Experimental Study on Aggregation Regulation and Plugging Performance of Nanoparticles in Low‐permeability Heterogeneous Cores

Abstract

AbstractTo solve the defects of existing particles in in‐depth profile control of low permeability reservoirs, a cross‐linked polystyrene nanoparticles named as CSA was synthesized by emulsion polymerization method, and its aggregation plugging performance was investigated. Characterization analysis indicated that CSA particles displayed uniform microsphereical morphology and core‐shell heterogeneous structure. The CSA particles with the mean diameter ranging from 155.4 to 273.8 nm could be readily produced by moderate dosage change of acrylamide and surfactant. The property evaluation results showed that there was competition between the fatty alcohol polyoxyethylene ether carboxylate (AEC) and aggregation control agent. Aggregation control agent promoted the aggregation of CSA particles, while AEC can ensure the long‐term dispersion stability of CSA particles. Core tests suggested that CSA can not only properly propagate to deep formation, but also seal water channels through aggregation particle clusters, revealing the good injectivity and in‐depth conformance control capability in low‐permeability heterogeneous cores.