Industrial & Engineering Chemistry Research, Vol.50, No.23, 13030-13036, 2011
Polymer-Functionalized Nanoparticles for Improving Waterflood Sweep Efficiency: Characterization and Transport Properties
Water-dispersible polymer silica nanocomposite particles, SiO2-ethylene oxide-based polymer nanopartides hybrids, were synthesized using a "grafting-from" method, where polymer brushes were grown on silica nanoparticles using living radical polymerization. Water-soluble polymer chains were grown from initiator-tethered 15-nm silica nanoparticles with similar to 600 chains grafted per nanoparticle, resulting in a surface grafting of similar to 1 chain per square nanometer. The single-phase and multiphase transport properties of low concentration brine dispersions of these polymer nanopartides hybrids through a Berea sandstone core were measured. Experiments show that, while the viscosity increase is modest for dispersions with concentrations of 0.5-2 wt % of the nanoparticle hybrid, the dispersions were able to transport without hindrance through the porous media and, furthermore, were found to be effective at mobilizing waterflood residual oil.