in this work. A high-permeability sandstone core was used to test the plugging efficiency of this novel green gel system. This polyacrylamide/lysine system has a controllable gelation time. It can form gels at temperatures higher than 80 °C, with the gelation time from hours to days, and the elastic modulus of the gel can reach over 400 Pa. In addition, the crosslinked gels have been stable at 80 to 130 °C for over 200 days. This novel gel system could decrease rock permeability by over 1000 times. Besides, the is two times higher than the , confirming that the current gel system can reduce the permeability to water more than that to oil. As a green gel system, this novel polymer gel system could replace the current toxic gel systems for the preferential fluid control for water management projects in oil and gas reservoirs, enhanced geothermal systems, and carbon capture and sequestration projects.
丙烯酰胺基聚合物凝胶已被应用于控制地下水中的优先流达数十年之久。然而，一些常用的交联剂，如三价铬（Cr(III)）和酚醛，具有高毒性，并且由于严格的环境法规，正逐步被淘汰。本工作使用赖氨酸作为绿色交联剂来制备丙烯酰胺基聚合物凝胶。本文系统研究了赖氨酸和聚合物浓度、盐度、pH 值和温度对凝胶行为和热稳定性的影响。此外，本工作还阐明了凝胶的成胶机制和交联密度。我们使用高渗透率的砂岩岩心来测试这种新型绿色凝胶体系的封堵效率。这种聚丙烯酰胺/赖氨酸体系具有可控的成胶时间。它可以在 80°C 以上的温度下形成凝胶，成胶时间从几小时到几天不等，凝胶的弹性模量可达到 400Pa 以上。此外，交联凝胶在 80-130°C 下稳定 200 天以上。这种新型凝胶体系可使岩石渗透率降低 1000 倍以上。此外， 是 的两倍，这表明当前的凝胶体系可以降低水相渗透率，而对油相渗透率的降低程度更高。作为一种绿色凝胶体系，这种新型聚合物凝胶体系可替代当前用于油气藏水管理项目、增强型地热系统和碳捕获与封存项目中的有毒凝胶体系，以实现对优先流体的控制。
