Interfacial tension of acidic heavy crude oil type and dolomite surface wettability: salinity and nanoparticles impact

Abstract

ABSTRACT Waterflooding is the widespread method for displacing the residual oil toward well production because of its accessibility and low cost. Currently, several oil-rich countries are investigating to untangle the current shortcomings to make waterflooding method efficacious more. On the other side, salinity composition has been considered in enhanced oil recovery (EOR) for better sweep efficiency and has captured great interest for EOR techniques. In this study, oil–water interfacial tension (IFT) was measured between acidic heavy crude oil (AHCO) and brine solutions of MgCl2, CaCl2, KCl, NaCl, and Na2SO4 in various concentrations from 0.1 to 1 M and analyzed to obtain the highest IFT reduction. Moreover, the effects of AHCO and water composition on initial wettability of carbonate rock were investigated. The variations of surface properties of dolomite rock samples were investigated by contact angle (CA) measurements after aging thin sections in oil and brine. In addition, silica nanoparticles (NPs) as the IFT reducer and wettability alteration affordable agent were examined to compare their effects on salinity. The lowest IFT value between AHCO and brine solutions was reported 6.5 mN/m by magnesium chloride at 1 M concentration. Likewise, the highest impact on wettability alteration from oil-wet system (137.37◦) to strongly water-wet system (30.79◦) was obtained by magnesium chloride at 1 M concentration as well. Moreover, the application of silica NPs based on different salinity showed an inconspicuous impact in this study.