Evaluation of Produced Water Reuse within and outside the Energy Sector

Bridget Scanlon, Qian Yang, Robert Reedy, J.P. Nicot, and Svetlana Ikonnikova

Bureau of Economic Geology, Jackson School of GeosciencesUniversity of Texas at Austin

Bureau of Economic Geology

Module 2: Produced Water Reusein Unconventional Oil and Gas Operations

Module 3: Produced Water Reuse and Research Needs Outside Oil and Gas Operations

950

440

860

300

Hydraulic Fracturing (HF)Produced Water (PW)

10,400

2,850

1,380

5801,960

2,620

Projected Totals - Billion galb)

Delaware Basin207,000 wells

Bakken 68,700 wells

Midland Basin113,000 wells

Eagle Ford105,000 wells

Marcellus 124,000 wells

• PW from oil reservoirs >> than that from gas reservoirsPermian PW = 50× Marcellus PW • Reuse PW for HF • Projected PW volumes = ~ 4×HF water demand in the Delaware

YES

Highlights• Irrigation demand exceeds produced water

(PW) volumes by 5× in the U.S.• PW volumes would not substantially

alleviate overall water scarcity.

• PW quality is variable with salinity up to 7 that of seawater.• Intensive treatment is required for PW use outside of energy.• Knowledge gaps related to PW quality preclude reuse outside of energy.

U.S. ~20% of global total production in oil and gasUnconventional production: 60% of U.S. oil and 70% of U.S. natural gas

0.0

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8

2009

2010

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2015

2016

2017

2018

2019

109

L/d

106

bbl/d

Permian Bakken Eagle Ford

Niobrara Other

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0.5

1.0

1.5

0

10

20

30

40

50

60

70

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

109

m3 /

d

109

ft3 /

d

Marcellus/Utica Permian Eagle FordHaynesville Barnett Fayetteville

Scanlon et al., ES&T, 2020

Oil plays insemiarid regions

Gas plays inhumid regions

Scanlon et al., ES&T, 2020

Basic Questions

1. What is the potential for reusing produced water within and outside the energy sector based on historical data?

2. What is the potential for reusing produced water within and outside the energy sector based on projections?

Data Types• Geology, hydrology• Reservoir data• Well completions• Production

Historical Trends • HF water • Produced water

Future Projections• Play lifetime HF, PW• 2018-2050 Outlook

Impacts• Water scarcity• GW depletion• PW management

Mitigation PW reuse for HF

Work Flow

Scanlon et al., ES&T, 2020

130

24

49

Hydraulic Fracturing

110

34

30

Barnett

2009-2017 Billion gallons1 billion gal = 3.785 billion liters

Bakken

Eagle Ford

Permian

Oklahoma Fayetteville

Haynesville

64

Niobrara28

Marcellus-Utica

96

Scanlon et al., ES&T, 2020

HF water demandin the Permian is ~ 20% of water usein the play (excludingmining) in 2017.

Salado

Castille

Ellenburger

Wolfcamp

SaladoDockum

San Andres

Ellenburger

UnconventionalDelaware

Basin

UnconventionalMidlandBasin

ConventionalCentral Basin

Platform

Permian Basin

PWEORI

HFOilPW

SWD

OilOil

PW

SWD SWDHF

ConventionalCentral Basin Platform

UnconventionalMidland Basin

UnconventionalDelaware Basin

Conventional reservoirBig recycle loop 11

Permian basin

-

50

100

150

200

250

0

10

20

30

40

50

60

70

2009 2011 2013 2015 2017To

tal H

F w

ater

use

(109

L/yr

)

Tota

l HF

wat

er u

se (1

09ga

l/yr)

Total Water Use for Hydraulic Fracturing by Play

HF water use increased by ~ 10× in Permian Basin (2011 – 2017)

Scanlon et al., ES&T, 2020

Total Lateral Length Drilled= 4 x Earth’s circumference

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30

2009 2011 2013 2015 2017

Tota

l lat

eral

leng

th (1

06m

)

Tota

l lat

eral

leng

th (1

06ft

)

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10

20

30

40

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

2009 2011 2013 2015 2017

HF w

ater

use

(m3 /

m)

HF w

ater

use

(100

0 ga

l/ft)

HF water use/foot of lateral

Lateral length drilled peaked in 2017 in Permianand 2014 in many other plays

HF water use/length of lateral in Permian increased by 4× 2011 – 2017; ~300%

Scanlon et al., ES&T, 2020

Water Use for Hydraulic Fracturing as a % of Total Water Use in the Play

HF water use (maximum annual): 3% to 22% of total non-mining water use (TWU; USGS 2015).HF water use in the Permian = 20% of water use in the play.

