http://epa.gov/airquality/qa/monprog.html#SLAMS. LIMITED DATA. Poor spatial correlation .... max daily 8-hr ave. CAMx si
Air pollutant emissions from shale gas development and production
Allen L. Robinson Department of Mechanical Engineering Department Engineering and Public Policy Carnegie Mellon University Pittsburgh, PA
Air Pollution and Oil and Gas Development • Criteria Pollutants – O3 (VOC + NOx + sunlight) – NO2 – PM2.5
• Hazardous Air Pollutants / Air toxics – Diesel particulate matter – Formadehyde – Benzene, toluene, ethylbenzene, xylenes
• Climate – CH4
– Black carbon
Condensate Tanks
Compressor stations
Frac pumps
Drill Rigs Drilling
Fracing
Completion Fugitives Flaring
http://www.marcellus-shale.us
Pneumatics
Source
NOx
VOC
PM
Air Toxics
Data Quality
Well development Drill Rigs
Medium
Frac Pumps
Medium
Truck Traffic
Medium
Completion Venting
Poor
Frac ponds
?
Poor
Gas Production Compressor Stations
Medium
Wellhead compressors
Medium
Heaters and dehydrators
Medium
Blowdown venting
Poor
Condensate Tanks
Poor
Fugitives
Poor
Pneumatics
Poor
= major source
= minor source
Spatial Scales
Natural gas drill rigs in Hopewell Township, news.nationalgeographic.com
Site ~ 1 km
Widely distributed with significant aggregate emissions Field ~ 10-100s km
Site ~ 1 km
Natural gas drill rigs in Hopewell Township, news.nationalgeographic.com
Jonah WY
wilderness.org
Regional ~ 100s to 1000s of km
Marcellus Wells in PA as of Mar 2012
Very large chemical plant or refinery distributed over 1000s of sq miles?! Refinery
Marcellus Wells in PA
www.fractracker.org (data from PA DEP)
LIMITED DATA Poor spatial correlation between air monitoring networks and oil and gas development and production State and local air monitoring stations
http://epa.gov/airquality/qa/monprog.html#SLAMS
Estimating air emissions in Marcellus region Actual region Inventory Domain
9
(USGS, 2009)
Past and future Marcellus well development and gas production
Wells drilled
5000
Projections Actual
4000 3000 2000 1000
2020
2015
2009
2008
2007
2006
2005
0
Considine, 2010; Considine et al. (2009, 2011); The Nature Conservancy, 2010; NETL, 2010; Annual Energy Outlook, EIA, 2011
10
Development of Process Level Emisions Inventory Process-level inputs -
Emission factors Duty cycle Source profiles Load factor Future controls
Process-level estimates e.g. drill rigs or compressors
Development Emissions
Production Emissions
Ton per well
Ton per BCF
Activity data
Activity data
Wells drilled/year
Gas produced/year
Marcellus-level estimates Ton yr-1 Temporal and spatial allocation
Model-ready emissions
11
Accounting for Uncertainty Emission factors
Load factors
Horsepower
Drilling time
% on-time
Emissions = EFi x LF x HP x time x %on-time
Monte Carlo
Cumulative distributions of NOx emissions to drill one well 12
Marcellus NOx emissions (a) Total emissions 1.0
2009
1.0
0.8
2020
0.6 Mean, 202 tons per day
0.4
Mean, 71 tons per day
0.2 0.0
2009
0.8
Fractile
Fractile
(b) Regional contribution
Mean, 5%
0.6
Mean, 17%
0.4 0.2
0
100
200
300
400
0.0 0%
500
NOx emissions, tons per day
10%
150 100
Wellhead compressors
Trucks Fracing
50
Drilling
0
2009
2020
NOx emissions, tpd
Compressor stations
30%
40%
(d) Regional context
Others
200
20%
Contribution to regional NOx emissions
(c) Marcellus sources
NOx Emissions, tpd
2020
Other
1400 1200 1000 800
Industry Diesel
95% CI Marcellus
Gasoline
600 400 200
EGUs
0
2009
2020
13
Marcellus VOC emissions Marcellus Emissions
Regional Contribution
2009
1.0
1.0
2009
2020
Fractile
0.6 0.4
0
50
100 150 200 250 300 350
VOC emissions, tons per day Emissions, tons per day
2020
0.6 0.4 0.2
0.2 0.0
0.8
Marcellus Sources 80 60
Transmission GasPlant Wellhead Condensate Compressors Completion Trucks Fracing Drilling
40 20 0
2009
2020
0.0 0%
5% 10% 15% 20% 25% 30%
Contribution to regional VOC emissions Emissions, tons per day
Fractile
0.8
800
Marcellus in Context Marcellus Others Solvent Mobile
600 400 200 0
2009
2020
NOx + VOC + Sun = Ozone CAMx simulations of O3 from Haynesville Shale
Ozone (ppbv) max daily 8-hr ave
Kemabll-Cook et al. Environ. Sci. Technol. 2010, 44, 9357–9363
1.0
1.0
0.8
0.8
0.6 2009 2020 Mean, 2009 Mean, 2020
0.4 0.2 0.0
0
5
10
20 25 30 35
Formaldehyde, tons per day
Fractile
Fractile
Air Toxics – Formaldehyde Emissions
0.6 0.4
2009 2020 Mean, 2009 Mean, 2020
0.2 0.0 0%
20%
40%
60%
80%
% Regional Formaldehyde Emissions from Marcellus
Natural gas powered compressor stations are major source. This is for primary emissions – majority of formaldehyde in atmosphere is secondary.
1.0
1.0
0.8
0.8 2009 2020 Mean, 2009 Mean, 2020
0.6 0.4
Fractile
Fractile
Diesel particulate matter
0.2 0.0
0.6 0.4
2009 2020 Mean, 2009 Mean, 2020
0.2 0
4
8
12
16
DPM, tons per day
20
0.0 0%
20%
40%
60%
80%
% Regional DPM Emissions from Marcellus
Diesel powered drill rigs, frac pumps and trucks
Some characteristics of oil and gas development • • • •
Complex mix of “small” sources Widely distributed in space Poor coverage by routine network Aggregate emissions are significant in regional context: – NOx and VOC ( regional O3)
• Air toxic emission may create local problems – Diesel PM and formaldehyde (local air toxics)
•
More than just “fracing” – Other important sources: drill rigs, compressor stations, completion venting
Acknowledgements • Anirban Roy, Peter Adams • NETL, PA DEP, WV DEP, NY DEC, MARAMA, GASP, EQT • Heinz Endowment and DOE-NETL (funding)
