# Project to Develop Flowback Water Reuse Guidelines for Hydraulic Fracturing Operations
Keith Minnich Talisman Energy, Inc. 20 March 2012

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# Canadian Association of Petroleum Producers (CAPP) Guiding Principles for Hydraulic Fracturing 8 September 2011 News Release



## This presentation will focus on a project which supports the reuse of hydraulic fracturing fluid flowback and finishes with a case study.

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# Recycling of Flowback has Multiple Cost and Environmental Benefits

• Reduces demand for fresh water

• Reduces produced water disposal

• Reduces truck traffic related to water movement

• 50% flowback on a 20,000 m 3 

# frac would require ~ 300 truck trips for disposal



# • Ideally reduces overall production costs – multiple economies (disposal, trucking, water savings)

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# Reuse is not Limited by Water Treatment Technology

Water treatment technology can deliver treated produced water:

• Free of suspended solids

• Free of organics

• Free of color

• Free of dissolved salt
.......but not free of cost. 

# Is this quality really needed for reusing flowback ?

Rigzone, Monday, 16 August 2010

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# Experience has Shown that Near-Fresh-Quality Water is Not Always a Requirement for Fracturing

• Options exist for saline-tolerant chemical additives

• Reports of fracturing with > 75,000 ppm Total Dissolved Solids Water

Friction Reducer Source: Schlumberger Water Services 

## Good enough for fracturing in some cases

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# Benefits to Industry from a Reuse Guidance Tool

Operators, Service Providers, Water Treatment Providers would all benefit from an objective methodology to answer the questions:

• What water specification is required for the hydraulic fracture fluid?

• What are the options to condition the water to meet that specification?

• Chemical additives

• Physical/chemical water treatment processes

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# A CAPP Project was Initiated in 2011 to Provide a Methodology for Reusing Flowback

• Conducted by Schlumberger/MI SWACO with Alberta and British Columbia funding

• Peer Reviewed:

• Alberta Innovates Technology Futures

• British Columbia Oil and Gas Commission

• British Columbia Science and Community Environmental Knowledge Fund

• Industry



# • All results available to the public in early 2012

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# Hydraulic Fracture Fluid Reuse Manual

• Three Volumes and Decision Tree Poster

• Volume I – Introduction to Hydraulic Fracturing and Background Information for Reuse

• Volume II - Reuse Guidance Manual and Decision Tree

• Part 1 – Source and Flowback Fluid Blend Compatibility

• Part 2 – Formation and Blend Fluid Compatibility and Fracture Fluid Selection

• Part 3 - Flowback Handling



# • Volume III – Case Studies

• Montney, Horn River, and Cardium

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# Why this Guidance Document is a Step Forward

A structured decision process, in the form of a Decision Tree and Manual, which includes the following:

• Guidance for use of field data and scale saturation index prediction software for blended fresh, flowback, and formation water

• Options for addressing specific water quality issues

• Sensitivity of the hydraulic fracture fluids to various constituents

• A concept for evaluation of the impact of additives in flowback on the new hydraulic fluid.

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# Fresh, Flowback, and Formation Fluid Compatibility

• Requires sequential analysis of flowback from:

• Fresh only hydraulic fracture treatments

• Blend of fresh and reused flowback hydraulic fracture treatments



# • Traditional tools used to evaluate compatibility include:

• Scale saturation index software

• Mixing tests to identify precipitation

• Scale loop testing (e.g. PMAC System for evaluation of scaling tendency and inhibitor performance)

• Geochemical modelling

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# Options for Water Conditioning

Table A is based on water conditioning by chemical addition

Table B is based on water conditioning by physical/ chemical treatment

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# Fracture Fluid Sensitivity Tables

• Five different types of hydraulic fracture fluids

• Important water quality parameters are identified

• Allowable range for each parameter is listed

• Potential problems when parameters are outside of range are listed

• Remedial options are presented

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# The Concentration of Additives through Reuse

R e u s e d F l o w b a c k
F r e s h 2 0 , 0 0 0 m ^ 3 , F r e s h 0 m ^ 3 , F l o w b a c k W e l l 1 1 0 , 0 0 0 m ^ 3 , F l o w b a c k A

d d i t i v e 6 , 0 0 0 l i t e rs , A d d i t i v e 3 , 0 0 0 l i t e rs , A d d i t i v e l i t

e rs / m ^ 3 0

. 3 1 0 , 0 0 0 m ^ 3 , F r e s h 1 0 , 0 0 0 m ^ 3 , F l o w b a c k W e l l 2 1 0 , 0 0 0 m ^ 3 , F l o w b a c k 9 , 0 0 0 l i t e rs , A d d i t i v e 4 , 5 0 0 l i t e rs , A d d i t i v e
H F F l u i d 1 0 , 0 0 0 m ^ 3 , F r e s h H F = H y d r a u l i c F r a c t u r e F l u i d 1 0 , 0 0 0 m ^ 3 , F l o w b a c k W e l l 3 1 0 , 0 0 0 m ^ 3 , F l o w b a c k H F 2 0 , 0 0 0 m ^ 3 H F p e r w e l l 1 0 , 5 0 0 l i t e r

s , A d d i t i v e 5 , 2 5 0 l i t e r s , A d d i t i v e r 5 0 % F l o w b a c k R e c o v e r y ( o r R e u s e ) , % F B = H F x r m ^ 3 , F l o w b a c k 1 0 , 0 0 0 m ^ 3 , F r e s h F = H F

