Oil and Gas Sector E&P Reporting Protocol For Western Regional Air Partnership May 4, 2009 Presented by: Science Applications International Corporation and Environ International Corporation

Task 2: Significant Sources Technical team tasked to develop a list of significant source categories by basin for the 6 member states/provinces in the WCI Includes New Mexico, California, Utah, Montana, British Columbia and Manitoba Significance was defined as those sources contributing to the top 95% of GHG emissions in a basin Basins were defined using accepted USGS basin boundary definitions (consistent with past western states inventory efforts) Screening-level inventories vs. reporting Screening-level inventories developed at the basin level where possible, to attempt to account for regional variations in the significant sources This is only for purposes of determining significant sources – reporting regulations are considering field/operational control as the reporting basis

Task 2: Significant Sources Procedure for determining significant source categories Activity and equipment information obtained from a variety of sources including past inventory development efforts (e.g. WRAP, California districts) and survey data received from companies through API coordination Data represents the aggregate of quantitative information on equipment, processes, activity, configurations from dozens of individual companies operating across the western U.S. Aggregate data was used to develop screening-level inventories for each basin for which this data was available and presented as an estimate of the percentage contribution of source categories to total GHG emissions

Task 2: Significant Sources Limitations of the screening-level inventories Activity and equipment information could not be obtained for all basins – for this reason screening-level inventories were created for generic production types using available data Activity and equipment information could not be obtained for all source categories – where a source category was considered by the technical team to be potentially significant but for which no data was available, this was discussed Data was aggregated from many sources, including data collected confidentially through various prior WRAP inventory efforts for this sector – this limited the nature of the data that could be presented in the Task 2 report

Task 2: Significant Sources List of Significant Combustion Sources by Region (w/percent contribution representing 95% of all GHG sources) San Juan (South Basin)1 Uinta Basin2 Permitted Compressor Engines (24.5%) Heaters/Boilers (21.9%) Permitted Heaters/Boilers (13.9%) Unpermitted Compressor Engines (6.3%) Unpermitted Compressor Engines (13.0%) Permitted Compressor Engines (5.9%) Permitted NG Turbines (7.4%) Artificial Lift Engines (5.6%) Unpermitted Heaters/Boilers (6.8%) Drill Rigs (3.8%) Workover Rigs (1.6%)   Artificial Lift Engines (1.2%) 1 Note: The San Juan (South) Basin in northwestern New Mexico has a combination of tight sands gas, CBM gas and some oil production. 2 Note: The Uinta Basin in northeastern Utah has a combination of tight sands gas, CBM gas and conventional oil production.

Task 2: Significant Sources List of Significant Venting/Fugitive Sources by Region (w/percent contribution representing 95% of all GHG sources) San Juan (South Basin)1 Uinta Basin2 Well Completion Venting (17.8%) Pneumatic Devices (32.2%) Well Blowdowns (7.2%) Pneumatic Pumps (15.6%) Flaring (1.2%) Wellhead Fugitives (4.1%) Wellhead Fugitives (1.1%)   1 Note: The San Juan (South) Basin in northwestern New Mexico has a combination of tight sands gas, CBM gas and some oil production. 2 Note: The Uinta Basin in northeastern Utah has a combination of tight sands gas, CBM gas and conventional oil production.

Task 2: Significant Sources List of Significant Combustion Sources by Production Type (w/percent contribution representing 95% of all GHG sources) California Offshore Tight Sands Gas CBM Gas Gas Turbines (57.7%) Compressor Engines (33.0%) Compressor Engines (46.0%) Supply Boats (2.2%) Heaters/Boilers (17.5%) Heaters/Boilers (25.4%)   Drill Rigs (3.9%) Workover Rigs (1.8%) Turbines (1.6%)

Task 2: Significant Sources List of Significant Venting/Fugitive Sources by Production Type (w/percent contribution representing 95% of all GHG sources) California Offshore Tight Sands Gas Production CBM Gas Production Flaring (20.1%) Pneumatic Devices (14.3%) Well Blowdowns (15.3%) Fugitives (16.1%) Fugitives (10.9%) Fugitives (4.7%)   Flaring (7.6%) Pneumatic Devices (3.5%) Condensate Tanks (2.7%) Flaring (2.6%) Well Blowdowns (2.2%)

Task 2: Significant Sources List of Significant Combustion Sources by Production Type (w/percent contribution representing 95% of all GHG sources) Conventional Oil Production Conventional Gas Production Heaters/Boilers (26.6)% Compressor Engines (52.2%) Drill Rigs (6.0%) Heater/Boilers (11.26%)   Drill Rigs (7.36%)

Task 2: Significant Sources List of Significant Venting/Fugitive Sources by Production Type (w/percent contribution representing 95% of all GHG sources) Conventional Oil Production Conventional Gas Production Artificial Lift Engines (18.9%) Pneumatic Devices (11.5%) Pneumatic Devices (15.5%) Fugitives (8.2%) Oil Tanks (12.0%) Well Blowdowns (1.7%) Pneumatic Pumps (10.0%) Dehydrators (1.7%) Fugitives (6.7%)  

Task 2: Significant Sources Comments received on significant source categories lists List of significant sources useful in a qualitative manner (for inventory purposes), however since lists represent blended contributions they might skew data when assessing relevance to methodology development Data uncertainties and variability across and within production basins obscure how methodology used could help identify sources that contribute less than 5% of the inventory Examples from comments: Offshore sources developed using 2 typical platforms (one for shore-based power and one for on-board power) – Many platforms converting to shore-based power Relative ranking for CBM well blow-down seems very high Relative rankings of modeling software for E&P tanks and process simulation needs to be revisited and confirmed Fugitive emission contributions seem high from offshore platforms For conventional oil, compressors seem to comprise too small a percentage Footnote should be added to each table to discuss uncertainty associated with the rankings