The Oil Recovery Mechanism of Activated Indigenous Microorganisms by Nutrient Agents

KEYWORD: Indigenous Microorganisms; Nutrient Agent; Community Structure; Biogas Production ABSTRACT: In order to achieve a group of desired nutrient agent of indigenous microorganism of oil reservoir after polymer flooding in Daqing oilfield, biogas production experiments, physical simulation experiments and 16S rRNA gene library experiments were carried out. The first and second group of nutrient agents could make biogas pressure reach 0.85MPa and 1.15MPa in a high pressure vessel, respectively. The oil recovery efficiency of the first and second group of nutrient agents can be improved by 4.8% and 3.2% in physical simulation experiments, respectively. The major bacteria activated by the first activator system were Pseudomonas sp. 72%, Arcobacter sp. 18%, Thauera sp. 6%. The major bacteria activated by the second activator system were Thauera sp. 65%, Pseudomonas sp. 18%, Clostridium sp. 9%. Methanosaeta sp., Methanolinea sp., Methanobacterium sp. and Methanococcus sp. were the major archaea in oil reservoir after polymer flooding, which were not activated by the two activator systems.