Can I identify a flare with a performance issue: Satellite monitoring – Wide area methane emissions monitoring

Summary

Satellite monitoring can be used to monitor for flares with anomalous methane emissions. Whilst several technologies are now available, and further systems and services being launched in the coming years the technology can be broadly classed into two types of activity: 

1. Wide area survey – in which the spatial resolution is low. An example of this is the Tropomi sensor onboard the  Sentinel-5P satellite. Monitoring of this kind can identify trends in total methane emissions within a region. 
2. Directed satellite monitoring – here, the satellite is directed towards specific locations and monitored with a higher resolution (see separate technology entry for details).  

 There are advantages and  challenges associated with both technologies but both rely upon additional information – such as visible imagery or VIIRS to differentiate flaring from other potential sources of methane, such as intentional venting.  

 In addition to satellite operators, there are a growing number of service organisations that will process publicly available or privately sourced data and use analytics to give insights to an operator. 

How it Works

• The satellite is positioned with a low-altitude polar orbit designed to give global coverage. For example, Sentinel 5-P is at 824km which provides daily coverage to all parts of the earth.
• Methane and other gases such as NO2 are measured using multi-spectral imaging whereby sunlight that is scattered back to space by Earth’s surface and atmosphere, is measured and used to detect the unique fingerprints of gases in different parts of the spectrum.
• The sensor measured the total-column of methane in the atmosphere –it is not differentiating between background methane or emissions from different sources that overlap vertically. Tropomi measures methane to ppbv and has been validated relative to measurements taken at ground level
• The image is dictated by the resolution of the imager. For Tropomi this equates to 7km2 at the nadir (lowest point to the ground per orbit)
  Converting image data into emission rates requires additional data inputs, most notably windspeed

Flaring in Mexico 

Oil/gas production, flaring radiant heat, and TROPOMI NO2 column mixing ratio in eastern Mexico. (a) Oil production from the Hydrocarbon Information System 540 (https://sih.hidrocarburos.gob.mx/, accessed in June 2020). The unit Mbd is thousand barrels per day. (b) Same as (a) but for gas production. The unit MMcfd is million cubic feet per day. (c) Gas flaring radiant heat from the Visible Infrared Imaging Radiometer Suite (VIIRS) data (Elvidge et al., 2015). (d) Tropospheric column density of NO2 from TROPOMI. All data are averages for May 2018 – December 2019 in eastern Mexico.