- F B m ^ 3 , F r e s h 1 0 , 0 0 0 m ^ 3 , F l o w b a c k W e l l 4 1 0 , 0 0 0 m ^ 3 , F l o w b a c k

= H F x ( 1

- r ) 1 1 , 2 5 0 l i t e rs , A d d i t i v e 5 , 6 2 5 l i t e rs , A d d i t i v e D R 0

. 3 D o s i n g R a t e a s l i t e rs / ( m ^ 3 H F ) D o s e d = D R x H F l i t e rs o f A d d i t i v e d o s e d i n t o H F 1 0 , 0 0 0 m ^ 3 , F r e s h 1 0 , 0 0 0 m ^ 3 , F l o w b a c k W e l l 5 1 0 , 0 0 0 m ^ 3 , F l o w b a c k C y c l e d u p c o n c e n t r a t i o n o f A d d i t i v e 1 1 , 6 2 5 l i t e rs , A d d i t i v e 5 , 8 1 3 l i t e rs , A d d i t i v e i s a c o m b i n a t i o n o f R e u s e d a n d D o s e d A d d i t i v e



## 1 (1 - % Reused Flowback in Blend) Concentration Factor does not depend on dosing rate, only on % Reuse Steady State Concentration Factor =

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# The Concentration of Additives through Reuse

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# Sensitivity to Concentration Factor as a Result of Successive Reuse

More work is required to understand the impact of reused additives. H y d r a u l i c F r a c t u r e F l u i d T y p e S u g g e s t e d C o n c e n t r a t i o n F a c t o r T h r e s h o l d R e q u i r i n g A d d i t i o n a l I n v e s t i g a t i o n A d d i t i v e o r A d d i t i v e R e s i d u a l s w h i c h c a n i m p a c t f r e s h F r a c t u r e F l u i d R e m e d i a l O p t i o n s

S l i c k w a t e r F l u i d s 2 F r i c t i o n R e d u c e r B r e a k e r L i n e a r G e l s 2 P o l y m e r B r e a k e r

F i e l d T e s t s

R e q u i r e d B o r a t e D i s p o s a l o f F l o w b a c k o r P h y s i c a l / C h e m i c a l W a t e r T r e a t m e n t f o r D i s s o l v e d S o l i d s 2 P o l y m e r B r e a k e r

F i e l d T e s t s

R e q u i r e d B u f f e r s D i s p o s a l o f F l o w b a c k o r P h y s i c a l / C h e m i c a l W a t e r T r e a t m e n t f o r D i s s o l v e d S o l i d s C r o s s L i n k F l u i d s

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# Case Study: Potential Calcite and Barite Scaling

Data from sequential flowback analysis shows presence of both dissolved sulfate and barium in formation. How should barite scaling be controlled? Should barium be removed before reuse?

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# Case Study: Potential Calcite and Barite Scaling

Software shows potential for:

• Calcite scale formation

• Barite scale formation As % of flowback in hydraulic fracture fluid increases so does the calculated scaling potential.

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# Sequential Flowback Analysis Provides Data for Evaluating Barite Management Options Investigation into the potential impact of barium in reused flowback.

Barium in reused flowback had no apparent impact on sulfate concentration in this example.

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# PMAC Scale Loop Testing Investigation into Barite and Calcite Scaling

• Cation brine

• 4000 ppm Ca +2



## • 850 - 1250 ppm Ba +2



## • 1000 ppm Sr +2



# • Anion brine

• 100 - 500 ppm SO 4 -2



## • 600 ppm HCO 3 -



# • Total TDS = 65,000 balanced with NaCl

• pH = 6.4

• Conditions = 80 0 C; 10,000, 20,000 kPa

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# PMAC Testing for Simulated Brine

100 ppm SO 4 -2 

# , 850 ppm Ba +2 

# 600 ppm CO 3 -2 

# , 4000 ppm Ca +2


# Scale formation evident after 200 minutes of run time

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# PMAC Testing for Inhibitor Selection and Dosing

Conclusion: Down hole scale formation can be managed with scale inhibitor and barium removal is not required

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# Summary

The Decision Tree and Guidance Manual provide a consistent and systematic methodology to evaluate:

• Water specifications for a particular hydraulic fracture fluid

• Water conditioning by chemical addition

• Water conditioning by physical/chemical treatment

• When to consider alternative fracture fluid additives Operators and service providers can select cost effective solutions with the least environment impact. Water treatment companies will have better insight into the needs of the industry.