Silica/polyacrylamide nanocomposite for inhibition of asphaltene precipitation from unstable crude oils

Abstract

Among various flow assurance problems, asphaltene precipitation is a major issue. This study aims to evaluate the potential application of silica-polyacrylamide nanocomposite to inhibit asphaltene precipitation for the first time. The nanocomposites were synthesized and characterized by Fourier transform infrared and field emission scanning electron microscopy techniques. The inhibitory effect of nanocomposites in water-based nanofluid on two unstable crude oils was evaluated using viscometry, asphaltene dispersion test, dynamic light scattering, and polarized microscopy techniques. The viscosity measurements indicate that nanocomposites postpone asphaltene onset of precipitation from 34 to 44 and 23 to 36 vol% nC7 for crude oil A and B, respectively. The maximum dispersion efficiency of nanocomposite was 69% and 79% at the 1% and 2.5% nanofluid volume dosages for crude oil A and B, respectively. Dynamic Light Scattering and microscopy results indicated the asphaltene size change to lower values in the presence of nanocomposites. Polyacrylamide attached to the silica surface promotes a surface with efficient functional groups that increase the asphaltene adsorption. Asphaltene adsorption leads to decreased aggregate size and controlling the asphaltene precipitation. The prepared nanocomposite was evaluated as an efficient dispersant and inhibitor that reveals the potential application of Silica-polyacrylamide for handling the asphaltene precipitation in reservoirs.