Ferrite Quantum Dot/Graphene Nanohybrids for Interfacial Tension Reduction: A Reservoir Alteration Wettability for Enhancing Oil Recovery

This study introduces a new technique that utilizes nanohybrids made from graphene ferrite (CoFe₂O₄) quantum dots nanohybrids (G-FQDs). These nanohybrids are produced through a manufacturing process that is both inexpensive and scalable for commercial use. When these FQDs-G nanohybrids are dispersed in a fluid to form nanofluids, they significantly lower the interfacial tension the force at the boundary between oil and water. Reducing this tension helps to improve the displacement of oil in reservoirs, making these nanofluids highly effective for enhanced oil recovery (EOR) technologies. The graphene synthesis involves chemical exfoliation using deionized water, strong acids, and oxidants, while ferrite quantum dots (FQDs) are produced via a hydrothermal method using castor oil plant precursors. The G-FQDs nanohybrids are fabricated using a sol-gel process and characterized using techniques such as XRD, FTIR, and HRTEM. We investigated the mechanism of these nanofluids under reservoir-simulated conditions. The results demonstrate that ۰.۵-G-FQDs nanofluid optimally modifies wettability in oil-wet carbonate slabs while exhibiting the optimal stability through minimal droplet formation. These nanohybrids significantly reduce interfacial tension, with oil/water IFT dropping from ۱۴.۵ mN/m to ۱.۸۰ mN/m and n-decane/water IFT, which is a standard hydrocarbon phase that mimics the properties of crude oil decreasing from ۴۶.۶ mN/m to ۲۴.۳ mN/m. This study confirms the potential of G-FQDs nanohybrids for enhancing EOR efficiency.

Keywords:

Quantum dot hybrids , Nanofluid , Graphene quantum dots , Rock reservoir , Alteration wettability