An experimental investigation of rock wettability alteration, asphaltene molecular stability, and enhanced oil recovery using a new nanofluid

This study aims to present a novel nano-fluid for enhanced oil recovery (EOR) that simultaneously addresses two critical challenges: unfavorable rock wettability and asphaltene instability. The novelty of this work lies in the dual-functional design of novel nano-fluid, which not only maximizes oil displacement through wettability and interfacial tension (IFT) modification but also ensures long-term reservoir integrity by stabilizing asphaltenes. In this regard, a comprehensive experimental methodology was adopted, including stability assessments, contact angle and IFT measurements, asphaltene precipitation analysis, and core flooding experiments under simulated reservoir conditions. The results demonstrated that nanofluid significantly alters rock wettability from an oil-wet state (152°) to a strongly water-wet state (27°), while reducing IFT from 19.24 to 1.10 mN/m. Moreover, the nano-fluid effectively inhibits asphaltene precipitation, achieving a minimum asphaltene content of 0.55% in the presence of rock particles.