Liquid and Solid Waste Streams in Appalachian Basin Unconventional Gas by Paul Ziemkiewicz, PhD

1. Liquid and solid waste streams in
Appalachian Basin unconventional gas
Paul Ziemkiewicz, PhD
Water Research Institute
West Virginia University

2. LIQUID WASTE STREAMS
• Origins
• Volumes
• Chemistry
– Inorganics
– Organics
– NORM-naturally occurring radioactive materials

3. TERMINOLOGY: LIQUIDS
• Makeup water-impoundments/tanks
– fresh water
– waste water
• Hydraulic fracturing fluid-frac fluid
~ 100,000 to 120,000 bbl injected
– Makeup water +
– Proprietary mixture of chemicals
– Proppant
• Flowback-produced water
Fluids returned from the well after frac
~70-90% lost in formation
• Recycle
– Flowback-produced water used for makeup

4. FLUIDS AT THE WELL SITE
If major local well
completions:
Hydrofracing is a net
consumer of water
If not: then about

5. PRODUCED WATER
PROFILE
Flowback ^Q ^Q
day (bbl/day) (gpm)
1 4711 137
30 392 11
60 236 7
90 176 5
180 106 3
360 64 2
The decline in produced water returns varies from well
to well, not well documented out to 10 years

6. CHEMICAL CHARACTERIZATION
•Flowback/produced water
•Recycled flowback + makeup water + additives
•Hydraulic fracturing fluid
•Drilling mud

7. Flowback: predominantly Na, Ca, Cl
FPW 4 FPW 5 FPW 3 FPW 2 FPW 1
TDS 189,000 104,000 38,700 12,610 8,800
Cl 107,000 65,000 17,100 7,172 6,575
Na 48,100 33,700 8,560 2,863 3,550
Ca 22,200 12,800 1,640 1,749 319
Mg 2,000 1,470 193 122 31
Sr 2,970 1,440 301 nd nd
K 668 444 243 57
SO4 49 414 28 71 99
Ba 1,300 176 175 nd 27
Fe 48 30 37 27 37
pH 5.7 6.3 7.4 6.1 7.6
TSS 519 570 99 220 44
O&G 3 nd 5 49 5
Flowback inorganic chemistry from five Marcellus wells (mg/L)

8. Nearly all parameters were higher in flowback than frac fluid
Pink: exceeds drinking water MCL
Inorganics Organics
units MCL frac fluid flowback
As mg/L 0.01 - -
Ba mg/L 2 5.7 514.7
Cr mg/L 0.1 - 0.0
Hg mg/L 0.002 - -
Nitrate mg/L 10 - 0.0
Nitrite mg/L 1 - 0.1
Pb mg/L 0.015 - 0.0
Se mg/L 0.05 - 0.1
Ag mg/L 0.1 - -
Al mg/L 0.05 0.1 1.4
Cl mg/L 250 4,712.3 42,683.1
Fe mg/L 0.3 9.1 67.1
Mn mg/L 0.05 0.6 5.5
pH mg/L 6.5 7.2 6.6
SO4 mg/L 250 65.7 38.7
TDS mg/L 500 9,369.5 74,710.8
Zn mg/L 5 0.5 0.1
Br mg/L 54.6 466.0
Na mg/L 2,202.5 26,202.3
Sr mg/L 62.6 1,365.4
units MCL frac fluid flowback
Benzene µg/L 5 7.4 149.6
Ethylbenze µg/L 700 2.2 52.5
Toluene µg/L 1000 22.1 621.7
Xylene (m,p) µg/L 10000 41.0 698.7
Xylene (o) µg/L 10000 8.8 142.3
Xylene (total) µg/L 10000 49.8 841.0
Styrene µg/L 100 0.0 10.8
MBAS mg/L 0.5 0.0 0.2
COD mg/L 539.5 1420.1
O&G mg/L 6.0 63.5
TOC mg/L 105.4 176.4
Ethane µl/L 0.0 571.2
Methane µl/L 88.5 3420.5
Propane µg/L 0.0 86.9
TPH (Diesel) mg/L 38.7 60.6
TPH (Gas) mg/L 1.6 25.8
TPH (Oil) mg/L 3.3 10.2

9. Cation:Cl ion pairs dominate in FPW
equivalents
ion pairs? PA well WV well
Sr SrCl2 114.2 50.2
Mg MgCl2 160.5 250.2
K KCl 99.7 176.5
Na CaCL2 2,756.5 1,487.0
Ca NaCl 1,177.1 1,835.4
cation sum 4,308.0 3,799.3
Cl 4,197.2 3,526.8
% Cl 103% 108%

10. IN FPW CHLORIDE IS THE DOMINANT ANION:
SOLUBILITY VS. SULFATE AND CARBONATE MINERALS

11. FLOWBACK EVOLUTION-MAJOR INORGANIC IONS
Ziemkiewicz et al., 2011 Hayes 2009

12. FLOWBACK EVOLUTION-ORGANICS
Ziemkiewicz et al., 2011 Hayes, 2009

13. EVIDENCE THAT SULFATE PRECIPITATES
TO FORM SCALE
2,920 mg SO4 in HF fluid 11 mg SO4 in HF fluid
If this SO4 precipitated as
SrSO4, it would form 4 t/day of
scale over the first week

14. WATER TREATMENT TECHNOLOGIES
FALL INTO SIX MAIN CATEGORIES:
treatment
1. Bulk filtration
2. Lime softening
3. Sulfate addition
4. Nano filtration
5. Reverse osmosis
6. Evaporation/
Crystallization
removes
1. suspended solids
2. Mg, Ca –as carbonates
3. Sr, Ba, Ra- as sulfates
4. multivalent ions: Fe, Mg, Ca,
Sr, Ba, SO4
5. All ions
6. All inorganic ions

