1
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Han T, Liggio J, Narayan J, Liu Y, Hayden K, Mittermeier R, Darlington A, Wheeler M, Cober S, Zhang Y, Xie C, Yang Y, Huang Y, Wolde M, Smyth S, Barrigar O, Li SM. Quantification of Methane Emissions from Cold Heavy Oil Production with Sand Extraction in Alberta and Saskatchewan, Canada. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38832692 DOI: 10.1021/acs.est.4c02333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Cold heavy oil production with sand (CHOPS) is an extraction process for heavy oil in Canada, with the potential to lead to higher CH4 venting than conventional oil sites, that have not been adequately characterized. In order to quantify CH4 emissions from CHOPS activities, a focused aerial measurement campaign was conducted in the Canadian provinces of Alberta and Saskatchewan in June 2018. Total CH4 emissions from each of 10 clusters of CHOPS wells (containing 22-167 well sites per cluster) were derived using a mass balance computation algorithm that uses in situ wind data measurement on board aircraft. Results show that there is no statistically significant difference in CH4 emissions from CHOPS wells between the two provinces. Cluster-aggregated emission factors (EF) were determined using correspondingly aggregated production volumes. The average CH4 EF was 70.4 ± 36.9 kg/m3 produced oil for the Alberta wells and 55.1 ± 13.7 kg/m3 produced oil for the Saskatchewan wells. Using these EF and heavy oil production volumes reported to provincial regulators, the annual CH4 emissions from CHOPS were estimated to be 121% larger than CHOPS emissions extracted from Canada's National Inventory Report (NIR) for Saskatchewan. The EF were found to be positively correlated with the percentage of nonpiped production volumes in each cluster, indicating higher emissions for nonpiped wells while suggesting an avenue for methane emission reductions. A comparison with recent measurements indicates relatively limited effectiveness of regulations for Saskatchewan compared to those in Alberta. The results of this study indicate the substantial contribution of CHOPS operations to the underreporting observed in the NIR and provide measurement-based EF that can be used to develop improved emissions inventories for this sector and mitigate CH4 emissions from CHOPS operations.
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Affiliation(s)
- Tianran Han
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - John Liggio
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Julie Narayan
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Yayong Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Katherine Hayden
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Richard Mittermeier
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Andrea Darlington
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Michael Wheeler
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Stewart Cober
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Yuheng Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Conghui Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yanrong Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yufei Huang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Mengistu Wolde
- Flight Research Laboratory, National Research Council Canada Aerospace Research Centre, Ottawa, Ontario K1V 1J8, Canada
| | - Steve Smyth
- Pollutant Inventories and Reporting Division, Environment and Climate Change Canada, Gatineau, Québec K1A 0H6, Canada
| | - Owen Barrigar
- Pollutant Inventories and Reporting Division, Environment and Climate Change Canada, Gatineau, Québec K1A 0H6, Canada
| | - Shao-Meng Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
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Doris M, Daley C, Zalzal J, Chesnaux R, Minet L, Kang M, Caron-Beaudoin É, MacLean HL, Hatzopoulou M. Modelling spatial & temporal variability of air pollution in an area of unconventional natural gas operations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123773. [PMID: 38499172 DOI: 10.1016/j.envpol.2024.123773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/04/2024] [Accepted: 03/10/2024] [Indexed: 03/20/2024]
Abstract
Despite the growing unconventional natural gas production industry in northeastern British Columbia, Canada, few studies have explored the air quality implications on human health in nearby communities. Researchers who have worked with pregnant women in this area have found higher levels of volatile organic compounds (VOCs) in the indoor air of their homes associated with higher density and closer proximity to gas wells. To inform ongoing exposure assessments, this study develops land use regression (LUR) models to predict ambient air pollution at the homes of pregnant women by using natural gas production activities as predictor variables. Using the existing monitoring network, the models were developed for three temporal scales for 12 air pollutants. The models predicting monthly, bi-annual, and annual mean concentrations explained 23%-94%, 54%-94%, and 73%-91% of the variability in air pollutant concentrations, respectively. These models can be used to investigate associations between prenatal exposure to air pollutants associated with natural gas production and adverse health outcomes in northeastern British Columbia.
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Affiliation(s)
- Miranda Doris
- Civil and Mineral Engineering, University of Toronto, Canada.
| | - Coreen Daley
- Physical and Environmental Sciences, University of Toronto Scarborough, Canada.
| | - Jad Zalzal
- Civil and Mineral Engineering, University of Toronto, Canada.
| | - Romain Chesnaux
- Applied Sciences, University of Quebec at Chicoutimi, Canada.
| | - Laura Minet
- Civil Engineering, University of Victoria, Canada.
| | - Mary Kang
- Civil Engineering, McGill University, Canada.
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3
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Wang JL, Barlow B, Funk W, Robinson C, Brandt A, Ravikumar AP. Large-Scale Controlled Experiment Demonstrates Effectiveness of Methane Leak Detection and Repair Programs at Oil and Gas Facilities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38314689 DOI: 10.1021/acs.est.3c09147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Most jurisdictions around the globe use leak detection and repair (LDAR) programs to find and fix methane leaks from oil and gas operations. In this work, we empirically evaluate the efficacy of LDAR programs using a large-scale, bottom-up, randomized controlled field experiment across ∼200 oil and gas sites in Red Deer, Canada. We find that tanks are the single largest source of emissions, contributing to nearly 60% of the total emissions. The average number of leaks at treatment sites that underwent repair reduced by ∼50% compared to the control sites. Although control sites did not see a reduction in the number of leaks, emissions reduced by approximately 36%, suggesting potential impact of routine maintenance activities to find and fix large leaks. By tracking tags on leaking equipment over time, we find a high degree of persistence; leaks that are repaired remain fixed in follow-up surveys, while non-repaired leaks remain emitting at a similar rate, suggesting that any increase in observed leak emissions following LDAR surveys are likely from new leaks. Our results show that a focus on equipment and sites that are prone to high emissions, such as tanks and oil sites, is key to cost-effective mitigation.
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Affiliation(s)
- Jiayang Lyra Wang
- Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Data Science, Harrisburg University of Science and Technology, Harrisburg, Pennsylvania 17101, United States
| | | | - Wes Funk
- DXD Consulting, Incorporated, Calgary, Alberta T2P 0S5, Canada
| | | | - Adam Brandt
- Department of Energy Resources Engineering, Stanford University, Stanford, California 94305, United States
| | - Arvind P Ravikumar
- Department of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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4
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Wei C, Jafari Raad SM, Hassanzadeh H. Estimation of natural methane emissions from the largest oil sand deposits on earth. PNAS NEXUS 2023; 2:pgad260. [PMID: 37693212 PMCID: PMC10485889 DOI: 10.1093/pnasnexus/pgad260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023]
Abstract
Worldwide methane emission by various industrial sources is one of the important human concerns due to its serious climate and air-quality implications. This study investigates less-considered diffusive natural methane emissions from the world's largest oil sand deposits. An analytical model, considering the first-order methane degradation, in combination with Monte Carlo simulations, is used to quantitatively characterize diffusive methane emissions from Alberta's oil sands formations. The results show that the average diffusive methane emissions from Alberta's oil sands formations is 1.56 × 10-4 kg/m2/year at the 90th percentile of cumulative probability. The results also indicate an annual diffusive methane emissions rate of 0.857 ± 0.013 Million tons of CO2e/year (MtCO2e/year) from Alberta's oil sands formations. This finding suggests that natural diffusive leakages from the oil sands contribute an additional 1.659 ± 0.025 and 5.194 ± 0.079% to recent Canada's 2019 and Alberta's 2020 methane emission estimates from the upstream oil and gas sector, respectively. The developed model combined with Monte Carlo simulations can be used as a tool for assessing methane emissions and current inventories.
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Affiliation(s)
- Cao Wei
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University,Chengdu, Sichuan 610500, China
| | - Seyed Mostafa Jafari Raad
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Hassan Hassanzadeh
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada
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5
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Johnson MR, Tyner DR, Conrad BM. Origins of Oil and Gas Sector Methane Emissions: On-Site Investigations of Aerial Measured Sources. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2484-2494. [PMID: 36716186 PMCID: PMC9933527 DOI: 10.1021/acs.est.2c07318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Success in reducing oil and gas sector methane emissions is contingent on understanding the sources driving emissions, associated options for mitigation, and the effectiveness of regulations in achieving intended outcomes. This study combines high-resolution, high-sensitivity aerial survey data with subsequent on-site investigations of detected sources to examine these points. Measurements were performed in British Columbia, Canada, an active oil- and gas-producing province with modern methane regulations featuring mandatory three times per year leak detection and repair (LDAR) surveys at most facilities. Derived emission factors enabled by source attribution show that significant methane emissions persist under this regulatory framework, dominated by (i) combustion slip (compressor exhaust and also catalytic heaters, which are not covered in current regulations), (ii) intentional venting (uncontrolled tanks, vent stacks or intentionally unlit flares, and uncontrolled compressors), and (iii) unintentional venting (controlled tanks, unintentionally unlit/blown out flares, and abnormally operating pneumatics). Although the detailed analysis shows mitigation options exist for all sources, the importance of combustion slip and the persistently large methane contributions from controlled tanks and unlit flares demonstrate the limits of current LDAR programs and the critical need for additional monitoring and verification if regulations are to have the intended impacts, and reduction targets of 75% and greater are to be met.
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6
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Footer TL, Thoma ED, Clark N, Johnson D, Nash J, Herndon SC. Evaluating Natural Gas Emissions from Pneumatic Controllers from Upstream Oil and Gas Facilities in West Virginia. ATMOSPHERIC ENVIRONMENT: X 2023; 17:1-10. [PMID: 36643185 PMCID: PMC9835970 DOI: 10.1016/j.aeaoa.2022.100199] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In April of 2018, an optical gas imaging (OGI) and full flow sampler (FFS) emissions measurement study of pneumatic controllers (PCs) was conducted at 15 oil and natural gas production sites in West Virginia. The objective of the study was to identify and characterize PC systems with excessive emissions caused by maintenance issues or nonoptimized process conditions. A total of 391 PC systems were found on the sites and all were classified by the operator as snap-acting (on/off) intermittent venting PCs (IPCs) that should exhibit little gas release while the PC is closed between actuation events. The population was comprised of two groups, 259 infrequently actuating, lower emitting (LE) IPCs and 132 gas processing unit (GPU) liquid level IPCs and associated dump valve actuators that vent more frequently and have larger emission volumes. Using a PC-specific OGI inspection protocol with an assumed whole gas OGI detection threshold of 2.0 scfh, only 2 out of 259 LE-IPCs exhibited OGI detectable emissions indicating good inspection and maintenance practices for this category. Due to combined (ganged) GPU exhaust vents, the OGI inspection of the GPU liquid level IPCs was comparatively less informative and determination of single component IPC emissions by the FFS was more difficult. The time resolved FFS measurements of GPU IPCs defined three categories of operation: one that indicated proper function and two associated with higher emissions that may result from an IPC maintenance or process issues. The overall GPU IPC emission distribution was heavy tailed, with a median value of 12.8 scfh, similar to the 13.5 scfh whole gas IPC emission factor (EF). Total emissions were dominated by non-optimal temporal profile high-emitter IPC cases with the top 20% of IPC systems accounting for between 51.3% and 70.7% of GPU liquid level IPC emissions by volume. The uncertainty in the estimate was due to the ganged nature of the GPU exhaust vents. The highest GPU IPC emission came from a single malfunctioning unit with a measured whole gas value of 157 scfh. Up to six IPCs exceeded 100 scfh. An analysis of FFS emission measurements compared to liquids production per IPC unit employed indicated that production sites operating at a high level of liquids production test the limits of the site engineering, likely resulting in higher IPC emissions. Overall, this study found that the LE-IPCs with OGI-verified low closed bleed rates may emit well below the IPC EF while GPU liquid level IPC systems are likely well represented by the current IPC EF. IPCs that are experiencing a maintenance or process issue or that are operating at sites with a very high product throughput per IPC employed can emit at rates exceeding ten times IPC EF.
