TiO2/Sodium Dodecyl Sulfate/Xanthan Gum Nanofluid: A Promising Candidate for Enhanced Oil Recovery

In this study, a TiO2/sodium dodecyl sulfate (SDS)/xanthan gum (XG) nanofluid is prepared to investigate its effectiveness in additional oil recovery. TiO2 nanoparticles were synthesized via the sol–gel method and subsequently calcined at 350 °C. The crystalline nature and microstructural features of the synthesized TiO2 were characterized using X-ray diffraction, Fourier transform infrared, and scanning electron microscopy. The TiO2/SDS/XG nanofluid was prepared using a probe sonicator until a clear dispersion of the mixture was achieved. The particle size of the nanofluid was determined through a dynamic light scattering analyzer, revealing a size of approximately 12–18 nm. The prepared nanofluid altered the wettability toward water-wet and reduced the interfacial tension between crude oil and the nanofluid to 0.00771 mN/m, along with surface tension values dropping to 33.2 mN/m. Such changes led to a reduction in capillary force, which in turn facilitated enhanced oil recovery (EOR). An imbibition study was also conducted using collected sandstone cores to measure excess oil recovery in the presence of the prepared nanofluid at a temperature of 50 °C and atmospheric pressure. The imbibition study showed that the nanofluid comprising 0.1% XG, 0.1% SDS, and 0.01% TiO2 recovered 28% of the original oil in place, which is 33.33% higher than the formulation with 0.1% XG and 0.1% SDS and 100% higher than the 0.1% XG alone. Hence, the proposed formulation shows promise as a potential candidate for chemical EOR methods.