Emission rates of Volatile Organic Compounds Associated with Natural Gas Extraction Activities in Western Colorado

Processes associated with natural gas extraction activities have been known to emit volatile organic compounds (VOCs), but the data available on the rate and type of VOCs emitted are limited due to the difficulties in accurate estimations of emission rates from concentration measurements. The use of unconventional extraction methods have resulted in an increase in overall number of wells and activities and thus an anticipated increase in VOC emissions. Accurate measurements of VOC emission rates will play a critical role in estimating the local and regional effects of oil and gas activities and future mitigation measures adopted by companies and regulatory agencies. In order to collect data on the VOC emission rates, the tracer ratio method has been used to investigate the different stages of new well development, including drilling, fracking and flowback. Samples were collected from 2013-2015 near oil and gas pads in Garfield County, CO. Acetylene was released as a tracer gas on oil and gas pads, and three minute integrated whole air canisters were collected downwind at different distances from the source of the emission. The canisters were later analyzed for a suite of VOCs, including acetylene, using a five-channel gas chromatorgraphy system preceded by a cryogenic preconcentration unit. The data from these measurements will be presented, showing the differences in VOC types and emission rates linked to different types of natural gas extraction activities.