Improvement of Water Flooding Efficiency Using Mixed Culture of Microorganisms in Heterogeneous Micro-models

One of the possible methods for reducing unwanted problem of reservoir heterogeneity in flooding processes is the application of microbial slugs for bioplugging of high permeable zones. Objective of this research is visualization of potential of mixed-culture microorganisms as bioplugging agents for improving the efficiency of water flooding in two different heterogeneous micro-models: a glass bead and an inventive etched one. In both micro-models, water flooding removed the oil in high permeable zones while it had little effect on the oil in low permeable areas. Injection of a slug, containing a mixed culture of oil degrading microorganisms was done in glass bead micro-model. The etched micro-model was used to investigate the effect of in situ microbial growth and subsequent water flooding. In both cases the microbial treatment improved the oil recovery in comparison with water flooding in low permeable zone considerably. The results of this study showed that mixed-culture microorganisms have an acceptable potential for bioplugging of high permeable layers of heterogeneous porous media.