1. EPA Oil and Gas VOC Speciation Improvement Efforts
Madeleine Strum, EPA, OAQPS

2. VOC SPECIATION
Transforms inventory species (VOC) into Air Quality model species to support the chemistry of the model
VOC speciation feeds into the ozone and secondary organic aerosol chemistry
SPECIATE is EPA’s repository of speciation profiles
SPECIATE4.5 update slated for Sept 2016
Speciation could also be used to estimate HAPs from VOCs
Apply Profile to compute emissions of chemical compounds
Map chemical compounds to Air Quality model species
Assign Speciation Profile based on Process (SCC)
VOC

3. Oil and Gas Profiles Added to SPECIATE4
Oil and Gas Profiles Added to SPECIATE4.5 All location-specific, All Uncontrolled
WRAP Profiles – Modeling contractor
D-J, Piceance, Powder River, Permian Basin, South San Juan, SW Wyoming, Uinta, Wind River
Unita Basin Tribal Minor Source Registration (TMSR) –From Region 8
D-J Condensate Tanks – From ORD/Region 8, published paper, measurement study
San Joaquin – From SPECIATE contractor – 2 studies (measurements)
East Texas – From SPECIATE contractor – measurements
CA- Bakersfield – From SPECIATE contractor - measurements/adjustments
About 200 unique profiles being added

4. WRAP Profiles
D-J, Piceance, Powder River, Permian Basin, South San Juan, SW Wyoming, Uinta, Wind River
Processes
Flashing – condensate tanks, oil tanks (Uinta)
Produced Gas – non-CBM, CBM (some basins)
Already widely used in modeling
Vintage ~2006, based on measurements of gas composition and models (tanks), composited across operators (ranging from 1-28 samples)

5. Uinta TMSR Profiles Uinta basin Processes
Condensate Tanks and Oil Tanks
Untreated natural gas (leaks, pneumatic devices)
Glycol dehydrator
Operator Specific (~40) and production-weighted composites
Vintage ~2013, based on measurements of gas composition and models (TANKS, GLYCALC)

6. D-J Condensate Tank Profiles
Measurements- Samples were acquired from condensate tank thief hatch leaks or other emission point prior to the control device
27 sample specific and one composite based on mean
Halley L. Brantley, Eben D. Thoma & Adam P. Eisele (2015): Assessment of VOC and HAP Emissions from Oil and Natural Gas Well Pads Using Mobile Remote and Onsite Direct Measurements, Journal of the Air & Waste Management Association, DOI: /

7. San Juaquin Censullo – added 3 composites of SPECIATE4.4 profiles
Tests from 1989
Oil field wells, Oil field tanks, Oil field Vapor recovery
A. Censullo, California Polytechnic State University, San Luis Obispo, "Development of Species Profiles for Selected Organic Emission Sources; Volume I: Oil Field Fugitive Emissions", ARB Contract A , April 30, 1991.
USGS – added sample specific and composites
Tests from ~ 2003
77 sample specific. Sites described as “Oil well” “gas and condensate well” ; some are more detailed “gas well separator”
6 composites: gas wells, oil wells, oil and gas separators, oil well tanks, oil well casings, gas and oil condensate wells
Overlap with Censullo data; Less compounds than Censullo (10 vs 59)
U.S. Geological Survey, Professional Paper 1713, Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California, 2007,

8. Bakersfield, CA
Petroleum operations - extraction, processing, transmission
Reflects ambient data (not source)
Combined of observed data w/regressions
Emissions of organic carbon and methane from petroleum and dairy operations in California’s San Joaquin Valley, Atmos. Chem. Phys., 14, 4955–4978, 2014

9. Next Steps
Assign these new profiles to inventory sources (GSREF) for use in SMOKE
Update flare profile (next version of SPECIATE)

10. Opportunities for Improvements
More data for more sources/basins
Standard terminology/naming system
Consistency in estimation of HAPs in NEI vs speciation where possible
How do SCCs reflect sources of data in SPECIATE? – e.g., Liquid vs gas service
How to handle speciation of controlled streams