纳米N-A降黏剂的制备及性能评价

Preparation and performance evaluation of nano N-A viscosity reducer

针对普通纳米降黏剂对特稠油降黏效果差、洗油效率低等问题,制备了纳米N-A降黏剂,采用FTIR,TEM等方法表征了降黏剂的微观结构,考察了降黏剂的降黏效果、界面张力以及洗油效率。实验结果表明,纳米N-A降黏剂组成为:50%(w)纳米二氧化硅溶胶+40%(w)分散剂EB-1+4.2%(w)表面修饰剂+5.8%(w)增效剂。该降黏剂分散性能良好,粒径分布在20~60 nm之间,在降黏剂含量为1%(w)、油水质量比为7∶3、200℃,矿化度为0,8829.26 mg/L条件下老化48 h,特稠油降黏后黏度分别为6280,7213 mPa·s,降黏率分别达到83.77%,81.36%,降黏性能保持率分别为96.80%,95.39%。50℃下静置90 d后降黏性能保持率大于90%,可降低油水界面张力至0.076 mN/m,乳化液滴最大粒径9.5μm,洗油效率为30.9%,相对普通降黏剂,驱油效率提高22.3百分点。

Aiming at the problems of poor viscosity reduction effect and low oil washing efficiency of common nano-viscosity reducer for extra-heavy oil,the nano N-A composite viscosity reducer was prepared.The microstructure of the viscosity reducer was characterized by FTIR and TEM.The viscosity reduction effect,the ability to reduce interfacial tension and the oil washing efficiency of the viscosity reducer were investigated.The experimental results show that the composition of N-A viscosity reducer is 50%(w)nano silica sol+40%(w)dispersant EB-1+4.2%(w)surface modifier+5.8%(w)synergist.The viscosity reducer has good dispersion performance.The particle size distribution of the viscosity reducer is between 20-60 nm.Under the conditions of viscosity reducer content 1%(w),oil-water mass ratio 7∶3,After aging for 48 h at 200℃and salinity 0 or 8829.26 mg/L,and aging time 48 h,the viscosity of the extra-heavy oil after viscosity reduction is 6280,7213 mPa·s,and the viscosity reduction rates is 83.77%and 81.36%,respectively.The retention rate of viscosity reduction performance of the system is 96.80%and 95.39%,respectively.After standing at 50℃for 90 d,the retention rate of viscosity reduction performance is greater than 90%,the oilwater interfacial tension is reduced to 0.076 mN/m,the maximum particle size of the emulsified droplet is 9.5μm and the washing efficiency is 30.9%.Compared with the common viscosity reducer,the recovery rate can be increased by 22.3 percentage points.