EGU General Assembly 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Isotopic characterisation of methane emissions from oil and gas operation in Romania

Malika Menoud1, Carina van der Veen1, Hossein Maazallahi1, Julianne Fernandez2, Piotr Korben3, Andreea Calcan4, James France2, David Lowry2, Martina Schmidt3, and Thomas Röckmann1
Malika Menoud et al.
  • 1Institute for Marine and Atmospheric research Utrecht (IMAU), Utrecht University, Utrecht, The Netherlands (
  • 2Department of Earth Sciences, Royal Holloway, University of London, Egham, UK
  • 3Institute of Environmental Physics, Heidelberg University, Germany
  • 4National Institute for Aerospace Research "Elie Carafoli" (INCAS), Bucharest, Romania

Reducing methane emissions is an important goal of climate change mitigation policies. Recent studies focused on emissions from oil and gas industry, because fixing gas leaks presents a "no-regret" mitigation solution. Yet, uncertainties regarding the fossil fuel emission rates and locations, as well as temporal and spatial variability, are still large for individual source processes, in particular in regions without regular measurements. The Romanian Methane Emissions from Oil and gas (ROMEO) project brought 13 research teams to Romania in order to quantify emissions from this sector. Methane stable isotopes are widely used for source characterisation, but measurement data is lacking from many important geographical locations, such as Eastern Europe. 

A total of 380 air samples were collected in urban areas and around oil and gas extraction sites, from ground level vehicles and from an aircraft. There were measured for δ13C-CH4 and δD-CH4 using a continuous flow isotope ratio mass spectrometry (CF-IRMS) system. The results were analysed using the Keeling plot approach to derive source signatures at each sampled site. The source signatures obtained for 76 individual oil and gas operation sites range from -70.5 to -22.4 ‰ V-PDB, and from -252 to -144‰ V-SMOW, for δ13C and δD respectively. They show a large heterogeneity in δ13C, and more regularity in δD values. Variations are affected by the maturity of hydrocarbon deposits, and by different contributions from microbial and thermogenic gas. We will present how the signatures measured at the surface relate to the signatures found for larger plumes sampled from the aircraft. The results of the campaign in Bucharest city reveal a larger contribution from the waste system than fossil fuel fugitive emissions. 

The isotopic characterisation of methane emissions in this region will help to constrain the methane budget on a regional scale, and to improve national inventories.

How to cite: Menoud, M., van der Veen, C., Maazallahi, H., Fernandez, J., Korben, P., Calcan, A., France, J., Lowry, D., Schmidt, M., and Röckmann, T.: Isotopic characterisation of methane emissions from oil and gas operation in Romania, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13643,, 2020.


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