# “Identifying Best Practices For 

# Decreasing Bacteria To Acceptable Levels For Reuse In Hydraulic Fracturing”

Shale Play Water Management- 2014 

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# Real Time Water Quality Testing Benefits • Bacteria Disinfection Monitoring • Test Influent/Effluent • Test Working Tanks 

## • Monitor Water Quality Changes • Make Live Adjustment When Needed • Pre-Frac Planning • Determine Water Quality Baseline • Determine Bacteria Level Baseline • Allows for Pre- Treatment Planning • Treatment Requirements • Treatment Flow rate 

## • Blend rate

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# Bacteria Testing Methods Used • Real Time Bacteria via modified ATP • Adenosine Triphosphate • Found in all living cells, used for energy transfer 

## • Most Probable Number (MPN) • Uses statistical formula to estimate bacteria counts • Bug Bottles • Estimates bacteria counts in the form of ranges
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# Bacteria Testing Preservative ? Sterilized Bottles ? 

## • Sterilized Bottles/Gloves • Required for accurate tests • Preservatives • Negates effect of residual disinfection. • Give result of bacteria at that time • Shipping and testing delay will over estimate the disinfection

Shale Play Water Management- 2014 

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# Bacteria Sampling Preservative ? Sterilized Bottles ? 

# • Sterilized Bottles/Gloves • Required for 

# accurate tests • This is NOT proper sampling for bacteria

Shale Play Water Management- 2014 

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# Bacteria Testing How do I confirm disinfection ? 

## • Influent/Effluent Testing • MPN • Bug Bottles • Residual Disinfection / Working Tanks • Working tanks are typically dirty • Good disinfection can be compromised by dirty working tanks • Monitoring working tanks is critical 

## to ensure disinfection • Flowback Monitoring • Insures good overall disinfection Shale Play Water Management- 2014 

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# Residual Testing What Methods ? 

## • Test Strips • Convenient • Inaccurate • Colorimetric • Direct Read , Color Wheel, Color Change • Can be Reliable • Accuracy can be an issue • Titrations 

## • Most Accurate • Require more time and skill • May require dilutions to avoid interference Shale Play Water Management - 2014 

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# Residual Testing Chloride Dioxide Test Methods

Shale Play Water Management- 2014 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

Direct Reading Testing Strip Color Disc DPD Method C (ppm)



### • 1.8 ppm standard solution was used for all the tests. • Four testing methods were evaluated. • Testing strip was not able to detect any chlorine dioxide at this level. • Accuracy: Colorimetry > Direct Reading > Color Disc > Testing Strip. • Repeatability: Colorimetry > Color Disc > Direct Reading > Testing Strip. 

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# Residual Testing Free Chlorine Test Methods ?

Shale Play Water Management-

2014 0 10 20 30 40 50 60 70

Colorimetry - HR Colorimetry - MR Titration Strip - Company 1 Strip - Company 2 C (ppm)

• Water sample with unknown free chlorine level was used for all the tests. • Five testing methods were evaluated. • Little agreement was observed between different testing methods. • Testing strips provided by different companies gave quite different results. • Not considering the strips, the precision: Colorimetry - MR > Colorimetry – HR > Titration. 

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# Comparisons of ClO2

# , Total Chlorine and Free Chlorine

Tests in Different % of Produced Water

• Water samples were adjusted by standard solution to approximately 25 ppm of ClO2, 12.0 ppm of total chlorine and 12.0 ppm of free chlorine. The reducers in the produced water were oxidized before the adjustment to eliminate further oxidant consumption. • Colorimetry methods were used for all three tests. • Discrepancies were observed between the test results and the actual concentrations of the three chemicals. The higher the % of produced water, the larger the discrepancy. 0 5 10 15 20 25 30

10% 30% 50% 80% 100% Actual c (ppm)
% of Produced Water ClO2 Total Chlorine Free Chlorine

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# Comparisons of ClO2 

# Test in Different % of Produced Water

• The water samples supposed to have same level of ClO2. • The reading by colorimetry method is different from the reading by testing strip. • In most of the cases, the colorimetry method has a higher reading than the testing strip method. • Huge difference was observed for the 100% produced water, as the colorimetry reading was only half of the testing strip reading. 0 5 10 15 20 25

10% 30% 50% 80% 100% c (ppm)
% of Produced Water Colorimetry Testing Strip

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# Comparisons of Total Chlorine Test in Different % of

Produced Water

• The water samples have same level of total chlorine. • Huge differences were observed for different testing methods. The three different types of strips were provided by three different companies. • When compared within the same testing method, the readings at different percent of produced water are also different. Other species or the physical properties of the produced water could have lead to the interferences for the testing. • It appears that the readings by different testing methods are with the trend of: titration > colorimetry > strip 3 > strip 1 > strip 2.

0 5 10 15 20 25

10% 30% 50% 80% 100% c (ppm)
% of Produced Water

Colorimetry Titration Strip-1 Strip-2 Strip-3

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# Comparisons of Free Chlorine Test in Different % of

Produced Water

• The water samples supposed to have same level of free chlorine. • The readings by different testing methods are different from each other. • The readings with the same testing method but at different percent of produced water are also different, which indicates the different level of interferences. • Generally, the readings by different testing methods are with the trend of: titration > colorimetry > strip 1 > strip 2.

