Investigating the role of carbon dots in modifying reservoir rock and fluid properties for enhanced oil recovery

Enhanced oil recovery (EOR) methods face limitations with conventional nanoparticles, which suffer from stability, cost, and environmental concerns. This study addresses these challenges by investigating carbon dots (CDs) as a sustainable, high-performance additive for EOR. We conducted systematic experiments including interfacial tension (IFT) measurements, contact angle analysis, dynamic light scattering (DLS), and spectrometry on diverse crude oils (heavy/light) and reservoir rocks (sandstone/carbonate). Key results demonstrate that CDs significantly reduce oil-water IFT by 86% (heavy oil) and 71% (light oil) and alter rock wettability by up to 24%, promoting oil displacement. CDs also enlarge oil droplet sizes in emulsions, indicating improved flow dynamics. Critically, adsorption studies confirm CDs’ potential as reservoir tracers, with retention increasing predictably over time. These findings establish CDs as dual-functional agents for both monitoring fluid movement and enhancing oil recovery. This work provides a simultaneous evaluation of carbon dots (CDs) for their dual functionality as both quantitative tracers in porous media and chemical additives for IFT/wettability modification, offering new mechanistic insights into these combined roles. This dual-action capability offers transformative strategies for optimizing EOR efficiency.