Facility level measurement of offshore oil and gas installations from a medium-sized airborne platform: method development for quantification and source identification of methane emissions

James L. France*, Prudence Bateson, Pamela Dominutti, Grant Allen, Stephen Andrews, Stephane Bauguitte, Max Coleman, Tom Lachlan-Cope, Rebecca E. Fisher, Langwen Huang, Anna E. Jones, James Lee, David Lowry, Joseph Pitt, Ruth Purvis, John Pyle, Jacob Shaw, Nicola Warwick, Alexandra Weiss, Shona WildeJonathan Witherstone, Stuart Young

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Emissions of methane (CH4) from offshore oil and gas installations are poorly ground-truthed, and quantification relies heavily on the use of emission factors and activity data. As part of the United Nations Climate & Clean Air Coalition (UN CCAC) objective to study and reduce short-lived climate pollutants (SLCPs), a Twin Otter aircraft was used to survey CH4 emissions from UK and Dutch offshore oil and gas installations. The aims of the surveys were to (i) identify installations that are significant CH4 emitters, (ii) separate installation emissions from other emissions using carbon-isotopic fingerprinting and other chemical proxies, (iii) estimate CH4 emission rates, and (iv) improve flux estimation (and sampling) methodologies for rapid quantification of major gas leaks. In this paper, we detail the instrument and aircraft set-up for two campaigns flown in the springs of 2018 and 2019 over the southern North Sea and describe the developments made in both the planning and sampling methodology to maximise the quality and value of the data collected. We present example data collected from both campaigns to demonstrate the challenges encountered during offshore surveys, focussing on the complex meteorology of the marine boundary layer and sampling discrete plumes from an airborne platform. The uncertainties of CH4 flux calculations from measurements under varying boundary layer conditions are considered, as well as recommendations for attribution of sources through either spot sampling for volatile organic compounds (VOCs) /δ 13CCH4 or using in situ instrumental data to determine C2H6-CH4 ratios. A series of recommendations for both planning and measurement techniques for future offshore work within marine boundary layers is provided.

Original languageEnglish
Article numberamt-14-71-2021
Pages (from-to)71-88
Number of pages18
JournalAtmospheric Measurement Techniques
Issue number1
Publication statusPublished - 5 Jan 2021

Bibliographical note

Funding Information:
Acknowledgements. This work was funded under the Climate & Clean Air Coalition (CCAC) Oil and Gas Methane Science Studies (MSS) programme, hosted by the United Nations Environment Programme. Funding was provided by the Environmental Defense Fund, Oil and Gas Climate Initiative, European Commission, and CCAC.

Funding Information:
This research has been supported by the Climate & Clean Air Coalition (CCAC) (grant no. DTIE18-EN018).

© Author(s) 2021.

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