Novel Nanoparticle-Based Formulation to Mitigate Asphaltene Deposition

Asphaltene precipitation and subsequent deposition are challenging problems that hinder continuous crude oil production worldwide. Although this is a long-standing and complex problem and many efforts have been devoted to its mitigation, there is no commercial one size fits all type of product to reduce asphaltene deposition to date. In this work, a systematic investigation was conducted to assess the performance of commercial asphaltene inhibitors that are commonly used to disperse asphaltenes upon precipitation. In addition to their dispersion performance, each chemical was also tested by use of a packed bed column apparatus to evaluate its ability to reduce asphaltene deposition on carbon steel at high temperatures and under dynamic conditions. It was observed that the best dispersant performed very poorly on the deposition tests and the worst dispersant was a more effective deposition inhibitor. This observation highlights the limitation of dispersion tests for asphaltene deposition inhibitor screening. As a result, a novel nanoparticle-based formulation was proposed for the first time to reduce asphaltene deposition. The optimal formulation contains titanium oxide (TiO2) nanoparticles and a surfactant dispersed in aromatic naphtha, used as a carrier. After dissolution of this mixture in oil, the final blend contains 2000 ppm active ingredients, which are readily available commodity products. The proposed formulation reduced asphaltene deposition on carbon steel by 90% with respect to the blank experiment with no active ingredients. With this work, we aim to provide valuable knowledge and tools to develop cost-effective strategies to mitigate the long-standing asphaltene deposition problem. It is clear that the qualification process used to screen chemicals must be changed from dispersion analysis to actual asphaltene deposition tests, such as the ones conducted as part of this study.

Automated summary

This study evaluated the performance of commercial asphaltene inhibitors and proposed a novel nanoparticle-based formulation to reduce asphaltene deposition. The optimal formulation reduced asphaltene deposition on carbon steel by 90% compared to a blank experiment. Therefore, shifting from dispersion analysis to actual asphaltene deposition tests is a more effective way to screen chemicals.