1. 1 Western States Oil and Gas Emission Inventories Presentation to Four Corners Joint Air Quality Task Force January 8, 2007

2. 2 Todays Presentation Overview WRAP Phase I Emissions Inventory NMED Emissions Inventory WRAP Phase II Emissions Inventory Four Corners AQTF Emission Inventory and Modeling

3. 3 Prior to WRAP Phase I, inventories were spare and consisted mainly of larger point sources. Drill rigs, compressors, other wellhead emissions were largely unestimated WRAP Phase I was the first consistent region-wide emission inventory for O&G area sources, previously unestimated in most states NMED inventory focused only on San Juan and Rio Arriba counties in New Mexico with greater detail than Phase I inventory WRAP Phase II will improve on existing inventory by using producer information and revised emissions estimation methodology WRAP Phase II results will be used in 4C modeling Overview

4. 4 WRAP Phase I Adopted point source emissions from existing state inventories Focused on estimating area source emissions for important NOx sources: –Drill rig engines –Natural gas compressor engines –CBM pump engines Minor NOx and VOC wellhead processes were also estimated Reconciled point and area inventories Incorporated emission controls in future years

5. 5 WRAP Phase I: Well locations Much of the estimation methodology used well counts and locations Databases obtained from state oil & gas commissions Well locations not obtained for CA – CARB provided county-level emissions estimates

6. 6 WRAP Phase I: Emissions Methodology Drill rigs: –Emissions factors from WYDEQ study of Jonah-Pinedale area, derived from producer information –Adjusted for other formations based on average depth of wells and average drilling duration Natural Gas Compressor Engines: –Emission factor: 2.3x10-5 tons NOx/MCF, derived from NMOGA inventory –Gas production obtained from oil and gas commissions

7. 7 WRAP Phase I: Emissions Methodology CBM Pump Engines: –Controlled emission factor from WYDEQ; EPA NONROAD uncontrolled factor elsewhere –Assumptions on pump operation and well design to estimate engine power and hours of pumping/idling Minor NOx & VOC Wellhead Processes: –Divided production between oil wells and gas wells based on OGC data –Estimated emissions at oil wells by combining production with WYDEQ oil well emission factors –Estimated emissions at gas wells by combining production with WYDEQ gas well emission factors

8. 8 Grow 2002 emissions to 2018 based on estimated growth in oil and gas production Sources of data –Local Resource management plans (BLM) Alaska Department of Natural Resources –Regional, Energy Information Administration Oil production growth = 1.334 Gas production growth = 1.458 Adjust for post-2002 on-the-books controls Special cases –Sierra and Otero, NM –CBM development in Montana, North Dakota and Utah WRAP Phase I: Future Year (2018) Inventory Procedure

9. 9 WRAP Phase I 2002 and 2018 NOx Emissions

10. 10 WRAP Phase I 2002 and 2018 VOC Emissions

11. 11 NMED Inventory – Project Overview Estimated 2002 emissions from oil & gas activities in San Juan and Rio Arriba counties in NW New Mexico Obtained detailed data on equipment type, usage activity, well schematics and gas production and characterization directly from producers to improve emissions inventory for these two counties On a well count basis, 67% - 72% response by producers to emissions inventory survey

12. 12 NMED Inventory – Comparison with WRAP Phase I Emissions covered in WRAP Phase I and NMED inventories for Rio Arriba and San Juan counties indicates source category covered in NMED that was not covered in WRAP Phase I inventory

13. 13 WRAP Phase II Update 2002 WRAP Phase I regional emissions using detailed data to be provided by producers Use county-level OGC data to updating baseline emission inventory from 2002 2005 Identify and evaluate most promising control strategies Project emissions to 2018, then estimate emissions with control strategies implementation Update 2018 large point source SO 2 emissions to reflect estimated 2018 production and controls Tasks in the WRAP Phase II work plan:

14. 14 WRAP Phase II 2002 Emissions Inventory Update Major effort to update methodology for 2002 emissions inventory using detailed information from producers (a)Update drilling rig emissions estimates (b)Update compressor engine emissions estimates (c)Examine potential for improvement of VOC emissions from venting, flaring and dehydrators (d)Update CBM engine emissions estimates (e)Examine potential for estimating fugitive dust emissions from O & G operations in the WRAP region Subtasks (a) and (b) will be completed, subtasks (c) – (e) to be completed based on available resources

15. 15 WRAP Phase II New methodology will estimate emissions on a basin-wide average basis for all basins in the WRAP region, focusing on those basins where major O&G activities are occurring and detailed producer information is available In basins where significant activity is not occurring, or producer information is unavailable, will rely on Phase I estimates

16. 16 WRAP Phase II Drilling Rig Emissions Improve estimate of actual drilling time by formation and basin from producer information on drilling times (rather than spud date and well completion date) Improve estimate of average drilling rig engine load by formation and basin Determine average horsepower requirements by formation and basin and identify most often used or representative makes/models of drilling rig engines Incorporate manufacturers rated emissions factors for makes/models identified, or producers emissions tests where available Estimate SO 2 emissions (based on sulfur content of fuel) and PM emissions

