A regional assessment of methane emissions from natural gas production in the Transylvanian Basin, Romania
Abstract
Romania hosts one of the largest and oldest natural gas production sectors in Europe, yet direct measurements of methane emissions from its principal gas-producing region, the Transylvanian Basin, remain limited. Here, we present the first basin-scale, measurement-based assessment of methane emissions from natural gas production facilities in the Transylvanian Basin based on 160 methane emission quantifications performed at 127 facilities and complementary screening surveys covering 520 facilities. Methane emissions were quantified using multiple independent approaches, including the Tracer Release Method (TRM), Other Test Method 33A (OTM-33A), Gaussian Plume Method (GPM), High-Flow Sampling (HFS), and a novel Large-Scale Flow Chamber (LSFC). Site-level methane emissions exhibited strongly skewed, approximately log-normal distributions and pronounced temporal variability, with repeated measurements frequently differing by up to an order of magnitude. Combining all representative facility-scale measurements yielded a methane emission factor of 1.7 kg CH₄ h⁻¹ site⁻¹ (95% confidence interval: 1.1–2.6 kg CH₄ h⁻¹ site⁻¹). While emissions from natural gas production facilities were primarily associated with leaking infrastructure components, two previously undocumented water-degassing tanks were identified as methane super-emitters, with combined emissions exceeding those measured from all quantified production facilities. Upscaling the derived emission factor yielded methane emissions of approximately 42 kt CH₄ yr⁻¹ (95% confidence interval: 27–64 kt CH₄ yr⁻¹) from natural gas production well sites in the Transylvanian Basin. This estimate is comparable to currently available national-scale estimates for Romania’s natural gas sector, highlighting the importance of measurement-based approaches for improving greenhouse-gas inventories and identifying methane mitigation opportunities.
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BibTeX
@misc{necki2026regional,
title = {{A regional assessment of methane emissions from natural gas production in the Transylvanian Basin, Romania}},
author = {Jarosław M. Necki and Paweł Jagoda and Foteini Stavropoulou and Jakub Bartyzel and Piotr Korbeń and Sara Defratyka and Martina Schmidt and Hossein Maazallahi and Marius Corbu and Sebastian Iancu and Andreea Calcan and Magdalena Ardelean and Sorin Ghemulet and Cristian Pop and Andrei Radovici and Alexandru Mereuta and Horatiu Stefanie and Calin Baciu and Thomas Röckmann},
howpublished = {EarthArXiv},
year = {2026},
month = oct,
doi = {10.31223/x51n6j},
url = {https://eartharxiv.org/repository/view/15645/},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - A regional assessment of methane emissions from natural gas production in the Transylvanian Basin, Romania
AU - Jarosław M. Necki
AU - Paweł Jagoda
AU - Foteini Stavropoulou
AU - Jakub Bartyzel
AU - Piotr Korbeń
AU - Sara Defratyka
AU - Martina Schmidt
AU - Hossein Maazallahi
AU - Marius Corbu
AU - Sebastian Iancu
AU - Andreea Calcan
AU - Magdalena Ardelean
AU - Sorin Ghemulet
AU - Cristian Pop
AU - Andrei Radovici
AU - Alexandru Mereuta
AU - Horatiu Stefanie
AU - Calin Baciu
AU - Thomas Röckmann
PY - 2026
DA - 2026/10/21
PB - EarthArXiv
DO - 10.31223/x51n6j
UR - https://eartharxiv.org/repository/view/15645/
AB - Romania hosts one of the largest and oldest natural gas production sectors in Europe, yet direct measurements of methane emissions from its principal gas-producing region, the Transylvanian Basin, remain limited. Here, we present the first basin-scale, measurement-based assessment of methane emissions from natural gas production facilities in the Transylvanian Basin based on 160 methane emission quantifications performed at 127 facilities and complementary screening surveys covering 520 facilities. Methane emissions were quantified using multiple independent approaches, including the Tracer Release Method (TRM), Other Test Method 33A (OTM-33A), Gaussian Plume Method (GPM), High-Flow Sampling (HFS), and a novel Large-Scale Flow Chamber (LSFC). Site-level methane emissions exhibited strongly skewed, approximately log-normal distributions and pronounced temporal variability, with repeated measurements frequently differing by up to an order of magnitude. Combining all representative facility-scale measurements yielded a methane emission factor of 1.7 kg CH₄ h⁻¹ site⁻¹ (95% confidence interval: 1.1–2.6 kg CH₄ h⁻¹ site⁻¹). While emissions from natural gas production facilities were primarily associated with leaking infrastructure components, two previously undocumented water-degassing tanks were identified as methane super-emitters, with combined emissions exceeding those measured from all quantified production facilities. Upscaling the derived emission factor yielded methane emissions of approximately 42 kt CH₄ yr⁻¹ (95% confidence interval: 27–64 kt CH₄ yr⁻¹) from natural gas production well sites in the Transylvanian Basin. This estimate is comparable to currently available national-scale estimates for Romania’s natural gas sector, highlighting the importance of measurement-based approaches for improving greenhouse-gas inventories and identifying methane mitigation opportunities.
ER -