Objectives To prevent and control H2S efficiently,this study conducted structural analysis and functional prediction of the microbial community in the"water injection-oil extraction"system which is located in the Yangmijian block of Jingbian Oil Production Plant,and analyzed the key factors of sulfide generation.Methods The NovaSeq6000 high-throughput sequencing method was used to compare the differences in the microbial community structure of water samples from four stages:produced water,gathering and transportation,water treatment,and water injection.The FaPROTAX bacterial functional analysis method was used to predict the functions of these water samples.Results Firstly,the proportion of desulfurizing bacteria in sulfur-containing oil wells ranged from 16.7％to 43.0％,significantly higher than that in other stages,indicating that the anaerobic environment with suitable formation temperature is conducive to the growth and reproduction of sulfate-reducing bacteria(SRB),which is the main reason of hydrogen sulfide production.Secondly,in the water sample O.3.1 of the sulfur-containing well,the proportions of SRB and NRB in the bacterial community were 33.02％and 21.20％,respectively.However,the proportion of nitrate reduction function was more than 2.3 times higher than that of sulfate reduction,indicating that the presence of nitrate-reducing bacteria has a significant inhibitory effect on sulfate-reducing bacteria.Conclusions Lasting injection of water with nitrate mass concentration higher than 40 mg/L could significantly inhibit the growth of sulfate-reducing bacteria and reduce the production of hydrogen sulfide,thus ensuring the safety of on-site production.
H2Swater injection-oil production systemcommunity structuremicrobial function prediction
维普
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