The EOR performance of composite nanofluids of surface‐modified dendritic mesoporous silica and HMPAM

In this paper, a novel amphiphilic modified dendritic mesoporous silica nanoparticle (designated as DMSN‐C 14 ) was synthesized to combine with hydrophobically modified polyacrylamide (HMPAM) to create a new type of polymer nanofluid for enhancing oil recovery. The DMSN‐C 14 can interact with HMPAM through both hydrophobic interaction and electrostatic attraction, significantly enhancing the solution properties of HMPAM. Experimental results demonstrated that the viscosities of the solutions (at the same HMPAM concentration) followed the order: HMPAM/DMSN‐C 14 > HMPAM/DMSN > HMPAM. For the HMPAM/DMSN‐C 14 nanofluid, the viscosity initially increased and then decreased with increasing DMSN‐C 14 concentration. Notably, the viscosity of HMPAM/DMSN‐C 14 (1500 mg/L/600 mg/L) was 63% higher than that of 1500 mg/L HMPAM. The HMPAM/DMSN‐C 14 nanofluid exhibited superior temperature and shear resistance compared to HMPAM, with a viscosity retention rate of 70.4%, and its viscoelastic property was significantly stronger. Displacement experiments confirmed that the HMPAM/DMSN‐C 14 nanofluid had higher resistance and residual resistance coefficients than that of HMPAM. Specifically, the HMPAM/DMSN‐C 14 (1500 mg/L + 600 mg/L) enhanced oil recovery by 27.1%, which was 7.42% higher than that achieved by HMPAM. The findings of this study provide a new nanoparticle additive for polymer nanofluid system.