Applications of microbial-enhanced oil recovery technology in the past decade

The microbial-enhanced oil recovery method relies on microorganisms and their metabolic products to mobilize residual oil. It is environmentally friendly and easy to operate. In the past ten years, the microbial-enhanced oil recovery method has attracted a great deal of attention in both research and field applications. Previous reviews focused on microbial-enhanced oil recovery mechanisms, namely IFT reduction, selective plugging, gas production, biodegradation, and wettability alteration. This article summarizes the well-documented field cases in the past ten years. The objectives are to investigate the microbial-enhanced oil recovery mechanisms and application criteria based on field data. A total of ten field cases are reviewed, including cases in Malaysia, USA, Argentina, and China. It was concluded that most of the successful MEOR treatments were conducted for formations with a low temperature (below 55°C), low water salinity (less than 100,000 ppm), high water cut (above 75%), and low production rate. Reservoir permeability does not seem to determine the success of microbial-enhanced oil recovery. The current success rate for the microbial-enhanced oil recovery method stands at about 80%. With a better understanding of microbial-enhanced oil recovery mechanisms and field experiences, the microbial-enhanced oil recovery method is expected to prosper and the success rate will improve.