Presentation by Radisav D. Vidic,
University of Pittsburgh, for a hydrofracking forum hosted by the Cary Institute of Ecosystem Studies in Millbrook, NY on May 5, 2012.
Politician uddhav thackeray biography- Full Details
Water Quality, Quantity, and Management: Lessons from the Marcellus Shale Region
1. Water Quality, Quantity, and
Management: Lessons from the
Marcellus Shale Region
Radisav D. Vidic, PhD, PE
Department of Civil and Environmental Engineering
University of Pittsburgh
civil and environmental engineering
4. Water Supply Issues
• Need 2 to 6 Million gallons of water per well for hydraulic
fracturing
• Surface Water Withdrawals
– Concerns about depletion of water resources, especially in drought years
– Impacts to aquatic life
– Ability to get withdrawals approved
– Don’t really need high quality water, but consistent quality is important
• Transportation of water
– 1 MG = 200 trucks
– Cost can be significant (up to $2/bbl)
• Water storage on site
civil and environmental engineering
5. Water Withdrawal in PA
• Need 2 to 6 Million gallons of water per well for a multi-
stage hydrofracturing
Water-use category Water withdrawal Percentage
(MGD) (%)
Public supply 1420 15
Domestic 152 1.6
Irrigation 24.3 0.3
Livestock 61.8 0.6
Aquaculture 524 5.5
Industrial 770 8.1
Mining 95.7 1
Thermoelectric power plants 6430 67.7
Marcellus Shale exploitation in 2013 18.7 0.2
(Gaudlip et al. 2008)
civil and environmental engineering
6. Water Use in PA
Marcellus Shale Play is not a significant water user in PA
civil and environmental engineering
7. Water Transfer Issues
- Trucks
- Temporary surface lines
- Permanent subsurface lines
civil and environmental engineering
8. Water Storage Issues
Storage options:
• Centralized
impoundment—
now becoming
more prominent
• Single pad-
dedicated
impoundment
• Frac tanks
Storage based on
ultimate scale of
operations (long vs.
short term)
civil and environmental engineering
10. Fracture Fluid Composition
Additive type Main Compound Purpose
Diluted acid (15%) Hydrochloric or Dissolve minerals and initiates
Muriatic cracks in rock
Biocide Glutaraldehyde, DBNPA Bacterial control
Corrosion inhibitor N,n-dimethyl Prevents corrosion
formamide
Breaker Ammonium persulfate Delays breakdown of gel polymers
Crosslinker Borate salts Maintains fluid viscosity at high
temperature
Polyacrylamide Minimize friction between the
Friction reducers fluid and the pipe
Mineral oil
Gel Guar gum or Thickens water to suspend the
hydroxyethyl cellulose sand
civil and environmental engineering
11. Fracture Fluid Composition
Additive type Main Compound Purpose
Iron control Citric acid Prevent precipitation of metal
oxides
Oxygen scavenger Ammonium bisulfite Remove oxygen from fluid to
reduce pipe corrosion
pH adjustment Potassium or sodium Maintains effectiveness of other
carbonate compounds (e.g., crosslinker)
Proppant Silica quartz sand Keeps fractures open
Scale inhibitor Ethylene glycol Reduce deposition on pipe
Surfactant Isopropanol Increase viscosity of fluid
civil and environmental engineering
13. Anatomy of
a Vertical Well
Marcellus Shale wells are cased
and grouted (using special
cements) to prevent migration of
natural gas and fluid from the
producing zone up the well bore
into fresh-water aquifers.
