Underground Injection 

Wells For Produced 

Water Disposal

Rick McCurdy

Sr. Engineering Advisor 

Chemicals and Water Reclamation

Chesapeake Energy Corporation

6100 N. Western Avenue ı Oklahoma City, OK 76118 ı 405-935-8000

AskChesapeake@chk.com ı chk.com ı NYSE: CHK
3

Agenda

History 

Program Oversight

Well Classifications

Class II Wells

Reclamation / Disposal 

Combinations

Summary
4

History

1930s

Oilfield brine disposal (Texas)

EOR Injection

1940s

Oil refineries inject wastes

1950s

Deep well injection of chemical wastes

State regulations for brine disposal

1960s

Earthquake attributed to deep well injection in Colorado

1

st documented cases of contamination in potential sources 

of drinking water
5

History

1970s

Waste spilling from an abandoned oil well traced to paper 

mill injection well

SDWA gives EPA authority to control underground injection

1980s

UIC regulations

― 5 well classes

― Layout requirements for States to assume primacy

SDWA amended to allow for existing oil and gas programs to 

regulate

― Must be effective in protecting USDW

― Must include UIC program components

HSWA to RCRA

― Hazardous waste injection more stringent

― “No migration petition” – 10,000 years or rendered nonhazardous by reaction with surroundings
6

History

1990s

Class V management strategy

1

st International symposium on deep well injection (CA)

2000 to present

Energy Policy Act (2005) excludes hydraulic fracturing from 

regulation under UIC program

EPA initiates Study to Evaluate Impacts to USDW’s by HF of 

CBM reservoirs

Geologic sequestration of carbon dioxide (CO2)
7

Program Oversight

Primary Enforcement (Primacy)

States / tribes may request if they can 

demonstrate ability to meet minimum EPA 

requirements

Some states / tribes share primacy with EPA

Where neither of the above apply, EPA enforces UIC 

program through Region offices
8

Primacy
9

Well Classifications

Class I

Hazardous waste, non-hazardous liquids, municipal wastes

Inject under lowermost USDW

Class II

Class III

Extraction of minerals

― Salt, uranium, sulfur

Class IV

Banned (originally for hazardous or radioactive waste 

disposal into or above a USDW)

Currently limited to authorized clean-up sites

Class V

All other wells

Inject non-hazardous liquids into or above a USDW

Class VI

Geologic sequestration of carbon dioxide (CO2)
10

Agenda

History 

Program Oversight

Well Classifications

Class II Wells

Reclamation / Disposal 

Combinations

Summary
11

Class II Wells

Approximately 144,000 wells in the U.S.

Majority in TX, CA, KS and OK

CA, 26305

IL, 7944

KS, 16245

NM, 4699

OK, 11365

TX, 49957

WY, 4723

Others, 

19204
12

Class II Wells

~144,000 Class II Wells

Enhanced Oil Recovery

~80% of all Class II wells

Water injection wells (WIW) most common, but also includes

― Steam injection

― Water - alternating - gas (WAG)

― Simultaneous water and gas (SWAG)

― CO2injection

Salt Water Disposal

~20% of all Class II wells

Used only for disposal of fluids associated with oil and gas 

production

Hydrocarbon Storage

Used to inject and remove liquid hydrocarbons from 

underground storage (i.e. salt caverns)

Strategic Petroleum Reserve

More than 100 wells in the U.S. (<0.1% of Class II)
13

Agenda

History 

Program Oversight

Well Classifications

Class II Wells

Salt Water Disposal Wells

― Selection

― Well Construction

― Volume / Pressure

― Integrity Assurance

― Economics

― Pennsylvania / Texas Comparison

Reclamation / Disposal Combinations

Summary
14

Salt Water Disposal Wells

Selection

Non-hydrocarbon bearing formation or an 

unproductive / depleted formation

Barriers to USDWs

Area Review

Porosity

Permeability

Location, location, location!
15

Chesapeake Barnett SWD Construction

Texas Railroad Commission

Monitoring & Testing

*Areas in which Chesapeake exceeds Railroad Commission of Texas standards

(5) Packer

(1) Surface Casing

(6) Steel tubing

(2) Surface Casing Cement

(3) Production Casing

(4) Production Casing Cement

(7) Plastic coating

Drilling and Completion

• Casing*

• Cement*

• Tubing*

• Packer

Testing Prior to Service

• Cement Bond Log

• Pressure Testing

Operations

• Continuous Monitoring*

• Annual Integrity Testing*

Reporting

• Prior to Placing in Service

• Monthly

• Injection Date

• Pressure

• Volume
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Volume and Pressure

