Researchers from the University of Arizona and the environmental technology organization Carbon Mappers have determined that methane emissions from offshore oil and gas platforms can be mapped using sun-glint-based sensing technology.

While it is difficult to accurately determine offshore oil and gas emissions estimates via observational studies alone, researchers suggest that sun glint — which is a phenomenon wherein sunlight reflects off the surface of the ocean at the same angle that a satellite or other sensor is viewing the surface — could reveal reflected radiance enough to distinguish a methane signal.

Offshore emissions: the locations of targeted platforms are shown as diamonds. The average persistence adjusted emission rate for each source is shown in terms of both the circle radii and infill colours (yellow and the smallest circles correspond to a 500 kg/h emission rate, while cerise and the largest circles correspond to 2000 kg/h and higher). Source: AK Ayasse et al. 2022 Environ. Res. Lett. 17 084039Offshore emissions: the locations of targeted platforms are shown as diamonds. The average persistence adjusted emission rate for each source is shown in terms of both the circle radii and infill colours (yellow and the smallest circles correspond to a 500 kg/h emission rate, while cerise and the largest circles correspond to 2000 kg/h and higher). Source: AK Ayasse et al. 2022 Environ. Res. Lett. 17 084039

As such, the researchers have developed a remote sensing technique that captures the glint of the sun on the surface of the water in a bid to measure methane emissions. According to the researchers, the technology offered sufficiently reflected radiance to determine a methane signal.

“We achieve this by banking the aeroplane at the right time and place, so that the angle of the sensor — mounted to the plane — is at the same angle as the Sun and is in alignment with the target,” the researchers explained.

The researchers further explained that the technology could one day enable full-scale operational monitoring of offshore productions over large areas around the globe, and eventually be used to inform emissions reduction efforts.

This approach was used previously to measure emissions from roughly 150 offshore, shallow water oil and gas production platforms in the Gulf of Mexico. At that time, the researchers demonstrated the efficacy of the sun glint technique for the remote detection of methane release and also revealed that the emissions from the offshore platforms were estimated to be higher relative to production as well as more persistent than those from onshore oil and gas basins. Additionally, the emissions were highly skewed with the team noting that most emissions were derived from storage tanks and vent booms.

The article detailing the technology, Methane remote sensing and emission quantification of offshore shallow water oil and gas platforms in the Gulf of Mexico, appears in the journal Environmental Research Letters.

To contact the author of this article, email mdonlon@globalspec.com