Interactions between fine particles and heavy crude oil: an experimental study using thermo-gravimetric and rheological analyses

The dissolution of fine particles into flowing and stranded fluids is not only one of the most prominent formation damage problems but also, is prejudicial to economic viability of oil-bearing matrices. To this end, the present paper investigates the effect of fine particles dissolution on rheological properties of heavy crude oil (API 16.6°). Because of the siliceous nature of the candidate formation, fine particles were modeled by nanoparticles. Considerations were given to silica oxide (Si-NP), alumina oxide (Al-NP) and iron oxide (Fe- NP). NPs were mixed into the dead heavy oil. Both thermogravimetric and rheological studies were used to evaluate the effect of fine migration on crude oil properties. The former revealed that the dissolution of Si-NP has the most prominent effect on physical properties compared to Al-NP and Fe-NP. The dissolution of Si-NP increased the oil viscosity up to 26 cP which was 22% larger than the oil without Si-NP. Increasing the load in Si-NP enhanced the stripping of the heaviest fractions of the crude oil (asphaltenes) from the bulk. The study attributed these results to the decrease in activation energy. The findings of this study can help for better understanding of crude oil upgrading using NP dissolution.