Carbonate and sandstone reservoirs wettability improvement without using surfactants for Chemical Enhanced Oil Recovery (C-EOR)

In this paper, we have been proposed the preparation of Silica-MWCNT nanohybrid that can increase the water wettability of carbonate and sandstone reservoirs. Chemical agents such as surfactants have been used as wettability modifiers to increase oil recovery from oil-wet carbonate and sandstone reservoirs. Addition of chemical compounds such as polymers, ionic materials and nanoparticles can improve the effectiveness of the mentioned chemical agents. The effectiveness of nanohybrids without using surfactants has not been reported yet and it is still in its infancy. In this work, the effect of MWCNT-SiO2 nanohybrid-based nanofluids on the wettability alteration of a carbonate and a sandstone reservoir rocks was experimentally studied. Therefore, MWCNT-Silica nanohybrid has been prepared by adding the suitable amount of MWCNT in situ of silica nanostructure preparation. In this research, MWCNT-Silica nanohybrid was prepared with ultrasound assisted sol-gel method and characterized with X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM). The effect of the related nanofluid on the wettability of carbonate and sandstone rocks was investigated by measuring contact angle and interfacial tension. Results show that the nanofluid could significantly change the water wettability of the mentioned rocks from oil-wet to water-wet condition without using surfactant. (C) 2015 Elsevier Ltd. All rights reserved.