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Fracturing Water Quality
Western North Dakota Water Resources Opportunities
10 Dec 2009
Mike Eberhard P.E.
Technical Manager
Denver, CO
Water Considerations
 Water sources
• Well, municipal, river, reused,
etc.
 Environmental Impact
 Costs to acquire and dispose
• All inclusive
 Storage and handling
• Pits or tanks
• Trucking or pipeline
 Regulatory requirements
• Federal, State, BLM, etc.
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Water Quality Concerns
 Treatment Type
• Gelled fluid or water frac
 Bacteria, scaling, residual
chemicals
 Water analysis
• TDS, hardness, cations,
anions
• Scaling tendencies
 Consistency is
imperative
© 2009 Halliburton. All Rights Reserved.
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Water Quality Guidelines
Water Quality Targets
Limit*
6 – 8.5
pH
< 2,000 ppm
Ca & Mg
Comments
Interferes w/ hydration of polymer, scale
Scales, interferes w/ breakers
Fe
< 10 ppm
Catalyst for polymer oxidation, scale
Ba & Sr
< 5 ppm
Reducing agents, interferes w/ breakers
Chlorides
Bicarbonates
Phosphates
< 300 ppm
< 5 ppm
< 500 ppm
Sulfates
* Limits
<40,000 ppm
Interferes w/ hydration of polymer and breakers
In the presence of Ca and Mg will scale when
heated, delay crosslink
Interferes w/ metal crosslinker
Scales, crosslinker precipitation
are interdependent
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Bacteria
 Can double in population every 20 min
 Can cause formation damage and H2S
 Significant problem in reused fluids
© 2009 Halliburton. All Rights Reserved.
Bacterial Level
(count/mL)
Days to Gel
Degradation
< 104
3
105
2
>106
<1
5
Typical Gelled Frac Fluid Chemistry
 Base water
 Temporary clay control
 Biocide
 Scale inhibitor
 Gelling agent
 pH buffer
 Crosslinker
 Surfactant
 Breaker
© 2009 Halliburton. All Rights Reserved.
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Flowback Water/Produced Brines
 Mixing different waters may exaggerate scaling
problems
 Storage and handling
 Water treatment
• Filter as required
• Bacteria shock then store
 Retreat for bacteria on fly
• Remove bad actors
 (Ca, Mg, Ba, Sr, Fe)
• Add scale inhibitors as needed, based on source water
 Lab testing
• Cores for formation damage
• Chemical compatibility
 Dilute w/ fresh water to get below limits
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Bakken Water Analysis
BPW
RMW
Na+
54,690
40
(mg/l)
K+
2,232
7
(mg/l)
Mg2+
544
25
(mg/l)
< 2,000
Ca2+
4,131
37
(mg/l)
< 2,000
Sr2+
178
1
(mg/l)
<5
Ba2+
1
0
(mg/l)
<5
Fe2+
26
0
(mg/l)
< 10
Cl-
96,400
47
(mg/l)
< 40,000
SO42-
670
118
(mg/l)
< 500
Alkalinity
366
162
(mg/l)
< 300
160,000
440
(mg/l)
Calc. Density (STP)
1.100
0.997
(g/ml)
< 1.038
pH, measured (STP)
7.11
7.41
pH
6 - 8.5
TDS (Measured)
Bakken Produced Water – BPW, Referenced Municipal Water - RMW
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Limits
Formation Water Scaling Tendencies
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