civil and environmental engineering
14. Wastewater Issues
Flowback water Produced water
Flowrate High Low (10-50 bbl/day)
Duration 1 – 2 weeks Life of the well
TDS < 200,000 mg/L > 300,000 mg/L
Chemical additives Same as flowback but more
Composition
Naturally occuring constituents salts
Water recovery
10 – 40 %
Flowrate varies
with location
civil and environmental engineering
15. Wastewater Storage Issues
Storage options:
• Centralized
impoundment
• Single pad-
dedicated
impoundment
• Frac tanks
Environmental Risks
- Leakage
- Erosion and sediment control
civil and environmental engineering
20. Disposal Wells
• Require demonstration that injected fluids remain
confined and isolated from fresh water aquifers
• Limited capacities (1200 to 3000 bpd)
• Substantial capital investment with uncertain life
span ($1M to $2M)
• Probably will only play a limited role
• Depleted shallower wells are currently being
evaluated!?!?
civil and environmental engineering
24. Impact on Surface Water Quality
CROOKED CREEK & McKEE RUN
Bromide Concentration (ppb)
Oct Nov Dec Jan Feb March April May June July Aug Sept Oct
Sample Site
2010 2010 2010 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011
McKee Upstream of Plant B 29 79 61 36 27 17 32 66 93 63 26 25
Run Donwstream of Plant B 20 X 10 X 9X 10 X 1.1 X 3X 3X 8X 8X 27 X 34 X 4X 17X
Blue Spruce Bridge 57 39 64 87 37 38 13 53 83 116 114 56 25
Crooked
Creek Bridge St. Bridge 1130 345 639 774 42 111 44 414 640 3100 3900 214 427
Stitt Hil Rd. Bridge 280 467 396 173 74 53 112 258 578 582 426 103
(Casson, L., 2012)
civil and environmental engineering
25. Disposal to POTWs
• Chosen option in the past
• POTWs use biological processes
• Biological systems cannot handle high salinity
(few case studies above 35,000 mg/L)
• Require an approved pretreatment program
civil and environmental engineering
26. Treatment for Reuse in Fracking
Operations
• Reduce O&G industry needs for surface water
• Reduce overall management costs
– Volume reduction
– Transportation costs
– Disposal costs
• Reduce potential liability
civil and environmental engineering
27. Water Bank Concept
• Reuse difficult for smaller operators
– Insufficient well count
– Insufficient capital
• Develop rules for water banking
– Smaller operator dispose of their wastewater in
regional impoundments
– Larger operators get credit for water reuse and
pollution elimination
civil and environmental engineering
28. Recycling/Reuse
• 4800 wells on 625 mi2
• 3 refractures/well
• 33% water reuse
- Works for 12-15 yrs
- Eventually we are a
net producer of water
civil and environmental engineering
29. Total Water Balance Within a Gas Field
(Kujivenhoven et al., 2011)
civil and environmental engineering
29
30. Treatment Options
100
Crystallizers
Water Recovery (%)
Evaporation
75 Limited recovery
at high TDS
50
25,000 50,000 100,000 300,000
Total Dissolved Solids (mg/L)
civil and environmental engineering
31. Complete Treatment Process
FLOWBACK
WASTE
WATER FRAC BRINE
SOURCE OPERATIONS PRODUCED STORAGE
WATER
RECOVERED WATER Pretreatment
ROAD BRINE BRINE
DEICING CRYSTALLIZER CONCENTRATOR
Volume
SALT Reduction
Based on
TDS
PURGE TO
95% Volume
DISPOSAL
Reduction
civil and environmental engineering
33. Salt production in Marcellus region
• 100,000 wells
• 10 barrels/day/well of produced water
• 300,000 mg/L salinity of produced water
• 80% salt recovery
• Total NaCl produced in PA = 8 million tons
• Total salt use for deicing in the US = 12-15 million tons
civil and environmental engineering
34. AMD in Pennsylvania
• Pennsylvania’s single greatest source of water pollution
– Contaminated 4,000 miles of streams
• Elevated levels of iron and sulfate
• Can have elevated hardness
• TDS typically around 1,000 mg/L
• May be suitable as fracking water make up with little or
no treatment
civil and environmental engineering
36. Co-treatment of flowback water and AMD
Flowback water Abandoned mine
drainage (AMD)
Barium, Strontium, Calcium Sulfate
Hydraulic fracturing
Enables the reuse of flowback water for hydraulic fracturing with
limited treatment => decreases the treatment and transport cost
of flowback water
civil and environmental engineering
36
37. Summary
• Marcellus shale development hinges on
documenting environmental impacts and developing
sustainable water management
• Almost no direct disposal options and limited
treatment options for flowback/produced water
• Flowback water reuse appears to be the most
effective option
• Water reuse has a finite lifetime
• Salt management may become a major issue in PA
• AMD is a promising/convenient water source for
hydraulic fracturing
civil and environmental engineering
38. Thank You for
Your Attention
Questions?
