Extra-Heavy Crude Oil Viscosity Reduction Using and Reusing Magnetic Copper Ferrite Nanospheres

Abstract

The main objective of this study is the synthesis, use, and reuse of magnetic copper ferrite nanospheres (CFNS) for extra-heavy oil viscosity reduction. The CFNS were synthesized using a solvothermal method resulting in mean particle size of 150 nm. Interactions of CFNS with the crude oil were evaluated through asphaltene adsorption isotherms, as well as static and dynamic rheology measurements for two cycles at 25 °C. Adsorption and desorption experiments corroborated that most of the asphaltenes adsorbed can be removed for nanoparticle reuse. During the rheology tests, nanoparticles were evaluated in the first cycle at different concentrations from 300 to 1500 mg/L, leading to the highest degree of viscosity reduction of 18% at 500 mg/L. SiO2 nanoparticles were evaluated for comparison issues, obtaining similar results regarding the viscosity reduction. After measurements, the CFNS were removed with a magnet, washed with toluene, and further dried for the second cycle of viscosity reduction. Rheology tests were performed for a second time at a fixed concentration of 500 mg/L, and slight differences were observed regarding the first cycle. Finally, changes in the extra-heavy oil microstructure upon CFNS addition were observed according to the significant decrease in elastic and viscous moduli.