Microbiology relevant to hydraulic fracturing and oil sands

Abstract

Advances in drilling and stimulation technologies have greatly improved the economics of oil and gas production from deep, tight, hydrocarbon-rich shale formations. But the unconventional drilling required for this production is associated with challenges in the management of both the wastewater that is coproduced at the surface and the microbial communities in this water. The focus of this article is on the microbial ecology and biogeochemical processes that impact the production of oil and gas, management of wastewater (both flowback and produced water), and product quality from hydraulically fractured wells. Hydraulic fracturing is discussed from the perspective of water management, including the volume and makeup of fracturing fluids that give rise to produced water microbiology. Recent studies of the chemistry and microbiology of produced water from the Marcellus and Barnett shale regions are discussed. Microbial ecology present at wellheads is described as well as that of stratified impoundments for produced water. The concluding section considers the implications of microbial control for unconventional production and identifies research needed to address them.