Microbial Ecology in Environments Impacted by Hydraulic Fracturing Flowback and Produced Water

Abstract

The increased development of unconventional resources recovery has dramatically changed the global energy landscape over the past two decades. Hydraulic fracturing combined with horizontal drilling, a key technology in recovering these resources, requires large freshwater volumes to fracture the low-permeability shale formations that host the hydrocarbons. Biofouling, biocorrosion, and biodegradation, caused by persistent microbial communities in the fractured subsurface, may influence the efficiency and costs of oil and gas recovery. Following fracturing, return fluid, referred to here as flowback and produced water (FPW), returns to the surface. FPW may cause contamination of the environment when surface spills occur. Microbial communities are basic units of ecosystems and drive virtually all biogeochemical cycling in the environment. However, knowledge of the effects of FPW on freshwater and soil microbial communities is limited. This thesis aims to answer scientific questions about the influence of FPW to soil and water microbial ecology, in order to enhance our understanding of the impacts of microbial communities to downhole production and microbial ecology in environments impacted by FPW.