Molecular Viewpoint for the Stability Mechanism of SiO2/SDS Dispersion

Abstract

The dispersion of silica dioxide (SiO2)/sodium lauryl sulfate (SDS) have been widely used in the oilfield development and the remaining oil displacement, but its instability is still a problem in the practical engineering application. In this paper, the mechanism of foam stability was investigated by combining the measurement of interfacial energy of nanoparticles at the gas-liquid interface with the dynamics simulation of molecular diffusion. The results showed that the addition of SiO2 nanoparticles improved the interfacial energy and interfacial activity at the gas-liquid interface, meanwhile limited the movement of SDS molecules and water molecules, which was beneficial for the foam stability. Notably, the addition of modified SiO2 nanoparticles further enhanced the interfacial energy at the gas-liquid interface and strengthened the restriction of water/SDS molecular movement, thereby slowing down the drainage and decay of the foam dispersions. The mechanism investigation was of benefit for foam flooding engineering application.