0 10 20 30 40 50 60

Permian

Eagle Ford

Bakken

Niobrara

Marcellus

Barnett

Haynesville

Fayetteville

HF WU (109 gal) or % of TWU

HF WU as % of TWUHF WU

Scanlon et al., ES&T, 2020

Number of Water Wells Drilled to Supply Water for Hydraulic Fracturing

0

250

500

750

1000

1250

1500

1750

2009 2010 2011 2012 2013 2014 2015 2016 2017

No.

wat

er su

pply

wel

ls fo

r HF

Permian Eagle Ford Haynesville Barnett

Total: 8,500 wells in the Permian; 2,500 wells in the Eagle FordScanlon et al., ES&T, 2020

180

75

Produced WaterSalt water disposal

61

16

Barnett 74

Produced Water2009-2017 billion gallons

Bakken

Eagle Ford

Permian

OklahomaFayetteville

Haynesville

480

Niobrara 5.4

Marcellus-Utica

9.4

Produced water from oil playsgenerally much higher than that from gas plays

PW in the Permian in 2017 = 50×PW in the Marcellus

Scanlon et al., ES&T, 2020

-

50

100

150

200

250

0

10

20

30

40

50

60

70

2009 2011 2013 2015 2017

Tota

l PW

(BL/

yr)

Tota

l PW

(Bga

l/yr)

Produced Water Volume in Plays

Oklahoma

PW volume ↑ 30 times in Permian Basin (2011 – 2017)Oil plays produce much more water than gas plays

0102030405060708090

100

1 3 5 7 9 11 13 15

Decl

ine

rela

tive

to 1

stye

ar

Years of production

Bakken 3.5

Eagle Ford 2.3

Midland 3.0

Delaware 3.9

Marcellus 3.9

Decline Curves for Produced Water

Need to keep drilling wells to maintain production Scanlon et al., ES&T, 2020

Produced water is mostly managed using Saltwater Disposal Wells

740 wells

1,750 wells

336 wells

250 wells

Bakken

Permian

Eagle Ford

Marcellus/Utica

Haynesville

11 wells in Pennsylvania

Scanlon et al., ES&T, 2020

Bakken

OK

Permian

Eagle Ford

Haynesville

Fayetteville

Barnett

Marcellus/Utica

Induced seismicity highest in Oklahoma attributed to deeper disposal and larger volumes relative to Bakken, Permian, and Eagle Ford

UT-BEG

TexNet/CISR

Center for IntegratedSeismic Research

Recent study:EQs related to HF in Delaware Basin

Lomax & Savvaidis, 2019

Earthquake Events ≥ Magnitude 2 (monthly data; USGS Source)

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25

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018

Num

ber o

f Eve

nts i

n O

K

Num

ber o

f Eve

nts

Permian Eagle Ford Barnett Fayetteville Oklahoma

Seismicity increasing in the Permian and Eagle Ford plays

22

Main Findings:

High levels of seismicity in Oklahoma related to deep disposal of wastewater near the crystalline basement

Much lower levels of seismicity in the Bakken, Eagle Ford and Permian Basin plays related to shallow disposal of wastewater.

Depth of Water Disposal Affects Seismicity

Scanlon et al., Seism. Res. Lett., 2019

Shallow disposal Deep disposalCould impact overlying aquifer Little or no impact on aquifers

Impact oil well drilling (over-pressuring, extra casing)

Little or no direct impact on oil well drilling

Can impact oil production Little direct impact on oil production

Less seismicity More seismicity

Under-pressured, high injectivity

Inexpensive, drill many Expensive, few wells, high rates

Reducing Tradeoffs Between Shallow and Deep Disposal

Scanlon et al., Seism. Res. Lett., 2019

137 177

24

7549

HFPWSWD

112 61

34

30 16

Barnett 74

2009-2017 Billion gals

Bakken

Eagle Ford

Permian

Oklahoma Fayetteville

Haynesville

48064

Niobrara2165.4

Marcellus-Utica

70 12

Potential for Reusing Produced Waterfor Hydraulic Fracturing

SWD= 8 × HF water use in OK

X

Temporal Variations in PW to HF Ratios by Play

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2009

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2017

Eagle Ford Bakken Marcellus-Utica Midland Delaware Oklahoma

Volu

me

(109

L/yr

)

Volu

me

(109

gal/y

r)

HF water useProduced water

PW>>HFPW = 2 HF 2016

HF > PWHF >> PWPW ↑ relto HF

HF > PW

Scanlon et al., ES&T, 2020

Options for Managing Produced Water

24

43

24Hydraulic Fracturing (2017)Produced Water (2017)

Irrigation (2015)

18 9

0.03

Barnett11

Billion galMarcellus

Eagle Ford

Raton

Fayetteville

Haynesville

7

Black Warrior

310

PowderRiver

7

148

Bakken198

9

58

0.61.0 0.7

7 1.41.0

Oklahoma AOI

2952

Delaware

187

Niobrara

1.8230

7

1.3 4.5

Uinta600.5

San Juan

1.5226

32

26

35

Midland

272.1

Irrigation = 5 x PW (UOG)Irrigation = 50 x PW (CBM)

