纳米N-A降黏剂的制备及性能评价OA北大核心CSTPCD

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 8 829.26 mg/L,and aging time 48 h,the viscosity of the extra-heavy oil after viscosity reduction is 6 280,7 213 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 oil-water interfacial tension is reduced to 0.076 mN/m,the maximum particle size of the emulsified droplet is 9.5 μm and the washing efficiency is 30.9%.Compared with the common viscosity reducer,the recovery rate can be increased by 22.3 percentage points.