Western States Oil and Gas Emission Inventories

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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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Todays 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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Overview

• 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 OG 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

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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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WRAP Phase IFuture Year (2018) Inventory
Procedure

• 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

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WRAP Phase I2002 and 2018 NOx Emissions
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WRAP Phase I2002 and 2018 VOC Emissions
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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
indicates source category covered in NMED that
was not covered in WRAP Phase I inventory
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WRAP Phase II
Tasks in the WRAP Phase II work plan

• 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

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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
• Update drilling rig emissions estimates
• Update compressor engine emissions estimates
• Examine potential for improvement of VOC
  emissions from venting, flaring and dehydrators
• Update CBM engine emissions estimates
• 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
  OG 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 manufacturers 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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WRAP Phase II Control Strategies

• Control technology evaluations to be conducted
• 1 Development of Control Technology will
  depend on level of emissions
• 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)

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WRAP Phase II Control Strategies

• Control technologies/strategies by source
  category

• 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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WRAP Phase II Control Strategies
Typical calculation for a single basin wellhead
compressors using EGR
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
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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?