Permian Basin: Water Use relative to Other Sectors

0.01

0.1

1

10

100An

drew

s

Cran

e

Croc

kett

Culb

erso

n

Ecto

r

Eddy

Gla

ssco

ck

How

ard

Irion Le

a

Lovi

ng

Mar

tin

Mid

land

Peco

s

Reag

an

Reev

es

Upt

on

War

d

Win

kler

Volu

me

(109

gal/y

r)

2017 PW 2017 SWD 2017 HF Irrigation Public Supply Livestock Industrial RC Cooling

Permian (19 county area)

Produced Water Quality: Total Dissolved Solids

USGS Produced Waters DatabaseLiterature

Produced Water Quality

WolfcampResevoir

~200 points

Wolfcamp Prod. Water TDS (g/L)

25

50

Industrial Uses

Clean Brine for

HF

>125

100

75

Agricultural Uses

Groundwater recharge, potable

uses

Separation of oil, grease, suspended

solids

• Hydrocyclone

• Gas flotation

• Oil/Water separator

• Settling tank• Media

filtration (sand, walnut shell, etc)

• Cartridge filtration

• Membrane filtration

Desalination -Removal of dissolved

solids

ED

Post-treatment and restabilization (e.g.,

B)

• Biological treatment

• Electrocoag. & flotation

• Adsorption (carbon, zeolite, etc)

• Chemical oxidation

• Disinfection (ClO2, UV, etc)

Removal of target constituents (e.g., organics, Fe, Ba, Ca, Mg, Sr, SiO2, SO4, microbes)

BWRO

SWRO

MVR

MVC

MED

Emerging

FO

MD

• Ion Exchange• AOP• pH adjust.&

remineral.• Disinfection (Cl2,

UV)

PW treatment costs increase with higher salinity in PW and product water quality improvement

Appl

icab

le T

DS

rang

e (g

/L)

NF

Basic Questions

1. What is the potential for reusing produced water for hydraulic fracturing based on historical data?

2. What is the potential for reusing produced water for hydraulic fracturing based on projections?

Projections of water demand for HF and produced waterProjections based on Technically Recoverable Resource Development: all potential future wells could be drilled using current technology over the life of the plays.

Plays: Permian Delaware (Wolfcamp [WC] A & B), Permian Midland (WC A & B), Eagle Ford, Bakken, and Marcellus. Scale: 1 square mile.

Remaining Drillable volume of reservoirs

Volume required per future well

Total drillable length/well inventory

Historical and Projected Drilling Density at grid scale

Scanlon et al., ES&T, 2020

Bakken 68,700 wells

Eagle Ford 105,000 wells

440

860

Hydraulic Fracturing

Midland Basin 113,000 wells

1,900

Delaware Basin207,000 wells

Projected Totals – Bgal

2,800

Marcellus 124,000 wells

1,400

Permian: = 4,700 Bgal= ~14 maf

= TX total water use in 2017

Projections based on Technically Recoverable Resource development

Scanlon et al., ES&T, 2020

Bakken 69,000 wells

950

300

10,400

Produced Water

2,620

Projected Totals – Billion gal

Marcellus 124,000 wells

580

Eagle Ford 105,000 wells

Delaware Basin192,000 wells

Midland Basin 106,000 wells

Projections based on Technically Recoverable Resource development

Permian Basin: PW, 40 maf= 3× TX total water use in 2017 Scanlon et al., ES&T, 2020

Projected Produced Water at Grid Scale

Scanlon et al., ES&T, 2020

Ratio of Produced Water to Hydraulic Fracturing Water Demand

Scanlon et al., ES&T, 2020

Bakken 69,000 wells

950

300

10,400

Hydraulic Fracturing

Produced Water

2,620

Projected Totals – Bgal

Marcellus 124,000 wells

580

Eagle Ford 105,000 wells

Midland Basin 113,000 wells

Delaware Basin207,000 wells

Can we reuse PW for HF?

Scanlon et al., ES&T, 2020

Bakken 69,000 wells

950

860

300

10,400

Hydraulic Fracturing

Produced Water

2,620

Projected Totals – Bgal

2,850

Marcellus 124,000 wells

1,380

580

440

1,960

Eagle Ford 105,000 wells

Midland Basin 113,000 wells

Delaware Basin207,000 wells

Can we reuse PW for HF?

Scanlon et al., ES&T, 2020

Proposed Water Consortium at the Univ. TX Bureau of Economic Geology

Meeting HoustonFeb. 27 2020

Main Findings

Produced Water Management• Oil plays produce much more water than gas plays (Permian PW = 50 ×

Marcellus PW in 2017)• Potential issues with PW management (e.g. induced seismicity, disposal

capacity)Management strategies• Reusing PW for HF of new wells should mitigate water issues in most plays,

except Oklahoma or Delaware Basin where PW volume>>HF water demand• Beneficial reuse in other water sectors, problems with water quality, economics,

and regulations

Project Sponsors:

Bridget.Scanlon@beg.utexas.eduContact: Bridget Scanlon