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 Co3O4 nanoparticles were ingeniously selected as an inhibitor of asphaltene precipitation, and a porous SiO2 film was formed via the sol-gel method. The evaluation experiments indicated that the SiO2 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 Co3O4-SiO2 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 SiO2 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.

Automated summary

Asphaltene precipitation can lead to negative consequences in oil fields, and an effective asphaltene adsorption strategy is crucial. This study utilized Co3O4 nanoparticles as an inhibitor and formed a porous SiO2 film via the sol-gel method. Experimental results showed that the SiO2 film reduced self-aggregation and improved adsorption capacity. Molecular dynamics simulations confirmed the enhanced performance of the modified nanoparticles.