Systematic Extensive Laboratory Studies of Microbial EOR Mechanisms and Microbial EOR Application Results in Changqing Oilfield

Abstract

Abstract Microbial EOR was extensively laboratory tested to evaluate microbial affects on fluid properties and oil recovery then successfully applied in Changqing Oilfield. Fourteen different items were evaluated in 271 different tests to better understand the mechanisms of microbial EOR. Testing included core flooding, mobility improvement, crude compositional changes and microbe metabolite production and affects. Results are that the facultative anaerobic microbes can degrade the alkanes in crude into shorter chain alkanes and produce beneficial metabolites including carbon dioxide, surfactants and organic acids. The lower oil viscosity and beneficial metabolites are effective at increasing oil production rate and recovery. The lab testing is very complete and systematic leading to performance evaluation of the treatments in twenty-seven wells. Microbial EOR increased production 17.5 tons/day or eighteen percent.