TiO2 nanoparticle-induced Xanthan Gum Polymer for EOR: Assessing the underlying mechanisms in oil-wet carbonates

Abstract

This work systematically investigates the potential of Anatase TiO 2 nanoparticles-induced Xanthan-gum polymer as a Nano-polymer suspension for enhanced oil recovery (EOR) in carbonates. For this purpose, initially, viscosity of Xanthan gum polymer with and without the nanoparticles (NPs) was examined at different conditions. The stability of the suspensions was determined qualitatively and quantitatively. The capability of the Nano-polymer suspensions for wettability alteration was explored using contact angle measurement aided by a mathematical approach. Interfacial tension measurement was performed. Finally, oil displacement experiments were conducted to examine EOR efficiency of the Nano-polymer suspension. We found that while increasing temperature and adding salt to polymeric solutions caused a reduction in shear viscosity, the addition of NPs to the solutions could relatively recover the viscosity. The presence of polymers in the nanofluids improved dispersion stability of NPs. Also, the Nano-polymer suspensions could extend the ability of the NPs for wettability alteration and faster equilibrium states obtained than the polymer-free nanofluids. The mathematical model derived based on the equation of kinetic adsorption could describe the wettability alteration process well and successfully captured contact angle profiles. Results of the oil displacement tests revealed that whereas TiO 2 nanofluid and polymer solution showed additional oil recovery values of 12 and 19% of OOIP, respectively, 25% additional oil was produced using Anatase TiO 2 -induced Xanthan gum polymer flooding. • EOR potential of Anatase TiO 2 Nanoparticles-induced Xanthan Gum Polymer was investigated systematically. • TiO 2 nanoparticles relatively compensated the viscosity reduction of the polymer for thermal breakage and salt effect. • Xanthan gum polymer was helpful for nanofluids to remain stable for a long time range. • The performance of nanoparticles for rock wettability alteration was fortified by Xanthan gum polymer. • An extra oil recovery of 25% of OOIP was recovered using the Nano-polymer suspension.