Nitrogen Oxide Emissions from U.S. Oil and Gas Production: Recent Trends and Source Attribution

U.S. oil and natural gas production volumes have grown by up to 100% in key production areas between January 2017 and August 2019. Here we show that recent trends are visible from space and can be attributed to drilling, production, and gas flaring activities. By using oil and gas activity data as predictors in a multivariate regression to satellite measurements of tropospheric NO2 columns, observed changes in NO2 over time could be attributed to NOx emissions associated with drilling, production and gas flaring for three select regions: the Permian, Bakken, and Eagle Ford basins. We find that drilling had been the dominant NOx source contributing around 80% before the downturn in drilling activity in 2015. Thereafter, NOx contributions from drilling activities and combined production and flaring activities are similar. Comparison of our topâ down source attribution with a bottomâ up fuelâ based oil and gas NOx emission inventory shows agreement within error margins.Plain Language SummaryU.S. oil and natural gas production volumes have grown by up to 100% in key production areas between January 2017 and August 2019. Here we show that recent trends are visible from space as increases in NO2, an air pollutant that is released from combustion engines associated with the oil and gas industry. For three select regions, the Permian (TX and NM), Bakken (ND), and Eagle Ford (TX) basins, we report that the trend in NO2 columns over time can be explained by a combination of drilling activity, production numbers, and flared gas volume, which allows us to quantify the contributions from these sources to the total NOx (= NO + NO2) emissions from these areas. We find that drilling had been the dominant NOx source contributing around 80% before the downturn in drilling activity in 2015. But now, NOx contributions from drilling activities and combined production and flaring activities are similar. Both Permian and Bakken oil and gas production volumes are at an allâ time high and if current growth rates continue in the Eagle Ford basin, maximum production volumes will be exceeded in about 1 year.Key PointsRecent increases in U.S. oil and gas production are seen from space as increased tropospheric NO2 columns and increased gas flaringChanges in NO2 over time can be attributed to oil and gas NOx emissions associated with drilling, production, and gas flaring activitiesTopâ down and bottomâ up source attributions agree that drilling and, to a lesser extent, production are the main sources of NOx emissionsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153757/1/grl60007_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153757/2/grl60007.pd