Consistent Metrics Needed for Quantifying Methane Emissions from Upstream Oil and Gas Operations

Methane emissions from oil and natural gas sources are often characterized as a methane emissions intensity, which is typically defined as methane emissions divided by natural gas production. Reporting methane emission intensities implicitly assigns all methane emissions from production activities to natural gas, but many of the regions that supply large amounts of natural gas to world markets simultaneously produce natural gas, natural gas liquids, and oil. The importance of whether methane and other greenhouse gas emissions from production activities are allocated to natural gas alone or to multiple products was examined using data from the Eagle Ford Shale production region in south central Texas. In the Eagle Ford, differences in emission allocation methods can produce differences in estimated emissions of 50-110 g CO(2)e/MJ of natural gas. This is comparable to the difference in combustion emissions between coal and natural gas.

Automated summary

The study explores the impact of different allocation methods for methane and other greenhouse gas emissions from production activities in the Eagle Ford Shale region in Texas. Variations in emission allocation methods can result in differences in estimated emissions of 50-110 g CO(2)e/MJ of natural gas, similar to the difference in combustion emissions between coal and natural gas.