Step rate tests utilized to confirm the rate and 

pressure required to “break down” or fracture the 

targeted formation

Fracture gradient established based on step rate 

tests and instantaneous shut-in pressure (ISIP)

Wells are typically permitted for a pressure and 

rate that does not exceed the frac gradient when 

pumping the typical brine for a known area
17

Wellbore Integrity

Prior to service

Cement bond / cement evaluation logs

Pressure test casing

During operation

UIC minimum requirements

― Mechanical integrity test – every 5 years

― Monitor pressure – annually

Many States have more stringent 

requirements

― Texas

» Monitor and report mechanical integrity (H5) –

minimum once every five years, but permit may 

specify more frequent 

» Monitor injection pressure monthly & report annually 

(H10)
18

Economics

CHK SWD

Typically < $0.25 / barrel

Commercial SWD

$0.50 - $2.50 / barrel

Supply and demand

Trucking

$1.00 / barrel / hour (average)

SWD’s plentiful (TX)

― $0.50 - $1.00 / barrel

SWD’s scarce (PA)

― $4.00 – $8.00 / barrel

Salt Water Pipelines

More efficient than trucking

Reduces traffic and road wear
19

Pennsylvania / Texas Comparison

Pennsylvania

8 Class II saltwater disposal (SWD)wells

― Oriskany 3

― Oriskany / Huntersville 2

― Balltown 1

― Gatesburg 1

― Mine Void 1

Texas

~12,000 Class II SWD wells

Tarrant County – 10 SWD wells

― All Ellenburger
20 20

Brentwood SWD Site

Close-up of Brentwood SWD well 

in East Fort Worth. 
21

Disposal Capacity

Mann SWD – Cleburne, Texas

Ellenburger Formation

~26,000 barrels per day (BPD)

9.5 million barrels per year

Pennsylvania SWD’s

Operator BPD

Columbia 700

EXCO 142

CNX 5,000*

Range 665

XTO** 120

Cottonwood 900

EXCO 140

Dominion 1,000

8,667

* - Mine void ** - Reported as recently plugged
22

PA Experience

PA SWD Target

Trenton / Black River

SE of Towanda, PA

Targeted total depth (TD) – 14,300’

Budgeted - $3 MM

Final Spend - $ 7 MM

Limited fluid capacity

Well TA’d

― Permanent bridge plug @ 12,000’
23

Water Reuse

Lack of Suitable Disposal Infrastructure / Capacity in PA 

Originally Resulted in Produced Water Being Trucked (or 

railed) to Ohio and West Virginia

Aqua Renew

Filtration and reuse

Central filtration sites

Bermed and lined

Steel tanks for storage of all produced brine

Benefits

Decreases fresh water demand by 10-15%

~52,500 less truck road miles per well for water disposal

CO2 emissions reduced by ~88 metric tons per well 
24

Agenda

History 

Program Oversight

Well Classifications

Class II Wells

Reclamation / Disposal 

Combinations

Summary
25

Brentwood SWD Site
26

Reclamation / Disposal Combinations

Economics can work in areas where disposal 

capacity is limited

Water quality (total dissolved solids - TDS) greatly 

influences economics

Capacity multiplier – particularly with relatively 

low TDS brine 

Concentrated brine requires less energy for 

disposal

Evaporative systems – no backhaul of treated 

water
27

Agenda

History 

Program Oversight

Well Classifications

Class II Wells

Reclamation / Disposal 

Combinations

Summary
28

Summary

The Oil and Gas Industry Has Utilized Underground 

Injection of Brine Since the 1930’s and Class II UIC Wells 

Currently Inject Two Billion Gallons of Fluid Per Day For 

Enhanced Oil Recovery, Disposal and Storage.

Wells Used Exclusively To Dispose of Fluids From Oil and 

Gas Production Account For 20% of the 144,000 Class II 

Wells in the U.S.

Brine Disposal in Class II Wells Is Safe, Environmentally 

Sound and is the Most Economic Option in Most Areas.

In Areas of Limited Disposal Capacity or Where Water 

Resources Are Stressed, Reuse of Produced Brine is 

Proving To Be an Effective Alternative To Underground 

Injection.
Underground Injection 

Wells For Produced 

Water Disposal

Rick McCurdy

Sr. Engineering Advisor 

Chemicals and Water Reclamation

Chesapeake Energy Corporation

6100 N. Western Avenue ı Oklahoma City, OK 76118 ı 405-935-8000

AskChesapeake@chk.com ı chk.com ı NYSE: CHK