Methane and Nitrogen Oxides Emissions from the Offshore Oil and Gas Supply Chain in the U.S. Gulf of Mexico

Abstract:

Offshore production, processing, and transport of oil and natural gas can lead to emissions to the atmosphere of methane and nitrogen oxides with impacts on climate and air quality. Nearly one third of global production occurs offshore where there are few available measurements and almost no atmospheric monitoring of emissions. Here we introduce and present preliminary data from the Flaring and Fossil Fuels: Uncovering Emissions & Losses (F³UEL) airborne campaign in the U.S. Gulf of Mexico (GOM). A first set of flights in 2020 target production, processing, transport, and export activities. The GOM is an important and unique basin as it contributes to ~18% of U.S. oil production, is a site of increasing liquefied natural gas exports, contains some of the oldest and newest offshore platforms, and has recently seen substantial bankruptcy filings in shallow water. Our initial study, published earlier this year, suggested CH₄ emissions are higher than inventories, in part due to higher emission rates in shallow water and incorrect activity data. In this campaign, we follow up with aircraft in-situ measurements of CH₄, CO₂, NO, NO₂, O₃, and H₂O, airborne thermal camera imagery, and satellite observations to estimate emissions at multiple spatial scales (platform-level, regional-level, and basin-level), diagnose potential processes responsible for high emissions, analyze potential mitigation actions, and characterize emissions from key processes, such as incomplete flare combustion. This presentation will describe in detail the campaign objectives, sampling strategies, and results.