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Modeling Costs for

Produced Water Reuse Scenarios

Pei Xu, PhD

Associate Professor, Environmental Engineering

New Mexico State University

New Mexico Produced Water Conference

November 15-16, 2018

Environmental Lab of Innovative Technologies

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➢ Develop an i-DST capable of selecting produced water treatment options

based on the composition of produced water and intended beneficial use with

consideration of multiple factors, criteria, constraints and functions

➢ Identify cost-efficient and environmentally sound strategies for management

and treatment of flowback and produced water

• Reuse versus disposal options

Produced water

WaterReuse

Integrated Decision Support Tool (i-DST) for

Management of Flowback and Produced Water

Characterization, Treatment and Beneficial Use

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➢ Integrated Decision Support Tool (i-DST)

➢ Treatment Technologies

➢ Water Quality Database

➢ Approach for Treatment Selection

➢ Case study – Permian Basin

➢ Summary

Outline

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Produced Water Treatment Technologies

➢ Requirements

➢ High rejection of contaminants: meet reuse requirements

➢ Low demand on energy and chemicals

➢ Minimize waste disposal

➢ Robustness and low-maintenance: reduce labor and supervision

requirement

➢ Flexibility: able to handle high variation in water quality and

quantity

➢ Modular:

► small footprint

► minimal environmental disturbance

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Treatment Technology Assessment

A total of 62 technologies were reviewed- included in DST

An Integrated Framework for Treatment and

Management of Produced Water

TECHNICAL ASSESSMENT OF PRODUCED WATER TREATMENT

TECHNOLOGIES

2nd EDITION

RPSEA Project 11122-53

Dr. Pei Xu, Guanyu Ma,

Dr. Zachary Stoll

New Mexico State University

Department of Civil Engineering

Las Cruces, NM 88003-8001

E-mail: pxu@nmsu.edu

Phone: 575-646-5870

Dr. Mengistu Geza, Dr. Tzahi Cath, Dr. Jörg Drewes

Colorado School of Mines

Department of Civil and Environmental Engineering

Golden, CO 80401

E-mail: mgezanis@mines.edu; tcath@mines.edu;

jdrewes@tum.de

Phone: 720-982-5359; 303-273-3402

August 2016

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Produced Water

Pre-treatment

TDS Bins (mg/L)Deep Well

Injection

Removal of:

▪TSS

▪Organics

▪Hardness

Beneficial Use

Reuse for hydraulic fracturing

(No desalination required)

Recovery of valuable products and energy

(I2, NaCl, NH4Cl, MgCl2, Na2CO3, etc.)

Reuse for other purposes

(potable use, aquifer recharge, irrigation, industrial, etc.)

< 10,000 10,000 – 40,000 40,000 – 70,000 > 70,000

Mature, less

costly,

existing

technology

- RO/NF

- ED/EDR

Mature, cost

intensive,

existing

technology

- SWRO

- BWRO

Emerging,

cost

intensive

technology

- FO

- MD

Moderate

mature,

moderate costly

technology

- MVC

- MED

Treatment/Desalination

Waste Disposal

Treatment Technologies and TDS Bins

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• Colorado- 2 basins

• New Mexico- 2 basins

• New York-2 basins

• Pennsylvania-4 basins

• Pennsylvania- Frac flow back water

• California- SaltonSea

• Texas -Hidalgo

• Nevada-Washoe

• Nevada-Steamboat

Water Quality Database by Basin

➢A water quality database has been collected, summarized and built into the

i-DST

▪ Basins (4) with Geothermal

energy sources for desalination

▪ Basins (17) with produced water

• Ohio-1 basin

• Oklahoma -3 basins

• Texas-2 basins

• Wyoming- 1 basin

➢The i-DST compares water quality from a basin to the water quality

requirements for a user selected beneficial use and selects treatment options

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➢ A very large number of permutations

➢ 62 treatment processes and 46 water quality

parameters

➢ Complexity increases with number of treatment

technologies, number of water quality

parameters, and number of treatment/system

constraints to be added

➢ Intelligent process selection

Treatment Selection Approach

➢ Multi-Objective Optimization (MOO) approaches

-Algorithms based on a non-linear optimization with defined

constraints and objective function

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Overview of the i-DST

Water Quality Module

User & Expert

RankingModule

Selects the best treatment train with respect to technical & economic criteria while meeting water quality requirements.

➢ Constituents➢ Required TE

➢ A list of criteria➢ Weights, expert

ranking

➢ Treatment train➢ Cost Estimates, Energy

demand

➢ Treatment cost➢ Energy

requirement

Economic & Energy demand Module

Treatment Selection Module

[Optimization module]

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Simplified User Interaction

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User interaction

Output viewing options

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➢ Permian Basin, New Mexico

➢ Lea County

➢ Eddy County

Case Study

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Average TDS

90,000 mg/L.

Samples with lower

TDS values (yellow

circles) show

clusters in eastern

Lea County where

there is also

relatively high water

production.

