Application of the API Compendium of Greenhouse Gas Emissions Estimation Methodologies for the Oil and Gas Industry to Examine Potential Emission Reductions

Abstract

Greenhouse gas inventories and emission estimation methodologies have been evolving over the past decade. Inevitably, as different organizations and governing bodies develop inventories and emission estimation methodologies, the level of detail and type of emission sources will vary. This presents a logistical challenge to the oil and gas industry, whose operations span the globe and thus encounter a variety of rules, policies and guidelines. Recognizing the need for consistency in the methods used to quantify greenhouse gas emissions, American Petroleum Institute's (API's) member companies compiled recognized “best practices” for emission estimation methodologies applicable to oil and gas industry operations. The resulting compendium can be used to guide the estimation of GHG emissions for individual projects, entire facilities, or company-wide inventories. The compendium targets carbon dioxide (CO2) and methane (CH4) emissions at present, which are the two most significant GHG emissions for the oil and gas industry. Emissions from oil and gas industry operations are grouped into five categories: combustion devices, point sources, non-point sources, non-routine activities, and indirect emissions. The compendium includes calculation and estimation techniques for determining CO2 and CH4 emissions for sources within each of these categories. This chapter examines technical considerations associated with estimating pre- and post-project emissions and discusses the criteria being set forth in the international community regarding requirements for reliable emission reduction projects.