CASE STUDY IN EAGLE FORD SHALE

Routine emissions of light alkanes from oil and gas sources in the Eagle Ford Shale were modeled at 1-hour resolution using the Methane Emissions Estimation Tool (MEET). Emissions were spatially aggregated based on their distance from a centralized air quality monitor. A Gaussian-puff dispersion model (CALPUFF) was used to predicted ambient hydrocarbon concentrations at a virtual receptor in Karnes City, TX corresponding to the location of an automatically sampling gas chromatography system (Auto-GC) operated by the Texas Commission on Environmental Quality (TCEQ). Time-matched measurements from the Auto-GC and sensitivity analyses were used to evaluate the model predictions and predict the presence of non-routine emission events.

EFS Emissions Aggregation Scheme

≥ 90% reduction in the number of sources included in the dispersion model

Review Detailed Eagle Ford Shale (EFS) Case Study Framework Flowcharts:

Resources

EFS manuscript: Graves, et al. (2025)

Sources for model inputs (numbers correspond to flow diagram):

  1. Production and completion data: IHS Markit

  2. Estimating non-combustion emissions from well sites: Methane Emission Estimation Tool (MEET) 

  3. Estimating methane emissions from gathering sites: Zimmerle, et al. Methane Emissions from Gathering Compressor Stations in the U.S (2020)

  4. Estimating methane emissions from natural gas processing plants: Mitchell, et al. Measurements of methane emissions from natural gas  gathering facilities and processing plants: measurement results (2015)

  5. Land-use data: National Land-Use Consortium Database

  6. Elevation data: National Elevation Dataset (3D Elevation Program Products)

  7. Onsite meteorological data and hydrocarbon measurements: TCEQ TAMIS data request portal

  8. Surface meteorological data (hourly): Integrated surface database

  9. Surface meteorological data (5-minute): Automated surface observation system

  10. Numerical weather prediction products (meteorological data): High-resolution rapid refresh

Additional resources:
Upper air soundings: Integrated Global Radiosonde Archive
General NCEI/NOAA meteorological products: NCEI/NOAA data products

Model documentation:
AERMOD
CALPUFF

Examples of alternative air quality models:
HYSPLIT Dispersion Model
Community Multiscale Air Quality Model System (CMAQ)