A review of nanomaterials as viscosity reducer for heavy oil

Abstract

Heavy crude oil is one of the most potential fossil fuels at present and in the future. However, its high viscosity severely hinders its recovery from reservoir conditions. Heavy oil viscosity reduction is rather essential for its exploitation and transportation. Applying nanomaterials as viscosity reducer for heavy crude oil is an emerging research topic in petroleum industry. In this review, the recent progress about different nanomaterials that have been used in heavy oil viscosity reduction was summarized. These nanomaterials were roughly divided into four kinds: silicon oxide nanoparticles, metal oxide nanoparticles, carbon nanotubes, modified nanoparticles and nanocomposites. The properties of the nanomaterials, including chemical property, concentration and injection form, size and the operational conditions such as temperature, different heavy oil and field application were discussed. At the same time, the possible oil viscosity reduction mechanisms including asphaltenes adsorption, disruption of asphaltene aggregates and heavy oil viscoelastic network, recombination of hydrogen bonds for different nanoparticles were summarized. The challenges and future work for this technology are proposed at the end. Nanomaterials for heavy oil viscosity reduction are expected to make a huge impact on petroleum industry.