Catalytic Heaters\nat Oil and Gas Sites May be a Significant\nyet Overlooked Seasonal Source of Methane Emissions

Successful reduction\nof oil and gas sector methane emissions\nto\nmeet near-zero intensity targets requires the identification and mitigation\nof all possible sources. One potentially important source is catalytic\nheaters, which have largely escaped attention in regulatory and mitigation\nefforts despite being ubiquitous at upstream production sites in cold\nclimate regions. This study reports direct in situ measurements of\nthe exhaust streams of 38 natural gas-fired catalytic heaters at upstream\nproduction sites in British Columbia, Canada. All heaters in the sample\nshowed consistently poor methane conversion with mean destruction\nefficiencies of 61 ± 5% while releasing 235 [+31/–28]\ng of methane per cubic meter of fuel. Although individual units are\ngenerally small methane sources (mean of 0.28 ± 0.04 kg/h), their\nprevalence means they could represent 6% of the total provincial upstream\nmethane inventory and as an aggregate methane source could be 5×\nmore significant than abandoned wells. Notably, these heaters are\nseasonal sources whose emissions would be missed in measurement campaigns\noccurring solely in summer months. However, additional measurements\nfrom a small number of heat medium burners demonstrate that, where\nfeasible, methane emissions can be reduced by approximately 425×\nby replacing catalytic heaters with centralized heat systems.