Industry experience in deriving updated emission factors to characterize methane emissions for select emission sources in natural gas systems

Abstract

Natural gas production is rapidly expanding globally using advanced techniques that are opening new areas to exploration and development. New techniques and practices, including those involving hydraulic fracturing, have spurred growth in natural gas based power generation that is credited with reducing greenhouse gas (GHG) emissions with the co-benefit of improved air quality. These new operating practices necessitate a thorough review of existing quantification methods for methane emissions. This paper addresses the wide ranging efforts undertaken by the American Petroleum Institute over the past decade, or more, to provide robust data for characterizing methane emissions from natural gas operations. Industry efforts to characterize emission sources that are unique to natural gas production operations are also described. In order to inform the public debate on natural gas use and its role in mitigating overall GHG emissions this paper includes a comparison of new methane emission factors derived by industry to those used for the US National GHG Inventory.