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Affiliation(s)
- Tracey L Footer
- Eastern Research Group, Inc., 601 Keystone Park Drive, Suite 700, Morrisville, NC 27560, United States
| | - Eben D Thoma
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, United States
| | - Nigel Clark
- West Virginia University, Mechanical & Aerospace Engineering, PO Box 6106, Morgantown, WV 26506, United States
| | - Derek Johnson
- West Virginia University, Mechanical & Aerospace Engineering, PO Box 6106, Morgantown, WV 26506, United States
| | - Jennifer Nash
- Eastern Research Group, Inc., 601 Keystone Park Drive, Suite 700, Morrisville, NC 27560, United States
| | - Scott C Herndon
- Aerodyne, 45 Manning Road, Billerica, MA 01821, United States
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7
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Johnson D, Clark N, Heltzel R, Darzi M, Footer TL, Herndon S, Thoma ED. Methane emissions from oil and gas production sites and their storage tanks in West Virginia. ATMOSPHERIC ENVIRONMENT: X 2022; 16:1-11. [PMID: 37091901 PMCID: PMC10116818 DOI: 10.1016/j.aeaoa.2022.100193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A measurement campaign characterized methane and other emissions from 15 natural gas production sites. Sites were surveyed using optical gas imaging (OGI) cameras to identify fugitive and vented emissions, with the methane mass emission rate quantified using a full flow sampler. We present storage tank emissions in context of all site emissions, followed by a detailed account of the former. In total, 224 well pad emission sources at 15 sites were quantified yielding a total emission rate of 57.5 ± 2.89 kg/hr for all sites. Site specific emissions ranged from 0.4 to 10.5 kg/hr with arithmetic and geometric means of 3.8 and 2.2 kg/hr, respectively. The two largest categories of emissions by mass were pneumatic devices (35 kg/hr or ~61% of total) and tanks (14.3 kg/hr or ~25% of total). Produced water and condensate tanks at all sites employed emissions control devices. Nevertheless, tanks may still lose gas via component leaks as observed in this study. The total number of tanks at all sites was 153. One site experienced a major malfunction and direct tank measurements were not conducted due to safety concerns and may have represented a super-emitter as found in other studies. The remaining sites had 143 tanks, which accounted for 42 emissions sources. Leaks on controlled tanks were associated with ERVs, PRVs, and thief hatches. Since measurements represented snapshots-in-time and could only be compared with modeled tank emission data, it was difficult to assess real capture efficiencies accurately. Our estimates suggest that capture efficiency ranged from 63 to 92% for controlled tanks.
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Affiliation(s)
- Derek Johnson
- West Virginia University, Mechanical & Aerospace Engineering, PO Box 6106, Morgantown, WV, 26506, United States
| | - Nigel Clark
- West Virginia University, Mechanical & Aerospace Engineering, PO Box 6106, Morgantown, WV, 26506, United States
| | - Robert Heltzel
- West Virginia University, Mechanical & Aerospace Engineering, PO Box 6106, Morgantown, WV, 26506, United States
| | - Mahdi Darzi
- West Virginia University, Mechanical & Aerospace Engineering, PO Box 6106, Morgantown, WV, 26506, United States
| | - Tracey L. Footer
- Eastern Research Group, Inc., 601 Keystone Park Drive, Suite 700, Morrisville, NC, 27560, United States
| | - Scott Herndon
- Aerodyne, 45 Manning Road, Billerica, MA, 01821, United States
| | - Eben D. Thoma
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Mail Code E343-02, Research Triangle Park, NC, 27711, United States
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8
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Seymour SP, Festa-Bianchet SA, Tyner DR, Johnson MR. Reduction of Signal Drift in a Wavelength Modulation Spectroscopy-Based Methane Flux Sensor. SENSORS (BASEL, SWITZERLAND) 2022; 22:6139. [PMID: 36015904 PMCID: PMC9416658 DOI: 10.3390/s22166139] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/09/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Accurately quantifying unsteady methane venting from key oil and gas sector sources such as storage tanks and well casing vents is a critical challenge. Recently, we presented an optical sensor to meet this need that combines volume fraction and Doppler shift measurements using wavelength modulation spectroscopy with 2f harmonic detection to quantify mass flux of methane through a vent line. This paper extends the previous effort through a methodical component-by-component investigation of potential sources of thermally-induced measurement drift to guide the design of an updated sensor. Test data were analyzed using an innovative signal processing technique that permitted quantification of background wavelength modulation spectroscopy signal drift linked to specific components, and the results were successfully used to design a drift-resistant sensor. In the updated sensor, background signal strength was reduced, and stability improved, such that the empirical methane-fraction dependent velocity correction necessary in the original sensor was no longer required. The revised sensor improves previously reported measurement uncertainties on flow velocity from 0.15 to 0.10 m/s, while markedly reducing thermally-induced velocity drift from 0.44 m/s/K to 0.015 m/s/K. In the most general and challenging application, where both flow velocity and methane fraction are independently varying, the updated design reduces the methane mass flow rate uncertainty by more than a factor of six, from ±2.55 kg/h to ±0.40 kg/h. This new design also maintains the intrinsic safety of the original sensor and is ideally suited for unsteady methane vent measurements within hazardous locations typical of oil and gas facilities.
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Li J, Deng S, Tohti A, Li G, Yi X, Lu Z, Liu J, Zhang S. Spatial characteristics of VOCs and their ozone and secondary organic aerosol formation potentials in autumn and winter in the Guanzhong Plain, China. ENVIRONMENTAL RESEARCH 2022; 211:113036. [PMID: 35283079 DOI: 10.1016/j.envres.2022.113036] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/20/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
As critical precursors of tropospheric ozone (O3) and secondary organic aerosol (SOA), volatile organic compounds (VOCs) largely influence air quality in urban environments. In this study, measurements of 102 VOCs at all five major cities in the Guanzhong Plain (GZP) were conducted during Sep.09-Oct. 13, 2017 (autumn) and Nov. 14, 2017-Jan. 19, 2018 (winter) to investigate the characteristics of VOCs and their roles in O3 and SOA formation. The average concentrations of total VOCs (TVOCs) at Xi'an (XA), Weinan (WN), Xianyang (XY), Tongchuan (TC), and Baoji (BJ) sites were in the range of 55.2-110.2 ppbv in autumn and 42.4-74.3 ppbv in winter. TVOCs concentrations were reduced by 22.4%-43.5% from autumn to winter at XA, WN and BJ. Comparatively low concentrations of TVOCs were observed in XY and TC, ranging from 53.5 to 62.7 ppbv across the sampling period. Alkanes were the major components at all sites, accounting for 26.4%-48.9% of the TVOCs during the sampling campaign, followed by aromatics (4.2%-26.4%). The average concentration of acetylene increased by a factor of up to 4.8 from autumn to winter, indicating the fuel combustion in winter heating period significantly impacted on VOCs composition in the GZP. The OH radical loss rate and maximum incremental reactivity method were employed to determine photochemical reactivities and ozone formation potentials (OFPs) of VOCs, respectively. The VOCs in XA and WN exhibited the highest reactivities in O3 formation, with the OFP of 168-273 ppbv and the OH loss rates of 19.3-40.8 s-1. Alkenes and aromatics primarily related to on-road and industrial emissions contributed 57.8%-76.3% to the total OFP. The contribution of aromatics to the SOA formation at all sites reached 94.1%-98.6%. Considering the potential source-area of VOCs, regional transport of VOCs occurred within the GZP cities.
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Affiliation(s)
- Jianghao Li
- School of Water and Environment, Chang'an University, Xi'an, 710064, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, 710064, China
| | - Shunxi Deng
- School of Water and Environment, Chang'an University, Xi'an, 710064, China; Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education, Chang'an University, Xi'an, 710064, China.
| | - Abla Tohti
- School of Water and Environment, Chang'an University, Xi'an, 710064, China
| | - Guanghua Li
- School of Water and Environment, Chang'an University, Xi'an, 710064, China
| | - Xiaoxiao Yi
- School of Water and Environment, Chang'an University, Xi'an, 710064, China
| | - Zhenzhen Lu
- School of Water and Environment, Chang'an University, Xi'an, 710064, China
| | - Jiayao Liu
- School of Water and Environment, Chang'an University, Xi'an, 710064, China
| | - Shuai Zhang
- School of Water and Environment, Chang'an University, Xi'an, 710064, China
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10
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Ehret T, De Truchis A, Mazzolini M, Morel JM, d'Aspremont A, Lauvaux T, Duren R, Cusworth D, Facciolo G. Global Tracking and Quantification of Oil and Gas Methane Emissions from Recurrent Sentinel-2 Imagery. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10517-10529. [PMID: 35797726 DOI: 10.1021/acs.est.1c08575] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Methane (CH4) emission estimates from top-down studies over oil and gas basins have revealed systematic underestimation of CH4 emissions in current national inventories. Sparse but extremely large amounts of CH4 from oil and gas production activities have been detected across the globe, resulting in a significant increase of the overall oil and gas contribution. However, attribution to specific facilities remains a major challenge unless high-spatial-resolution images provide sufficient granularity within the oil and gas basin. In this paper, we monitor known oil and gas infrastructures across the globe using recurrent Sentinel-2 imagery to detect and quantify more than 1200 CH4 emissions. In combination with emission estimates from airborne and Sentinel-5P measurements, we demonstrate the robustness of the fit to a power law from 0.1 tCH4/h to 600 tCH4/h. We conclude here that the prevalence of ultraemitters (>25tCH4/h) detected globally by Sentinel-5P directly relates to emission occurrences below its detection threshold in the range >2tCH4/h, which correspond to large emitters covered by Sentinel-2. We also verified that this relation is also valid at a more local scale for two specific countries, namely, Algeria and Turkmenistan, and the Permian basin in the United States.