0 2 4 6 8 10 12 14 16 18

10% 30% 50% 80% 100% c (ppm)
% of Produced Water

Colorimetry Titration Strip - 1 Strip - 2

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# Bacteria Testing Where do I Sample ? 

## • Influent/Effluent of Treatment System • MPN • ATP • Continuous Testing • Residual Disinfection / Working Tanks • ATP • Continuous Testing 

## • Source Water • ATP • MPN • Baseline Testing Influent & Effluent Source Water Testing Working Tank Monitoring

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# MPN Testing: Frac Fluid Treatment in W. Texas Slide 1 of 2 

## • Permian Basin • Frac Fluid Treatment • Multi-stage slickwater frac • Rig up: treating 80/20 fresh water flowback mixture at 80 bpm

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# MPN Testing: Frac Fluid Treatment in W. Texas Slide 2 of 2

0

50,000 100,000 150,000 200,000 250,000 300,000

3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 # of Cells Per Milliliter



### Stage Number Bacteria Treatment Results Influent Effluent 

# 99.98% REDUCTION Shale Play Water Management - 2014 

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# Real Time Testing: Residual Disinfection Residual Disinfection - Free Chlorine and ATP

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

0 100 200 300 400 500 600

0 1 2 3 4 5 6 7 8 Free Chlorine, mg/L ATP, pg/mL

Time after treatment, hr ATP, pg/mL Free Chlorine

Tests were conducted at Bold Johnson 56-T1-34 #1H

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# MPN Testing: Residual Disinfection Residual Disinfection– Flowback Testing

BRL: Below Reporting Limits A: Permian– Pecos, TX; B&C: Permian– Midland, TX; D: Permian– Barnhart, TX; E&F: Marcellus– WV BRL BRL BRL BRL BRL 23 46 BRL 4

4 4 2400 46000 1100 2400 150 2400

BRL BRL BRL BRL BRL 9 BRL BRL BRL BRL BRL 2400 24000 1100 150 4 43

1 10 100 1000 10000 100000 E-Flowback D-Flowback C-Flowback B-Flowback A-Flowback F-Treated E-Treated D-Treated C-Treated B-Treated A-Treated F-Untreated E-Untreated D-Untreated C-Untreated B-Untreated A-Untreated

MPN/ml SRB APB

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# Residual Disinfection: Working Tank Monitoring Residual Disinfection - Free Chlorine and ATP

0 100 200 300 400 500 600 700

0 2 4 6 8 10 12 14 ATP, pg/ml

Time after Samples Were Taken, hr ATP Levels in the Treated Water Working Tanks Clean Buckets

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# Working Tank Monitoring Biocide vs. Hydrozonix

1452 1932 1822 5147 2996 1466 1529 436 158 0 1000 2000 3000 4000 5000 6000

Water Delivered Day 1 Day 2 Day 3 Biocide -15 min Biocide - 2 hr Biocide - 24 hr Hydrozonix-Day1 Hydrozonix-Day2 ATP, pg/ml ATP Level in the Working Tanks

 Untreated impaired was delivered to the working tanks, the initial ATP level was around 1,452 pg/ml.  Bacteria level increased as the water was stagnant in the tanks, after 3 days, the ATP level went up to 5,147 pg/ml.  0.5 gpt of biocide was dosed into the working tanks, this brought the ATP level down to 2,996 pg/ml 15 min after the dosing.  The ATP level stabilized to be around 1,500 pg/ml 24 hr after the dosing, which indicated that the bacteria level in the biocide treated water was still high.  After treated water form Hydrozonix treatment system sent to the working tank for one stage, the ATP level went down to 436 pg/ml. This was further reduced to be at 158 pg/ml after the treatment had continued for another day. Shale Play Water Management- 2014 

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# Working Tank Monitoring Chlorine Dioxide vs. Hydrozonix

0 100 200 300 400 500 600

HZO Chlorine Dioxide pg/ml
Treatment Technology

HZO vs. ClO2

Untreated Treated Tanks (2 days) 

## • 30% blend of produced water and fresh • Both treatment systems used side by side • Baseline untreated at 508 pg/ml ATP • Working tanks sampled after two days to determine overall disinfection and residual disinfection
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# Disinfection vs. Compatibility Disinfection Compatibility Oxidant Oxidation



## Potential, V Hydroxyl Radicals 2.8 Ozone 2.3 Hydrogen Peroxide 1.8 Chlorine Dioxide 1.5 Chlorine 1.4 Shale Play Water Management- 2014 

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# Disinfection vs. Compatibility Slickwater: HZO vs. Biocide vs. Chlorine Dioxide

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040

2012/10/18 2012/12/7 2013/1/26 2013/3/17 2013/5/6 2013/6/25 2013/8/14 2013/10/3 2013/11/22 Friction Reducer Concentration, % in mass

Fracturing Date

Hydrozonix Biocide ClO2

Water Treatment Technology # of Wells FR Concentration, % in mass

Biocide 22 0.0123 ClO2 9 0.0146 Hydrozonix 27 0.0042 Shale Play Water Management-

2014 23Flash Reactor
Mixing Vane 

## Venturi Reactor

Effluent Static Mixers

Static Mixers
1 2

3
4
5 

# 5 Points 

# of Mixing Shale Play Water Management - 2014 

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# www.hydrozonix.com 

# Questions ?

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