Study on Reducing Injection Pressure of Low Permeability Reservoirs Characterized by High Temperature and High Salinity

• 作者: Zhao Lin Qin Bing Wu Xiongjun Wang Zenglin Jiang Jianlin
• 来源期刊: 中国炼油与石油化工（英文版）
• 年，卷（期）: 2021,（2）
• 所属期刊栏目: Scientific Research
• 页码范围: 44-54
• 页数: 11页
• 语种: 英文

摘要

In view of the problems of high injection pressure and low water injection rate in water injection wells of low permeability reservoirs featuring high temperature and high salinity, two new surfactants were synthesized, including a quaternary ammonium surfactant and a betaine amphoteric surfactant. The composite surfactant system BYJ-1 was formed by mixing two kinds of surfactants. The minimum interfacial tension between BYJ-1 solution and the crude oil could reach 1.4×10-3 mN/m. The temperature resistance was up to 140 ℃, and the salt resistance could reach up to 120 g/L. For the low permeability core fully saturated with water phase, BYJ-1 could obviously reduce the starting pressure gradient of low permeability core. While for the core with residual oil, BYJ-1 could obviously reduce the injection pressure and improve the oil recovery. Moreover, the field test showed that BYJ-1 could effectively reduce the injection pressure of the water injection well, increase the injection volume, and increase the liquid production and oil production of the corresponding production well.