Identification And Inhibition Of SRB From The Produced Water Of A Off-shore High-temperature Oil Reservoirs At Bohai Bay,China

The growth and activity of sulfate-reducing prokaryotes?SRB?occurring in oilfield environment could produce considerable amount of H₂S,leading to multifaceted problems such as oilfield souring and microbially-influenced corrosion,yet knowledge about the diversity and physiology of SRB therein is quite limited.In order to know about the microbiology concerning souring in off-shore high-temperature oil reservoirs at Bohai Bay area and seek the control strategy,the selection of B oil field as the research object,were analyzed by Hungate techniques.We isolated 2 SRB strains from the produced water of a high-temperature off-shore oilfield located at Bohai Bay,China.We also presented the phenotypic features of SRB,and investigated the efficacy of different biocides or metabolic inhibitors,in suppressing the sulfidogenic activity of SRB flora and SRB strains.The main results and conclusions are:?1?The addition of nitrate could effectively inhibit the sulfate-reducing activity of SRB enrichment cultures.The inhibitory duration prolonged as the initial nitrate concentration increased.The use of 5mmol·L^-1 nitrate inhibited the SRB for 60 d.The nitrite produced when SRB utilized nitrate was possibly accounted for the inhibition.?2?The addition of nitrite could effectively inhibit the sulfate-reducing activity of SRB enrichment cultures,and its inhibition could reach up to 30 d at low concentration(3 mmol·L^-1).And the inhibitory effect increased with the increase of nitrate concentration.?3?BTAC(800 mg·L^-1),sodium hypochlorite(800 mg·L^-1)had no obvious inhibition effect on Sulfate reducing bacteria enrichment culture in produced water.glutaraldehyde(50 mg·L^-1),bronopol(50 mg·L^-1)could inhibited H₂S production by SRB enrichment cultures for at least 30 d,indicating that these compounds may serve as potent agents for the mitigation of microbial souring in this specific high-temperature offshore oilfield at Bohai Bay,China.?4?2 kinds of SRB strains were successfully screened by STM medium from produced water?strains A31-1 and B31-2?.Based on the alignment of the nearly full-length 16S rDNA gene sequences,the representative strains A31-1 and B31-2showed the highest similarity to Desulfovibrio vulgsri?99%?and Soehngenia saccharolytica?100%?.The physiological and biochemical evaluation was carried out,one of which was thermotolerant,halotolerant SRB strain,and the other was thermotolerant and alkaliphilic SRB strain,are adapted to the high temperature environment reservoir in Bohai Bay,China.?5?Nitrate(10 mmol·L^-1)failed to inhibit H₂S production by A31-1.By contrast,nitrite of 1 mmol·L^-1 was effective in inhibiting the sulfate-reducing activities of A31-1 for at least 30 d,which is a potential effective inhibitor.?6?glutaraldehyde(50 mg·L^-1),bronopol(30 mg·L^-1)could inhibited he sulfate-reducing activity by A31-1 for at least 30 d,and glutaraldehyde(50 mg·L^-1)or bronopol(10 mg·L^-1)could inhibited H₂S production by B31-2 for at least 30 d,indicating that these compounds may serve as potent agents for the mitigation of microbial souring in this specific high-temperature offshore oilfield at Bohai Bay,China.