DJ Basin Crude Oil Flammability Analysis
Background • Alignment of the OSHA Hazard Communication Standard (HCS) with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). • Required evaluation of chemical hazards
Background • North Dakota Industrial Commission crude oil stabilization requirements • Prior to shipment by rail, crude oil must be stabilized (volatile components removed) to a Total Vapor Pressure less than 13.7 psia
Background • EPA/CDPHE Fugitive Emission Regulations • Elimination of fugitive emissions from tanks caused an increase in flammable/toxic vapors present in tanks – resulting in worker exposure and increased vapor fires (OSHA Hazard Alert)
Crude Flammability Study • 3 producers -BBC -Great Western Oil & Gas -PDC Energy • 16 crude oil samples from 12 production facilities • 4 corresponding tank headspace and crude oil true vapor pressure (TVP) sample locations • Study area 78 miles x 84 miles • 1S to 12N and 61W to 68W • Mid-2011 to mid-2014 first production • Niobrara and Codell horizontals 5
Approximate Sample Locations 6
Crude Flammability Study • Boiling point by ASTM D2887 • Flammability (flash point) by ASTM D93 • Headspace volatile organic compounds (VOCs) by EPA TO-15 • TVP by ASTM D6377 7
FP and BP Sample Results • 15 samples had flash point below 50 deg F • 1 sample had flash point below 70 deg F • Wide variability in boiling points – 20% BP 151-295ºF • No correlations based on geography, formation, or age of well 8
TVP Sample Results • All four samples had TVP below 13.7 psia threshold recently established by NDIC for Bakken crude • Samples ranged from 6.04 to 11.05 psia • No correlation to 20% BP, however a correlation between age of well and TVP was observed • Older wells had lower true vapor pressures 9
VOC Sample Results • VOC concentrations in tanks exceeded OSHA PELs but did not exceed IDLH concentrations • Wide variability head space vapor composition • No apparent correlations to boiling point, age of well, or geographic location 10
Crude Classification • Results indicate crude is: • Class IB flammable liquid (NFPA 30)* • Class 3 flammable liquid (DOT - 49 CFR 173.120) • Flammable liquid (OSHA - 29 CFR 1910.106(a)(19)) • Crude oil tanks should be labeled with NFPA 704 label (aka NFPA diamond) flammability rating of “3” • Crude oil meets requirements of NDIC Order No. 25417 - oil conditioning order * Per Section 4.2.1.2 of NFPA 30 the 20% boiling point of the distillation analysis is used for characterization 11
Data Analysis
Data Analysis • Bill Barrett Corporation, Great Western Oil and Gas and PDC each contributed samples to the study • Identifying data masked to provide confidentiality • Well name not provided • Location limited to Township and Range • Spud date limited to quarter and year 13
