Effect of Rhamnolipid Biosurfactant on Enhanced Oil Recovery Through Imbibition Performance of Crude Oils: A Literature Review

Abstract

Biosurfactants applied in enhanced oil recovery (EOR) have attracted significant attention due to their biodegradability, low toxicity, and ability to modify the interactions between oil, rock, and brine. Rhamnolipids—glycolipid biosurfactants synthesized by bacterial species—have a unique amphipathic structure that can alter the characteristics of crude oil at the molecular and macroscopic levels. This study examines the impact of rhamnolipid biosurfactant on the imbibition performance of crude oils, exploring it as a potential green alternative to conventional surfactants. Laboratory experiments were designed to evaluate the reduction of interfacial tension and oil displacement efficiency under various reservoir conditions. The results demonstrate that rhamnolipid significantly enhances oil recovery by promoting water-wet conditions and improving spontaneous imbibition rates, with recovery increments surpassing those observed in conventional systems. The novelty of this work lies in the direct integration of rhamnolipid biosurfactant into imbibition-driven recovery processes, which has rarely been addressed in previous EOR studies. While prior works have primarily focused on coreflooding and micellar flooding performance, this study provides mechanistic insights into how rhamnolipids modulate capillary forces and rock–fluid interactions during imbibition. By coupling environmental sustainability with improved oil recovery efficiency, the findings highlight rhamnolipid as a dual-function agent—both as an effective surfactant and as a sustainable alternative for next-generation EOR strategies.