LAUSR

In this work, poly(acrylamide-co-acrylic acid)/silica [poly(AM-co-AA)/SiO2] microspheres were prepared by inverse phase suspension polymerization in the presence of γ-3-(trimethoxysilyl) propyl methacrylate (or 3-methacryloxypropyltrimethoxysilane) modified SiO2. The effects of SiO2 nanoparticles on tuning morphology and properties of the nanocomposite microspheres were studied. Plugging ability and oil displacement performance were also systematically investigated by single- and double-tube sand pack models. The results showed that SiO2 nanoparticles can effectively adjust surface smoothness, swelling behavior, and thermal stability of the nanocomposite microspheres. Compared with pure copolymer microspheres, these nanocomposite microspheres also displayed better salt tolerance and shear resistance. Such multifunctional nanocomposite microspheres can provide effective plugging in the high-permeability channels and can also achieve deep profile control. The highest plugging rate can be 86.11% and the oil recovery for low-permeability tube was enhanced by 19.69%. This research will provide a candidate material for the further enhanced oil recovery (EOR) research and supply the theoretical support for profile control system in field application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45502.