civil and environmental engineering
39. Natural Gas Production
Source: Annual Energy Outlook, EIA, 2011
civil and environmental engineering
40. History of Hydrofracturing
• First test in 1903
• First commercial use in 1949
• More than 1,000,000 wells by 1998
• Nowadays, 35,000 wells per year with new
technology
civil and environmental engineering
44. Typical Efficiencies of Thermoelectric
Power Plants
Source: Stilwell et al., 2009
civil and environmental engineering
45. Water Use in Thermoelectric Power Plants
civil and environmental engineering
46. Flow scheme 1: Conventional Water Management
Flowback
“Fresh” Class II Well
Water Disposal
Well 1
Represents Maximum Water Demand
(No Water Reuse)
Conventional approach in Barnett and other plays
Difficult in Marcellus (only 7 Class II wells)
civil and environmental engineering
47. Flow scheme 2: On-Site Primary Treatment for Reuse
On-Site
Settling
SS & FR Rem
Well 1
High TDS
Reuse Water
Blend
Makeup Water
(Fresh Water)
Well 2
civil and environmental engineering
48. Flow scheme 3: Off-Site Primary Treatment for
Reuse
Sedimenta-
On-Site Rapid Mix tion & Hard- Rapid Sand
Settling w/ Caustic Filter
ness Rem
SS Removal & Flocculant
Well 1 Near-Field Disinfect
Belt Press
Primary (Ozone or
Treatment Peroxide)
Solids to Landfill
High TDS Water
For Reuse
Blend
Makeup Water
(Fresh Water)
Well 2
civil and environmental engineering
49. Flow scheme 4: Off-Site Primary Treatment and
Demineralization
Demineral- Concentrated
On-Site Near Field Ization Brine
Settling
SS Removal
Primary
Treatment Mechanical
Well 1
Vapor
Recomp Disposal
(Class II Well)
Or
By-Product
Recovery
Distilled Water (Crystallizer)
For Reuse
Blend
Makeup Water
(Fresh Water)
Well 2
civil and environmental engineering
50. Economic Comparison of Flow Schemes
Basis: 1 million gallons of flowback (23,800 barrels)
Flow Scheme FS 1 FS 2 FS 3 FS4
Method Transport to “In Field” Primary “Near Field” “In-Field”
Class II Well Treatment Precipitation Evaporation
for Disposal for Reuse for Reuse for Reuse
Treatment $ - 71 83 119
Transport $ 75 1 24 24
Brine Disposal $ 60 - - 19
Sludge Disposal $ - 2 6 6
Total Cost ($x1000) 135 74 113 168
Cost per barrel 5.67 3.10 4.75 7.05
Hardness Removal 100% 0% 97% 100%
Ba removal 100% 0% 99% 100%
Salt Removal 100% 0% 0% 100%
Water reused 0 99% 97% 90%
civil and environmental engineering
51. Geosteering
civil and environmental engineering
There is infinitely small chance that the frac fluids will reach the groundwater supply once it is injected at 5-8,000 ft depth
AMD Source is plentiful and local. Greater source of water pollution in PA Presence of discharges, mine poolActive mines treat their water but a lot are abandoned. Some watershed associations install passive treatments.Possibility of readilya and locally available water source for HF