Enhanced residual oil mobilization in carbonate reservoirs using novel superhydrophilic SiO2-TiO2 nanoparticles with Tween 80 and Carbomer 940: A synergistic approach

The application of nanoparticles and nanocomposites, in particular base fluids, has recently been recognized as an emerging technique for enhanced oil recovery (EOR), mainly due to its effectiveness in altering rock wettability in carbonate oil reservoirs. This study focuses on the development of a novel nanocomposite made up of nanoparticles, polymer, and surfactant for EOR purposes. The structure of the synthesized composition was analyzed using techniques such as Fourier-transform infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), and X-ray diffraction (XRD). Subsequently, a new nanocomposite was prepared synergistically using low-salinity water (LSW). The novel nanofluid was tested through various experimental analyses, including evaluations of stability, contact angle, interfacial tension (IFT) behavior, and core-flooding performance at different nanofluid concentrations. The findings revealed that nanoparticles enhanced the thermal stability of the nanofluid. In the presence of synthetic nanofluid, IFT decreased from the reference value to 2.26 mN/m. Furthermore, flooding conducted on an oil-wet core in a tertiary recovery environment yielded a maximum incremental oil recovery of 25 % via the injection of the nanofluid solution as an EOR technique. • This research presents a new improved nanofluid for oil production from oil reservoirs. • A highly stable active nanofluid that could withstand high salinity and high temperature was formulated. • Nano-fluid at optimum concentration changed wettability from oil-wet to strongly water-wet condition. • The interfacial tension (IFT) of water and oil in the presence of nanofluid (0.04 wt%) decreased to 2.26 mN/m.