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One of the most significant challenges associated with predicting reservoir fluid properties is accounting for the effect of microbial activity, which catalyzes chemical reactions that lead to corrosion and sulfide release during or after hydraulic fracturing operations. The current understanding of microbial populations living in hydraulic fracturing systems is based on a limited number of samples and well sites, necessitating additional research efforts to confirm preliminary findings and identify factors driving the microbial ecology. The project objective is to profile the geochemistry and microbiology of three different oil and gas basins to order increase the understanding of how microbial activity affects reservoir fluids. We evaluated the geochemistry, microbial community structure, and microbial abundance of produced water samples collected from the Marcellus Shale, Permian Basin, and Bakken Formation, which represent three of the most productive oil and gas regions in the United States. We also performed a network analysis in order to visualize the microbial interactions occurring across all the hydrocarbon regions and within specific shale plays. For these analyses, we sampled 155 produced waters to account for inter- and intra-basin heterogeneities. Results suggested all three shale plays have a high abundance of Halanaerobiaceae, a bacterium with the metabolic potential to contribute to acid production, sulfide production, and biofouling. Less abundant bacterial families including Pseudomonadaceae and Methanobacteriaceae varied between shale plays, demonstrating some regions to have a high potential for biologically driven corrosion and others to have a high potential for biogenic methane generation. Findings from this research will contribute to the development of better predictability in fluid properties, with the goal to limit corrosion, control fouling and souring issues, protect well infrastructure, and minimize unnecessary biocide application. This istudy takes a comprehensive approach to characterizing biogeochemistry of reservoir fluids and compares these results across three distinct basins. |
