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1 / 9 �
Hydraulic Fracturing of Unconventional Shale Gas Wells and Environmental Testing of Water William Lipps Analytical & Measuring Instrument Division Shimadzu Scientific Instruments, Columbia, Md., USA �
3 / 9 �3 / 28 �
Compound Percent (%) by Volume Water and sand 99.51
Surfactant 0.085
KCL 0.06
Gelling Agent 0.056
Scale inhibitor 0.043
pH adjustment 0.011
Breaker 0.01
Cross linker 0.007
Iron Control 0.004
Corrosion Inhibitor 0.002
Biocide 0.001
Acid 0.123
Friction Reducer 0.088
Example Composition
Example composition of a fracking solution water listing constituents that could be detected in a water sample:
4 / 9 �4 / 28 �
Component Concentration (mg/L)
pH 6.6 (S.U)
Alkalinity as CaCO3 140
Total Dissolved Solids (TDS) 67,300
Total Suspended Solids (TSS) 100
Total Organic Carbon (TOC) 63
Biochemical Oxygen Demand (BOD) 3
Oil & Grease < 5
Sodium as Na 18,000
Calcium as Ca 4,950
Magnesium as Mg 560
Barium as Ba 690
Iron as Fe 40
Chloride as Cl- 41,850
Bicarbonate as HCO3- 74
Ammonium as NH4+ 82
Volatiles ND – 1 (BTEX and acetone)
Semi-volatile ND – 1 ppm (PAH)
Example Analysis of Flow Back Water
5 / 9 �5 / 28 �
Component Concentration (mg/L)
pH 6.5 – 8.5 (S.U)
Total Dissolved Solids (TDS) 500
Foaming Agents (MBAS) 0.5
Chloride as Cl- 250
Color 15 (CU)
Sulfate as SO4 -2
250
Manganese as Mn 0.05
Iron as Fe 0.3
Barium as Ba 2
Arsenic as As 0.01
Selected USEPA Drinking Water Maximum Contaminant Levels (MCL)…
…of contaminants that have been detected in flow-back water.
6 / 9 �6 / 28 �
However,
• Methane?
• Alcohols?
• Glycols?
Drinking water and source water contamination is easy to detect because of chloride.
Water Contamination
7 / 9 �7 / 28 �
Wastewater “Pre-Treatment” Requires Analysis by Part 136 Approved Methods
Have these methods been validated in the produced water matrices?
8 / 9 �8 / 28 �
Alkalinity
EPA Approved Method Interferences
SM 2540C
• Highly mineralized water may be hygroscopic à prolonged drying, rapid weighing (constant weight?)
• 200 mg residue limit (1 milliliter samples?)
9 / 9 �9 / 28 �
Ammonia
EPA Approved Method Interferences
EPA 350.1 or SM 4500 NH3
• Co-distillation of surfactants, fatty acids, amines, ketones, alcohols and aldehydes
• Surfactants and fatty acids interfere with electrode
• Amines are detected by electrode • Amines interfere with Berthelot
10 / 9 �10 / 28 �
A Possible Solution is to Replace Distillation With Gas Diffusion
EPA ASTM WK42422
Distillation Automated Diffusion
Phenolate Salicylate
EDTA Citrate
0.02 – 2.0 ppm Estimated 0.01 – 10 ppm
11 / 9 �11 / 28 �
Total Kjeldahl Nitrogen (TKN)
EPA Approved Method Interferences
EPA 351.2 or SM 4500 org
• High salts raise boiling point à low recovery • Multiple step procedure • Incomplete recovery on refractory organics
12 / 9 �12 / 28 �
A Possible Solution is to Replace TKN With HTCO TN
EPA ASTM WK46665
TKN digestion / distillation 720ºC catalytic oxidation
Titration or Colorimetric Chemiluminescence
Time consuming (hours) < 5 minutes per sample
Boiling sulfuric acid Compressed air, dilute acid
13 / 9 �13 / 28 �
Oil and Grease (O&G)
EPA Approved Method Interferences
1664
• Elemental sulfur, surfactants, organic dyes are detected
• Heavier petroleum and light polar are not detected
• High salts allows co-extraction of non Oil and Grease
• Emulsions or samples that don’t filter
14 / 9 �14 / 28 �
A Possible Solution is to Replace 1664 With ASTM D7575
EPA ASTM D7575
LL or SPE extraction
Selective SPE Extraction
Gravimetric Detection IR Detection
Time consuming (hours)
< 15 minutes per sample
Large volumes (100 – 1000 ml) 10 milliliter sample
15 / 9 �15 / 28 �
Metals by ICP-AES
EPA Approved Method Interferences
200.7
• Spectral interferences • Transport and ionization efficiency
differences • Clogging of nebulizer
16 / 9 �16 / 28 �
Possible Solutions for EPA 200.7
• High salt nebulizer
• High resolution spectrometer
• Internal standard and total element correction
