American Petroleum Institute

Compendium of Greenhouse Gas Emissions Estimation Methodologies for the Oil and Gas Industry - Pilot Test Version
 N GHG1

Annotation

The schematic presented in Figure 1-1 depicts the overall building blocks that might be considered in developing a comprehensive emissions inventory. The other blocks, aside from directly operated emission sources, should to be evaluated carefully to prevent either under- or over-estimation of facility/company/industry segment emissions.

Source applicability considerations and other boundary issues are often an integral part of the emissions inventory development process. Although answers to the following questions are company-specific decisions, some of the issues considered by the API along with some recommended approaches are summarized below:

• Issue: What compounds or emissions should be targeted?

Recommendation: Focus on carbon dioxide (CO 2) and methane (CH 4) first, assess other GHGs later if industry is a significant emitter.

• Issue: What industry sectors should be included?

Recommendation: It is advisable to have a common framework for all sectors, from well-head to retail. Nonetheless, special attention is needed for specific operating practices and unique process units.

• Issue: Should the inventory scope include all operations globally?

Recommendation: The methods compiled are universally applicable. Specific needs for local, national, regional, or global summaries should determine the inventory scope. In applying the methods globally, care should be taken to allow for regional differences in the definition of standard conditions and fuel properties specifications.