Recently, smart water (SmW) and nanocomposite (NC) flooding have shown good potential for Enhanced Oil Recovery (EOR) processes. Although SmW and NCs are found to influence the oil recovery, there are still some controversies regarding their performance on wettability alteration (WA). To address this important question, we synthesized new NC materials with high hydrophilic properties. In this research, in the first stage, a NC was synthesized. The obtained compound was known as (UiO-66-NH2/TiO2/ZnO) (UNTZ). For the identification of NC, Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and X-ray Diffraction (XRD) techniques were used. Furthermore, zeta-potential analysis was done to investigate the stability of nanofluids (NFs). To investigate the effect of NFs on oil recovery, 8 concentrations (1600, 1400, 1200, 900, 700, 500, 300, and 100 ppm) of UNTZ nanofluids were prepared. In the current work, to investigate the effectiveness of the combination of SmW (sulfate (SO42-) and calcium (Ca2+)) + NCs, tests such as interfacial tension (IFT), contact angle, and core flooding were used. The results of contact angle tests showed improved SmWs capabilities in the presence of NCs that a very effective reduction was accessible and highly hydrophilic wettability was obtained when using SmWs with stable NC as a minimum contact angle of 28° was achived. The findings of the coreflood experiment indicated that at SmW(SmW2sulfate)+100ppm NC and SmW(SmW2calcium)+100ppm NC concentrations, the NF enhanced the oil recovery by 9.8 and 5.9%, respectively. This research offers new findings that can help oil recovery by understanding smart water technology with nanoparticle (NPs) in reservoirs (carbonate).
