Evaluation and mechanisms of modified SiO2 and biosurfactant compound system for viscosity reduction of heavy oil

The development and preparation of viscosity reducers are important for the extraction and transportation of heavy oil. In this study, we investigated the viscosity reduction effect of SiO2 in terms of size and mass fraction. Then we modified SiO2 with salicylic acid (SA) and sodium 3-sulfobenzoate (SS) to obtain two types of modified SiO2: SiO2-SA and SiO2-SS. Through screening, SiO2-SS was compounded with the biosurfactant sapindus saponin (BSS) to prepare a high-efficiency viscosity reducer. When the mass fraction of BSS was 1 wt%, and the mass fraction of SiO2-SS was 0.5 wt%, the DVR could reach 87.6 %. X-ray diffraction and rheological experiments proved that this viscosity reducer could destroy the structure of heavy components in heavy oil to reduce the flow resistance. This investigation of the synergistic interaction between nanoparticles and biosurfactants may help the development of environmentally friendly viscosity reducers.