On evaluating the potential of nanocomposites for heavy oil recovery

The present work investigates potential of nanocomposite (NCP) for enhancing the production in heavy oil formation. NCP was extracted from bauxite ore and the spectral characterization revealed that NCP was a crystalline material whose matrix consists of 64.5 wt.% alumina oxide (Al₂O₃), 15.7 wt.% iron oxide (Fe₂O₃), and 19.8 wt.% silica oxide (SiO₂). The nanocomposite fluid, obtained by dispersing NCP into the targeted formation brine, showed a good dispersion over the two first days beyond which a hetero-aggregation, visible to the naked eye, was observed. Coreflooding assays, performed on Berea sandstone saturated with a heavy mineral oil (ρ = 0.854 g/cm³), revealed that 0.25wt.% of NCP dispersed in the formation brine yields a poor recovery. However, increasing the load in NCP from 0.25 to 0.75 wt.% and subsequently 1 wt.% using the same formation brine, showed an increase in the oil recovery up to 14.1% after the waterflooding stage. It was further found that the RF could be as high as 18.3% if 0.25 wt.% NCP was dispersed in a surface-active material (Polyvinyl alcohol, PVA in this study). The result was 4% higher than a scenario in which PVA was used alone. Moreover, it was shown that altering the composition of the preflush could increase the production to up to 11.3%. A comparative analysis with single nanoparticle revealed that the EOR using NCP was six-fold higher compared to that of SiO₂ taken alone and 1.5-fold lower than those of Al₂O₃ or Fe₂O₃ taken alone.