Laboratory studies of rice bran as a carbon source to stimulate indigenous microorganisms in oil reservoirs

Abstract

There is a great interest in developing cost-efficient nutrients to stimulate microorganisms in indigenous microbial enhanced oil recovery (IMEOR) processes. In the present study, the potential of rice bran as a carbon source for promoting IMEOR was investigated on a laboratory scale. The co-applications of rice bran, K2HPO4 and urea under optimized bio-stimulation conditions significantly increased the production of gases, acids and emulsifiers. The structure and diversity of microbial community greatly changed during the IMEOR process, in which Clostridium sp., Acidobacteria sp., Bacillus sp., and Pseudomonas sp. were dominant. Pressurization, acidification and emulsification due to microbial activities and interactions markedly improved the IMEOR processes. This study indicated that rice bran is a potential carbon source for IMEOR.