ROMEO - ROmanian Methane Emissions from Oil and Gas

<p>According to UNFCCC statistics, in 2015 Romania was the country in the European Union that reported the highest emissions of CH<sub>4</sub> from the oil and gas sector to the atmosphere, in particular related to methane production and end use. Limiting these oil and gas-related emissions could provide an attractive greenhouse gas emission reduction target for the EU. However, the reported estimates are derived using standard emission factors and there are only very few observations which investigate whether the reported emissions are realistic. The ROMEO project was designed to provide experimental quantification of methane emissions from the oil and gas sector in Romania. This may strengthen the scientific basis for establishing effective emission mitigation measures. ROMEO is part of the international Climate and Clean Air Coalition's (CCAC's) Methane Science Studies. In August 2019, the first  phase of ROMEO was a city campaign in Bucharest and Ploiesti, where methane emissions were quantified at the street level, using three vehicles. Source attribution was carried out by isotopic analysis and measurement of the ethane-methane ratio. The main ROMEO campaign took place in October 2019, using as campaign base the Strejnicu airfield near Ploiesti. Eight ground measurement teams visited more than 1000 individual facilities and performed methane measurements by stationary and mobile measurements from vehicles, using tracer release approaches and by plume mapping from drones. Very low wind speeds during the campaign period made emission quantification challenging, but about 200 quantifications were attempted. An optical gas imaging team visited many facilities in order to investigate the origin of the emissions at the component scale. Our project partner OMV-Petrom provided information on the facilities and site access where needed. Sites for emissions quantification were selected independent of the operator. To connect the facility scale to the regional scale, two research aircraft from INCAS and Scientific Aviation Inc. performed more than 20 research flights to identify and quantify methane emissions from individual facilities, facility clusters and extended regions. Ground-based in situ and total column measurements provide additional information on the background levels of CH<sub>4</sub>. Various models are used for emission quantification, from plume dispersion and mass balance models for individual facilities to atmospheric chemistry and transport models for interpretation of the larger scale aircraft measurements. The final goal of ROMEO is to provide a combined bottom-up and top-down approach to quantify CH<sub>4</sub> emissions related to oil and gas exploration, natural gas distribution and gas use from Romania. I will present the overall setup of the ROMEO project, interesting examples from individual facilities and preliminary results from ground and airborne measurements.</p>