Asphaltene adsorption of Co3O4 nanoparticles modified by SiO2 film

Asphaltene precipitation could have several negative consequences, including production decline, wellbore plugging, and even severe safety concerns. Therefore, an effective strategy of asphaltene adsorption is highly significant. Nanoparticles possess a large surface area, showing a high adsorption potential for asphaltene. However, the self-aggregation property limits its adsorption capacity. In this work, the Co 3 O 4 nanoparticles were ingeniously selected as an inhibitor of asphaltene precipitation, and a porous SiO 2 film was formed via the sol-gel method. The evaluation experiments indicated that the SiO 2 film significantly reduced the self-aggregation. Hence, the specific surface area of nanoparticles increased from 20.87 m 2 /g to 29.25 m 2 /g. Meanwhile, molecular dynamics simulations confirmed that the modified nanoparticles exhibited 1.6 times higher adsorption energy and a lower mean square displacement than the fundamental nanoparticles. With these improvements, the Co 3 O 4 -SiO 2 nanoparticles developed greater stability and dispersion, which raised the adsorption of the nanoparticles on asphaltene from 1.24 mg/m 2 to 1.53 mg/m 2 , presenting a considerable adsorption capacity. This study broadens the selection of nanoparticles for asphaltene adsorption. It demonstrates the improvement of nanoparticles by porous SiO 2 film in various aspects, which can provide a solution for inhibiting asphaltene precipitation in oil fields as well as guidance for subsequent functionalization of nanoparticles.