The Impact of Chemical Additives and Chemical Transformations on Water Quality in Hydraulic Fracturing

The U.S. Energy Information Administration (EIA) predicts that electricity generation from natural gas will increase by 30 to 40% until 2040 [1]. Natural gas is produced via hydraulic fracturing, which does not come without environmental health and safety concerns. Many of the concerns are due to the insufficient knowledge about what hydraulic fracturing fluids contain pre-and post-fracture and how they impact water quality [2]. Consequently, knowledge gaps remain concerning how the additives transform and how they interact with the geological formations downhole. Failure to address this issue has caused the public to question whether the benefits outweigh the perceived risks as the environmental and ecosystem concerns surrounding hydraulic fracturing are still present [3].To address these concerns, this research investigates the interactions and transformations of chemical additives used in hydraulic fracturing with one another and with shale rock. Specifically, the adsorption of a surfactant-like chemical, 2-butoxyethanol (2-BE), found in the chemical additive Revert Flow, and a non-surfactant chemical, 3-furaldehyde, found in enzyme breaker additives, will be monitored in shale rock and with granular activated carbon to assess the potential for chemical migration through geological formations. This dissertation will also investigate the reactions between 2-BE, shale rock, and chemical additives, including sodium persulfate and hydrochloric acid. In turn, the changes in shale properties, including particle size and heavy metal leaching, due to contact with chemical additives will be assessed. The organic byproducts produced or metals precipitated in each set of reactions will be used to determine how hydraulic fracturing fluids transform water quality.Hydraulic fracturing transformations must be understood to evaluate how hydraulic fracturing fluids impact water quality. A better understanding of how chemicals interact under hydraulic fracturing conditions will increase awareness and knowledge of what the waste fluids contain, aid in developing environmental policies that protect the ecosystems surrounding a well, and facilitate spill preparedness to mitigate hydraulic fracturing pollution based on the information in this study.