Evaluation of Nanoparticle Performance for Enhanced Oil Recovery in Harsh Carbonate Reservoirs: A Mechanistic Study with Field-Specific Insights from Shadgan

While nanoparticle-enhanced oil recovery (nano-EOR) has shown promise in controlled laboratory settings, its application in extreme reservoir environments-characterized by high salinity, elevated temperature, and heterogeneous carbonate lithology-remains underexplored. This study presents a comprehensive mechanistic evaluation of five engineered nanoparticles (SiO۲, Al۲O۳, TiO۲, Fe۳O۴, and nano-clay) under conditions mimicking the harsh Shadgan field (۷۵°C, ۱۸۰,۰۰۰ ppm salinity, ۴۵ cP oil viscosity). We integrate advanced characterization techniques-including in situ zeta potential, temperature-dependent interfacial tension (IFT), and post-flooding SEM/EDS-with core-flooding experiments and a ۱D advection–dispersion transport model to deconvolute governing mechanisms. Results reveal that SiO۲ outperforms other nanoparticles due to its sustained colloidal stability (zeta ≈ −۴۲ mV), profound wettability shift (۱۲۰° to ۴۵°), and low retention (۸.۵% ± ۱.۲%), yielding the highest incremental recovery (۹.۲% ± ۰.۹% OOIP). In contrast, Fe۳O۴ exhibited severe aggregation and the highest retention (۲۴.۸% ± ۳.۵%), leading to negligible recovery improvement. A strong inverse correlation (r = −۰.۸۹) between retention and recovery underscores retention as a critical performance-limiting factor. We further propose a hybrid SiO۲-TiO۲ formulation to synergize IFT reduction and wettability alteration while mitigating retention. This work provides novel mechanistic insights into nanofluid behavior in harsh carbonate systems and delivers a robust, transport-informed selection criterion for field-scale pilot design.

کلیدواژه ها:

nanoparticles ، enhanced oil recovery ، high salinity ، wettability alteration ، retention