Application of the large-scale flux chamber for quantification of methane release rate at Transylvanian gas fields.

The oil and gas (O&G) sector contributes significantly to the anthropogenic part of the methane cycle in the atmosphere while having the most effective opportunities for emission mitigation with technically feasible and cost-effective options. Romania is a key O&G producer within the EU Region of Transylvania with its active gas fields being in the focus of the second measurement campaign in the ROMEO project. Teams from European collaborations were deploying various techniques (GPM, OTM-33A, High Flow Sampler, Tracer release) for quantifications of the methane emission rates. In June of 2021, AGH deployed the large-scale flux chamber with help of scientists from  UBB, Romania,  and in cooperation with local O&G operator – Rom-Gas. Construction was designed and built to be used in the case of small gas installations like the single Christmas tree and was tested intensively during this campaign. A hemispheric structure with a diameter of 6 meters and volume of approximately 55 m³ was used to check the tightness of different gas wells in suitable conditions (size, terrain, meteorology). The methane concentration increase was measured by the OA-ICOS technique. We used an LGR MGGA-918 analyser while additional airflow and air mixing inside the chamber were provided with additional ventilators.

 

In this presentation, methane emission rates calculations based on deployments of large-scale flux chambers in Transylvania will be compared to other techniques. Verification of the chamber was developed using controlled release tests of methane and acetylene. Moreover, the estimated uncertainty of the measurement technique will be presented. Finally, the potential for use of a large-scale flux chamber as a direct ground based measurement technique and complementary to other direct and indirect techniques will be discussed.

 

The research results presented in this paper have been developed with the use of equipment financed from the funds of the "Excellence Initiative - Research University" program at AGH University of Science and Technology. The authors thank all the members of the ROMEO campaign, in particular, Thomas Roeckmann for providing an opportunity to be part of this measurement campaign.