Abstract
Understanding the rheological behavior and thermal stability of hybrid polymer-nanoparticle solutions is crucial for designing enhanced oil recovery (EOR) processes under reservoir conditions. The graphene oxide (GO)-hydrolyzed polyacrylamide (HPAM) hybrid has recently emerged as a promising approach, drawing significant attention for its potential to improve EOR efficiency. This study evaluates the impact of polymer concentration, content of GO nanoparticles and ionic strength on the hybrid solution's performance through rheological measurements, long-term thermal stability tests, and ANOVA statistical analyses. Using a 2k factorial design and ANOVA, polymer concentration in the range of 1000-1500 ppm was identified as the primary factor, accounting for 58.34% contribution on the viscosity of hybrid solution, followed by divalent ion (18%), salinity (9%), and GO (5%). Accordingly, the Carreau rheological model was used to fit the rheological behavior of the hybrid solution. The hybrid formulation with 300 ppm GO retained 78% of its initial viscosity after 28 days at 80 °C, compared to lower retention for other formulations, highlighting the role of GO nanoparticles in improving polymer thermal stability. These findings advance the understanding of hybrid polymer-nanoparticle systems, highlight the specific role of GO nanoparticles to increase polymer performance, and provide valuable insights for designing the GO-polymer hybrid method for EOR purposes.