Quantifying methane emissions in the Uintah Basin during wintertime stagnation episodes

Abstract

This study presents a meteorologically-based methodology for quantifying basin-scale methane (CH4) emissions in Utah’s Uintah Basin, which is home to over 9,000 active and producing oil and natural gas wells. Previous studies in oil and gas producing regions have often relied on intensive aircraft campaigns to estimate methane emissions. However, the high cost of airborne campaigns prevents their frequent undertaking, thus providing only daytime snapshots of emissions rather than more temporally-representative estimates over multiple days. Providing estimates of CH4 emissions from oil and natural gas production regions across the United States is important to inform leakage rates and emission mitigation efforts in order to curb the potential impacts of these emissions on global climate change and local air quality assessments. Here we introduce the Basin-constrained Emissions Estimate (BEE) method, which utilizes the confining topography of a basin and known depth of a pollution layer during multi-day wintertime cold-air pool episodes to relate point observations of CH4 to basin-scale CH4 emission rates. This study utilizes ground-based CH4 observations from three fixed sites to calculate daily increases in CH4, a laser ceilometer to estimate pollution layer depth, and a Lagrangian transport model to assess the spatial representativity of surface observations. BEE was applied to two cold-air pool episodes during the winter of 2015–2016 and yielded CH4 emission estimates between 44.60 +/– 9.66 × 103 and 61.82 +/– 19.76 × 103 kg CH4 hr–1, which are similar to the estimates proposed by previous studies performed in the Uintah Basin. The techniques used in this study could potentially be utilized in other deep basins worldwide.

Daily Satellite Observations of Methane from Oil and Gas Production Regions in the United States

“…The Horsepool and Roosevelt monitors are situated at lower elevation in the basin and are frequently exposed to high methane in the winter when emissions are trapped under cold-pool conditions. The Fruitland monitor is situated at a higher elevation and does not see similarly high methane enhancements 27 . Figure 2B compares the TROPOMI methane columns between December 2018 and March 2019 with data from the three monitors.…”

“…We conclude that the TROPOMI hotspot observed over the Uintah Basin is caused by enhanced methane in the boundary layer in agreement with surface monitors. Continued surface and TROPOMI measurements over the Uintah Basin will be useful to further develop and evaluate emissions estimates under cold-pool conditions 27 , which can then be applied with more confidence for other, similar basins. permian basin.…”

The Utah urban carbon dioxide (UUCON) and Uintah Basin greenhouse gas networks: instrumentation, data, and measurement uncertainty

“…UUCON collects near-surface data used to (a) understand spatial and temporal variability of emissions (Pataki et al, 2003(Pataki et al, , 2005Mitchell et al, 2018b;, (b) evaluate the accumulation of pollutants during complex meteorological conditions (Pataki et al, 2005;Gorski et al, 2015;Baasanbdorj et al, 2017;Fiorella et al, 2018), (c) develop and improve atmospheric transport models (Strong et al, 2011;Nehrkorn et al, 2013;Mallia et al, 2015), (d) validate emissions inventory estimates (McKain et al, 2012;, (e) investigate relationships between urban emissions and air pollution (Baasandorj et al, 2017;Mouteva et al, 2017;, and (f) inform stakeholders and policymakers (Lin et al, 2018).…”

Meteorological Drivers of Permian Basin Methane Anomalies Derived from TROPOMI

“…A recent study in the Permian Basin observed entire months where coverage was sparse in certain locations [19], and arial and tower measurements with gridded ONG production data between January and August 2020 were used to estimate methane fluxes in several small targeted subregions of the Basin, but a limited number of satellite estimates over their targeted regions precluded any direct comparisons between observations and TROPOMI [19]. Better determining which ONG regions and basins can be utilized for TROPOMI satellite observations, which ones have too high surface reflectance or too frequent cloud or snow cover, and which basins have ground observations to validate satellite data against will all be important considerations in the future analysis of TROPOMI CH 4 retrievals over these regions [25,69]. Using satellite data in concert with multiple in situ measurements to validate the results is also recommended as future work.…”