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Affiliation(s)
- Thibaud Ehret
- Université Paris-Saclay, CNRS, ENS Paris-Saclay, Centre Borelli, Gif-sur-Yvette, 91190, France
| | | | | | - Jean-Michel Morel
- Université Paris-Saclay, CNRS, ENS Paris-Saclay, Centre Borelli, Gif-sur-Yvette, 91190, France
| | - Alexandre d'Aspremont
- Kayrros SAS, Paris, 75009, France
- CNRS, Ecole Normale Supérieure, Paris, 75230, France
| | - Thomas Lauvaux
- Laboratoire des Sciences du Climat et de l'Environnement, CEA, CNRS, UVSQ/IPSL, Saint-Aubin, 91190, France
| | - Riley Duren
- Arizona Institutes for Resilience, University of Arizona, Tucson, Arizona 85721, United States
- Carbon Mapper, Pasadena, California 91105, United States
| | - Daniel Cusworth
- Arizona Institutes for Resilience, University of Arizona, Tucson, Arizona 85721, United States
- Carbon Mapper, Pasadena, California 91105, United States
| | - Gabriele Facciolo
- Université Paris-Saclay, CNRS, ENS Paris-Saclay, Centre Borelli, Gif-sur-Yvette, 91190, France
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11
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A Wavelength Modulation Spectroscopy-Based Methane Flux Sensor for Quantification of Venting Sources at Oil and Gas Sites. SENSORS 2022; 22:s22114175. [PMID: 35684796 PMCID: PMC9185548 DOI: 10.3390/s22114175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/17/2022] [Accepted: 05/27/2022] [Indexed: 11/16/2022]
Abstract
An optical sensor employing tunable diode laser absorption spectroscopy with wavelength modulation and 2f harmonic detection was designed, prototyped, and tested for applications in quantifying methane emissions from vent sources in the oil and gas sector. The methane absorption line at 6026.23 cm−1 (1659.41 nm) was used to measure both flow velocity and methane volume fraction, enabling direct measurement of the methane emission rate. Two configurations of the sensor were designed, tested, and compared; the first used a fully fiber-coupled cell with multimode fibers to re-collimate the laser beams, while the second used directly irradiated photodetectors protected by Zener barriers. Importantly, both configurations were designed to enable measurements within regulated Class I / Zone 0 hazardous locations, in which explosive gases are expected during normal operations. Controlled flows with methane volume fractions of 0 to 100% and a velocity range of 0 to 4 m/s were used to characterize sensor performance at a 1 Hz sampling rate. The measurement error in the methane volume fraction was less than 10,000 ppm (1%) across the studied range for both configurations. The short-term velocity measurement error with pure methane was <0.3 m/s with a standard deviation of 0.14 m/s for the fiber-coupled configuration and <0.15 m/s with a standard deviation of 0.07 m/s for the directly irradiated detector configuration. However, modal noise in the multimode fibers of the first configuration contributed to an unstable performance that was highly sensitive to mechanical disturbances. The second configuration showed good potential for an industrial sensor, successfully quantifying methane flow rates up to 11 kg/h within ±2.1 kg/h at 95% confidence over a range of methane fractions from 25−100%, and as low as ±0.85 kg/h in scenarios where the source methane fraction is initially unknown within this range and otherwise invariant.
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12
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Omara M, Zavala-Araiza D, Lyon DR, Hmiel B, Roberts KA, Hamburg SP. Methane emissions from US low production oil and natural gas well sites. Nat Commun 2022; 13:2085. [PMID: 35440563 PMCID: PMC9019036 DOI: 10.1038/s41467-022-29709-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 03/30/2022] [Indexed: 11/09/2022] Open
Abstract
Eighty percent of US oil and natural gas (O&G) production sites are low production well sites, with average site-level production ≤15 barrels of oil equivalent per day and producing only 6% of the nation’s O&G output in 2019. Here, we integrate national site-level O&G production data and previously reported site-level CH4 measurement data (n = 240) and find that low production well sites are a disproportionately large source of US O&G well site CH4 emissions, emitting more than 4 (95% confidence interval: 3—6) teragrams, 50% more than the total CH4 emissions from the Permian Basin, one of the world’s largest O&G producing regions. We estimate low production well sites represent roughly half (37—75%) of all O&G well site CH4 emissions, and a production-normalized CH4 loss rate of more than 10%—a factor of 6—12 times higher than the mean CH4 loss rate of 1.5% for all O&G well sites in the US. Our work suggests that achieving significant reductions in O&G CH4 emissions will require mitigation of emissions from low production well sites. Only 6 percent of US oil and natural gas production output is from low production well sites. Here the authors show that total methane emissions from these low producing well sites in the US is substantial, representing about one-half of all production site methane emissions.
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Affiliation(s)
- Mark Omara
- Environmental Defense Fund, Austin, TX, 78701, USA.
| | - Daniel Zavala-Araiza
- Environmental Defense Fund, Austin, TX, 78701, USA.,Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3584 CC, Utrecht, The Netherlands
| | - David R Lyon
- Environmental Defense Fund, Austin, TX, 78701, USA
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13
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Abstract
In order to investigate the seasonal variation in chemical characteristics of VOCs in the urban and suburban areas of southwest China, we used SUMMA canister sampling in Jinghong city from October 2016 to June 2017. Forty-eight VOC species concentrations were analyzed using atmospheric preconcentration gas chromatography–mass spectrometry (GC–MS), Then, regional VOC pollution characteristics, ozone formation potentials (OFP), source identity, and health risk assessments were studied. The results showed that the average concentration of total mass was 144.34 μg·m−3 in the urban area and 47.81 μg·m−3 in the suburban area. Alkanes accounted for the highest proportion of VOC groups at 38.11%, followed by olefins (36.60%) and aromatic hydrocarbons (25.28%). Propane and isoprene were the species with the highest mass concentrations in urban and suburban sampling sites. The calculation of OFP showed that the contributions of olefins and aromatic hydrocarbons were higher than those of alkanes. Through the ratio of specific species, the VOCs were mainly affected by motor vehicle exhaust emissions, fuel volatilization, vegetation emissions, and biomass combustion. Combined with the analysis of the backward trajectory model, biomass burning activities in Myanmar influenced the concentration of VOCs in Jinghong. Health risk assessments have shown that the noncarcinogenic risk and hazard index of atmospheric VOCs in Jinghong were low (less than 1). However, the value of the benzene cancer risk to the human body was higher than the safety threshold of 1 × 10−6, showing that benzene has carcinogenic risk. This study provides effective support for local governments formulating air pollution control policies.
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14
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Irakulis-Loitxate I, Guanter L, Maasakkers JD, Zavala-Araiza D, Aben I. Satellites Detect Abatable Super-Emissions in One of the World's Largest Methane Hotspot Regions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:2143-2152. [PMID: 35102741 PMCID: PMC9940854 DOI: 10.1021/acs.est.1c04873] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Reduction of fossil fuel-related methane emissions has been identified as an essential means for climate change mitigation, but emission source identification remains elusive for most oil and gas production basins in the world. We combine three complementary satellite data sets to survey single methane emission sources on the west coast of Turkmenistan, one of the largest methane hotspots in the world. We found 29 different emitters, with emission rates >1800 kg/h, active in the 2017-2020 time period, although older satellite data show that this type of emission has been occurring for decades. We find that all sources are linked to extraction fields mainly dedicated to crude oil production, where 24 of them are inactive flares venting gas. The analysis of time series suggests a causal relationship between the decrease in flaring and the increase in venting. At the regional level, 2020 shows a substantial increase in the number of methane plume detections concerning previous years. Our results suggest that these large venting point sources represent a key mitigation opportunity as they emanate from human-controlled facilities, and that new satellite methods promise a revolution in the detection and monitoring of methane point emissions worldwide.
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Affiliation(s)
- Itziar Irakulis-Loitxate
- Research
Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València
(UPV), Valencia 46022, Spain
| | - Luis Guanter
- Research
Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València
(UPV), Valencia 46022, Spain
| | | | - Daniel Zavala-Araiza
- Environmental
Defense Fund, Reguliersgracht
79, Amsterdam 1017 LN, The Netherlands
- Institute
for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht 3584 CC, The Netherlands
| | - Ilse Aben
- SRON
Netherlands Institute for Space Research, Utrecht 3584 CA, The Netherlands
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15
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Yang S, Li X, Song M, Liu Y, Yu X, Chen S, Lu S, Wang W, Yang Y, Zeng L, Zhang Y. Characteristics and sources of volatile organic compounds during pollution episodes and clean periods in the Beijing-Tianjin-Hebei region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 799:149491. [PMID: 34426340 DOI: 10.1016/j.scitotenv.2021.149491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Volatile organic compounds (VOCs) play an important role in air pollution. In this study, we conducted comprehensive field observations to investigate wintertime air pollution in Beijing, Wangdu, and Dezhou in the Beijing-Tianjin-Hebei region during 2017 and 2018. The average VOC concentrations of the three sites were 35.6 ± 26.6, 70.9 ± 56.3, and 50.5 ± 40.0 ppbv, respectively. The species with the highest concentration were similar in all three sites and included ethane, ethylene, acetylene, acetone, and toluene. The VOC mixing ratios of the three sites showed synchronous growth during pollution episodes and were 1.2-2 times higher than those during clean periods. Moreover, the OH loss rates (LOH) during pollution episodes were 1.2-1.7 times that during clean periods. The crucial reactive species in the three sites were ethylene, propylene, and acetaldehyde, contributing approximately 70% to the total LOH during pollution periods. According to the source apportionment analysis, vehicle exhausts were the largest source of VOCs in Beijing, accounting for more than 50% of the total emissions. During the pollution episodes, Beijing's industrial emissions decreased, but the secondary and background sources increased. Coal combustion was significant (approximately 40%) in Wangdu and should therefore be prioritized in emission reduction policies. In Dezhou, industrial emissions had a considerable impact on the VOC mixing ratio during pollution periods and should therefore be prioritized. The backward trajectory analysis showed that VOCs from the southern region likely contribute to Beijing's VOC pollution, highlighting the importance of regional integration for air quality management.
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Affiliation(s)
- Suding Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xin Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Mengdi Song
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Ying Liu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xuena Yu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shiyi Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Sihua Lu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Wenjie Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yiming Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Limin Zeng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yuanhang Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
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16
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Lin JC, Bares R, Fasoli B, Garcia M, Crosman E, Lyman S. Declining methane emissions and steady, high leakage rates observed over multiple years in a western US oil/gas production basin. Sci Rep 2021; 11:22291. [PMID: 34785727 PMCID: PMC8595340 DOI: 10.1038/s41598-021-01721-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 10/26/2021] [Indexed: 11/22/2022] Open
Abstract
Methane, a potent greenhouse gas, is the main component of natural gas. Previous research has identified considerable methane emissions associated with oil and gas production, but estimates of emission trends have been inconsistent, in part due to limited in-situ methane observations spanning multiple years in oil/gas production regions. Here we present a unique analysis of one of the longest-running datasets of in-situ methane observations from an oil/gas production region in Utah’s Uinta Basin. The observations indicate Uinta methane emissions approximately halved between 2015 and 2020, along with declining gas production. As a percentage of gas production, however, emissions remained steady over the same years, at ~ 6–8%, among the highest in the U.S. Addressing methane leaks and recovering more of the economically valuable natural gas is critical, as the U.S. seeks to address climate change through aggressive greenhouse emission reductions.
