title: Constructing a Spatially Resolved Methane Emission Inventory for the Barnett Shale Region.
abstract: Methane emissions from the oil and gas industry (O&G) and other sources in the Barnett Shale region were estimated by constructing a spatially resolved emission inventory. Eighteen source categories were estimated using multiple data sets, including new empirical measurements at regional O&G sites and a national study of gathering and processing facilities. Spatially referenced activity data were compiled from federal and state databases and combined with O&G facility emission factors calculated using Monte Carlo simulations that account for high emission sites representing the very upper portion, or fat-tail, in the observed emissions distributions. Total methane emissions in the 25-county Barnett Shale region in October 2013 were estimated to be 72,300 (63,400-82,400) kg CH4 h(-1). O&G emissions were estimated to be 46,200 (40,000-54,100) kg CH4 h(-1) with 19% of emissions from fat-tail sites representing less than 2% of sites. Our estimate of O&G emissions in the Barnett Shale region was higher than alternative inventories based on the United States Environmental Protection Agency (EPA) Greenhouse Gas Inventory, EPA Greenhouse Gas Reporting Program, and Emissions Database for Global Atmospheric Research by factors of 1.5, 2.7, and 4.3, respectively. Gathering compressor stations, which accounted for 40% of O&G emissions in our inventory, had the largest difference from emission estimates based on EPA data sources. Our inventory's higher O&G emission estimate was due primarily to its more comprehensive activity factors and inclusion of emissions from fat-tail sites.
authors.affiliation: †Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States.|‡Environmental Dynamics Program, University of Arkansas, Fayetteville, Arkansas 72701, United States.
authors.forename: David R
authors.initials: DR
authors.lastname: Lyon
authors.affiliation: †Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Zavala-Araiza
authors.affiliation: †Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States.
authors.forename: Ramón A
authors.initials: RA
authors.lastname: Alvarez
authors.affiliation: †Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Harriss
authors.affiliation: †Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States.
authors.forename: Virginia
authors.initials: V
authors.lastname: Palacios
authors.affiliation: §Department of Earth and Atmospheric Sciences, University of Houston, Houston, Texas 77004, United States.
authors.forename: Xin
authors.initials: X
authors.lastname: Lan
authors.affiliation: §Department of Earth and Atmospheric Sciences, University of Houston, Houston, Texas 77004, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Talbot
authors.affiliation: ∥Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
authors.forename: Tegan
authors.initials: T
authors.lastname: Lavoie
authors.affiliation: ∥Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Shepson
authors.affiliation: ⊥Aerodyne Research, Inc., Billerica, Massachusetts 01821, United States.
authors.forename: Tara I
authors.initials: TI
authors.lastname: Yacovitch
authors.affiliation: ⊥Aerodyne Research, Inc., Billerica, Massachusetts 01821, United States.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Herndon
authors.affiliation: #Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, United States.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Marchese
authors.affiliation: #Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Zimmerle
authors.affiliation: ∇Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Allen L
authors.initials: AL
authors.lastname: Robinson
authors.affiliation: †Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Hamburg
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D019015:Geologic Sediments / Q000737:chemistry*; D017752:Greenhouse Effect; D008697:Methane / Q000032:analysis*; D013781:Texas; D014481:United States; D014484:United States Environmental Protection Agency
chemical_list: D000393:Air Pollutants; D008697:Methane