A nano-Fe3O4 material coated with AM/AMPS copolymer for viscosity enhancement at harsh reservoir conditions

A Fe 3 O 4 nonaparticles coated with acrylamide/2-acrylamido-2-methyl-1-propanesulfonic acid copolymer(Fe 3 O 4 -Polymer NPs) was synthesized by emulsion polymerization. The structure of Fe 3 O 4 -Polymer NPs was then characterized by infrared spectroscopy, thermo-gravimetric analysis, and scanning electron microscopy. Meanwhile, the rheological properties of Fe 3 O 4 -Polymer NPs solution were systematically studied. The results showed that when dosage of hydrophobic Fe 3 O 4 -Oleic NPs is 10%, the synthesized Fe 3 O 4 -Polymer NPs was with the best viscosity enhancement performance, and the maximum saturation magnetization could reach to 20.0 emu/g. The apparent viscosity value of 5000 mg/L magnetic nano-composite solution was 154.6 mPa·s at 30°C. It shows strong viscosity enhancement ability and good temperature performance. Hence, it has great application potential in well stimulation of medium and high temperature oil and gas reservoirs.