A plant-based natural surfactant for enhanced oil recovery application

Abstract

It is generally known that only one-third of the petroleum present in known reservoirs can be recovered economically using established technology. To improve the recovery of oil from these reservoirs various Enhanced Oil Recovery (EOR) methods have been tested and implemented worldwide. One of the most widely used methods is surfactant flooding. The use of synthetic surfactant usually has serious environmental and financial implications, which have made it important to find new surfactants to solve these problems. In this study, saponin was extracted from the leaves of Vernonia Amygdalina by ultra-sonication and used to formulate surfactant solutions capable of achieving low interfacial tension (IFT). Saponins are a group of naturally occurring plant glycosides, characterized by their strong foam-forming properties in aqueous solution. In addition, the effect of the surfactant solution on the IFT and emulsion stability of the surfactant solution as well was evaluated. Finally, oil displacement efficiency of the formulated surfactant solution was examined and compared. The surfactant solution can effectively emulsify oil and could reduce the IFT with crude oil from 18 mN/m to 3.9 mN/m. The displacement experiments through 100 – 170 mD sandstone cores indicated that the EOR could reach 11.2% OOIP by the surfactant flooding after water flooding. The newly formulated surfactant based on saponin extract from Vernonia Amygdalina can efficiently enhance oil recovery after water flooding. This work adds Vernonia Amygdalina to the list of plant-based surfactant to be used in the petroleum industry.