Evidence of Emissions from Oil and Gas Drilling Operations in - PowerPoint PPT Presentation

Evidence of Emissions from Oil and Gas Drilling Operations in Northeastern Colorado NOAA GMD: Gaby Petron, Steve NOAA CSD: Greg Frost, Michael Trainer Montzka, Ben Miller, Adam Hirsch*, NOAA PSD: David Welsh, Dan Wolfe Anna Karion, Colm Sweeney, Jon Kofler, Arlyn Andrews, Ed Acknowledgments Dlugokencky, Laura Patrick, Pieter Western Regional Air Partnership: Tom Moore Tans & NOAA Carbon Cycle Group * now at the National Renewable Environ: Amnon Bar-Ilan and John Grant Energy Laboratory, Golden, CO

Methane emissions (Tg) from natural gas systems EPA US GHG inventory 2010 vs 2011 Field production Processing Transmission and Storage Distribution 12 12 20 10 EPA 20 11 EPA 10 x 2 10 8 8 6 6 4 4 2 2 0 0 0 2 4 6 8 0 2 4 6 8 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 9 9 9 9 9 0 0 0 0 0 9 9 9 9 9 0 0 0 0 0 1 1 1 1 1 2 2 2 2 2 2009 Methane emission estimates: TOTAL 32.7 Tg, Natural gas system s 10 .5 Tg , Enteric fermentation 6.6 Tg, Landfills 5.6 Tg, Coal mining 3.4 Tg, Manure management 2.4, Petroleum Systems 1.5 Tg

Examples of air pollution from O&G operations in Western States Pinedale smog Jonah, Feb 2008 Green River Basin, WY: Very high winter time ozone in natural gas field (Schnell et al., Nature, 2009) Uinta Basin, UT: hourly ozone in Northern Colorado Front Range natural gas ozone non attainment area: field up to 155 Estimated 40% of total VOC in the to 159 ppb last region due to oil and gas operations winter in Denver Julesburg Basin (DJB)

Outline • Oil and gas operations emission signature in Colorado Northern Front Range • Source estimates & • Comparison with inventories • Conclusions

NOAA Cooperative Tower Long Term Measurement and Sampling Network Boulder Atmospheric Observatory, Erie, Weld county (NOAA PSD) Non attainment area for summer time ozone NWF SGP Denver o 300 meter tall tower Denver Julesburg Basin o 30 sec- Meteorological Data o Daily discrete air samples from 12,000 gas wells in Weld County ~ 900 new ones in 2006 300 meter level since Aug 2007 Tower team: Arlyn Andrews, Jonathan Kofler, Jonathan Williams

Discrete Air Samples Analyses standard NOAA Boulder Lab MAGICC s analyzers MAGICC System (Carbon Cycle o Group):  CO 2 , CH 4 , N 2 O, CO , H 2 , SF 6  CH 4 repeatability error: 1.2 ppb GC/ MS System (HATS group): o  C 3 H 8 , nC 4 H 10 , iC 5 H 12 , nC 5 H 12 , C 2 H 2 , air samples C 6 H 6 , CFCs, HFCs, PFCs… Logistics: Molly Heller, Chris  Most species: total uncertainty <5% Carparelli, Jack Higgs,…  n-butane and C 2 H 2 : 10-15% Analysis: GMD: Tom Conway, Andy Crotwell, o High precision long term well Ed Dlugokencky, Pat Lang, Paul calibrated m easurem ents Novelli, Kelly Stroker HATS: Ben Miller, Carolina Siso, Steve Montzka http:/ / www.esrl.noaa.gov/ gmd/ ccgg/ & http:/ / www.esrl.noaa.gov/ gmd/ hats/

BAO: Distinct Alkane Signature Median summer mixing ratio at 7 NOAA Towers Midday data only (June-Aug 2007-2009) STR, CA WGC, CA NWF, CO - Night BAO, CO WKT, TX SGP, OK LEF, WI 500 BAO 400 NWF Median mixing ratio SGP 300 200 100 NOAA Cooperative Tall Tower 0 Measurement and Sampling Network CH4 ppb - C3H8 ppt nC4H10 ppt iC5H12 ppt nC5H12 ppt 1800 /10 /4 Air samples collected at the BAO and SGP* have a strong alkane signature. Both sites are in major oil and gas production regions. * SGP is a NOAA aircraft site in Northern Oklahoma. Samples collected below 650 meters were used for this analysis. GMD aircraft program leader: Colm Sweeney.

Alkane source in N&E wind sector: Denver Julesburg Basin N&E Summer N&E Winter S Winter W Winter 1000 North & Median mixing ratios (N>30) West East 800 Aug 2007-April 2010 600 400 South 200 Boulder Atmospheric Observatory 0 - 30-sec met data at 3 vertical CH4-1800 C3H8 ppt nC4H10 iC5H12 nC5H12 levels (NOAA PSD) ppb /10 ppt /5 ppt ppt - daily* midday air sample collection from 300 meter level Air samples from the North and East wind and analysis in NOAA GMD labs sector have the strongest alkane signature (all year round), suggesting this is where the alkane source is likely located.