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Affiliation(s)
- John C Lin
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, USA.
| | - Ryan Bares
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, USA.,Division of Air Quality, Utah Department of Environmental Quality, Salt Lake City, USA.,Division of Air Quality, Utah Department of Environmental Quality, Salt Lake City, USA
| | - Benjamin Fasoli
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, USA
| | - Maria Garcia
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, USA
| | - Erik Crosman
- Department of Life, Earth and Environmental Sciences, West Texas A&M University, Canyon, USA
| | - Seth Lyman
- Bingham Research Center, Utah State University, Salt Lake City, USA
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17
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Neininger BG, Kelly BFJ, Hacker JM, LU X, Schwietzke S. Coal seam gas industry methane emissions in the Surat Basin, Australia: comparing airborne measurements with inventories. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2021; 379:20200458. [PMID: 34565226 PMCID: PMC8480229 DOI: 10.1098/rsta.2020.0458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 06/02/2021] [Indexed: 06/13/2023]
Abstract
Coal seam gas (CSG) accounts for about one-quarter of natural gas production in Australia and rapidly increasing amounts globally. This is the first study worldwide using airborne measurement techniques to quantify methane (CH4) emissions from a producing CSG field: the Surat Basin, Queensland, Australia. Spatially resolved CH4 emissions were quantified from all major sources based on top-down (TD) and bottom-up (BU) approaches, the latter using Australia's UNFCCC reporting workflow. Based on our TD-validated BU inventory, CSG sources emit about 0.4% of the produced gas, comparable to onshore dry gas fields in the USA and The Netherlands, but substantially smaller than in other onshore regions, especially those where oil is co-produced (wet gas). The CSG CH4 emission per unit of gas production determined in this study is two to three times higher than existing inventories for the region. Our results indicate that the BU emission factors for feedlots and grazing cattle need review, possibly requiring an increase for Queensland's conditions. In some subregions, the BU estimate for gathering and boosting stations is potentially too high. The results from our iterative BU inventory process, which feeds into TD data, illustrate how global characterization of CH4 emissions could be improved by incorporating empirical TD verification surveys into national reporting. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.
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Affiliation(s)
| | - Bryce F. J. Kelly
- School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Jorg M. Hacker
- Airborne Research Australia, Parafield Airport, South Australia 5106, Australia
- College of Science and Engineering, Flinders University, Adelaide, South Australia 5001, Australia
| | - Xinyi LU
- School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Stefan Schwietzke
- Environmental Defense Fund, Third Floor, 41 Eastcheap, London EC3M 1DT, UK
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18
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Rutherford JS, Sherwin ED, Ravikumar AP, Heath GA, Englander J, Cooley D, Lyon D, Omara M, Langfitt Q, Brandt AR. Closing the methane gap in US oil and natural gas production emissions inventories. Nat Commun 2021; 12:4715. [PMID: 34354066 PMCID: PMC8342509 DOI: 10.1038/s41467-021-25017-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/27/2021] [Indexed: 11/09/2022] Open
Abstract
Methane (CH4) emissions from oil and natural gas (O&NG) systems are an important contributor to greenhouse gas emissions. In the United States, recent synthesis studies of field measurements of CH4 emissions at different spatial scales are ~1.5-2× greater compared to official greenhouse gas inventory (GHGI) estimates, with the production-segment as the dominant contributor to this divergence. Based on an updated synthesis of measurements from component-level field studies, we develop a new inventory-based model for CH4 emissions, for the production-segment only, that agrees within error with recent syntheses of site-level field studies and allows for isolation of equipment-level contributions. We find that unintentional emissions from liquid storage tanks and other equipment leaks are the largest contributors to divergence with the GHGI. If our proposed method were adopted in the United States and other jurisdictions, inventory estimates could better guide CH4 mitigation policy priorities.
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Affiliation(s)
- Jeffrey S Rutherford
- Department of Energy Resources Engineering, Stanford University, Stanford, CA, USA
| | - Evan D Sherwin
- Department of Energy Resources Engineering, Stanford University, Stanford, CA, USA
| | - Arvind P Ravikumar
- Department of Systems Engineering, Harrisburg University of Science and Technology, Harrisburg, PA, USA
| | - Garvin A Heath
- Joint Institute for Strategic Energy Analysis (JISEA), National Renewable Energy Laboratory, Golden, CO, USA
| | - Jacob Englander
- Industrial Strategies Division, California Air Resources Board, Sacramento, CA, USA
| | - Daniel Cooley
- Department of Statistics, Colorado State University, Ft. Collins, CO, USA
| | - David Lyon
- Environmental Defense Fund, Austin, TX, USA
| | - Mark Omara
- Environmental Defense Fund, Austin, TX, USA
| | - Quinn Langfitt
- Industrial Strategies Division, California Air Resources Board, Sacramento, CA, USA
| | - Adam R Brandt
- Department of Energy Resources Engineering, Stanford University, Stanford, CA, USA.
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19
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Irakulis-Loitxate I, Guanter L, Liu YN, Varon DJ, Maasakkers JD, Zhang Y, Chulakadabba A, Wofsy SC, Thorpe AK, Duren RM, Frankenberg C, Lyon DR, Hmiel B, Cusworth DH, Zhang Y, Segl K, Gorroño J, Sánchez-García E, Sulprizio MP, Cao K, Zhu H, Liang J, Li X, Aben I, Jacob DJ. Satellite-based survey of extreme methane emissions in the Permian basin. SCIENCE ADVANCES 2021; 7:7/27/eabf4507. [PMID: 34193415 PMCID: PMC8245034 DOI: 10.1126/sciadv.abf4507] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 05/13/2021] [Indexed: 05/12/2023]
Abstract
Industrial emissions play a major role in the global methane budget. The Permian basin is thought to be responsible for almost half of the methane emissions from all U.S. oil- and gas-producing regions, but little is known about individual contributors, a prerequisite for mitigation. We use a new class of satellite measurements acquired during several days in 2019 and 2020 to perform the first regional-scale and high-resolution survey of methane sources in the Permian. We find an unexpectedly large number of extreme point sources (37 plumes with emission rates >500 kg hour-1), which account for a range between 31 and 53% of the estimated emissions in the sampled area. Our analysis reveals that new facilities are major emitters in the area, often due to inefficient flaring operations (20% of detections). These results put current practices into question and are relevant to guide emission reduction efforts.
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Affiliation(s)
- Itziar Irakulis-Loitxate
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València (UPV), Valencia, Spain
| | - Luis Guanter
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València (UPV), Valencia, Spain.
| | - Yin-Nian Liu
- CAS Key Laboratory of Infrared System Detection and Imaging Technology, Shanghai Institute of Technical Physics, Shanghai, China.
| | - Daniel J Varon
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- GHGSat Inc., Montréal, Quebec, Canada
| | | | - Yuzhong Zhang
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province (KLaCER), School of Engineering, Westlake University, Hangzhou, Zhejiang, China
- Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Apisada Chulakadabba
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Steven C Wofsy
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Andrew K Thorpe
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Riley M Duren
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
- University of Arizona, Tucson, AZ, USA
| | - Christian Frankenberg
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
- California Institute of Technology, Pasadena, CA, USA
| | | | | | - Daniel H Cusworth
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Yongguang Zhang
- International Institute for Earth System Sciences, Nanjing University, Nanjing, China
| | - Karl Segl
- Helmholtz Center Potsdam, GFZ German Research Center for Geosciences, Potsdam, Germany
| | - Javier Gorroño
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València (UPV), Valencia, Spain
| | - Elena Sánchez-García
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València (UPV), Valencia, Spain
| | - Melissa P Sulprizio
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Kaiqin Cao
- CAS Key Laboratory of Infrared System Detection and Imaging Technology, Shanghai Institute of Technical Physics, Shanghai, China
| | - Haijian Zhu
- CAS Key Laboratory of Infrared System Detection and Imaging Technology, Shanghai Institute of Technical Physics, Shanghai, China
| | - Jian Liang
- CAS Key Laboratory of Infrared System Detection and Imaging Technology, Shanghai Institute of Technical Physics, Shanghai, China
| | - Xun Li
- CAS Key Laboratory of Infrared System Detection and Imaging Technology, Shanghai Institute of Technical Physics, Shanghai, China
| | - Ilse Aben
- SRON Netherlands Institute for Space Research, Utrecht, Netherlands
| | - Daniel J Jacob
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
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20
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Chan E, Worthy DEJ, Chan D, Ishizawa M, Moran MD, Delcloo A, Vogel F. Eight-Year Estimates of Methane Emissions from Oil and Gas Operations in Western Canada Are Nearly Twice Those Reported in Inventories. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14899-14909. [PMID: 33169990 DOI: 10.1021/acs.est.0c04117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The provinces of Alberta and Saskatchewan account for 70% of Canada's methane emissions from the oil and gas sector. In 2018, the Government of Canada introduced methane regulations to reduce emissions from the sector by 40-45% from the 2012 levels by 2025. Complementary to inventory accounting methods, the effectiveness of regulatory practices to reduce emissions can be assessed using atmospheric measurements and inverse models. Total anthropogenic (oil and gas, agriculture, and waste) emission rates of methane from 2010 to 2017 in Alberta and Saskatchewan were derived using hourly atmospheric methane measurements over a six-month winter period from October to March. Scaling up the winter estimate to annual indicated an anthropogenic emission rate of 3.7 ± 0.7 MtCH4/year, about 60% greater than that reported in Canada's National Inventory Report (2.3 MtCH4). This discrepancy is tied primarily to the oil and gas sector emissions as the reported emissions from livestock operations (0.6 MtCH4) are well substantiated in both top-down and bottom-up estimates and waste management (0.1 MtCH4) emissions are small. The resulting estimate of 3.0 MtCH4 from the oil and gas sector is nearly twice that reported in Canada's National Inventory (1.6 MtCH4).
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Affiliation(s)
- Elton Chan
- Climate Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Douglas E J Worthy
- Climate Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Douglas Chan
- Climate Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Misa Ishizawa
- Climate Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Michael D Moran
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Andy Delcloo
- Royal Meteorological Institute of Belgium, B-1180 Ukkel, Brussels, Belgium
| | - Felix Vogel
- Climate Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
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21
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Cardoso-Saldaña FJ, Allen DT. Projecting the Temporal Evolution of Methane Emissions from Oil and Gas Production Sites. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14172-14181. [PMID: 33108865 DOI: 10.1021/acs.est.0c03049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Many recent studies have reported methane emissions from oil and gas production regions, often reporting results as a methane emission intensity (methane emitted as a percentage of natural gas produced or methane produced). Almost all of these studies have been instantaneous snapshots of methane emissions; however, total methane emissions from a production site and the methane emission intensity would be expected to evolve over time. A detailed site-level methane emission estimation model is used to estimate the temporal evolution of methane emissions and the methane emission intensity for a variety of well configurations with and without emission mitigation measures in place. The general pattern predicted is that total emissions decrease over time as production declines. Methane emission intensity shows complex behavior because production-dependent emissions decline at different rates and some emissions do not decline over time. Prototypical uncontrolled wet gas wells can have approximately half of their emissions over a 10 year period occur in the first year; instantaneous wellsite methane emission intensities range over a factor of 3 (0.62-2.00%) in the same period, with a 10 year production weighted-average lifecycle methane emission intensity of 0.79%. Including emission control in the form of a flare can decrease the average lifecycle methane emission intensity to 0.23%. Emissions from liquid unloadings, which are observed in subsets of wells, can increase the lifecycle methane emission intensity by up to a factor of 2-3, between 1.2 and 2.3%, depending on the characteristics of the unloadings. Emissions from well completion flowbacks raise the average lifecycle methane emission intensity from 0.79 to 0.81% for flowbacks with emission controls; for flowbacks with uncontrolled emissions, lifecycle methane emissions increase to 1.26%. Dry gas and oil wells show qualitatively similar temporal behavior but different absolute emission rates.
