Understanding the sources and quantities of greenhouse gas (GHG) emissions are critical to developing an emissions inventory that accurately represents various oil and natural gas industry segment operations. To address this, API formed a Greenhouse Gas Emissions Methodology Working Group. The working group's objectives are to review, summarize, and recommend methodologies for consistent estimation of greenhouse gas emissions from oil & gas industry facilities.
This paper will discuss the process undertaken to review and compare methodologies used by member companies, national governmental bodies, and intergovernmental experts. It will highlight technical, scope, and boundary considerations that play key roles in the final inventory calculations. It will also present a general classification scheme for all oil & gas industry devices and operations, while identifying the parameters needed to generate robust estimates of emissions for each equipment category and oil & gas industry segment.