Oil and Gas Sector E&P Reporting Protocol For Western Regional Air Partnership Task 2 Presentation – Santa Fe Meeting February 13, 2009 Presented by: Science Applications International Corporation and Environ International Corporation

Agreed definition of a significant source: Task 2 - Definitions Agreed definition of a significant source: Sources that contribute significantly to GHG emissions and pair them with the highest tier methodology available Proposed approach to account for minor sources: Take a top to bottom ranking approach of source categories by region, look at the differences between them (this will help CA and NM) and present the list of sources in the Task 2 work without leaving any source out.

Definition of significance: Task 2 - Definitions Definition of significance: 95% materiality threshold Definition of accuracy: 5% accuracy threshold API accuracy ranking system for methodologies (Tiers A, B, C) Available information: Industry needs to provide SAIC-ENVIRON team with the data required to develop rankings, the availability of this data will vary by region but it will help structure going forward For example: Compression (CO2 and methane), run time, fuel usage, device counts, throughput, etc. Availability varies per facility and by region, it depends on whether the facility is subject to Title V regulations and the age of the equipment or facility

Task 2 – Conceptual Framework Develop a matrix of source category rankings by basin to determine significant source categories with respect to fractional contribution to basin-level CO2e GHG inventory Identify those source categories which collectively contribute to 95% of GHG emissions in the basin For those significant source categories in a region, identify methodologies available to estimate GHG emissions Describe the accuracy of these methodologies – could use API tier rankings for accuracy Describe the availability of input data for these estimation methodologies For source categories not determined to be significant, recommend simplified methodologies

Task 2 – Conceptual Framework

Task 2 – Conceptual Framework Methodology evaluation for example significant source categories for a specific region

Task 2 – Conceptual Framework Additional comments There may be regions with in sufficient inventory data to develop ranked list of source categories Suggestion was floated that EPA’s top-down national GHG inventory for oil and gas could be used in combination with detailed production statistics for specific basins to develop rough ranking of categories The list of categories contributing significantly (>95%) to the GHG inventory for a basin will not be necessarily the same across basins The list of minor source categories (<5%) will also not likely be the same across basins However, the combination of significant source categories across basins will likely capture the majority of combustion and process-related sources If data is determined to be not readily available for a high-tier methodology, recommendations can be made based on additional measurement methods as they are being developed by CARB, EPA and others