Development of eco-engineered silica-ZnO hybrid nanocomposite for asphaltene deposition control: performance evaluation using modified ADT and fluorescence microscope

One of the most enduring flow assurance issues in oil production is asphaltene deposition, particularly during periods of static oil conditions, like long-term oil well shut-ins. This work developed a green, multifunctional NC capable of inhibiting asphaltene aggregation across diverse oil systems, with emphasis on long-term asphaltene stabilization during oil wells’ shut-in periods. The modified ADT results demonstrated robust colloidal stability and prevented asphaltene aggregation by a combination of mechanisms, including surface adsorption via ZnO NPs, steric hindrance via SiO2, and π-π stacking with aromatic cores, hydrogen bonding, or dipole-driven interactions with heteroatoms conferred by chlorotetrazole functional groups. Most notably, at 25 ppm, NC sustained ̴ 90% inhibition for up to 7 days in light and medium crudes, despite their high colloidal instability and asphaltene content. The results also demonstrate that increasing NC dosages does not necessarily improve inhibition, as shown in S2. Even in the most challenging systems, characterized by high salinity and water content, inhibition exceeded 65%. These results were subsequently confirmed by a fluorescence microscope, showing an apparent inhibition of asphaltene cluster formation at the microscopic scale. This study advances green nanotechnology for petroleum flow assurance and offers a practical avenue for further field applications.