Preparation of magnetic polymer nanosphere and its profile control

Abstract

Fe₃O₄ nanoparticles with a particle size of approximately 16.5 nm were prepared by the chemical coprecipitation method with the raw materials of ferric chloride, ferrous chloride, and sodium hydroxide. The optimum reaction conditions were determined by the single factor control method; then, magnetic polymer nanoparticles were produced by microemulsion polymerization, and the synthesis conditions were optimized by orthogonal experiments with four factors and three levels. As expected, spherical particles of approximately 60 nm were obtained. The morphology, structure, and properties of the product were characterized and analyzed. The results showed that the particles possessed a uniform spherical shape, good thermal stability, and superparamagnetism, which will ensure these particles have a wide application of directional flooding profile control. Average EOR of magnetic polymer nanospheres with magnetic field was 14.41 wt%. The magnetized magnetic polymer nanospheres had better profile control ability, and were less damage to the low permeability layer. Separation experiment showed that magnetized magnetic polymer nanospheres can be effectively separated due to the low viscosity and the good magnetism. Furthermore, the separated polymer nanospheres can be reused again.

GRAPHICAL ABSTRACT

Keywords:

• Superparamagnetism
• nanosphere
• microemulsion polymerization
• profile control
• separation

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

This research is supported by The Key Project of Extracurricular Open Experiment Program of the Southwest Petroleum University (Projects No. X20182166) and Project of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Projects No. PLN1419).