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Affiliation(s)
- Felipe J Cardoso-Saldaña
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnett Road, Austin, Texas 78758, United States
- ExxonMobil Upstream Integrated Solutions, Spring, Texas 77389, United States
| | - David T Allen
- Center for Energy and Environmental Resources, University of Texas at Austin, 10100 Burnett Road, Austin, Texas 78758, United States
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22
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Robertson AM, Edie R, Field RA, Lyon D, McVay R, Omara M, Zavala-Araiza D, Murphy SM. New Mexico Permian Basin Measured Well Pad Methane Emissions Are a Factor of 5-9 Times Higher Than U.S. EPA Estimates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13926-13934. [PMID: 33058723 DOI: 10.1021/acs.est.0c02927] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Methane emission fluxes were estimated for 71 oil and gas well pads in the western Permian Basin (Delaware Basin), using a mobile laboratory and an inverse Gaussian dispersion method (OTM 33A). Sites with emissions that were below detection limit (BDL) for OTM 33A were recorded and included in the sample. Average emission rate per site was estimated by bootstrapping and by maximum likelihood best log-normal fit. Sites had to be split into "complex" (sites with liquid storage tanks and/or compressors) and "simple" (sites with only wellheads/pump jacks/separators) categories to achieve acceptable log-normal fits. For complex sites, the log-normal fit depends heavily on the number of BDL sites included. As more BDL sites are included, the log-normal distribution fit to the data is falsely widened, overestimating the mean, highlighting the importance of correctly characterizing low end emissions when using log-normal fits. Basin-wide methane emission rates were estimated for the production sector of the New Mexico portion of the Permian and range from ∼520 000 tons per year, TPY (bootstrapping, 95% CI: 300 000-790 000) to ∼610 000 TPY (log-normal fit method, 95% CI: 330 000-1 000 000). These estimates are a factor of 5.5-9.0 times greater than EPA National Emission Inventory (NEI) estimates for the region.
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Affiliation(s)
- Anna M Robertson
- Department of Atmospheric Science, University of Wyoming, 1000 E University Ave, Laramie, Wyoming 82071, United States
| | - Rachel Edie
- Department of Atmospheric Science, University of Wyoming, 1000 E University Ave, Laramie, Wyoming 82071, United States
| | - Robert A Field
- Department of Atmospheric Science, University of Wyoming, 1000 E University Ave, Laramie, Wyoming 82071, United States
| | - David Lyon
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States
| | - Renee McVay
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States
| | - Mark Omara
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States
| | - Daniel Zavala-Araiza
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, United States
| | - Shane M Murphy
- Department of Atmospheric Science, University of Wyoming, 1000 E University Ave, Laramie, Wyoming 82071, United States
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Hajny KD, Salmon OE, Rudek J, Lyon DR, Stuff AA, Stirm BH, Kaeser R, Floerchinger CR, Conley S, Smith ML, Shepson PB. Observations of Methane Emissions from Natural Gas-Fired Power Plants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8976-8984. [PMID: 31283190 DOI: 10.1021/acs.est.9b01875] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Current research efforts on the atmospheric impacts of natural gas (NG) have focused heavily on the production, storage/transmission, and processing sectors, with less attention paid to the distribution and end use sectors. This work discusses 23 flights at 14 natural gas-fired power plants (NGPPs) using an aircraft-based mass balance technique and methane/carbon dioxide enhancement ratios (ΔCH4/ΔCO2) measured from stack plumes to quantify the unburned fuel. By comparing the ΔCH4/ΔCO2 ratio measured in stack plumes to that measured downwind, we determined that, within uncertainty of the measurement, all observed CH4 emissions were stack-based, that is, uncombusted NG from the stack rather than fugitive sources. Measured CH4 emission rates (ER) ranged from 8 (±5) to 135 (±27) kg CH4/h (±1σ), with the fractional CH4 throughput lost (loss rate) ranging from -0.039% (±0.076%) to 0.204% (±0.054%). We attribute negative values to partial combustion of ambient CH4 in the power plant. The average calculated emission factor (EF) of 5.4 (+10/-5.4) g CH4/million British thermal units (MMBTU) is within uncertainty of the Environmental Protection Agency (EPA) EFs. However, one facility measured during startup exhibited substantially larger stack emissions with an EF of 440 (+660/-440) g CH4/MMBTU and a loss rate of 2.5% (+3.8/-2.5%).
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Affiliation(s)
- Kristian D Hajny
- Purdue University , Department of Chemistry , West Lafayette , Indiana 47907 , United States
| | - Olivia E Salmon
- Purdue University , Department of Chemistry , West Lafayette , Indiana 47907 , United States
| | - Joseph Rudek
- Environmental Defense Fund , Austin , Texas 78701 , United States
| | - David R Lyon
- Environmental Defense Fund , Austin , Texas 78701 , United States
| | - Andrew A Stuff
- Purdue University , Department of Chemistry , West Lafayette , Indiana 47907 , United States
| | - Brian H Stirm
- Purdue University , School of Aviation and Transportation Technology , West Lafayette , Indiana 47906 , United States
| | - Robert Kaeser
- Purdue University , Department of Chemistry , West Lafayette , Indiana 47907 , United States
| | - Cody R Floerchinger
- Harvard University , Department of Earth and Planetary Sciences , Cambridge , Massachusetts 02138 , United States
| | - Stephen Conley
- Scientific Aviation, Inc. , Boulder , Colorado 80301 , United States
| | - Mackenzie L Smith
- Scientific Aviation, Inc. , Boulder , Colorado 80301 , United States
| | - Paul B Shepson
- Purdue University , Department of Chemistry , West Lafayette , Indiana 47907 , United States
- Stony Brook University , School of Marine and Atmospheric Sciences , Stony Brook , New York 11794 , United States
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24
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Cardoso-Saldaña FJ, Kimura Y, Stanley P, McGaughey G, Herndon SC, Roscioli JR, Yacovitch TI, Allen DT. Use of Light Alkane Fingerprints in Attributing Emissions from Oil and Gas Production. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5483-5492. [PMID: 30912428 DOI: 10.1021/acs.est.8b05828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Spatially resolved emission inventories were used with an atmospheric dispersion model to predict ambient concentrations of methane, ethane, and propane in the Eagle Ford oil and gas production region in south central Texas; predicted concentrations were compared to ground level observations. Using a base case inventory, predicted median propane/ethane concentration ratios were 106% higher (95% CI: 83% higher-226% higher) than observations, while median ethane/methane concentration ratios were 112% higher (95% CI: 17% higher-228% higher) than observations. Predicted median propane and ethane concentrations were factors of 6.9 (95% CI: 3-15.2) and 3.4 (95% CI: 1.4-9) larger than observations, respectively. Predicted median methane concentrations were 7% higher (95% CI: 39% lower-37% higher) than observations. These comparisons indicate that sources of emissions with high propane/ethane ratios (condensate tank flashing) were likely overestimated in the inventories. Because sources of propane and ethane emissions are also sources of methane emissions, the results also suggest that sources of emissions with low ethane/methane ratios (midstream sources) were underestimated. This analysis demonstrates the value of using multiple light alkanes in attributing sources of methane emissions and evaluating the performance of methane emission inventories for oil and natural gas production regions.
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Affiliation(s)
- Felipe J Cardoso-Saldaña
- Center for Energy and Environmental Resources , University of Texas at Austin , 10100 Burnet Road , Austin , Texas 78758 , United States
| | - Yosuke Kimura
- Center for Energy and Environmental Resources , University of Texas at Austin , 10100 Burnet Road , Austin , Texas 78758 , United States
| | - Peter Stanley
- Center for Energy and Environmental Resources , University of Texas at Austin , 10100 Burnet Road , Austin , Texas 78758 , United States
- Now at ONEOK , Tulsa , Oklahoma 74103 United States
| | - Gary McGaughey
- Center for Energy and Environmental Resources , University of Texas at Austin , 10100 Burnet Road , Austin , Texas 78758 , United States
| | - Scott C Herndon
- Aerodyne Research Inc. , Billerica , Massachusetts 01821 United States
| | - Joseph R Roscioli
- Aerodyne Research Inc. , Billerica , Massachusetts 01821 United States
| | - Tara I Yacovitch
- Aerodyne Research Inc. , Billerica , Massachusetts 01821 United States
| | - David T Allen
- Center for Energy and Environmental Resources , University of Texas at Austin , 10100 Burnet Road , Austin , Texas 78758 , United States
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25
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Long CM, Briggs NL, Bamgbose IA. Synthesis and health-based evaluation of ambient air monitoring data for the Marcellus Shale region. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2019; 69:527-547. [PMID: 30698507 DOI: 10.1080/10962247.2019.1572551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 06/09/2023]
Abstract
In recent years, there has been a marked increase in the amount of ambient air quality data collected near Marcellus Shale oil and gas development (OGD) sites. We integrated air measurement data from over 30 datasets totaling approximately 200 sampling locations nearby to Marcellus Shale development sites, focusing on 11 air pollutants that can be associated with OGD operations: fine particulate matter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), acetaldehyde, benzene, ethylbenzene, formaldehyde, n-hexane, toluene, xylenes, and hydrogen sulfide (H2S). We evaluated these data to determine whether there is evidence of community-level air quality impacts of potential health concern, making screening-level comparisons of air monitoring data with acute and chronic health-based air comparison values (HBACVs). Based on the available air monitoring data, we found that only a small fraction of measurements exceeded HBACVs, which is similar to findings from integrative air quality assessments for other shale gas plays. Therefore, the data indicate that air pollutant levels within the Marcellus Shale development region typically are below HBACV exceedance levels; however, the sporadic HBACV exceedances warrant further investigation to determine whether they may be related to specific site characteristics, or certain operations or sources. Like any air monitoring dataset, there is uncertainty as to how well the available Marcellus Shale air monitoring data characterize the range of potential exposures for people living nearby to OGD sites. Given the lesser amounts of air monitoring data available for locations within 1,000 feet of OGD sites as compared to locations between 0.2 and 1 miles, the presence of potential concentration hotspots cannot be ruled out. Additional air monitoring data, in particular more real-time data to further characterize short-term peak concentrations associated with episodic events, are needed to provide for more refined assessments of potential health risks from Marcellus Shale development. Implications: While there is now a sizable amount of ambient air monitoring data collected nearby to OGD activities in the Marcellus Shale region, these data are currently scattered among different databases and studies. As part of an integrative assessment of Marcellus Shale air quality impacts, ambient air data are compiled for a subset of criteria air pollutants and hazardous air pollutants that have been associated with OGD activities, and compared to acute and chronic health-based air comparison values to help assess the air-related public health impacts of Marcellus Shale development.
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26
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Garcia-Gonzales DA, Shonkoff SB, Hays J, Jerrett M. Hazardous Air Pollutants Associated with Upstream Oil and Natural Gas Development: A Critical Synthesis of Current Peer-Reviewed Literature. Annu Rev Public Health 2019; 40:283-304. [DOI: 10.1146/annurev-publhealth-040218-043715] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Increased energy demands and innovations in upstream oil and natural gas (ONG) extraction technologies have enabled the United States to become one of the world's leading producers of petroleum and natural gas hydrocarbons. The US Environmental Protection Agency (EPA) lists 187 hazardous air pollutants (HAPs) that are known or suspected to cause cancer or other serious health effects. Several of these HAPs have been measured at elevated concentrations around ONG sites, but most have not been studied in the context of upstream development. In this review, we analyzed recent global peer-reviewed articles that investigated HAPs near ONG operations to ( a) identify HAPs associated with upstream ONG development, ( b) identify their specific sources in upstream processes, and ( c) examine the potential for adverse health outcomes from HAPs emitted during these phases of hydrocarbon development.
