Methane Emissions from Offshore Shuttle Tanker Loader Installations in the North Sea

The full range of emissions from oil and gas production, especially offshore, is still not fully understood due to the vast number of sources and lack of observational data. Emissions from shuttle tanker loading are not well characterised, with research limited and mainly non methane volatile organics (NMVOCS) rather than methane (CH4). There is also a grey area on where they should be included in inventories and the latest National Atmospheric Emissions Inventory United Kingdom Green House Gas (NAEI_UK_GHG) Inventory Improvement Report (July 2022) cited evidence for emissions factors from methane (CH4) and non methane volatile organics (NMVOCS) compounds from oil loading as a future priority research area. 

This work shows CH4 emissions results from a campaign in October 2023 designed to investigate CH4 and NMVOC emissions from oil loading to shuttle tankers over the whole loading cycle.  The project used aircraft measurements from a research aircraft and unmanned aerial vehicle along with different modelling techniques to evaluate emissions from the complete tanker loading process. Increases in CH4 emissions were observed when the shuttle tanker was present when compared to the standard platform operating conditions.