Reinforcing Polymer Flooding System with Dendritic Mesoporous Silica Nanoparticles for Improved Oil Recovery

Dendritic mesoporous silica nanoparticles (DMSNs), characterized by a high specific surface area and abundant hydroxyl groups, offer a promising approach to enhancing the performance of amphiphilic polymers in challenging enhanced oil recovery (EOR) conditions. In this study, DMSNs were successfully synthesized, and systematically evaluated for their impact on the solution properties of a betaine amphiphilic polymer (PADC). The unique “flower-like” mesoporous structure of DMSNs provided approximately 7-fold higher surface area than conventional SiO2, facilitating enhanced polymer–nanoparticle interactions. The DMSN/PADC composite system exhibited significantly improved viscosity, salt resistance, thermal tolerance, and shear resistance compared to PADC and SiO2/PADC systems. Quantum chemical calculations elucidated the interaction mechanisms, highlighting the role of silanol groups in forming electrostatic interactions and hydrogen bonds with PADC, thereby reinforcing the three-dimensional network structure. Enhanced oil recovery (EOR) tests demonstrated a 17.91% tertiary oil recovery using the DMSN/PADC composite system, nearly double that of the SiO2/PADC system (9.48%). This study underscores the potential of DMSNs as a novel additive for optimizing polymer flooding formulations, enabling superior EOR performance in high-temperature, high-salinity reservoirs.