Investigation of natural surfactant for oil recovery potential

Advancing the use of natural surfactants in enhanced oil recovery is crucial for sustainable practices in the oil and gas industry. This research assesses the applicability of neem-derived natural surfactants in offshore fields, encompassing surfactant synthesis via saponification, characterization through FT-IR, SEM, and EDS, and measuring surface and interfacial tension across various conditions. Adsorption studies determined the surfactant's adsorption characteristics onto rock, and core flooding tests assessed its efficacy. Surface tension measurements in deionized water (DIW) and brine confirmed the surfactant's surface activity. As the concentration increased from 1 wt% to 6 wt%, the interfacial tension (IFT) significantly decreased from 22.5 mN/m to 7.9 mN/m, marking a 64.8% reduction. Additionally, surfactants formed micelles more efficiently in saline water, with the critical micelle concentration (CMC) dropping from 4.0 wt% in DIW to 0.9 wt%.Adsorption on limestone showed over 50% higher adsorption than sandstone, confirming stronger interactions and higher adsorption saturation. Core flooding experiments demonstrated the surfactant's effectiveness in oil and water-wet conditions. When injected into sandstone, the surfactant achieved a significant additional oil recovery of 24.6% in deionized water, compared to 10.2% in limestone. Conversely, in saline conditions, the surfactant's performance was better in limestone, achieving an additional recovery of 4.9%, whereas in sandstone, it was only 1.6%. This research offers a unique perspective on how natural surfactants perform across different rock types. The findings suggest that neem-derived surfactants hold significant promise for enhancing oil recovery in Kazakhstan's oil fields. • EDS confirms the presence of Na salts, imparting anionic characteristics in solutions. • The IFT decreased from 22.5 mN/m to 7.9 mN/m represents a remarkable 64.8 % reduction. • The surfactant achieved a significant additional oil recovery in sandstone of 24.6 %, compared to 10.2 % in limestone. • In saline conditions, the surfactant's performance was better in limestone.