无盐耐高温黏弹性表面活性剂LQ-FJ压裂液性能

Property and Rheology of High Temperature Salt-free Fracturing Fluid LQ-FJ

研究了由两性表面活性剂LQ-FJ在不同浓度下形成的清洁压裂液及其性能。结果表明,两性表面活性剂LQ-FJ在水中4 min可均匀溶解、自增稠为黏弹性清洁压裂液;当LQ-FJ浓度达2%时无需反离子盐即可形成耐温达110℃的清洁压裂液。黏温曲线表明,2%LQ-FJ体系具有热增稠和热变稀特性。流变特性研究表明,2%LQ-FJ体系具有温度滞后环和剪切触变性,流动曲线可用共转Jeffreys本构方程表征。破胶实验表明,煤油、阴离子表面活性剂J1均可作为2%LQ-FJ体系的破胶剂,室温下破胶液黏度均小于1.5 m Pa·s。

Study on the property of clear fracturing fluid formulated by amphoteric surfactant LQ-FJ showed that LQ-FJ dissolved completely in water in 4 minutes and made the water viscosified into a clear fracturing fluid. At 2% of LQ-FJ, no counter-ionic salts were needed for the preparation of a clear fracturing fluid which had temperature stability up to 110 ℃. Viscosity-temperature curves of the fracturing fluid demonstrated that the 2% LQ-FJ fracturing fluid had thermal-thickening and thermal-thinning properties. Rheology study showed that the 2% LQ-FJ fracturing fluid had a temperature hysteresis loop and shear thinning property. Jeffrey's co-rotational constitutive equation can be used to characterize the flow curve of the fracturing fluid. Gel breaking experiment indicated that kerosene and ionic surfactant J1 all can be used as gel breaker for the 2% LQ-FJ fracturing fluid, and the gel-broken fluid had viscosity at room temperature of less than 1.5 m Pa s.