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Affiliation(s)
- Diane A. Garcia-Gonzales
- Environmental Health Sciences Division, School of Public Health, University of California, Berkeley, California 94720, USA
| | - Seth B.C. Shonkoff
- PSE Healthy Energy, Oakland, California 94612, USA;,
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720, USA
- Environment Energy Technology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jake Hays
- PSE Healthy Energy, Oakland, California 94612, USA;,
- Weill Cornell Medicine, Cornell University, New York, NY 10065, USA
| | - Michael Jerrett
- Department of Environmental Health Sciences and Center for Occupational and Environmental Health, Fielding School of Public Health, University of California, Los Angeles, California 90095-1772, USA
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27
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Schwietzke S, Harrison M, Lauderdale T, Branson K, Conley S, George FC, Jordan D, Jersey GR, Zhang C, Mairs HL, Pétron G, Schnell RC. Aerially guided leak detection and repair: A pilot field study for evaluating the potential of methane emission detection and cost-effectiveness. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2019; 69:71-88. [PMID: 30204538 DOI: 10.1080/10962247.2018.1515123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/10/2018] [Accepted: 08/20/2018] [Indexed: 06/08/2023]
Abstract
Novel aerial methane (CH4) detection technologies were used in this study to identify anomalously high-emitting oil and gas (O&G) facilities and to guide ground-based "leak detection and repair" (LDAR) teams. This approach has the potential to enable a rapid and effective inspection of O&G facilities under voluntary or regulatory LDAR programs to identify and mitigate anomalously large CH4 emissions from a disproportionately small number of facilities. This is the first study of which the authors are aware to deploy, evaluate, and compare the CH4 detection volumes and cost-effectiveness of aerially guided and purely ground-based LDAR techniques. Two aerial methods, the Kairos Aerospace infrared CH4 column imaging and the Scientific Aviation in situ aircraft CH4 mole fraction measurements, were tested during a 2-week period in the Fayetteville Shale region contemporaneously with conventional ground-based LDAR. We show that aerially guided LDAR can be at least as cost-effective as ground-based LDAR, but several variable parameters were identified that strongly affect cost-effectiveness and which require field research and improvements beyond this pilot study. These parameters include (i) CH4 minimum dectectable limit of aerial technologies, (ii) emission rate size distributions of sources, (iii) remote distinction of fixable versus nonfixable CH4 sources ("leaks" vs. CH4 emissions occurring by design), and (iv) the fraction of fixable sources to total CH4 emissions. Suggestions for future study design are provided. Implications: Mitigation of methane leaks from existing oil and gas operations currently relies on on-site inspections of all applicable facilities at a prescribed frequency. This approach is labor- and cost-intensive, especially because a majority of oil and gas-related methane emissions originate from a disproportionately small number of facilities and components. We show for the first time in real-world conditions how aerial methane measurements can identify anomalously high-emitting facilities to enable a rapid, focused, and directed ground inspection of these facilities. The aerially guided approach can be more cost-effective than current practices, especially when implementing the aircraft deployment improvements discussed here.
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Affiliation(s)
- Stefan Schwietzke
- a Cooperative Institute for Research in Environmental Sciences , University of Colorado , Boulder , CO , USA
- b Global Monitoring Division , Earth System Research Laboratory, National Oceanic and Atmospheric Administration , Boulder , CO , USA
| | | | | | - Ken Branson
- d Kairos Aerospace , Mountain View , CA , USA
| | - Stephen Conley
- e Department of Land, Air, and Water Resources , University of California , Davis , CA , USA
- f Scientific Aviation, Inc , Boulder , CO , USA
| | | | - Doug Jordan
- g Southwestern Energy Company , Spring , TX , USA
| | | | | | - Heide L Mairs
- i ExxonMobil Upstream Research Co , Spring , TX , USA
| | - Gabrielle Pétron
- a Cooperative Institute for Research in Environmental Sciences , University of Colorado , Boulder , CO , USA
- b Global Monitoring Division , Earth System Research Laboratory, National Oceanic and Atmospheric Administration , Boulder , CO , USA
| | - Russell C Schnell
- b Global Monitoring Division , Earth System Research Laboratory, National Oceanic and Atmospheric Administration , Boulder , CO , USA
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28
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Omara M, Zimmerman N, Sullivan MR, Li X, Ellis A, Cesa R, Subramanian R, Presto AA, Robinson AL. Methane Emissions from Natural Gas Production Sites in the United States: Data Synthesis and National Estimate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12915-12925. [PMID: 30256618 DOI: 10.1021/acs.est.8b03535] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We used site-level methane (CH4) emissions data from over 1000 natural gas (NG) production sites in eight basins, including 92 new site-level CH4 measurements in the Uinta, northeastern Marcellus, and Denver-Julesburg basins, to investigate CH4 emissions characteristics and develop a new national CH4 emission estimate for the NG production sector. The distribution of site-level emissions is highly skewed, with the top 5% of sites accounting for 50% of cumulative emissions. High emitting sites are predominantly also high producing (>10 Mcfd). However, low NG production sites emit a larger fraction of their CH4 production. When combined with activity data, we predict that this creates substantial variability in the basin-level CH4 emissions which, as a fraction of basin-level CH4 production, range from 0.90% for the Appalachian and Greater Green River to >4.5% in the San Juan and San Joaquin. This suggests that much of the basin-level differences in production-normalized CH4 emissions reported by aircraft studies can be explained by differences in site size and distribution of site-level production rates. We estimate that NG production sites emit total CH4 emissions of 830 Mg/h (95% CI: 530-1200), 63% of which come from the sites producing <100 Mcfd that account for only 10% of total NG production. Our total CH4 emissions estimate is 2.3 times higher than the U.S. Environmental Protection Agency's estimate and likely attributable to the disproportionate influence of high emitting sites.
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Affiliation(s)
- Mark Omara
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Naomi Zimmerman
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Melissa R Sullivan
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Xiang Li
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Aja Ellis
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Rebecca Cesa
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - R Subramanian
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Albert A Presto
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Allen L Robinson
- Center for Atmospheric Particle Studies, Department of Mechanical Engineering , Carnegie Mellon University , 5000 Forbes Avenue , Pittsburgh , Pennsylvania 15213 , United States
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29
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Englander JG, Brandt AR, Conley S, Lyon DR, Jackson RB. Aerial Interyear Comparison and Quantification of Methane Emissions Persistence in the Bakken Formation of North Dakota, USA. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8947-8953. [PMID: 29989804 DOI: 10.1021/acs.est.8b01665] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We performed an infrared optical gas imaging (OGI) survey by helicopter of hydrocarbon emissions in the Bakken formation of North Dakota. One year after an earlier survey of 682 well pads in September of 2014, the same helicopter crew resurveyed 353 well pads in 2015 to examine the persistence of emissions. Twenty-one newly producing well pads were added in the same sampling blocks. An instrumented aircraft was also used to quantify emissions from 33 plumes identified by aerial OGI. Well pads emitting methane and ethane in 2014 were far more likely to be emitting in 2015 than would be expected by chance; Monte Carlo simulations suggest >5σ deviation ( p < 0.0001) from random assignment of detectable emissions between survey years. Scaled up using basin-wide leakage estimates, the emissions quantified by aircraft are sufficient to explain previously observed basin-wide emissions of methane and ethane.
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Affiliation(s)
- Jacob G Englander
- Department of Energy Resources Engineering , Stanford University , Stanford , California 94305 , United States
| | - Adam R Brandt
- Department of Energy Resources Engineering , Stanford University , Stanford , California 94305 , United States
| | - Stephen Conley
- Scientific Aviation , Boulder , Colorado 80301 , United States
| | - David R Lyon
- Environmental Defense Fund , Austin , Texas 78701 , United States
| | - Robert B Jackson
- Department of Earth Systems Science, Woods Institute for the Environment, and Precourt Institute for Energy , Stanford University , Stanford , California 94305 , United States
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30
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Alvarez RA, Zavala-Araiza D, Lyon DR, Allen DT, Barkley ZR, Brandt AR, Davis KJ, Herndon SC, Jacob DJ, Karion A, Kort EA, Lamb BK, Lauvaux T, Maasakkers JD, Marchese AJ, Omara M, Pacala SW, Peischl J, Robinson AL, Shepson PB, Sweeney C, Townsend-Small A, Wofsy SC, Hamburg SP. Assessment of methane emissions from the U.S. oil and gas supply chain. Science 2018; 361:186-188. [PMID: 29930092 DOI: 10.1126/science.aar7204] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 05/18/2018] [Indexed: 11/02/2022]
Abstract
Methane emissions from the U.S. oil and natural gas supply chain were estimated by using ground-based, facility-scale measurements and validated with aircraft observations in areas accounting for ~30% of U.S. gas production. When scaled up nationally, our facility-based estimate of 2015 supply chain emissions is 13 ± 2 teragrams per year, equivalent to 2.3% of gross U.S. gas production. This value is ~60% higher than the U.S. Environmental Protection Agency inventory estimate, likely because existing inventory methods miss emissions released during abnormal operating conditions. Methane emissions of this magnitude, per unit of natural gas consumed, produce radiative forcing over a 20-year time horizon comparable to the CO2 from natural gas combustion. Substantial emission reductions are feasible through rapid detection of the root causes of high emissions and deployment of less failure-prone systems.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Anna Karion
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | | | - Thomas Lauvaux
- The Pennsylvania State University, University Park, PA, USA
| | | | | | - Mark Omara
- Environmental Defense Fund, Austin, TX, USA
| | | | - Jeff Peischl
- University of Colorado, CIRES, Boulder, CO, USA.,NOAA Earth System Research Laboratory, Boulder, CO, USA
| | | | | | - Colm Sweeney
- NOAA Earth System Research Laboratory, Boulder, CO, USA
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31
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Johnson MR, Tyner DR, Conley S, Schwietzke S, Zavala-Araiza D. Comparisons of Airborne Measurements and Inventory Estimates of Methane Emissions in the Alberta Upstream Oil and Gas Sector. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13008-13017. [PMID: 29039181 DOI: 10.1021/acs.est.7b03525] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Airborne measurements of methane emissions from oil and gas infrastructure were completed over two regions of Alberta, Canada. These top-down measurements were directly compared with region-specific bottom-up inventories that utilized current industry-reported flaring and venting volumes (reported data) and quantitative estimates of unreported venting and fugitive sources. For the 50 × 50 km measurement region near Red Deer, characterized by natural gas and light oil production, measured methane fluxes were more than 17 times greater than that derived from directly reported data but consistent with our region-specific bottom-up inventory-based estimate. For the 60 × 60 km measurement region near Lloydminster, characterized by significant cold heavy oil production with sand (CHOPS), airborne measured methane fluxes were five times greater than directly reported emissions from venting and flaring and four times greater than our region-specific bottom up inventory-based estimate. Extended across Alberta, our results suggest that reported venting emissions in Alberta should be 2.5 ± 0.5 times higher, and total methane emissions from the upstream oil and gas sector (excluding mined oil sands) are likely at least 25-50% greater than current government estimates. Successful mitigation efforts in the Red Deer region will need to focus on the >90% of methane emissions currently unmeasured or unreported.
