Abstract
ABSTRACTIn this study, emissions of ozone precursors from oil and gas operations in Utah’s Uinta Basin are predicted (with uncertainty estimates) from 2015–2019 using a Monte-Carlo model of (a) drilling and production activity, and (b) emission factors. Cross-validation tests against actual drilling and production data from 2010–2014 show that the model can accurately predict both types of activities, returning median results that are within 5% of actual values for drilling, 0.1% for oil production, and 4% for gas production. A variety of one-time (drilling) and ongoing (oil and gas production) emission factors for greenhouse gases, methane, and volatile organic compounds (VOCs) are applied to the predicted oil and gas operations. Based on the range of emission factor values reported in the literature, emissions from well completions are the most significant source of emissions, followed by gas transmission and production. We estimate that the annual average VOC emissions rate for the oil and gas industry over the 2010–2015 time period was 44.2E+06 (mean) ± 12.8E+06 (standard deviation) kg VOCs per year (with all applicable emissions reductions). On the same basis, over the 2015–2019 period annual average VOC emissions from oil and gas operations are expected to drop 45% to 24.2E+06 ± 3.43E+06 kg VOCs per year, due to decreases in drilling activity and tighter emission standards.Implications: This study improves upon previous methods for estimating emissions of ozone precursors from oil and gas operations in Utah’s Uinta Basin by tracking one-time and ongoing emission events on a well-by-well basis. The proposed method has proven highly accurate at predicting drilling and production activity and includes uncertainty estimates to describe the range of potential emissions inventory outcomes. If similar input data are available in other oil and gas producing regions, then the method developed here could be applied to those regions as well.
Highlights
Oil and gas operations in Utah’s Uinta Basin are both a key part of the region’s economy and the primary source of ozone precursor emissions that lead to winter-time, ground-level ozone formation events
If similar input data are available in other oil and gas producing regions, the method developed here could be applied to those regions as well
Assuming that the emission factors found in our literature review are representative, the annual average volatile organic compounds (VOCs) emission rate for the oil and gas industry over the 2010–2015 time period would be 44.2E+06 ± 12.8E+06 (SD) kg VOCs per year
Summary
Oil and gas operations in Utah’s Uinta Basin are both a key part of the region’s economy and the primary source of ozone precursor emissions that lead to winter-time, ground-level ozone formation events. Developing a state implementation plan to meet NAAQS for ground-level ozone will require accurate estimates of the emissions inventory from the oil and gas industry so that state regulators can make informed decisions about potential reduction and control strategies. This study seeks to improve upon the previous method for estimating emissions from the oil and gas industry in the Uinta Basin by tracking one-time (well drilling, completion, and reworks) and ongoing (production, processing, transport) emission events from both oil and gas wells on a well-by-well basis with uncertainty estimates. If similar input data are available in other oil and gas producing regions (namely, energy price, drilling activity, and oil and gas production records), the method developed here could be applied to those regions as well
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
