Date of Award
Master of Science (MS)
Hydraulic fracturing and horizontal drilling for oil and gas in low-permeability formations has created a boom for the United States energy sector. This rapid increase in oil and gas development in the contiguous United States has put hydraulic fracturing development in direct conflict with development in urban and peri-urban areas. A major concern of hydraulic fracturing proximity to residential development is the potential threat of groundwater contamination due to surface spills. This study addresses the threat of groundwater contamination by developing a risk analysis framework to quantify the groundwater contamination risk posed by 302 chemicals. This framework was then applied to 116,231 hydraulic fracturing jobs in the most recently available version of FracFocus as of February 22nd, 2018. This processed FracFocus data was used to determine spatial and temporal changes in risk. Case studies were done on regions of concern, and compounds of concern to see what compounds contribute most to risk. There were 106,691 hydraulic fracturing jobs for which combined risk scores could be calculated that were used in spatial trend analysis. Temporal analysis was limited to 2011 through 2016 data. This included 96,516 jobs for which combined risk scores could be calculated. This study concluded that the groundwater contamination risk of hydraulic fracturing jobs was quasi-significantly increasing with time for the entire United States, and identified several regions of the United States with elevated risk and risk that significantly increased with time. This is indicative of a trend towards the use of riskier compounds over time. Spatio-temporal trends of elevated risk were attributed to propargyl alcohol, acrylamide, 1,4-dioxane, and N,N-dimethylformamide. Case studies on the prominent contaminants 2-butoxyethanol and naphthalene showed that while there has been a focus on these compounds as contaminants of concern, quantitatively they do not appear to be the most significant contaminants. This study represents a major effort which utilizes all FracFocus data for an applied data analysis and makes valuable steps toward making the FracFocus database more accessible. The integrated risk analysis and data analysis framework setup in this study may prove to be a valuable tool for regulator and oil and gas operators alike to help assess risk and promote environmental friendliness of their hydraulic fracturing fluids.
Stults, John Forrest, "Are Hydraulic Fracturing Fluids Getting Riskier? - an Integrated Approach to Risk Analysis and Data Analytics Using the Fracfocus Database" (2018). Civil Engineering Graduate Theses & Dissertations. 357.