STD1 STD2 STD3 STD4 As, Cr, Mn, Pb, Pd, Pt 0 1 5 -
Mg 0 1 5 10 Y 10 10 10 10
Na 5000 5000 5000 5000 HCI (mol/L) 0.36 0.36 0.36 0.36
HNO3 (mol/L) 0.42 0.42 0.42 0.42
17 / 9 �17 / 28 �
EPA 200.7 Modified to Correct for High Salt Content
In solid (wt%)
Validation Test Value
(%)
In solid (wt%)
Validation Test Value
(%)
In solid (wt%)
Validation Test Value
(%)
As 0.016 0.016 100 0.015 94 0.015 96 Cr 0.017 0.016 95 0.016 95 0.017 98 Mg 0.033 0.032 95 0.033 99 0.033 99 Mn 0.0020 0.0021 105 0.002 101 0.0020 101Pb 0.012 0.013 107 0.012 99 0.013 102Pd 0.025 0.026 105 0.026 106 0.026 106Pt 0.039 0.039 99 0.038 98 0.040 102
Sample 1
Sample Elem-ent
Analysis Result by Validation
Test (wt%)
Analysis Result by Direct Analysis
Internal Standard Method
Total Correction Method
Internal Standard Method and Total
Correction Method
18 / 9 �18 / 28 �
Volatiles by Purge and Trap GCMS
EPA Approved Method Interferences
624
• Surfactants may cause excessive foaming • Variable purge efficiency • Contamination of purge vessel
• Target analytes are mostly chlorinated solvents
19 / 9 �19 / 28 �
Possible Solutions for EPA 624
Replace purge and trap with headspace trap GCMS
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5(x10,000)
VOCs in drinking water at 0.1 ppb RSD < 3%
20 / 9 �20 / 28 �
Possible Solutions for EPA 624
Highly reproducible and can measure alcohols
Methanol 5000ppm CV%=0.47
0.0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
21 / 9 �21 / 28 �
Headspace Trap is a Very Minimal Modification to 624
Headspace Trap
Equilibrate vial
Pressurize vial
Load trap (pressure and
time) Dry purge
trap Desorb to GC
Purge and Trap
Transfer sample to
sparge Purge sparge
tube Load trap
(Time) Dry purge
trap Desorb to GC
22 / 9 �22 / 28 �
Replacing Purge with Headspace for EPA 624
• Maintains BFB tuning criteria
• Low MDL - <0.1 ppb for most
• See Shimadzu app note No. AD-0073
• P&T was developed because in 1970’s GC instruments were not sensitive.
• TA Bellar and JJ Lichtenberg, Determination of Volatile Organics at Microgram per Litre Levels
by Gas Chromatography, JAWWA, 739-744, December 1974
23 / 9 �23 / 28 �
Semi-Volatiles by Liquid-Liquid Extraction GCMS
EPA Approved Method Interferences
625
• Surfactants and other constituents may cause emulsions
• High organics may require surrogates be “diluted out”
• Contamination of injection port
• Target analytes are mostly chlorinated and industrial solvents
24 / 9 �24 / 28 �
Problems with EPA 625 and Fracking Solutions and Possible Solutions
• Complex matrices
• Samples need “cleanup”
• Use GPC, or
• Use GCMSMS
25 / 9 �25 / 28 �
Modify Method 625 to Allow Triple Quadrupole GCMS
7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 37.5 40.0
0.25
0.50
0.75
1.00
1.25 (x100,000,000)
21.25 21.50 21.75 22.00
1.0
2.0
3.0
4.0
5.0
6.0
(x1,000,000)
135.00
28.50 28.75 29.00 29.25 0.25
0.50
0.75
1.00
1.25
1.50 (x100)
357.90>287.90 359.90>289.90
26 / 9 �26 / 28 �
Retain Full-Scan Capability (like 625), Only Add MRM for Greater Selectivity and Sensitivity
11.0� 11.5 � 12.0 � 12.5 � 13.0� 13.5� 14.0� 14.5� 15.0� 15.5� 16.0� 16.5� 17.0� 17.5�
1.0�2.0�3.0�4.0�
(x1,000,000)�
0� 50� 100� 150� 200� 250� 300� 350� 400�0�25�50�75�100� %� 97�
223�162�65�
279�117�251�173�59� 135� 203�259� 341� 397�
365�305�13.50� 13.75� 14.00� 14.25�
0.25�0.50�0.75�1.00�(x10,000)�279.00>204.90�279.00>222.90�
Qualification Quantification
Scan Chromatogram
MRM Chromatogram
27 / 9 �27 / 28 �
Triple Quadrupole is a Very Minimal Modification to 625
625 Extract 1000 ml Sample
Add Internal Standards Inject Full Scan (SQ)
625 modified
Extract 100 ml Sample
Add Internal Standards Inject Full Scan
(SQ) MRM (TQ)
28 / 9 �28 / 28 �
Summary of Problems Associated with Analysis of Fracking Solutions and Production Water
• Matrix can be very complex
• TDS and chloride can be very high
• Part 136 methods may not be validated
• May need to add new target analytes
• Simple modifications can be made
• Methods need validation