Abstract
The United States Environmental Protection Agency Greenhouse Gas Inventory only recently updated the emission factors of natural gas gathering pipelines in April 2019 from the previous estimates based on a 1990s study of distribution pipelines. Additional measurements are needed from different basins for more accurate assessments of methane emissions from natural gas midstream industries and hence the overall climate implications of natural gas as the interim major energy source for the next decade. We conducted an unmanned aerial vehicle (UAV) survey and a ground-based vehicle sampling campaign targeting gathering pipeline systems in the Utica Shale from March to April in 2019. Out of 73 km of pipeline systems surveyed, we found no leaks on pipelines and two leaks on an accessory block valve with leak rates of 3.8 ± 0.4 and 7.6 ± 0.8 mg/s. The low leak frequency phenomenon was also observed in the only existing gathering pipeline study in Fayetteville Shale. The UAV sampling system facilitated ease of access, broadened the availability of pipelines for leak detection, and was estimated to detect methane leaks down to 0.07 g/s using Gaussian dispersion modeling. For future UAV surveys adopting similar instrument setup and dispersion models, we recommend arranging controlled release experiments first to understand the system’s detection limit and choosing sampling days with steady and low wind speeds (2 m/s).
Highlights
Methane is the main component (76 to 92%, vol%) of natural gas and the second most abundant greenhouse gas after carbon dioxide (CO2 ) [1,2]
The unmanned aerial vehicle (UAV) surveyed pipelines were all stainless steel based on the Ohio Public Utilities Commission (PUC) and Rextag data sources
Most of the pipelines were surveyed by the UAV platform (56 km out of 73 km)
Summary
Methane is the main component (76 to 92%, vol%) of natural gas and the second most abundant greenhouse gas after carbon dioxide (CO2 ) [1,2]. States is experiencing a shale gas boom, with its annual dry natural gas production increased by 67 percent from 18 to 30 trillion cubic feet between 2005 and 2018 [4]. In 2017, the United States became a net natural gas exporter and natural gas is predicted to be the interim major energy source for the decade [5,6]. According to Alvarez et al [8], if the leak rates of methane in the natural gas supply chain were less than 3.2% of the total natural gas production, the utilization of natural gas would be a short-term mitigation approach for battling climate change and fulfilling the Atmosphere 2020, 11, 716; doi:10.3390/atmos11070716 www.mdpi.com/journal/atmosphere
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.