Two strains of bacteria degrading polycyclic aromatic hydrocarbons(PAHs)were isolated using enrichment culture...
Yuehui She1,2,Fuchang Shu1,Fan Zhang3,Zhengliang Wang1,Shuqiong Kong1,Longjiang Yu2 1 College of Chemistry and Environmental Engineering,Yangtze University,Jingzhou 434023,China 2 School of Life Science and Technology,Huazhong University of Science&Technology,Wuhan 430074,China 3The Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism,Ministry of Education,China
The distribution of indigenous microorganisms was surveyed in Block 1 of Daqing Oilfield. Based on this survey,the indigenous microorganisms in the formation water were activated with different activator systems at the simulated stratum ecological environment. The changes of the number of bacteria of various physiological groups were determined during the process of activation. Also changes of pH value and composition of gas productions were analyzed at the end of culturing. The results showed that the selected block formation water contained a great number of saprophytic bacteria,hydrocarbon-oxidizing bacteria,fermentative bacteria,methane-producing bacteria and sulfate-reducing bacteria. Under the conditions that the growth of sulfate-reducing bacteria was controlled the block had the potential to enhance oil recovery by activating beneficial bacteria. The growth of sulfate-reducing bacteria can be inhibited through the activation of nitrate-reducing bacteria. The number of nitratereducing bacteria reached 106―107 cells/mL,but sulfate-reducing bacteria reached only 0―45 cells/mL in A system. Methane-producing bacteria can be activated by C,D activators. The relative content of biological methane in the light hydrocarbon gas reached 80% in C,D systems. B activator was conducive to the propagation of acid-producing bacteria,so that the pH value of the culture medium decreased from 7.5 to around 5.0. Hydrocarbon-oxidizing bacteria can be activated by various activator systems. There was low molecular light hydrocarbon in gas production according to the analysis of gas chromatograph. According to the content of methane and the number of methane-producing bacteria,methane only can be generated through activating methane-producing bacteria. By choosing different activator systems,various populations of indigenous microorganisms can be activated accordingly.
XIANG TingSheng1,LIU XiaoBo2,ZHANG Min1,LIU Fang2,LI BaiGuang2,FU HuaE1,ZHAO Li3 & HU WangShui1 1 Department of Geochemistry,Yangtze University,Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education of China,Jingzhou 434023,China