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Affiliation(s)
- Matthew R Johnson
- Energy & Emissions Research Laboratory, Department of Mechanical and Aerospace Engineering, Carleton University , Ottawa, ON Canada , K1S 5B6
| | - David R Tyner
- Energy & Emissions Research Laboratory, Department of Mechanical and Aerospace Engineering, Carleton University , Ottawa, ON Canada , K1S 5B6
| | - Stephen Conley
- Scientific Aviation, Inc. , 3335 Airport Road Suite B, Boulder, Colorado 80301, United States
| | - Stefan Schwietzke
- CIRES/University of Colorado , NOAA ESRL Global Monitoring Division, 325 Broadway R/GMD 1, Boulder, Colorado 80305-3337, United States
| | - Daniel Zavala-Araiza
- Environmental Defense Fund , 301 Congress Avenue Suite 1300, Austin, Texas 78701, United States
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32
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Allen DT, Cardoso-Saldaña FJ, Kimura Y. Variability in Spatially and Temporally Resolved Emissions and Hydrocarbon Source Fingerprints for Oil and Gas Sources in Shale Gas Production Regions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:12016-12026. [PMID: 28805050 DOI: 10.1021/acs.est.7b02202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A gridded inventory for emissions of methane, ethane, propane, and butanes from oil and gas sources in the Barnett Shale production region has been developed. This inventory extends previous spatially resolved inventories of emissions by characterizing the overall variability in emission magnitudes and the composition of emissions at an hourly time resolution. The inventory is divided into continuous and intermittent emission sources. Sources are defined as continuous if hourly averaged emissions are greater than zero in every hour; otherwise, they are classified as intermittent. In the Barnett Shale, intermittent sources accounted for 14-30% of the mean emissions for methane and 10-34% for ethane, leading to spatial and temporal variability in the location of hourly emissions. The combined variability due to intermittent sources and variability in emission factors can lead to wide confidence intervals in the magnitude and composition of time and location-specific emission inventories; therefore, including temporal and spatial variability in emission inventories is important when reconciling inventories and observations. Comparisons of individual aircraft measurement flights conducted in the Barnett Shale region versus the estimated emission rates for each flight from the emission inventory indicate agreement within the expected variability of the emission inventory for all flights for methane and for all but one flight for ethane.
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Affiliation(s)
- David T Allen
- Center for Energy and Environmental Resources, University of Texas at Austin , 10100 Burnet Road, Austin, Texas 78758, United States
| | - Felipe J Cardoso-Saldaña
- Center for Energy and Environmental Resources, University of Texas at Austin , 10100 Burnet Road, Austin, Texas 78758, United States
| | - Yosuke Kimura
- Center for Energy and Environmental Resources, University of Texas at Austin , 10100 Burnet Road, Austin, Texas 78758, United States
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33
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Robertson AM, Edie R, Snare D, Soltis J, Field RA, Burkhart MD, Bell CS, Zimmerle D, Murphy SM. Variation in Methane Emission Rates from Well Pads in Four Oil and Gas Basins with Contrasting Production Volumes and Compositions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017. [PMID: 28628305 DOI: 10.1021/acs.est.7b00571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Atmospheric methane emissions from active natural gas production sites in normal operation were quantified using an inverse Gaussian method (EPA's OTM 33a) in four major U.S. basins/plays: Upper Green River (UGR, Wyoming), Denver-Julesburg (DJ, Colorado), Uintah (Utah), and Fayetteville (FV, Arkansas). In DJ, Uintah, and FV, 72-83% of total measured emissions were from 20% of the well pads, while in UGR the highest 20% of emitting well pads only contributed 54% of total emissions. The total mass of methane emitted as a percent of gross methane produced, termed throughput-normalized methane average (TNMA) and determined by bootstrapping measurements from each basin, varied widely between basins and was (95% CI): 0.09% (0.05-0.15%) in FV, 0.18% (0.12-0.29%) in UGR, 2.1% (1.1-3.9%) in DJ, and 2.8% (1.0-8.6%) in Uintah. Overall, wet-gas basins (UGR, DJ, Uintah) had higher TNMA emissions than the dry-gas FV at all ranges of production per well pad. Among wet basins, TNMA emissions had a strong negative correlation with average gas production per well pad, suggesting that consolidation of operations onto single pads may reduce normalized emissions (average number of wells per pad is 5.3 in UGR versus 1.3 in Uintah and 2.8 in DJ).
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Affiliation(s)
- Anna M Robertson
- Department of Atmospheric Science, University of Wyoming , 1000 East University Avenue, Laramie, Wyoming 82071, United States
| | - Rachel Edie
- Department of Atmospheric Science, University of Wyoming , 1000 East University Avenue, Laramie, Wyoming 82071, United States
| | - Dustin Snare
- All4, Inc. , Kimberton, Pennsylvania 19442, United States
| | - Jeffrey Soltis
- Department of Atmospheric Science, University of Wyoming , 1000 East University Avenue, Laramie, Wyoming 82071, United States
| | - Robert A Field
- Department of Atmospheric Science, University of Wyoming , 1000 East University Avenue, Laramie, Wyoming 82071, United States
| | - Matthew D Burkhart
- Department of Atmospheric Science, University of Wyoming , 1000 East University Avenue, Laramie, Wyoming 82071, United States
| | - Clay S Bell
- Energy Institute and Mechanical Engineering, Colorado State University , 430 North College, Fort Collins, Colorado 80524, United States
| | - Daniel Zimmerle
- Energy Institute and Mechanical Engineering, Colorado State University , 430 North College, Fort Collins, Colorado 80524, United States
| | - Shane M Murphy
- Department of Atmospheric Science, University of Wyoming , 1000 East University Avenue, Laramie, Wyoming 82071, United States
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Lavoie TN, Shepson PB, Cambaliza MOL, Stirm BH, Conley S, Mehrotra S, Faloona IC, Lyon D. Spatiotemporal Variability of Methane Emissions at Oil and Natural Gas Operations in the Eagle Ford Basin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8001-8009. [PMID: 28678487 DOI: 10.1021/acs.est.7b00814] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Methane emissions from oil and gas facilities can exhibit operation-dependent temporal variability; however, this variability has yet to be fully characterized. A field campaign was conducted in June 2014 in the Eagle Ford basin, Texas, to examine spatiotemporal variability of methane emissions using four methods. Clusters of methane-emitting sources were estimated from 14 aerial surveys of two ("East" or "West") 35 × 35 km grids, two aircraft-based mass balance methods measured emissions repeatedly at five gathering facilities and three flares, and emitting equipment source-types were identified via helicopter-based infrared camera at 13 production and gathering facilities. Significant daily variability was observed in the location, number (East: 44 ± 20% relative standard deviation (RSD), N = 7; West: 37 ± 30% RSD, N = 7), and emission rates (36% of repeat measurements deviate from mean emissions by at least ±50%) of clusters of emitting sources. Emission rates of high emitters varied from 150-250 to 880-1470 kg/h and regional aggregate emissions of large sources (>15 kg/h) varied up to a factor of ∼3 between surveys. The aircraft-based mass balance results revealed comparable variability. Equipment source-type changed between surveys and alterations in operational-mode significantly influenced emissions. Results indicate that understanding temporal emission variability will promote improved mitigation strategies and additional analysis is needed to fully characterize its causes.
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Affiliation(s)
| | | | - Maria O L Cambaliza
- Department of Physics, Ateneo de Manila University , Loyola Heights, Quezon City 1108, Philippines
| | | | - Stephen Conley
- Department of Land, Air and Water Resources, University of California , Davis, California 95616, United States
| | - Shobhit Mehrotra
- Department of Land, Air and Water Resources, University of California , Davis, California 95616, United States
| | - Ian C Faloona
- Department of Land, Air and Water Resources, University of California , Davis, California 95616, United States
| | - David Lyon
- Environmental Defense Fund, Austin, Texas 78701, United States
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35
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Schwietzke S, Pétron G, Conley S, Pickering C, Mielke-Maday I, Dlugokencky EJ, Tans PP, Vaughn T, Bell C, Zimmerle D, Wolter S, King CW, White AB, Coleman T, Bianco L, Schnell RC. Improved Mechanistic Understanding of Natural Gas Methane Emissions from Spatially Resolved Aircraft Measurements. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7286-7294. [PMID: 28548824 DOI: 10.1021/acs.est.7b01810] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Divergence in recent oil and gas related methane emission estimates between aircraft studies (basin total for a midday window) and emissions inventories (annualized regional and national statistics) indicate the need for better understanding the experimental design, including temporal and spatial alignment and interpretation of results. Our aircraft-based methane emission estimates in a major U.S. shale gas basin resolved from west to east show (i) similar spatial distributions for 2 days, (ii) strong spatial correlations with reported NG production (R2 = 0.75) and active gas well pad count (R2 = 0.81), and (iii) 2× higher emissions in the western half (normalized by gas production) despite relatively homogeneous dry gas and well characteristics. Operator reported hourly activity data show that midday episodic emissions from manual liquid unloadings (a routine operation in this basin and elsewhere) could explain ∼1/3 of the total emissions detected midday by the aircraft and ∼2/3 of the west-east difference in emissions. The 22% emission difference between both days further emphasizes that episodic sources can substantially impact midday methane emissions and that aircraft may detect daily peak emissions rather than daily averages that are generally employed in emissions inventories. While the aircraft approach is valid, quantitative, and independent, our study sheds new light on the interpretation of previous basin scale aircraft studies, and provides an improved mechanistic understanding of oil and gas related methane emissions.
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Affiliation(s)
- Stefan Schwietzke
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , 216 UCB, Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Gabrielle Pétron
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , 216 UCB, Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Stephen Conley
- Scientific Aviation, Inc. , 3335 Airport Road Suite B, Boulder, Colorado 80301, United States
- Department of Land, Air, and Water Resources, University of California , One Shields Avenue, Davis, California 95616, United States
| | - Cody Pickering
- Department of Mechanical Engineering, Colorado State University , 400 Isotope Dr, Fort Collins, Colorado 80521, United States
| | - Ingrid Mielke-Maday
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , 216 UCB, Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Edward J Dlugokencky
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Pieter P Tans
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Tim Vaughn
- Department of Mechanical Engineering, Colorado State University , 400 Isotope Dr, Fort Collins, Colorado 80521, United States
| | - Clay Bell
- Department of Mechanical Engineering, Colorado State University , 400 Isotope Dr, Fort Collins, Colorado 80521, United States
| | - Daniel Zimmerle
- Department of Mechanical Engineering, Colorado State University , 400 Isotope Dr, Fort Collins, Colorado 80521, United States
| | - Sonja Wolter
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , 216 UCB, Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Clark W King
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Allen B White
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Timothy Coleman
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , 216 UCB, Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Laura Bianco
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , 216 UCB, Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
| | - Russell C Schnell
- NOAA Earth System Research Laboratory , 325 Broadway, Boulder, Colorado 80305, United States
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36
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Smith ML, Gvakharia A, Kort EA, Sweeney C, Conley SA, Faloona I, Newberger T, Schnell R, Schwietzke S, Wolter S. Airborne Quantification of Methane Emissions over the Four Corners Region. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:5832-5837. [PMID: 28418663 DOI: 10.1021/acs.est.6b06107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Methane (CH4) is a potent greenhouse gas and the primary component of natural gas. The San Juan Basin (SJB) is one of the largest coal-bed methane producing regions in North America and, including gas production from conventional and shale sources, contributed ∼2% of U.S. natural gas production in 2015. In this work, we quantify the CH4 flux from the SJB using continuous atmospheric sampling from aircraft collected during the TOPDOWN2015 field campaign in April 2015. Using five independent days of measurements and the aircraft-based mass balance method, we calculate an average CH4 flux of 0.54 ± 0.20 Tg yr-1 (1σ), in close agreement with the previous space-based estimate made for 2003-2009. These results agree within error with the U.S. EPA gridded inventory for 2012. These flights combined with the previous satellite study suggest CH4 emissions have not changed. While there have been significant declines in natural gas production between measurements, recent increases in oil production in the SJB may explain why emission of CH4 has not declined. Airborne quantification of outcrops where seepage occurs are consistent with ground-based studies that indicate these geological sources are a small fraction of the basin total (0.02-0.12 Tg yr-1) and cannot explain basinwide consistent emissions from 2003 to 2015.
