Ran Yunling, Zhang Guicai, Jiang Ping, Pei Haihua
School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Gels. 2023 Jun 14;9(6):489. doi: 10.3390/gels9060489.
High water cut of produced fluid is one of the most common problems in reservoir development. At present, injecting plugging agents and other profile control and water plugging technologies are the most widely used solutions. With the development of deep oil and gas resources, high-temperature and high-salinity (HTHS) reservoirs are becoming increasingly common. Conventional polymers are prone to hydrolysis and thermal degradation under HTHS conditions, making polymer flooding or polymer-based gels less effective. Phenol-aldehyde crosslinking agent gels can be applied to different reservoirs with a wide range of salinity, but there exist the disadvantage of high cost of gelants. The cost of water-soluble phenolic resin gels is low. Based on the research of former scientists, copolymers consisting of acrylamide (AM) and 2-Acrylamido-2-Methylpropanesulfonic acid (AMPS) and modified water-soluble phenolic resin were used to prepare gels in the paper. The experimental results show that the gelant with 1.0 wt% AM-AMPS copolymer (AMPS content is 47%), 1.0 wt% modified water-soluble phenolic resin and 0.4 wt% thiourea has gelation time of 7.5 h, storage modulus of 18 Pa and no syneresis after aging for 90 days at 105 °C in simulated Tahe water of 22 × 10 mg/L salinity. By comprehensively comparing the effectiveness of the gels prepared by a kind of phenolic aldehyde composite crosslinking agent and modified water-soluble phenolic resin, it is found that the gel constructed by the modified water-soluble phenolic resin not only reduces costs, but also has shorter gelation time and higher gel strength. The oil displacement experiment with a visual glass plate model proves that the forming gel has good plugging ability and thus improves the sweep efficiency. The research expands the application range of water-soluble phenolic resin gels, which has an important implication for profile control and water plugging in the HTHS reservoirs.
采出液的高含水率是油藏开发中最常见的问题之一。目前，注入堵剂等调剖堵水技术是应用最为广泛的解决方法。随着深层油气资源的开发，高温高盐（HTHS）油藏日益普遍。传统聚合物在高温高盐条件下容易发生水解和热降解，使得聚合物驱或基于聚合物的冻胶效果变差。酚醛交联剂冻胶可应用于不同矿化度的油藏，但存在胶凝剂成本高的缺点。水溶性酚醛树脂冻胶成本较低。本文在前人研究的基础上，采用由丙烯酰胺（AM）和2-丙烯酰胺基-2-甲基丙磺酸（AMPS）组成的共聚物以及改性水溶性酚醛树脂制备冻胶。实验结果表明，在矿化度为22×10 mg/L的模拟塔河水中，含1.0 wt% AM-AMPS共聚物（AMPS含量为47%）、1.0 wt%改性水溶性酚醛树脂和0.4 wt%硫脲的冻胶剂的成胶时间为7.5 h，储能模量为18 Pa，在105℃老化90天后无脱水收缩现象。通过综合比较一种酚醛复合交联剂和改性水溶性酚醛树脂制备的冻胶的效果，发现由改性水溶性酚醛树脂构建的冻胶不仅降低了成本，而且成胶时间更短，冻胶强度更高。用可视玻璃板模型进行的驱油实验证明，形成的冻胶具有良好的封堵能力，从而提高了波及效率。该研究拓展了水溶性酚醛树脂冻胶的应用范围，对高温高盐油藏的调剖堵水具有重要意义。