15. COSTS
INCREASE
FROM LEFT TO
RIGHT
Treatment end points
Sulfate addition
Nanofiltration
Reverse osmosis
Costs:
pre treatment
solids disposal
transportation
disposal fee
Bulk filtration:
TSS/Organics
surface dischargerecycle Deep well
injection
Bulk filtration:
TSS/Organics
Bulk filtration:
TSS/Organics
Lime softening
Evaporation/
Crystalization
Costs:
transportation
solids disposal
Costs:
astronomical
Do not over
treat your
water

16. SUMMARY
• Shale gas development creates large volumes of
contaminated waste water
• Pollutants include inorganic and organic
constituents
• Most flowback water is recycled
• Recycling is contingent on nearby well development
• Need efficient treatment for end of life cycle waste
water

17. TERMINOLOGY: SOLID WASTES
• Drilling mud
– Returns to the surface with cuttings during drilling
– Recycled after cuttings removed
– To disposal after well completed
• Drill cuttings
– Rock fragments-clay to fine gravel
– ~500-800 tons/well or 25 to 50 truckloads
– To disposal after separation from drilling mud
• Flowback Solids-filter cake, precipitates, suspended solids

18. DRILLING WASTES
Mud Cuttings

19. SOLIDS SEPARATION
Cuttings pit
Flowback pit
Plate and
frame filter
press
Bag filters
Flowback tank

20. Liquid
fraction:
Drill Cuttings
% samples
> TCLP limit
Drill %>
Cuttings TCLP min max
Cr 100% 6.7 32.8 mg/L
As 90% 2.4 30.6 mg/L
Pb 80% 3.5 84.9 mg/L
Ba 70% 23.9 7,870.0 mg/L
Benzene 70% 0.0 300.0 µg/L
Se 40% 0.0 3.3 mg/L
Hg 10% 0.0 0.3 mg/L
Drill Cuttings: Vertical Section

21. Radioactivity: Naturally occurring
radioactive materials (NORM)
• Flowback/produced water
• Drill cuttings
• Drilling mud
• Special handling as dictated by exposure risk

22. Radioactive isotopes increase during flowback

23. FLOWBACK SOLIDS
ARE MORE
RADIOACTIVE THAN
VERTICAL DRILLING
MUDS/CUTTINGS:
BUT IS THE
DIFFERENCE
SIGNIFICANT?
Vertical only Marcellus
Drilling mud solid
samples
Flowback
solids
Solids units average Donna C pit
Gross Alpha pCi/g 17.35 65.10
Gross Beta pCi/g 25.22 28.80
Potassium-40 pCi/g 24.51 19.69
Radium-226 pCi/g 1.22 26.95
Radium-228 pCi/g 1.33 5.12
Thorium-228 pCi/g 1.23 2.33
Thorium-230 pCi/g 1.01 1.10
Thorium-232 pCi/g 0.90 1.11
Uranium-234 pCi/g 0.91 1.08
Uranium-235 pCi/g 0.03 0.07
Uranium-238 pCi/g 0.85 0.69
Alpha + beta pCi/g 42.6 93.9
gamma pCi/g 32.0 58.2
Total pCi/g 74.6 152.1

24. POTENTIAL EXPOSURE PATHWAYS:
• Migration from horizontal leg to
surface/shallow groundwater
• Poor casing/cement integrity
• Handling failures at the drill pad
• Fires, tank ruptures
• Pit and tank leakage
• Flowback transportation-truck
accidents, pipeline failures

25. EXPOSURE
PATHWAYS
A. JUDGING BY THE PRESS, YOU
MIGHT THINK THAT THE PRIMARY
RISK INVOLVES MIGRATION OF FRAC
FLUID TO A DOMESTIC AQUIFER.
B. SHALLOW AQUIFER
CONTAMINATION FROM BAD CASING
IS MORE LIKELY TO OCCUR.
maybe
doubtful
A
B

26. Domestic
well ~30 m
Well site spills
and pit leakage
Flowback pit
Spring
Well
MOST LIKELY HUMAN/ENVIRONMENTAL
EXPOSURE PATHWAYS
Casing/cement
failure
Volatile organics

27. Protective measures: Polymer liner across drill pad will be
covered with gravel. Containment around tanks

28. MSEEL ENVIRONMENTAL STUDY
Background
• Funding: USDOE/NETL,
Northeast Natural Energy
Inc.
• WVU prime, OSU sub
• Begin April 2015
• Two wells installed in 2010
• Project will study two new
horizontal wells
• Test bed for new
technologies
Environmental objectives
• Reduce environmental
uncertainty and improve
environmental performance
• Characterize:
– Air emissions
– Liquid and Solid wastes
• Organic
• Inorganic
• Radiologicals

29. RECOMMENDATIONS: REDUCING
ACCIDENTAL RELEASES OF FPW
• Recycle/reuse flowback and produced water for frac water
makeup
• On site containment:
– Production casing integrity-testing prior to well completion
– Drill pad-lined and bermed
– Pits-construction/design/inspection according to State standards
– Flowback lines to be properly installed/protected
• Transportation:
– Tracking and accountability
• Solid waste characterization and disposal according to protective
standards (RCRA?)

30. FOR MORE INFORMATION
PLEASE CONTACT:
Paul Ziemkiewicz, Director
WVU Water Research Institute
304 293 6958
pziemkie@wvu.edu