Methane by the Numbers: The Need for Clear and Comparable Methane Intensity Metrics

Matthew R Johnson , Bradley Conrad, Daniel J. Zimmerle, Robert L Kleinberg 

Global efforts to track methane emissions from oil and natural gas operations have recently converged around measures of methane emissions intensity, including emergent requirements for reporting as part of import standards. However, multiple definitions of methane intensity have led to conflicting approaches that hinder clear comparisons among regions and obstruct the development of effective policy. This study analyzes six of the predominant methane intensity metrics and shows how half, by attributing methane exclusively to gas production while overlooking co-produced oil and liquids, can bias comparisons among jurisdictions and have limited practical utility. These naïve loss rates are strongly dependent on gas-oil ratios and tend toward meaningless infinite methane intensities in oil-dominant operations. The three remaining metrics overcome this limitation and are recommended as unbiased and directly intercomparable measures of methane performance. We further show how these latter metrics, which effectively benchmark methane emissions against total energy production, are computationally and functionally equivalent when emissions are allocated to oil and gas operations using energy production. Finally, we address the challenge of propagating emissions through the supply chain, and demonstrate how, for the recommended intensity metrics, embodied intensities of any facility’s outputs can be easily calculated from feeder-facility intensities and energy production.