Results Summary – Boiling Point Initial Sample Flash Full Boiling Boiling 5% 10% 20% 30% 40% 50% 60% 70% 80% 90% 95% ID Point Point Point 1 <50 56.5 110.9 183.4 267.0 337.0 427.3 512.7 591.9 671.4 766.1 858.1 903.5 962.9 2 <50 52.2 85.2 152.2 233.1 307.5 389.1 477.5 560.5 645.2 740.1 840.4 892.8 961.8 3 <50 62.5 186.1 235.8 295.5 368.7 441.3 512.2 587.8 666.9 758.5 861.7 914.4 984.2 4 <70 62.4 177.8 205.1 282.4 347.7 426.7 499.6 572.9 659.9 749.0 852.6 910.2 982.7 5 <50 51.8 61.9 84.6 165.9 204.6 266.5 315.6 388.5 481.9 575.2 715.2 823.0 923.1 6 <50 51.9 84.7 139.2 204.8 266.6 322.5 395.5 481.9 569.8 666.4 795.3 875.0 953.9 7 <50 51.9 84.8 139.2 229.0 290.5 352.4 437.4 511.8 592.8 689.0 799.8 873.6 952.9 8 <50 51.9 84.8 139.2 221.4 282.3 336.2 420.7 499.5 579.0 670.6 781.5 852.3 934.6 9 <50 61.8 138.7 190.1 250.6 313.8 381.7 465.2 539.3 630.5 728.8 839.3 902.2 982.5 10 <50 51.8 62.0 84.7 177.4 204.7 266.5 313.9 376.7 450.3 539.4 647.7 727.4 852.1 11 <50 51.7 84.5 128.5 197.5 261.2 322.3 403.5 481.7 569.4 666.1 781.2 852.0 934.4 12 <50 51.8 66.9 109.9 177.4 204.6 250.8 295.5 359.0 450.3 539.3 670.3 758.0 888.9 13 <50 55.9 84.8 151.3 228.9 285.0 352.2 438.8 511.6 597.6 688.8 799.6 862.8 937.9 14 <50 51.8 84.7 139.1 204.7 270.6 330.2 414.4 496.9 581.8 674.1 787.2 860.7 937.8 15 <50 51.8 61.9 84.5 151.1 197.3 241.5 282.1 330.6 403.7 481.5 592.5 674.1 883.4 16 <50 51.9 67.0 110.0 190.3 237.6 292.5 356.1 437.1 511.6 603.1 712.5 787.3 883.4 NOTES: All temperatures are in degrees Fahrenheit 14 < - less than
Boiling Point Analysis
Results Summary - TVP Sample TVP 20% BP (ºF) Spud Date ID (psia @ 100ºF) 1 6.04 267.00 Q4 2011 2 7.07 233.10 Q3 2013 3&4 11.05 288.90 Q1 2014 5&6 10.90 185.35 Q1 2014 16
Results Summary - VOCs 10% Compound Unit Site 1 Site 2 Site 3 & 4 Site 5 & 6 IDLH LEL Methylene Chloride ppm 25 30 -- -- 5,000 13,000 Hexane ppm -- 730 2,100 740 5,000 1,100 Benzene ppm 610 140 380 73 3,000 1,200 Cyclohexane ppm 910 170 520 150 10,000 1,300 Heptane ppm 1,000 170 440 140 5,000 1,050 Toluene ppm 360 76 140 32 2,000 1,100 Chlorobenzene ppm 14 -- -- -- 2,400 1,300 Ethyl benzene ppm 34 4.3 9.3 1.9 2,000 800 m,p-Xylene ppm 35 5.9 13 5.2 1,000 900 o-Xylene ppm 15 2.7 5.4 -- 1,000 900 1,2,4-Trimethylbenzene ppm 2.5 -- -- -- NL NL Propane ppm 570 780 540 510 20,000 2,100 Isobutane ppm 390 560 400 650 NL NL Cyclopropane ppm -- -- 600 -- NL NL Butane ppm 630 890 -- 880 19,000 1,900 Butane, 2-methyl- ppm 450 480 430 570 NL NL Pentane ppm 450 520 440 560 15,000 1,500 Pentane, 2-methyl- ppm 200 160 200 180 NL NL Pentane, 3-methyl- ppm -- 84 110 83 NL NL Cyclobutane, methyl- ppm -- -- 110 79 NL NL Cyclopentane, methyl- ppm 170 130 140 87 NL NL Cyclopentane, 1,2,3-trimethyl- ppm 210 -- -- -- NL NL Hexane, 2-methyl- ppm -- -- -- 53 NL NL Hexane, 3-methyl- ppm -- 66 -- 71 NL NL Hexane 2,5-dimethyl- ppm -- 68 -- -- NL NL Heptane, 2-methyl- ppm 410 -- 140 -- NL NL Heptane, 3-methyl- ppm 150 -- -- -- NL NL Cyclohexane, methyl- ppm 170 110 140 100 10,000 1,200 Cyclohexane, 1,2-dimethyl- ppm 230 -- -- -- NL NL Cylcohexane, 1,3-dimethyl-, trans- ppm -- -- 110 -- NL NL Octane ppm 290 -- 100 -- 5,000 1,000 NOTES: ppm = parts per million -- = not detected IDLH = immediately dangerous to life and health 17 LEL = lower explosive limit NL = not listed
Results Summary - LEL • Mixture LEL ranges from 11500 ppm to 15360 ppm • Average LEL = 12250 ppm • Methane LEL = 10000 ppm
Boiling Point Analysis
Boiling Point Analysis
Boiling Point Analysis
Head Space Composition Tank Head Space VOC Composition 2,500 Site 1 Site 2 2,000 Concentration (ppm) Site 3 & 4 1,500 Site 5 & 6 1,000 500 0
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