Nowadays, the implementation of chemical enhanced oil recovery (CEOR) techniques improves the oil recovery by injecting synthetic surfactants in reservoir. However, the recent use of this synthetic surfactant is quite expensive and possesses toxicity problems when exposed to the environment. This issue has forced the search for alternative, cheaper and natural synthetic surfactant to enhance oil recovery. Hence, this study aims to provide some insights into the effect of saponin as natural plant-based non-ionic surfactant on the surface of paraffin oil-wet sandstone. The effectiveness of saponin depends on the critical micelle concentration (CMC), interfacial tension (IFT) and wettability alteration. The surfactant concentration containing saponin was varying from 0.005wt% to 0.07wt% to determine CMC value using surface tension measurement, meanwhile for IFT measurement was conducted at 0.5wt% to 8wt% concentration using Krus Tensiometer K6. The experiments were conducted at standard condition with 25°C and 14.7psia. The findings showed that surface tension for CMC value of saponin is 0.05wt%. Approximately 27% reduction from initial IFT was achieved with 8wt% of saponin concentration. The saponin successfully alter the wetting state of oil-wet sandstone to intermediate-wet through quantitatively measurement of contact angle. Saponin with low CMC value is favourable to become a reference concentration as natural surfactant, effective to alter of reservoir rock properties, facilitate oil mobilization, increase oil recovery and suggested as an additive for mitigating wax deposition.

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In empowering the United Nations (UN) Sustainable Development Goal, the oil industry is inclined toward organic wax inhibitor applications when combatting the wax deposition issue during crude oil production. This is because synthetic chemical inhibitors are costly and have the potential to create environmental problems when oil spillage or seepage occurs during transportation or operation. This study evaluates the impact of low-cost, natural plant-based inhibitors such as Jatropha seed oil (JSO), crude palm oil, and crude palm kernel oil (CPKO) on paraffin inhibition efficiency (PIE, %) and rheological properties of Malaysian waxy crude oil. By using cold finger equipment and a Fann viscometer, the amount of solid wax deposits, apparent viscosity, plastic viscosity, yield value, and gel strength were determined. Commercialized ethylene- co -vinyl acetate and triethanolamine compounds were used for a comparative study. For the wax deposition test, the results revealed that the highest average PIE obtained was 86.30% when 5% JSO was blended with Penara crude oil. Meanwhile, the rheological test proved that 5% JSO and 1% CPKO were acting as highest viscosity-reducing agents at 60 °C below the wax appearance temperature (WAT). The discovery of palm-based and Jatropha-based inhibitors from Malaysia’s palm oil plantation and Malaysian JSO as a wax inhibitor was found to be beneficial for the application of wax deposition and rheological studies in crude oil production with a less harmful environment for sustainable energy production.