Relationship between Dynamic Interfacial Tension and Ultimate Recovery in Gemini Surfactant Flooding: An Exploration through Fractured Micromodels

The promising performance of gemini surfactants (GmS) in reducing interfacial tension (IFT) and their low critical micelle concentration (CMC) have made them a subject of interest in chemical enhanced oil recovery (CEOR) research. A locally synthesized GmS with high stability, salt tolerance, and CEOR potential was evaluated in this study for its ability to reduce IFT in both equilibrium and dynamic states as well as its potential for enhancing oil recovery. A range of GmS concentrations ranging from 0.0005 to 1 wt % was tested, with rheology results indicating no deviation from seawater rheology. The study found that, as the GmS concentration increased, IFT also increased, with the lowest IFT value of 0.12 mN/m obtained at 0.0005 wt % and the highest value of 0.84 mN/m recorded at 0.5 and 1 wt %. The IFT curve for each concentration gradually decreases over time as the system takes time to reach equilibrium. The highest ultimate recovery of 50.26% was obtained at a concentration of 0.005% GmS as a result of the IFT effect, which mobilized the trapped oil in the pore network. The novel GmS was also successfully evaluated for dynamic IFT using fractured real geometry micromodels compared to its equilibrium value of the spinning drop.