Identification of Persistent Sulfidogenic Bacteria in Shale Gas Produced Waters
Identification of Persistent Sulfidogenic Bacteria in Shale Gas Produced Waters
复制标题
DOI：
10.3389/fmicb.2020.00286
复制
发表时间：
2020-02-21
影响因子：
5.2
通讯作者：
Lloyd, Jonathan R.
中科院分区：
文献类型：
--
作者：
Cliffe, Lisa;Nixon, Sophie L.;Lloyd, Jonathan R.
水力压裂页岩地层的产出沃茨可深入了解井下微生物生态和地球化学条件。本研究探讨了从Marcellus页岩地层采集的采出水样品中回收的持久性微生物产生硫化物的潜力。硫化氢具有高度毒性和腐蚀性，并可导致形成精炼成本高昂的“酸性气体”。此外，水力压裂页岩的微生物定殖可导致地层堵塞和井生产率降低。评估持久性微生物类群中硫化物产生的潜力至关重要，特别是考虑到将采出沃茨作为输入流体再利用的趋势，可能会富集有问题的微生物。使用最大可能数（MPN）计数和16 S rRNA基因测序，从储存的生产沃茨中鉴定出多种活的细菌菌株，主要属于嗜盐菌属（Halanaerobium），其能够通过发酵生长，并在供应硫代硫酸盐时产生硫化物。通过培养没有检测到硫酸盐还原菌（SRB），尽管通过高通量16S rRNA基因测序检测到相对较低数量的硫酸盐还原谱系。这些结果表明，产硫采出水群体在生产后的数年内仍然是可行的，如果不加以控制，有可能导致页岩气开采过程中天然气酸化。
Produced waters from hydraulically fractured shale formations give insight into the microbial ecology and biogeochemical conditions down-well. This study explores the potential for sulfide production by persistent microorganisms recovered from produced water samples collected from the Marcellus shale formation. Hydrogen sulfide is highly toxic and corrosive, and can lead to the formation of "sour gas" which is costly to refine. Furthermore, microbial colonization of hydraulically fractured shale could result in formation plugging and a reduction in well productivity. It is vital to assess the potential for sulfide production in persistent microbial taxa, especially when considering the trend of reusing produced waters as input fluids, potentially enriching for problematic microorganisms. Using most probable number (MPN) counts and 16S rRNA gene sequencing, multiple viable strains of bacteria were identified from stored produced waters, mostly belonging to the Genus Halanaerobium, that were capable of growth via fermentation, and produced sulfide when supplied with thiosulfate. No sulfate-reducing bacteria (SRB) were detected through culturing, despite the detection of relatively low numbers of sulfate-reducing lineages by high-throughput 16S rRNA gene sequencing. These results demonstrate that sulfidogenic produced water populations remain viable for years post production and, if left unchecked, have the potential to lead to natural gas souring during shale gas extraction.