Abstract
Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells grow from 726 in 2001 to 15,870 in 2011. This study aimed to measure fence line concentrations of methane and hydrogen sulfide at natural gas production sites (wells, liquid storage tanks, and associated equipment) in the four core counties of the Barnett Shale (Denton, Johnson, Tarrant, and Wise). A mobile measurement survey was conducted in the vicinity of 4788 wells near 401 lease sites, representing 35% of gas production volume, 31% of wells, and 38% of condensate production volume in the four-county core area. Methane and hydrogen sulfide concentrations were measured using a Picarro G2204 cavity ring-down spectrometer (CRDS). Since the research team did not have access to lease site interiors, measurements were made by driving on roads on the exterior of the lease sites. Over 150 hr of data were collected from March to July 2012. During two sets of drive-by measurements, it was found that 66 sites (16.5%) had methane concentrations >3 parts per million (ppm) just beyond the fence line. Thirty-two lease sites (8.0%) had hydrogen sulfide concentrations >4.7 parts per billion (ppb) (odor recognition threshold) just beyond the fence line. Measured concentrations generally did not correlate well with site characteristics (natural gas production volume, number of wells, or condensate production). t tests showed that for two counties, methane concentrations for dry sites were higher than those for wet sites. Follow-up study is recommended to provide more information at sites identified with high levels of methane and hydrogen sulfide.Implications:Information regarding air emissions from shale gas production is important given the recent increase in number of wells in various regions in the United States. Methane, the primary natural gas constituent, is a greenhouse gas; hydrogen sulfide, which can be present in gas condensate, is an odor-causing compound. This study surveyed wells representing one-third of the natural gas production volume in the Texas Barnett Shale and identified the percent of sites that warrant further study due to their fence line methane and hydrogen sulfide concentrations.
Highlights
Production of natural gas from hydrocarbon-rich shale formations, or shale gas, is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past (Alvarez and Paranhos, 2012; Lev-On and Levy, 2012; Mueller, 2012)
Our study surveyed the vicinity of 4788 wells near 401 lease sites, representing 34.6% of the gas production volume, 31% of the wells, and 38% of the condensate production volume in the four-county area
For each of the four counties, methane and hydrogen sulfide concentrations measured at each lease site were plotted versus lease site natural gas production volume, number of wells, and condensate volume
Summary
Production of natural gas from hydrocarbon-rich shale formations, or shale gas, is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past (Alvarez and Paranhos, 2012; Lev-On and Levy, 2012; Mueller, 2012). Natural gas drilling and production have occurred in sparsely populated areas for decades, their widespread occurrence in close proximity to large population centers is relatively new (Alvarez and Paranhos, 2012; Lev-On and Levy, 2012; Mueller, 2012). Criteria air pollutants from natural gas drilling and production include particulate matter, nitrogen oxides, sulfur oxides, and carbon monoxide These criteria pollutants stem primarily from compressor engines, typically diesel powered, which are used to compress the gas for transport in pipelines (Armendariz, 2009; Bar-Ilan et al, 2008; Eastern Research Group, 2011). Volatile organic compounds from natural gas drilling and production include benzene and formaldehyde
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
