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

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(degrees)) to strongly water-wet system (30.79(degrees)) 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.

Automated summary

Water flooding is a commonly used method for increasing oil recovery, and the salinity composition plays an important role in enhanced oil recovery. This study measured the interfacial tension between acidic heavy crude oil and different brine solutions, and investigated the effect of oil composition and water composition on the wettability of carbonate rock. Additionally, the use of silica nanoparticles as an agent for reducing interfacial tension and altering wettability was examined. The results showed that magnesium chloride at 1 M concentration had the lowest interfacial tension and the highest impact on wettability alteration. The application of silica nanoparticles showed insignificant effects in this study.