959169 - Ambient Air Monitoring of Well Pads During Drilling Activities

Hydraulic fracturing is a process by which fluids are injected into an oil-producing formation in order to increase extraction. While increasing production of the well, hydraulic fracturing also has unintended consequences in the production of greenhouse gases. Using a mobile air monitoring laboratory, seven well pads in the Appalachian Basin were analyzed during the beginning stages of horizontal and vertical drilling through to production in order to determine associations with increased greenhouse gas emissions. Methane, carbon dioxide, ozone, and NOx were each detected, along with volatile organic compounds. Wind speed and direction were used to positively attribute peaks in greenhouse gas emissions to activity on the well pads. Seasonal and diurnal variations in emissions were also considered as possible factors in observed emissions. Overall, the increase of one greenhouse gas was usually associated with a concomitant increase in other measured gases, regardless of activity. While sporadic increases in emissions were observed, overall average emissions during the phases of drilling were not statistically significantly different. However, large but short increases in emissions may indicate periods of intense well pad activity and suggest the need for more emissions mitigation strategies to reduce greenhouse gas emissions from hydraulic fracturing activities.