Supplementary materials

Table S1. Ionic composition of saline solutions used in rheological and flooding tests.

Table S2. Physical properties and dimensions of core samples.

Table S3. Pressure differential profiles of the three displacing fluids (XG, XG/SiO₂, and XG-g-silica composite).

Fig. S1. Fourier Transformation spectroscopy of SiO₂, and XG-g-silica composite.

Fig. S2. ¹H NMR spectra (a) Xanthan gum and (b) XG-gsilica composite respectively.

Fig. S3. Thermal gravimetric analysis of SiO₂, Xanthan gum, and XG-g-silica composite.

Fig. S4. TEM photographing of (a) SiO₂, and (b) XG-gsilica composite.

Scheme S1. Formation reaction of XG-g-silica composite.

© A. Ashraf Soliman et al., published by IFP Energies nouvelles, 2020