Synthesis of a Novel Hydrophobic Associating Polymer Stabilizer and Its Mechanism in Enhancing Viscosity Retention and Oil Recovery

Abstract

: The viscosity of polymer solutions often decreases significantly due to shear degradation in near-wellbore zones and chemical/aging degradation during long-term transport, which seriously compromises the efficiency of polymer flooding. In this study, a hydrophobic monomer, hexadecyl dimethyl-5-enhexyl ammonium bromide (HAB), was synthesized. Subsequently, a novel viscosity stabilizer (LC12) was prepared via micellar polymerization of acrylamide and HAB using sodium dodecyl sulfate (SDS) as a solubilizer. The effect of this stabilizer on a hydrophobic associating polymer (AP-P4) was evaluated. Experimental results revealed that the addition of LC12 accelerated the dissolution rate of the polymer concentrate and significantly improved the viscoelasticity of the solution before and after degradation. Mechanistically, LC12 facilitates the formation of robust hydrophobic aggregates, shifting the retention mechanism from adsorption to mechanical trapping. Consequently, the shear viscosity retention of the AP-P4 solution increased by 28.4%, and the incremental oil recovery margin was improved by 4.49 percentage points after aging.