SiO₂纳米材料对降低稠油粘度的影响

Effect of SiO₂ Nanomaterials on Reducing Viscosity of Heavy Oil

摘要: 稠油中的胶质和沥青质易吸附并聚集在岩石中，导致稠油粘度大、流动性弱，给稠油开采、运输造成严重的困难。SiO₂纳米材料形成的硅烷醇基对沥青质的亲和力较高，可以分解沥青质聚集体，改变沥青质胶体结构，从而降低稠油粘度。室内通过对比不同粒径的纳米SiO₂材料，在不同粒径、不同浓度、不同温度和剪切速率下，评价了纳米SiO₂材料对稠油粘度的影响。试验结果表明，浓度为1000 mg/L，粒径为6 nm的SiO₂纳米能较大幅度地降低稠油粘度，稠油粘度降低率超过40%，且提高温度及高剪切速率有利于降低稠油粘度。表明了SiO₂纳米粒子有效防止沥青质聚集体的形成，起到分散沥青的作用，达到降低稠油粘度的目的。

Abstract: The colloids and asphaltene in heavy oil are easy to adsorb and accumulate in rocks, resulting in high viscosity and weak fluidity of heavy oil, which causes serious difficulties in the exploitation and transportation of the heavy oil. The silane alcohol group formed by the SiO₂ nanomaterials has a high affinity to asphaltene, which can decompose asphaltene aggregates, change the colloidal structure of asphaltene, and reduce the viscosity of heavy oil. The effect of nano-SiO₂ on viscosity of heavy oil was evaluated by comparing nano-SiO₂ with different particle size, concentration, temperature and shear rate. The results show that the viscosity of heavy oil can be greatly reduced by a concentration of 1000 mg/L and a particle size of 8 nm, SiO₂ nanoparticles, and the viscosity reduction rate of heavy oil is more than 40%, and the increase of temperature and high shear rate is conducive to reduce the viscosity of heavy oil. It shows that SiO₂ nanoparticles can effectively prevent the formation of asphaltene aggregates, play the role of dispersing asphalt, and achieve the purpose of reducing the viscosity of heavy oil.