Microbes present in the subsurface exploit local changes in physical and chemical conditions and therefore are highly associated with the local subsurface areas. The differences in microbial communities are seen from the DNA sequences being analyzed via bioinformatics.
We look at the presence/absence, abundance, diversity, and evolutionary relationships, which are used to create a database of DNA marker sequences that become highly associated with different spatial regions throughout the vertical strata, formations and along laterals.
Microbes exist in the subsurface pore space, even if that is at the micrometer scale, which is typically seen in oil and gas reservoirs. Furthermore, they can be found in extreme environments like high temperatures and living bacteria can be found in 100M year old formations. (Science, July 2020)
Stanford Research at Sanford Underground Research Facility, SD (2019), used technology co-developed by Biota’s technology team. They analyzed formation water samples from new boreholes near mine shafts and used microbial fluid signatures to ID well connectivity from natural fractures. The hypothesis supported by analysis of coring run intersecting wells.