17. 17 WRAP Phase II Compressor Engine Emissions Determine for each basin either (1) the average percentage of wells with wellhead, lateral and central compression or (2) percentage of total HP with wellhead, lateral or central compression Remove all central and lateral compressors that have been counted in a point source inventory for each state Determine for each basin a representative or most often used make/model of compressor, including HP and rated or tested emissions factors Determine for each basin an average load factor for wellhead/lateral compressors Basin-wide emissions estimate on the basis of total well count

18. 18 WRAP Phase II VOC Emissions Previous Work included: –Tanks – flashing, working and breathing losses (VOC) –Glycol dehydration units (VOC) –Heaters (VOC and NOx) –Pneumatic Devices (VOC) –Completion-venting and flaring (VOC, NOx, CO) New work will look at VOC from: –Venting (from unloading fluids) –Fugitives (using typical well diagrams) –Dehydrators (look at point source vs. area source distribution)

19. 19 WRAP Phase II CBM Engine and Fugitive Dust Emissions CBM Engines Estimate drilling rig and compressor emissions in basins with significant CBM activity Estimate CBM pump engine emissions estimated based on producer information Fugitive Dust Emissions Explore feasibility of estimating fugitive dust emissions on the basis of annual vehicle activity, unpaved/paved road mileage in WRAP region and dust emissions characteristics Evaluate other sources of information

20. 20 WRAP Phase II: Emissions Estimates Depend on Producers Providing Information Requested Timeliness and quality of the revised 2002 and 2005 emissions dependent on producers data ENVIRON questionnaire has been distributed to all major producers, and some mid-level producers in WRAP region. Most have agreed to provide requested data To date only a small fraction of required data has been received – we need data from producers!!

21. 21 WRAP Phase II: Updated 2002 2005 Baseline Emissions 2005 represents a more current base year for projections and can be used as a second data point to verify projections methodology Methodology will be to first update 2002 emissions using the Phase II tasks described here, then to scale up 2002 emissions using 2005 county-level OGC well count or production data In areas with no production or wells in 2002, but with production or wells in 2005, emissions will be scaled based on state average emissions per well (or per production unit)

22. 22 Control technology evaluations to be conducted: 1 Development of Control Technology will depend on level of emissions 2 SOx emissions will be a function of the sulfur content of fuels Develop white papers on control technologies that detail control effectiveness, costs, potential emissions reduction, cost-effectiveness ($/ton) WRAP Phase II: Control Strategies

23. 23 Control technologies/strategies by source category: WRAP Phase II: Control Strategies Drill Rigs: Injection Timing SCR Low-Sulfur Fuel DPF DOC EGR Crankcase Emission Controls Other retrofit technologies (i.e. LNC, NOx adsorbers) Compressor Engines: Rich-burn engines –Ignition Timing –Air-Fuel Ratio Adjustment –NSCR –Pre-stratified Charge Lean-burn engines –Ignition Timing –Air-Fuel Ratio Adjustment –SCR –High Energy Ignition System –EGR Other strategies: Replace/repower with low-emissions engine, electrification

24. 24 Typical calculation for a single basin wellhead compressors using EGR: WRAP Phase II: Control Strategies Identify 3 representative makes/models of well-head compressors based on hp Calculate emissions reductions (ton/year) per engine Calculate cost-effectiveness using BACT methodology

25. 25 WRAP Phase II: Control Strategies Per-engine emissions reductions scaled to entire basin using OGC well count data and percent of wells with wellhead compressors Total reductions will be calculated for a range of penetration rates for each control technology Final county- and state-level emissions reductions calculated by determining fraction of basin wells located in each county

26. 26 WRAP Phase II 2018 Emissions Projections Re-evaluate projected well count data from RMPs and check older RMPs 2002 (or 2005) well count accuracy Convert EIA production-based data to well count data by determining average production per well by basin –Determine projected percentage of well count with wellhead compression vs. lateral or central compression –Obtain information from producers, future forecasts, or state OGCs Project to 2018 using 2005 base case and growth factors Calculate range of projected emissions based on range of well counts or production – report range of estimates

27. 27 WRAP Phase II 2018 Emissions Projections – Controls Evaluation Recommend control strategy (-ies) in terms of feasibility, emissions reductions and cost-effectiveness Incorporate control strategy (-ies) to determine range of potential reductions in 2018 inventory on a state-by-state basis For basins in states outside areas of focus, apply control factors to inventory including a review of additional control technologies implemented since previous inventory and any control strategies in the works

28. 28 WRAP Phase II 2018 Point Source SO 2 Emissions Objective is to revise existing Pechan report on 2018 SO 2 emissions projections to incorporate ENVIRON projection methodology and producers information on growth forecasts and emissions controls Identify major SO 2 point source emissions sources in each state of interest Obtain producer information on control strategy effectiveness, implementation rate, timetable and growth trends from 2002 – 2005 as well as for 2018 based on production forecasts Conduct review of Title V Permits to determine emissions with and without control technologies Revise estimates of 2018 emissions

29. 29 Four Corners AQTF Mitigation Assessment Modeling Project Model air quality, visibility, deposition impacts of air emissions in the Four Corners region Evaluate impacts of alternative mitigation strategies Primary focus on impacts in Mesa Verde and Weminuche Class I areas and surrounding Class II areas

30. 30 Four Corners AQTF Modeling Use WRAP Phase II updated 2005 emissions as base case inventory for oil & gas area source emissions Use WRAP Phase II projected 2018 emissions inventory Model air quality effects of up to 5 mitigation scenarios by source category

31. 31 Questions?