DETERMINING THE MINIMUM 

TREATMENT LEVELS REQUIRED FOR 

PRODUCTION EFFICIENCY: STATING 

THE LOWEST ACCEPTABLE WATER 

QUALITY LEVELS FOR EFFECTIVE 

REUSE IN FRACS

NOVEMBER 19TH 2014
 Operational Logistics

 Field Specific 

Parameters

 Produced Water Quality

 Treatment Trials

 Path Forward

A JOURNEY IN WATER RECYCLE
 Economy of Scale

 Available non-fresh water

 Transportation logistics

 Processing capacity

 Effective treatment 

WATER REUSE: KEYS TO SUCCESS
 Completions: Active 

frac program w/ 85K 

– 185K Bbls/well 

 Availability: ~15K 

Bbls/day

 Logistics: Move from 

trucking to pipeline

 Processing: 240,000 

Bbls 

 Treatment: 250 - 400 

gpm

 Reused ~ 1.9 Million 

Bbls to date 

WHEELER COUNTY WATER LOGISTICS
Basic Frac Water Criterion:

1) Water must be compatible with completion 

fluid design.

2) Water must not be damaging to well production 

(IP & EUR).

WATER QUALITY AND TREATMENT

5
 Simple Treatment Design:

 Iron and Iron Sulfide

 Suspended Solids

 Bacteria

 Mitigate Scale Potential

WHEELER CO PRODUCED WATER CHEMISTRY

PW Component 

(PPM)

Average Rough Guideline for 

Upper Limit:

PH 7.2 Between 6-9

Calcium 800 2,000

Bacteria: APB & SRB >106 102

Chloride 15,000 120,000

Alkalinity 723 800

Barium and Sulfates 4 25

Ferrous Iron 1 10

Total Iron 18 25

Boron 17 20 for XL; NA for SW

TSS 245 100
Batch Treatment in Processing Tanks: 

 Treat 20K – 30K bbls at a time in a tank

 Various treatment options utilized

 Waste generation skimmed off, or settled to bottom

 Relatively low cost, $0.15-$0.40/bbl 

 Operationally challenging with mixed results

LEARNING WHILE IN MOTION
Utilizing automation to generate Chlorine Dioxide for 

produced water treatment:

 99.999% Reduction in Bacteria 

 88% Reduction in Oil and Grease 

 70% Reduction in Iron 

 55% reduction in Suspended Solids

UPFRONT WATER TREATMENT

CLO2, WEIR TANKS, FILTERS
UPFRONT WATER TREATMENT

CLO2, WEIR TANKS, FILTERS
Centrifuge trialed both before and after ClO2:

 40% Reduction in TSS 

 Oil/Water emulsions impact performance

 Will not remove particles <6 microns

UPFRONT WATER TREATMENT

CLO2, WEIR TANKS, CENTRIFUGE
UPFRONT WATER TREATMENT

CLO2, WEIR TANKS, CENTRIFUGE
Utilizing ClO2 and chemical precipitation through a clarifier:

 99.999% Reduction in Bacteria 

 99% Reduction in Oil and Grease 

 99% Reduction in Iron 

 92% reduction in Suspended Solids

UPFRONT WATER TREATMENT

CLO2, WEIR TANKS, CHEMICAL PRECIPITATION
UPFRONT WATER TREATMENT

CLO2, WEIR TANKS, CHEMICAL PRECIPITATION

 Is the additional 

expense providing 

value? 

 How do we measure 

water treatment 

value?
RESULTS AND COST:

PW Component 

(PPM)

Average Weir Output: Centrifuge 

Output:

Clarifier 

Output:

PH 7.2 6.6 – 7.0 6.6 – 7.0 7.1 – 8.1

Calcium 800 700 – 1000 700 – 1000 400 – 475

Bacteria: APB & 

SRB

>106 100 100 100

Chloride 15,000 14,000 – 17,000 14,000 – 17,000 14,000 -17,000

Alkalinity 723 400 - 700 400 - 700 400 – 475

Barium and 

Sulfates

4 3-4 3-4 3-4

Ferrous Iron 1 ND ND ND

Total Iron 18 3-5 3-5 ND

Boron 17 16 -21 16 -21 16-21

TSS 245 43 - 141 30 - 90 16 - 40

Cost: $0.20 – $1.00 $0.25 – $1.25 $0.75 – $1.75
WATER TREATMENT OPTIMIZATION:

WHAT TREATMENT IS NECESSARY?

 Production comparisons are difficult due to large 

number of variables in well production:

 Water treatment technique

 Formation

 Percentage of PW used

 Completion design

 IP’s on FW and PW wells appear similar

 More data, and controlled comparisons are needed to 

draw trending conclusions on impact of production 

from PW reuse.
IMPACT TO THE FRAC: SLICKWATER VS. GELS

16

Raw Water:

Unusable

After ClO2:

Stable FR

After Clarifier:

Stable Gel

0

50

100

150

200

250

Untreated Weir Clarifier Tap

Viscosity (cP)

Crosslinked Viscosity, pH 8-9 @ 300 rpm

0.5 hr 4.5 hr

0

20

40

60

80

100

0 1 2 3 4 5 6

% FR

Time (min)

ClO2 & Clarified Water + 0.5 gpt FR

ClO2

Clarifier

Tap Water
 Batch treatment, ClO2 and 

Clarification all created a water 

quality sufficient for 

slickwater/linear jobs. 

 Friction reduction and gel 

hydration increased with water 

quality.

 Calcium hydroxide precipitate at 

high PH (pictured) in some 

water. Borate XL jobs require 

further water treatment.

 Treated water was compatible 

with low PH and cellulose type 

XL fluid systems.

WHEELER COUNTY WATER LOGISTICS
 Bacteria Growth in storage tanks is 

challenging in warm months. 

 Water treated to a higher standard 

(Clarifier) retained lower bacterial 

counts (less smell, higher 

transmittance) for weeks.

 Holding processing tanks in a biostatic environment for weeks in 

the summer is cost prohibitive

 Treat bacteria for the frac, with an 

on the fly system providing an 

economic high log kill

 Understand and test bacteria kill 

system design. Optimize for cost.

TREATMENT OBSERVATIONS

Inlet Untreated

Treated
Analysis of a 2-8 well completion program showed 3X-5X 

cost increase for re-use water compared to fresh water

MOBILE TREATMENT OPTIONS:

WATER REUSE FOR SMALL SCALE OPERATIONS:

Water 

Treatment

Tank in 

Tank 

Storage
 The technology is 

available to reuse water.

 Logistical challenges can 

be met. 

 Economics ultimately 

trump: Low cost 

acquisition/disposal of 

water create financial 

barriers to reuse.

 Logistics, disposal, 

incentives, regulations 

and supply constraints 

will together shape the 

future of water reuse in 

an economic manner.

WATER RE-USE

WHERE DO WE GO FROM HERE?