Investigation on the preparation of nanoparticles by inverse micro-emulsion polymerization for enhanced oil recovery

Abstract

Polyacrylamide nanoparticles attracted increasing interest as profile control agents in oilfield development owing to the characteristics of deformation and continuous expansion in core pore. In this article, the structure and morphology of polyacrylamide nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). And the fluorescence microscopy and core displacement equipment were used to evaluate the properties of the expansion and plugging properties. Results showed that the nanoparticles prepared by inverse emulsion polymerization can be able to pass through the pores in the rocks due to the uniform particle size which is less than 500 nm. When the nanoparticles were in contact with water for 72 hours, the average particle size increased to 12.2 μm. The water-swelled nanoparticles can effectively block the high-permeability layer and improve the oil recovery in the low-permeability layer. The results obtained in this paper reveal the mechanism of elastic deformation and expansion characteristics of polyacrylamide nanoparticles, and further prove the great potential of nanoparticles to enhance oil recovery in the development of low permeability oilfields.