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Affiliation(s)
- Mackenzie L Smith
- Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Alexander Gvakharia
- Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Eric A Kort
- Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Colm Sweeney
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , Boulder, Colorado 80305, United States
| | - Stephen A Conley
- Scientific Aviation , Boulder, Colorado 80301, United States
- Department of Land, Air, & Water Resources, University of California Davis , Davis, California 95616, United States
| | - Ian Faloona
- Department of Land, Air, & Water Resources, University of California Davis , Davis, California 95616, United States
| | - Tim Newberger
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , Boulder, Colorado 80305, United States
| | - Russell Schnell
- NOAA Earth System Research Laboratory , Boulder, Colorado 80305, United States
| | - Stefan Schwietzke
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , Boulder, Colorado 80305, United States
| | - Sonja Wolter
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , Boulder, Colorado 80309, United States
- NOAA Earth System Research Laboratory , Boulder, Colorado 80305, United States
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37
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Zavala-Araiza D, Alvarez RA, Lyon DR, Allen DT, Marchese AJ, Zimmerle DJ, Hamburg SP. Super-emitters in natural gas infrastructure are caused by abnormal process conditions. Nat Commun 2017; 8:14012. [PMID: 28091528 PMCID: PMC5241676 DOI: 10.1038/ncomms14012] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/21/2016] [Indexed: 11/23/2022] Open
Abstract
Effectively mitigating methane emissions from the natural gas supply chain requires addressing the disproportionate influence of high-emitting sources. Here we use a Monte Carlo simulation to aggregate methane emissions from all components on natural gas production sites in the Barnett Shale production region (Texas). Our total emission estimates are two-thirds of those derived from independent site-based measurements. Although some high-emitting operations occur by design (condensate flashing and liquid unloadings), they occur more than an order of magnitude less frequently than required to explain the reported frequency at which high site-based emissions are observed. We conclude that the occurrence of abnormal process conditions (for example, malfunctions upstream of the point of emissions; equipment issues) cause additional emissions that explain the gap between component-based and site-based emissions. Such abnormal conditions can cause a substantial proportion of a site's gas production to be emitted to the atmosphere and are the defining attribute of super-emitting sites.
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Affiliation(s)
- Daniel Zavala-Araiza
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, USA
| | - Ramón A Alvarez
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, USA
| | - David R. Lyon
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, USA
| | - David T. Allen
- Center for Energy and Environmental Resources, The University of Texas at Austin, 10100 Burnet Road, Austin, Texas 78758, USA
| | - Anthony J. Marchese
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Daniel J. Zimmerle
- The Energy Institute, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Steven P. Hamburg
- Environmental Defense Fund, 301 Congress Avenue, Suite 1300, Austin, Texas 78701, USA
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38
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Ravikumar AP, Wang J, Brandt AR. Are Optical Gas Imaging Technologies Effective For Methane Leak Detection? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:718-724. [PMID: 27936621 DOI: 10.1021/acs.est.6b03906] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Concerns over mitigating methane leakage from the natural gas system have become ever more prominent in recent years. Recently, the U.S. Environmental Protection Agency proposed regulations requiring use of optical gas imaging (OGI) technologies to identify and repair leaks. In this work, we develop an open-source predictive model to accurately simulate the most common OGI technology, passive infrared (IR) imaging. The model accurately reproduces IR images of controlled methane release field experiments as well as reported minimum detection limits. We show that imaging distance is the most important parameter affecting IR detection effectiveness. In a simulated well-site, over 80% of emissions can be detected from an imaging distance of 10 m. Also, the presence of "superemitters" greatly enhance the effectiveness of IR leak detection. The minimum detectable limits of this technology can be used to selectively target "superemitters", thereby providing a method for approximate leak-rate quantification. In addition, model results show that imaging backdrop controls IR imaging effectiveness: land-based detection against sky or low-emissivity backgrounds have higher detection efficiency compared to aerial measurements. Finally, we show that minimum IR detection thresholds can be significantly lower for gas compositions that include a significant fraction nonmethane hydrocarbons.
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Affiliation(s)
- Arvind P Ravikumar
- Department of Energy Resources Engineering, Stanford University , 367 Panama Street, Stanford, California 94305, United States
| | - Jingfan Wang
- Department of Energy Resources Engineering, Stanford University , 367 Panama Street, Stanford, California 94305, United States
| | - Adam R Brandt
- Department of Energy Resources Engineering, Stanford University , 367 Panama Street, Stanford, California 94305, United States
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Laurenzi IJ, Bergerson JA, Motazedi K. Life cycle greenhouse gas emissions and freshwater consumption associated with Bakken tight oil. Proc Natl Acad Sci U S A 2016; 113:E7672-E7680. [PMID: 27849573 PMCID: PMC5137726 DOI: 10.1073/pnas.1607475113] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In recent years, hydraulic fracturing and horizontal drilling have been applied to extract crude oil from tight reservoirs, including the Bakken formation. There is growing interest in understanding the greenhouse gas (GHG) emissions associated with the development of tight oil. We conducted a life cycle assessment of Bakken crude using data from operations throughout the supply chain, including drilling and completion, refining, and use of refined products. If associated gas is gathered throughout the Bakken well life cycle, then the well to wheel GHG emissions are estimated to be 89 g CO2eq/MJ (80% CI, 87-94) of Bakken-derived gasoline and 90 g CO2eq/MJ (80% CI, 88-94) of diesel. If associated gas is flared for the first 12 mo of production, then life cycle GHG emissions increase by 5% on average. Regardless of the level of flaring, the Bakken life cycle GHG emissions are comparable to those of other crudes refined in the United States because flaring GHG emissions are largely offset at the refinery due to the physical properties of this tight oil. We also assessed the life cycle freshwater consumptions of Bakken-derived gasoline and diesel to be 1.14 (80% CI, 0.67-2.15) and 1.22 barrel/barrel (80% CI, 0.71-2.29), respectively, 13% of which is associated with hydraulic fracturing.
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Affiliation(s)
- Ian J Laurenzi
- Corporate Strategic Research, ExxonMobil Research and Engineering, Annandale, NJ 08801;
| | - Joule A Bergerson
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB Canada T2N 1N4
| | - Kavan Motazedi
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB Canada T2N 1N4
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Marrero JE, Townsend-Small A, Lyon DR, Tsai TR, Meinardi S, Blake DR. Estimating Emissions of Toxic Hydrocarbons from Natural Gas Production Sites in the Barnett Shale Region of Northern Texas. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10756-10764. [PMID: 27580823 DOI: 10.1021/acs.est.6b02827] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Oil and natural gas operations have continued to expand and move closer to densely populated areas, contributing to growing public concerns regarding exposure to hazardous air pollutants. During the Barnett Shale Coordinated Campaign in October, 2013, ground-based whole air samples collected downwind of oil and gas sites revealed enhancements in several potentially toxic volatile organic compounds (VOCs) when compared to background values. Molar emissions ratios relative to methane were determined for hexane, benzene, toluene, ethylbenzene, and xylene (BTEX compounds). Using methane leak rates measured from the Picarro mobile flux plane (MFP) system and a Barnett Shale regional methane emissions inventory, the rates of emission of these toxic gases were calculated. Benzene emissions ranged between 51 ± 4 and 60 ± 4 kg h-1. Hexane, the most abundantly emitted pollutant, ranged from 642 ± 45 to 1070 ± 340 kg h-1. While observed hydrocarbon enhancements fall below federal workplace standards, results may indicate a link between emissions from oil and natural gas operations and concerns about exposure to hazardous air pollutants. The larger public health risks associated with the production and distribution of natural gas are of particular importance and warrant further investigation, particularly as the use of natural gas increases in the United States and internationally.
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Affiliation(s)
- Josette E Marrero
- NASA Ames Research Center, Moffett Field, California 94035, United States
| | - Amy Townsend-Small
- Departments of Geology and Geography, University of Cincinnati , Cincinnati, Ohio 45221, United States
| | - David R Lyon
- Environmental Defense Fund, Austin, Texas 78701, United States
| | - Tracy R Tsai
- Picarro, Inc., Santa Clara, California 95054, United States
| | - Simone Meinardi
- Department of Chemistry, University of California, Irvine , Irvine, California 92697, United States
| | - Donald R Blake
- Department of Chemistry, University of California, Irvine , Irvine, California 92697, United States
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Airborne methane remote measurements reveal heavy-tail flux distribution in Four Corners region. Proc Natl Acad Sci U S A 2016; 113:9734-9. [PMID: 27528660 DOI: 10.1073/pnas.1605617113] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Methane (CH4) impacts climate as the second strongest anthropogenic greenhouse gas and air quality by influencing tropospheric ozone levels. Space-based observations have identified the Four Corners region in the Southwest United States as an area of large CH4 enhancements. We conducted an airborne campaign in Four Corners during April 2015 with the next-generation Airborne Visible/Infrared Imaging Spectrometer (near-infrared) and Hyperspectral Thermal Emission Spectrometer (thermal infrared) imaging spectrometers to better understand the source of methane by measuring methane plumes at 1- to 3-m spatial resolution. Our analysis detected more than 250 individual methane plumes from fossil fuel harvesting, processing, and distributing infrastructures, spanning an emission range from the detection limit [Formula: see text] 2 kg/h to 5 kg/h through [Formula: see text] 5,000 kg/h. Observed sources include gas processing facilities, storage tanks, pipeline leaks, and well pads, as well as a coal mine venting shaft. Overall, plume enhancements and inferred fluxes follow a lognormal distribution, with the top 10% emitters contributing 49 to 66% to the inferred total point source flux of 0.23 Tg/y to 0.39 Tg/y. With the observed confirmation of a lognormal emission distribution, this airborne observing strategy and its ability to locate previously unknown point sources in real time provides an efficient and effective method to identify and mitigate major emissions contributors over a wide geographic area. With improved instrumentation, this capability scales to spaceborne applications [Thompson DR, et al. (2016) Geophys Res Lett 43(12):6571-6578]. Further illustration of this potential is demonstrated with two detected, confirmed, and repaired pipeline leaks during the campaign.
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