利用硅烷偶联剂KH550对纳米SiO₂进行改性,并加入MA、SSS、AA和AMPS单体成功合成了一种新型改性纳米SiO₂降黏剂。利用红外光谱仪、热重分析仪和扫描电镜对合成的改性纳米SiO₂降黏剂进行表征,并优化了新型降黏剂合成的单体质量比、反应温度、反应时间、单体质量分数、引发剂质量分数和合成环境pH;研究了JN-54和新型改性纳米SiO₂降黏剂的加量、实验温度和剪切速度对降黏效果的影响。结果表明,最佳合成条件为:单体质量比m(AMPS):m(MA):m(SSS):m(AA):m(SiO₂)=7.5:3:13.5:4:2或7:2.5:13:3.5:4、单体质量分数为30%、反应温度为40℃、pH为6.5、引发剂质量为单体总质量的0.3%、反应时间为8 h;改性纳米SiO₂降黏剂在110℃、100 s^-1条件下降黏率仍可达到98.7%且最佳质量分数为1.5%;对比JN-54,改性纳米SiO₂降黏剂有更好的降黏效果和耐温耐剪切性能。

A new type of modified nano SiO₂ viscosity reducer is successfully synthesized through modifying nano SiO₂ with silane coupling agent (KH550) and adding MA,SSS,AA and AMPS monomers,and characterized by means of infrared spectroscopy,thermogravimetric analysis and scanning electron microscopy.The mass ratio of monomers,reaction temperature,reaction time,mass fractions of monomers,mass fraction of initiator and synthetic environment pH for the synthesis of the new viscosity reducer are optimized.The influences of the dosages of JN-54 and the new modified nano-SiO₂ viscosity reducer,experimental temperature and shear rate on the viscosity reduction effect are studied.The optimum synthesis conditions are determined as follows:m(AMPS):m(MA):m(SSS):m(AA):m(SiO₂)=7.5:3:13.5:4:2 or 7:2.5:13:3.5:4,mass fraction of monomers is 30%,reaction temperature is 40℃,pH = 6.5,mass fraction of initiator is 0.3% of the total monomer mass,and reaction time is 8 h.The viscosity reduction rate of the modified nano-SiO₂ viscosity reducer can still reach 98.7% at 110℃ and 100 s^-1,and the optimum mass fraction is 1.5%.Compared with JN-54,the modified nano-SiO₂ viscosity reducer has better viscosity reduction effect,temperature resistance and shear resistance.

程云龙(1995-),男,硕士,助理工程师,研究方向为油藏工程、提高采收率理论与技术,通讯联系人,18155922861@163.com。