Comparative Investigation of Synthetic and Novel Natural Surfactants’ Role in Oil Emulsion Creation

Abstract Global trends show a growing need to reduce environmental impacts while maintaining high performance. As a result, the oil and gas industry is witnessing the rise of innovative, greener solutions to meet this critical need. Surfactants are of multiple industrial importance. This includes stabilizing emulsions, which are of pivotal importance for Enhanced Oil Recovery (EOR). Also, it is a pressing issue for Kazakhstan, where complex reservoir conditions exist. This study examines anionic surfactants, SDS, and a Henna-based surfactant for emulsifying light and heavy crude oils. Focus is placed on Kazakhstan's reservoirs. Heavy oil from West Kazakhstan and synthetic decane were tested. A 1:9 oil-to-water ratio was used for emulsions, replicating typical reservoir conditions. Tests were conducted at room temperature and 60°C. Henna consistently outperformed SDS, yielding a smaller creaming index (CI) and better emulsion stability across all concentrations. CI of 0.3 % for henna/crude oil systems could be achieved after 360 min and a significantly lower interfacial tension (IFT) was demonstrated by the interface (0.7 mN/m vs. 2.5 mN/m). Low CI values are supported by small droplet sizes of henna emulsions, compared to that of SDS (27.19 µm vs. 76.96 µm). These results demonstrate Henna's effectiveness in reducing IFT, viscosity and enhancing emulsion stability. The results show future potential for natural surfactant application in Kazakhstan.