Effect of SiO2-based nanofluids in the reduction of naphtha consumption for heavy and extra-heavy oils transport: Economic impacts on the Colombian market

The main objective of this study is twofold. First, we evaluate the effect of nanofluids as additives to optimize the transport of heavy crude oil using steady-state rheological measurements and dynamic flow tests. The use of these additives produces viscosity reduction for heavy (HO) and extra heavy (EHO) crude oils. Second, we show how the addition of nanofluids can lead to significant economic and environmental impacts in Colombia as a country and possibly the region through optimization in the use of naphtha for transportation. Four nanofluids were prepared using different solvents and fumed silica nanoparticles. Mixtures of nanofluids with naphtha were prepared to reduce the viscosity of the crude oil as to attain mobility targets (400-500 cP at 311 K). To this end, 27% and 63% v/v of naphtha were required for heavy and extra-heavy crude oils, respectively. Through steady-state rheological measurements and dynamic flow tests in a pipeline, we found that the best performing material turned out to be the nanofluid composed of 1000 mg/L of SiO2 and biodiesel without surfactant. This nanofluid yielded a reduction in the consumption of naphtha of approximately 50% v/v. Our results show that the best-performing nanofluid can serve as an optimizing agent for the transport conditions of heavy and extra-heavy crude. The proposed technology was evaluated through a preliminary economic analysis that shows a potential reduction of dilution costs of almost 50%, equivalent to more than USD $2.5 million per day, as well as a decreased energy consumption associated with pumping of 37%, able of generating savings of more than USD $2 million per year. Additionally, a discussion on environmental impacts are presented, and the advantages of reducing naphtha consumption are discussed. A nanofluid-based technology could generate savings in both energy and fuel consumptions for the oil and gas industry and resolve national or regional issues constrained by limited access to diluent.