Development of consistent methodology for estimating greenhouse gas emissions from petroleum industry facilities and operations

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 petroleum 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 both technical and scope and boundary considerations that play a key role in the final inventory calculations. It will also present a general classification scheme for all petroleum industry devices and operations, while identifying the parameters needed to generate robust estimates of emissions for each equipment category and petroleum industry segment.