Microbial enhanced oil recovery: process perspectives, challenges, and advanced technologies for its efficient...

The depletion of crude oil resources, coupled with increasing energy demands, underscores the urgency for innovative recovery strategies. Despite traditional oil recovery operations, a substantial portion of residual oil (~70%) persists within the intricate capillary networks of oil reservoirs' pore spaces. Microbial Enhanced Oil Recovery (MEOR) is an ecofriendly and cost-effective tertiary oil recovery method that offers a sustainable approach by utilizing microorganisms and their metabolites to extract this residual oil from mature or depleted reservoirs. MEOR is an emerging process gaining global attention, with numerous research studies and field trials underway worldwide. This review explores microbial strategies for modifying reservoir rheological properties, underscores the significance of microbial physiology and diversity, and examines omics technologies for deciphering microbial mechanisms to enhance the efficiency of MEOR. Cutting-edge advancements, including genetically modified microbes, enzyme-based techniques, and nanotechnology, have been discussed as potential enhancers of MEOR efficiency. The economic feasibility and integration of MEOR with Carbon Capture and Utilization (CCUS) are also assessed, emphasizing its role amid declining conventional oil production. Further, the economic and application feasibility along with patents related to MEOR technologies is presented which underscores its commercial viability. By addressing challenges and proposing solutions, this review provides a comprehensive outlook on MEOR's future, aiming to guide research and development for its successful application in sustainable oil recovery.