Scientific Publications Methane Emissions from Offshore Oil and Gas Platforms in the Gulf of Mexico Published 2020 Share SHARE Facebook share Twitter LinkedIn Copy URL Email Download Download 2020_methane-study-gulf-mexico.pdf en Added on: 09 March, 2020 Breadcrumb Home Resource Library Methane Emissions From Offshore Oil and Gas Platforms In The Gulf of Mexico Shipboard measurements of offshore oil and gas facilities were conducted in the Gulf of Mexico in February 2018. Species measured at 1 s include methane, ethane, carbon-13 (13C) and deuterium (D) isotopes of methane, and several combustion tracers. Significant variability in the emission composition is observed between individual sites, with typical ethane/methane ratios around 5.3% and 13C and D methane isotopic compositions around −40 and −240‰, respectively. Offshore plumes were spatially narrower than expectations of the plume width based on terrestrial atmospheric stability classes; a modified Gaussian dispersion methodology using empirically measured horizontal plume widths was used to estimate the emission rates. A total of 103 sites were studied, including shallow and deepwater offshore platforms and drillships. Methane emission rates range from 0 to 190 kg/h with 95% confidence limits estimated at a factor of 10. The observed distribution is skewed with the top two emitters accounting for 20% of the total methane emissions of all sampled sites. Despite the greater throughput of the deepwater facilities, they had moderate emission rates compared to shallow-water sites. Analysis of background ethane enhancements also suggests a source region in shallow waters. A complete 1 s measurement database is published for use in future studies of offshore dispersion. This paper was published by ACS Publications. Tags Themes Fossil fuels Pollutants (SLCPs) Methane Regions North America Related partners Climate and Clean Air Coalition (CCAC) Environmental Defense Fund (EDF) European Commission