Microbial Community Composition in Deep-Subsurface Reservoir Fluids Guides Fracture Characterization

The characterization of natural fractures is crucial for the development of geological reservoirs because it may have an important impact on reservoir model construction and hydraulic fracture propagation. In this study we investigated the use of a novel data source, the microbial community composition in the reservoir formation fluids, for identification of interwell connectivity caused by natural fractures. We verified this concept at a newly-developed mesoscale Enhanced Geothermal System (EGS) field testbed located 4850 ft (1478 m) beneath ground surface at the Sanford Underground Research Facility in Lead, SD. Besides the field case described in this study, microbial community composition as a reservoir diagnostic tool would be applicable in a much broader context such as unconventional hydrocarbon exploitation, ground water reservoir characterization, environmental remediation, etc., adding valuable “hard” data capable of pinpointing the origins of fluids unambiguously. Please cite: Y. Zhang et al., Microbial community composition in deep-subsurface reservoir fluids reveals natural interwell connectivity. Water Resour. Res. 56, e2019WR025916 (2020). https://doi.org/10.1029/2019WR025916