Succession law of bacterial community in fracturing fluid preparation water and produced water of a platform in Weiyuan shale gas block

Objective The study is aiming to explore the key corrosion bacteria in the production process of shale gas, and analyze the potential succession law of bacteria.

Methods The 16S rRNA high-throughput sequencing analysis technology was used to sequence the bacterial flora in the fracturing fluid preparation water and produced water of a shale gas platform in Weiyuan area.

Results The bacterial structure of fresh water is completely different from that of produced water and recycled flowback fluid, the richness and diversity of bacteria decreased after fracturing. The key corrosive bacteria include Arcobacter, Marinobacterium and Pseudomonas, etc. The bacterial community in the freash water is mainly composed of mesophilic, aerobic bacteria with weak functions such as sulfate reduction and acid production. While in the recycled flowback fluid, there are a large number of bacteria with functions of sulfur metabolism, acid production and biofilm production. After fracturing, in the produced water there are mainly facultative anaerobic, anaerobic or strictly anaerobic bacteria with functions such as sulfate reduction, sulfur reduction, sulfur oxidation, acid production, biofilm production, iron reduction, and some thermophilic bacteria were identified.

Conclusion  This provides theoretical and technical support for further research on bacterial corrosion of gathering and transportation pipelines and pipeline protection.