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

摘要

Microbial EOR was extensively laboratory tested to evaluaternmicrobial affects on fluid properties and oil recovery thenrnsuccessfully applied in Changqing Oilfield. Fourteen differentrnitems were evaluated in 271 different tests to better understandrnthe mechanisms of microbial EOR. Testing included corernflooding, mobility improvement, crude compositional changesrnand microbe metabolite production and affects. Results arernthat the facultative anaerobic microbes can degrade thernalkanes in crude into shorter chain alkanes and producernbeneficial metabolites including carbon dioxide, surfactantsrnand organic acids. The lower oil viscosity and beneficialrnmetabolites are effective at increasing oil production rate andrnrecovery. The lab testing is very complete and systematicrnleading to performance evaluation of the treatments in twentysevenrnwells. Microbial EOR increased production 17.5rntons/day or eighteen percent.