The Adsorption of Polyacrylamide Nanocomposite Hydrogels on Sandstone

A key parameter for the application of polymer gels in water shut off treatment is the adsorption of polymer gel onto the rock surface. So, the adsorption properties of a nanocomposite hydrogel were discussed in this research by crosslinking of sulfonated polyacrylamide/sodium montmorillonite aqueous solutions with chromium triacetate. The X-ray diffraction patterns indicated that exfoliated type of microstructure was formed. In addition, fourier transform infrared spectroscopy was used to prove the nanocomposite hydrogel interacted with the rock surface qualitatively and the scanning electron microscopy to determine the surface characteristics of the nanocomposite hydrogel layer adsorbed on powdered rock surface. The general behavior of the response indicated that in comparison with the pressure, the adsorption is much more sensitive to the S/L ratio change. The addition of nanoclay of Na-montmorillonite increased the adsorption of NC hydrogel on the surface of powdered sandstone. The influence of pressure and solid/liquid ratio was investigated on adsorption amount. The results showed that nanocomposite hydrogel adsorption decreased continuously by increase of solid/liquid ratio while its adsorption was almost independent of the pressure. Besides, the maximum amount of nanocomposite hydrogel adsorption was obtained in 2500 psi pressure and 0.005 ratio of solid/liquid.