Polymer flooding is a mature technology in onshore oilfields but faces challenges in offshore applications. In China, partially hydrolyzed polyacrylamide (HPAM) is predominantly used as the flooding agent. HPAM exhibits excellent hydrophilicity and strong viscosity-enhancing properties, effectively improving oil recovery. However, offshore platforms typically use produced water containing various inorganic salts to prepare polymer solutions. The complex saline environment, coupled with the intense shear forces during injection, significantly reduces the shear viscosity of HPAM solutions, impairing the flooding efficiency. Due to the limitations of experimental methods in revealing the underlying microscopic mechanisms, this study employs Non-Equilibrium Molecular Dynamics (NEMD) simulations to deeply analyze, at the molecular scale, the influence mechanism of inorganic salt types and concentrations on the viscosity of HPAM solutions. This provides a theoretical foundation for optimizing polymer flooding strategies in the complex saline environments encountered offshore.
 

Inorganic salt, HPAM, Shear, Viscosity, NEMD.