Satellite-based Assessment of Continuous and Episodic Flaring Regimes across Major Oil and Gas-producing Basins

Lulu Si, Shanyu Zhou , Walker Debbie, Itziar Irakulis-Loitxate , Javier Gorroño , Mark F. Lunt, Luis Guanter

Gas flaring wastes valuable natural gas while emitting large amounts of harmful air pollutants; however, existing flare inventories rarely distinguish the operational behavior across various basins and fuel types, namely oil- and gas-associated flaring.This limits their value for targeted mitigation efforts. Here, we present a satellite-based classification framework for characterizing flaring behavior by combining coarse resolution Visible Infrared Imaging Radiometer Suite (VIIRS) Nightfire (VNF) products with high-spatial resolution Sentinel-2 and Landsat~8/9 imagery. The framework quantifies temporal persistence and identifies operational interruptions from daily VIIRS thermal records, while using Sentinel-2 and Landsat 8/9 imagery to characterize flare site conditions at higher spatial resolution. It then assigns fuel type as oil or gas, yielding four operational categories: continuous oil/gas and episodic oil/gas. Applied to Algeria, Iran, Mexico, Nigeria, Saudi Arabia, and Turkmenistan, the framework identified 1,910 confirmed flare sites, approximately 1.8 times the number detected by VIIRS alone. Our analysis shows that continuous oil flares are the largest category, with 728 sites representing 56% of the classified inventory. Iran has the largest number of continuous oil flares (262) and a more geographically concentrated pattern. Gas flares account for 25% of the classified sites and form the majority of the classified flares in Turkmenistan. These sites were then linked to the gas pipeline infrastructure and compared with multi-scale methane observations. The analysis shows that Iran and Algeria contain the largest flare volumes near gas pipelines, whereas Mexico has a more spatially concentrated recovery opportunity close to existing infrastructure. Oil flares, particularly continuous oil flares, are more frequently co-located with methane plumes in Algeria and Iran than in other countries. Although Saudi Arabia has a high flare count, it has no matched methane plumes. These results reveal systematic differences in the proximity of the infrastructure and the detectability of methane, providing a transferable basis for mitigation prioritization and source attribution.