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Western States Oil and Gas Emission Inventories

Presentation to Four Corners Joint Air Quality Task Force

January 8, 2007

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Today’s Presentation

• Overview

• WRAP Phase I Emissions Inventory

• NMED Emissions Inventory

• WRAP Phase II Emissions Inventory

• Four Corners AQTF Emission Inventory and Modeling

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• 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

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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

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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

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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

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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

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• 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

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WRAP Phase I2002 and 2018 NOx Emissions

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CompressorEngines

Drill Rigs Wellhead CBM PumpEngines

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WRAP Phase I2002 and 2018 VOC Emissions

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Oil Wells Gas Wells CondensateTanks

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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

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NMED Inventory – Comparison with WRAP Phase I

Emissions covered in WRAP Phase I and NMED inventories for Rio Arriba and San Juan counties

WRAP NMED Category NOx VOC SO2 NOx VOC SO2

Compressor Engines x x x x Drilling Rigs x x x x x CBM Engines x x x x Artificial Lift Engines x x x x Tanks x x Completions x x x Heaters x x Pneumatics x x Venting x x Fugitives x Truck Loading x indicates source category covered in NMED that was not covered in WRAP Phase I inventory

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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 SO2 emissions to reflect estimated 2018 production and controls

Tasks in the WRAP Phase II work plan:

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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

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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

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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 manufacturer’s rated emissions factors for makes/models identified, or producers’ emissions tests where available

• Estimate SO2 emissions (based on sulfur content of fuel) and PM emissions

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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

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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)

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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

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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!!

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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)

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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

Equipment NOx PM SOx VOC Drill Rigs x x X2 Compressor Engines x X1 CBM Engines x X1 Tanks x Glycol Dehydration Units x Heaters x Pneumatic Devices x Completion Flaring and Venting

x x

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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

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Typical calculation for a single basin wellhead compressors using EGR:

WRAP Phase II: Control Strategies

Baseline EGR Baseline EGR Baseline EGR

Annual usage (hr/yr) 7,884 7,884 7,884 7,884 7,884 7,884Initial Capital Cost 16,840$ 16,840$ 16,840$ Useful Life (years) 10.0 10.0 10.0 10.0 10.0 10.0Annual Operational/Maintenance Costs ($/yr) $0 $0 $0NOx Emission Factor (g/bhp-hr) 17.68 10.61 16.7 10.04 21.2 12.70VOC Emission Factor (g/bhp-hr) 0.35 0.35 1.3 1.33 1.02 1.02SO2 Emission Factor (g/bhp-hr) 0.00038 0.00038 0.00038 0.00038 0.00038 0.00038Engine Size (bhp) 133.6 133.6 91.78 91.78 64.29 64.29Avg. Load 0.7 0.7 0.73 0.73 0.58 0.58NOx g/hr 1,620.63 972.38 1,126.78 676.07 782.87 469.72 VOC g/hr 32.38 32.38 89.46 89.46 37.82 37.82 SO2 g/hr 0.03 0.03 0.03 0.03 0.01 0.01 NOx tons/year 14.08 8.45 9.79 5.88 6.80 4.08VOC tons/year 0.28 0.28 0.78 0.78 0.33 0.33SO2 tons/year 0.00 0.00 0.00 0.00 0.00 0.00NOx Reduction tons/year 5.63 3.92 2.72PM Reduction tons/year 0.00 0.00 0.00HC Reduction tons/year 0.00 0.00 0.00BACT Cost-Effectiveness (NOx Only) $299 $430 $619BACT Cost-Effectiveness (VOC Only) N/A N/A N/ABACT Cost-Effectiveness (SO2 Only) N/A N/A N/A

Caterpillar 3306NA Caterpillar 3304NA Waukesha VRG330Identify 3 representative makes/models of well-head compressors based on hp

Calculate emissions reductions (ton/year) per engine

Calculate cost-effectiveness using BACT methodology

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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

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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

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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”

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WRAP Phase II 2018 Point Source SO2 Emissions

• Objective is to revise existing Pechan report on 2018 SO2 emissions projections to incorporate ENVIRON projection methodology and producers’ information on growth forecasts and emissions controls

• Identify major SO2 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

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Four Corners AQTFMitigation 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

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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

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Questions?