Guo Hongbin, Ge Jijiang, Li Longjie, Zhang Guoliang, Li Ziwei, Wang Wenhui, Liu Mingjia
School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Research Institute of Exploration and Development, Tarim Oilfield Company, PetroChina, Korla 841000, China.
Gels. 2022 Jun 8;8(6):362. doi: 10.3390/gels8060362.
The properties of a reinforced gel with partially hydrolyzed polyacrylamide (HPAM) as the main agent, water-soluble phenolic resin (WSPR) as the crosslinker, and nano-SiO as the stabilizer were evaluated in terms of gelation time, gel strength and thermal stability under the conditions of 110 °C and 12.124 g/L salinity in water. The results showed that the gelation time of the gel with high strength was adjustable from 3 to 23 h, remaining stable for more than 180 days under stratigraphic conditions, although with a certain degree of early dehydration in the gel. Cryo-scanning electron microscopy (cryo-SEM) and dynamic light scattering (DLS) analysis revealed that nano-SiO improves the dispersion of the polymer in water, resulting in a more homogeneous structure of the formed gel and thus improving the strength of the gels. In addition, rheological tests and cryo-SEM showed that the interaction between nano-SiO and the polymer could inhibit the degradation of polymer to a certain extent and improve the thermal stability of the gel. However, the oxidative degradation of the gel is still the main cause of early dehydration of water-soluble phenolic resin gel, and the addition of a small amount of hydroquinone to the gelants can significantly improve the antioxidative degradation properties of phenolic resin gel.
以部分水解聚丙烯酰胺（HPAM）为主剂、水溶性酚醛树脂（WSPR）为交联剂、纳米SiO为稳定剂的增强凝胶，在110℃和水中盐度为12.124g/L的条件下，对其凝胶化时间、凝胶强度和热稳定性进行了评价。结果表明，高强度凝胶的凝胶化时间可在3至23小时内调节，在地层条件下可保持稳定超过180天，尽管凝胶存在一定程度的早期脱水现象。低温扫描电子显微镜（cryo-SEM）和动态光散射（DLS）分析表明，纳米SiO改善了聚合物在水中的分散性，使形成的凝胶结构更加均匀，从而提高了凝胶的强度。此外，流变学测试和cryo-SEM表明，纳米SiO与聚合物之间的相互作用在一定程度上可以抑制聚合物的降解，提高凝胶的热稳定性。然而，凝胶的氧化降解仍然是水溶性酚醛树脂凝胶早期脱水的主要原因，在凝胶剂中添加少量对苯二酚可以显著提高酚醛树脂凝胶的抗氧化降解性能。
