Comparing Continuous Methane Monitoring Technologies for High-Volume Emissions: A Single-Blind Controlled Release Study

Abstract

Methane emissions from oil and gas operations are a primary concern for climate change mitigation. While traditional methane detection relies on periodic surveys that yield episodic data, continuous monitoring solutions promise to offer consistent insights and a richer understanding of emission inventories. Despite this promise, the detection and quantification abilities of continuous monitoring solutions remain unclear. To address this uncertainty, our study comprehensively assessed 8 commercial continuous monitoring solutions using controlled release tests to simulate high-volume venting (e.g., uncontrolled tanks, pneumatics, and unlit flares), which accounts for a significant fraction of total emissions from oil and gas systems. The performance of each team varied: when comparing reported results on a second-bysecond basis, all teams reported false positive rates below 10%. For true positive rates, 4 out of 8 systems exceed 80%. In the field test where continuous monitoring solutions identified and reported an emission event, all systems' reliability of identification surpassed 70%. When systems reported that there was no emission event, the reliability of nonemission identification varied from 29.4% to 96.2%. Among 5 systems tested for quantifying the daily average emission rate released by the Stanford team, all were underestimated by an average of 74.38% emissions. This indicates that their application in emissions reporting or regulation may be premature. The variability in monitor performance underscores the importance of understanding systems' strengths and limitations before their broader adoption in methane mitigation approaches or regulatory frameworks.