Methane emission measurements at the North Sea

In July and November 2018 measurements campaigns were performed at the North Sea. This campaign was aimed to assess independently total methane emissions of a selected group offshore oil and gas platforms using concentration measurements at multiple distances from the source in combination with meteorological conditions and dispersion calculations. This measurement set-up is in line with methane measurements carried out near onshore gas production locations in 2016-2017.

First observations with tracer experiments showed different behavior of the plumes offshore, compared to onshore plume behavior.

The Gaussian Plume model was modified with the methodology of the Offshore and Coastal Dispersion (ODC) model, to incorporate the effect of the sea surface and the building effect of the offshore installations on the dilution and mixing of the plume. Together with the performed tracer experiments, this resulted in more reliable calculations of the source strength of methane emissions from the installations.