An experimental study of the effect of three metallic oxide nanoparticles on oil-water relative permeability curves derived from the JBN and extended JBN methods

Abstract The relative permeability curves of SiO2, TiO2 and Al2O3 nanofluids-oil and deionized water-oil were carried out by the unsteady state method. Combined with a T2 spectrum comparison of the sandstone core before and after displacement, the influence of different nanofluids on the oil-water relative permeability curve and pore size distribution of the core samples were analyzed. In this paper, the traditional relative permeability data evaluation method (JBN method) is extended by considering capillary pressure changes and the threshold pressure gradient caused by the Jamin effect at the micro pore-throat of the consolidated core sample. The micro capillary force with consideration of the Jamin effect was determined via the gas Jamin effect equation. The relative permeability curve calculated using the extended JBN method was compared with that obtained by the traditional JBN method. The results showed that hydrophilic SiO2, TiO2 and Al2O3 nanoparticles could change the end value of the relative permeability curve relative to that of the deionized water-oil two-phase relative permeability curve. When the relative permeability of the oil phase is minimum, the corresponding water saturation changes from about 0.7 to about 0.9. This means that the oil phase is still able to flow with high nanofluid saturation. The most important point was that the isotonic point shifted to the right, which is very useful for oil displacement and reducing residual oil saturation. The water saturation corresponding to the isotonic point changes from 0.5 to about 0.7, which indicates that hydrophilic nanoparticles can significantly change the wetting properties of the core after entering the core.