Produced Water Quality

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Combining GIS Mapping for Evaluating

Beneficial Use Feasibility - Irrigation

➢ Irrigation water TDS 1500 mg/L

➢ Eliminated wells with TDS over

40,000 mg/L

➢ 983 active oil and gas wells

included in the cluster

➢ Annual produced water

production: ~170 million bbls

➢ Average distance to irrigation

areas: 1.9 miles

➢ Treatment: three-phase separator

– settling tank - chemical softening

- media filtration - seawater RO -

solid and liquid waste disposal.

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Combining GIS Mapping for Evaluating

Feasibility – Surface Water Augmentation

➢ Pecos River TDS 5,000 mg/L

➢ Produced water TDS ~ 35,000

mg/L

➢ 759 active oil and gas wells

included in the cluster

➢ Annual produced water production:

~17 million bbls

➢ Average distance to Pecos River:

4.5 miles

➢ Treatment: three-phase separator –

settling tank - chemical softening -

media filtration - electrodialysis-

solid and liquid waste disposal.

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Combining GIS Mapping for Evaluating

Beneficial Use Feasibility - Mining

➢ Acceptable water quality is 100 g/L

TDS

➢ Average PW quality 145 g/L

➢ Average distance to mining sites:

10 miles

➢ Produce ”clean brine” with three-

phase separator - settling tank –

chemical softening/coag./floc./sed. -

media filter - waste disposal.

➢ Blending with lower TDS water

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Combining GIS Mapping for Evaluating

Beneficial Use Feasibility - Fracturing

Hydraulic Fracturing System Cross Link Gel Slickwater

pH 6.0 - 8.0 > 5

Total Suspended Solids < 0.1 mg/L

Microbes Require disinfection

Hardness (Ca+Mg) < 2,000 mg/L -

Iron < 20 mg/L -

Sulfate 200 - 1,000 mg/L -

Chloride < 40,000 mg/L -

Bicarbonate < 1,000 mg/L -

Boron < 10 mg/L -

Multivalent Ions - < 5,000 mg/L

TDS - < 40,000 mg/L

Reducing Agent < 25 mg/L -

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Combining GIS Mapping for Evaluating

Beneficial Use Feasibility - Fracturing

➢ Cross-link gel system does not require TDS concentration, but limits

hardness: three-phase separator - settling tank - chemical

coagulation/flocculation/settling - media filtration – disinfection

➢ Slickwater system requires desalination: three-phase separator - settling

tank - chemical coagulation/flocculation/settling - media filtration –

disinfection – SWRO at low recovery

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Case Study – Permian Basin

Irrigation

w/SWRO

Cross-

link Gel

Slickwater

w/ SWRO

Slickwater w/

Blending

Pecos River

Augmentation

Mining

Disposal Cost

($/day)

18,000 18,000 18,000 18,000 18,000 18,000

Unit Cost*

($/kgal)

12.81 6.33 7.07 6.33 10.62 10.82

Unit Treatment

Cost ($/bbl)*

0.54 0.27 0.30 0.27 0.45 0.45

Product Flow

(bbl/day)

9,000 18,000 9,000 18,000 9,000 18,000

Marginal

benefits

($/day)

4,158 13,213 6,327 13,215 4,986 9,820

The cost estimates are in the range of -30% to +50% for feasibility study.

• Unit costs including water treatment and distribution

• Benefits do not include the saving from use of freshwater

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➢ The i-DST provides an integrated produced water

management tool that accounts for quantifiable and non-

quantifiable criteria in the selection of treatment processes

➢ Offers additional flexibility considering factors, constraints

and objectives in selecting the final treatment trains

➢ Simulates logical treatment trains for various source water

types

➢ Provides a screening-level economic estimate for produced

water treatment and reuse

Summary and Concluding Remarks

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➢ Use of produced water for hydraulic fracturing is economically

feasible, while agricultural irrigation and instream augmentation

of Pecos River are expensive. The transportation cost to mining

is estimated high.

➢ Investments on infrastructure of water treatment, storage,

collection and distribution.

➢ Liability and users of treated water

➢ Public acceptance, water rights and regulations

➢ Environmental and social benefits should be included

➢ Innovative technologies for water quality characterization,

treatment and resources recovery, in particular for brines

➢ Renewable energy driven, low costs treatment technologies

(visit posters)

Summary and Concluding Remarks

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➢ DOE/RPSEA (Research Partnership to Secure Energy for

America)

➢ New Mexico Environmental Department

➢ Guanyu Ma at New Mexico State University

➢ Mengistu Geza, Tzahi Cath, Jorg Drewes at Colorado

School of Mines

➢ Katharine Dahm and Katie Guerra at BoR

➢ Robert Sabie, Sam Fernald, Kenneth Carroll, Jeri Sullivan-

Graham, Martha Cather

➢ Brent Van Dyke and Donnie Hill

Acknowledgement

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Thank you! (pxu@nmsu.edu)