Synthesis and characterization of core–shell associative polymer that prepared by oilfield formation water for chemical flooding

A novel core–shell polymer (HBAPAM) with functionalized nano-SiO 2 as core, multibranched associative polymeric chains as shell was synthesized through in-situ free radical polymerization strategy. TGA, IR, 1 H NMR, and SEM proved the notion and method of preparing of HBAPAM was applicable. The core–shell structure and multibranched morphology enhanced the supramolecular interaction of HBAPAM, which displayed the desirable viscosified efficiency and viscoelasticity, especially, long-term stability in harsh temperature and salinity condition. HBAPAM featured the rheology in multiscale consistently in deionized water and formation water. Core flooding experiments confirmed that HBAPAM had high cost performance in the variable permeability of oilfields.