Mobile Lab intensive sampling in Front Range Mobile Platform to sam ple close to sources Boulder Waste w ater treatm ent plant July 31, 2008 (up to 3.2 ppm ) 2200 600 Landfill (up to PFP 2 PFP 9,10,11  2.4ppm ) Picarro Sensor: 500 PFP 4,5 CO2, CH4, H2O 2100 PFP 7,8 (Colm Sweeney, CO2 400 Anna Karion) Denver 2000  Ozone 2B Julesburg 300 Analyzer (Laura Basin, PFP 6 Patrick) 1900 stop at BAO O&G wells CH4  GPS 200 1800 Targeted flask O3 100 PFP 3 sam pling on m ost drives: total of 88 1700 0 flasks collected over 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 June-July 2008 Local Time on 7/31/2008

Regional alkanes enhancements vs point CH 4 sources Waste w ater treatm ent plant July 31, 2008 (up to 3.2 ppm ) Landfill (up to 2.4ppm ) CO2 Denver Julesburg Basin, O&G wells CH4 O3

Same alkane signature at BAO and in Mobile Lab samples Mobile Lab BAO N&E summer The alkanes are strongly correlated in BAO N&E wind sector samples and in Slope: 0.11 Slope: 0.10 Mobile Lab samples.  The alkanes come from the same source located in NE part of y=0.48x y=0.50x the Front Range. r 2 =1 r 2 =0.98

Multi species analysis: Separation of various methane sources July 14, 2008 Sample collection: Lloyd Miller, 2150 William Kolodzey (no Picarro) subset Methane ppb 2050 Feedlots contribution Oil and gas 1950 contribution 1850 Background methane 1750 0 5000 10000 15000 20000 25000 30000 Propane ppt C H t Samples collected with the Mobile Lab close to feedlots, a landfill, and a waste water treatment plant are above the oil and gas methane-to- propane correlation line.

Outline • Oil and gas operations emission signature in Colorado Northern Front Range • Source estimates & Comparison with inventories • Conclusions

Upstream and Western Region Air Partnership midstream operations only Oil and Gas Total VOC Inventory Other Categories 50 Compressor Engines* Emission estimates for Front Range NAA 2006 based 2010 Venting - recompletions on industry projected VOC emissions Gg/yr 40 Venting - initial data and completions reported Venting - blowdowns emissions 30 Pneumatic pumps for permitted Pneumatic devices 20 sources Unpermitted Fugitives Permitted Fugitives* 10 Glycol Dehydrator* Small condensate tanks 0 2006 other 2010 other 2006 venting 2010 venting 2006 flashing 2010 flashing Large condensate tanks* State regulated sources in the Front Range O3 non Amnon Bar Ilan et al. [2008] attainment area (NAA)

Speciation profiles of raw natural gas and condensate tanks flash emissions C6+ heavies 2,2,4- Used to derive Not included trimethylpentane speciated emissions in GWA n-pentane nC5 study for fugitive/ vented xylenes emissions (raw gas) and i-pentane iC5 ethylbenzene flashing emissions from n-butane nC4 condensate tanks. toluene i-butane iC4 The WRAP inventory benzene propane C3 used average emission profile. 0.00% 0.05% 0.10% 0.15% ethane C2 methane C1 We used the entire Venting GWA documented range. N2 Venting WRAP CO2 Flashing WRAP 0% 20% 40% 60% 80% 100% Venting WRAP: average of industry data for DJB (company proprietary data) Venting Greater Wattenberg Area Study: natural gas samples from 77 wells in DJB (2006, COGCC) Flashing WRAP: EPA TANK model output for 16 condensate tanks in DJB (2002, CDPHE)

Atmospheric Molar Ratios versus Bottom-up Inventory Emission Ratios 2.0 Very good agreem ent. Flashing GWA raw gas WRAP F+V Vertical bars BAO N&E Mobile Lab 1.5 show : • min and max molar ratios values for flashing and 1.0 fugitive emissions 0.5 • 2 sigma for observed atmospheric molar ratios 0.0 1 1 3 3 3 4 4 5 C C C C C C C C / / / / / n n n 3 4 4 5 5 / / / C C C C C 5 5 5 C C C n n i n i n i C1: methane, C3: propane, nC4: n-butane, i or nC5: i or n-pentane, C2: ethane*

Emission estimates comparison The bottom-up propane source estimate is used to derive top-down* emissions for all other species based on observed atmospheric ratios 200 Bottom-up Methane source Error bars show BAO = 1.6 to 6% of Weld min/max range County natural gas Mobile Lab 150 production in 2008 Gg/yr 100 Used to derive top- ~ 50% discrepancy down* estimates for between bottom-up and other measured top-down estimates for species methane. 50 0 C1 C2 C3 iC4 nC4 iC5 nC5

Fraction of total natural gas withdrawal vented to the atmosphere Percentage 0 1 2 3 4 5 6 Weld Co/Mobile Lab Estimates for Weld County Weld Co/BAO Conventional gas and Shale Shale gas gas estimates from Howarth et al. [2011]: Conventional gas % of methane produced over the lifecycle of a well. 2011 EPA US average (no error bars) 2010 EPA These estimates are still highly uncertain.