Fabrication and evaluation of hydrophilic cross-linked polystyrene nanoparticles as a potential in-depth conformance control agent for low-permeability reservoirs

摘要

To address the poor injectivity of conventional chemicals, and the drawbacks of existing nanoparticles (NPs) in in-depth conformance control in low-permeability reservoirs, a hydrophilic cross-linked polystyrene NPs named as CPSAs was fabricated via emulsion polymerization in this study. The reaction conditions were determined through orthogonal experiments, and the influence of each condition on the particle size of CPSAs was investigated with single factor experiments. The results showed that CPSAs with the mean diameter ranging from 73 to 95 nm could be readily produced by moderately changing the polymerization conditions, and the yield could be larger than 80%. The property evaluation results indicated that CPSAs can disperse well under reservoir conditions and was able to properly propagate to deep formation and block breakthrough regions, revealing the good injectivity and in-depth conformance control capability in low-permeability reservoirs.