Overview of the Use of CO2 as Applied to Enhanced Oil Recovery (EOR) Projects EGRC 6th Session Geneva, Switzerland April 2015

What is CO2 Enhanced Oil Recovery (EOR)?

• Carbon dioxide mobilizes oil to improve recovery

o Mainly through miscible processes, but can be immiscible

• Viscosity of oil trapped in the reservoir is reduced providing ability for more efficient displacement

• Injected CO2 produced with oil is captured & recycled

• Up to 50% of the injected CO2 is trapped in the reservoir

• Industry has produced, transported & injected CO2 without notable incident for over 40 years

• Many similarities & experience applicable to Carbon Capture & Storage (CCS)

2

CO2 EOR Process

Water injection (blue) recovers oil in large pores; leaving trapped oil (red) in small pores

Waterflood

CO2 flood

Chase Waterflood 3

CO2 (yellow) dissolves and displaces trapped oil; leaving only heavy ends (brown) in the reservoir

The process is normally finalized by injecting chase water (blue) after the CO2

CO2 EOR Process

CO2 Recycled from Gas Plant

Pipeline CO2 from CO2 source fields and natural gas separation plants

Injection well

Produced GasCO2

Injection

Oil Sales

Natural Gas & Natural Gas Liquid (NGL) Sales

Re

serv

oir

DriveWater

CO2 Water CO2MiscibleZone

OilBank

AdditionalOil

Recovery

Production

well

Produced Brine

Vapor Recovery

Produced Liquids

4

CO2 EOR Applicability

•Requires specific geological characteristicsoAdequate flood sweep efficiency (formation

heterogeneity, stratified or low vertical permeability, few fractures)

oAdequate processing rate (CO2 velocity: permeability and porosity)

oLow minimum miscibility pressure (low reservoir temperature, low reservoir pressure)

•Requires CO2 source

•Requires sufficient oil target to be profitable

5

1

10

100

1,000

1938 1947 1957 1967 1977 1987 1997 2007 2017

Oil Production, MBOPD

Primary

CO2

Waterflood

Benefits of CO2 EOR

Significant long term cash generation

Shallow decline, long lived production

Proven technology

No exploration risk

Four times the recovery from primary operations

Low Finding & Development (F&D) costs

Synergistic with carbon capture projects

Primary15%

Primary6-12%

Waterflood 30%

CO2 15%

0%

10%

20%

30%

40%

50%

60%

Conventional

Reservoirs

Unconventional

Reservoirs

Recovery of Oil in Place

6Recovery Percentages Represent Typical Recovery Efficiencies

0

0.5

1

1.5

2

2.5

3

3.5

4

0 10 20 30 40

Fo

recaste

d G

as P

rod

(M

MC

FP

D)

Per

Typ

ical 7

0 A

cre

-Patt

ern

Year

CO2 Flooding Injection Strategies

7

CO2 WATER

CONTINUOUS CO2

ALTERNATING WATER AND GAS

TAPERED INJECTION SCHEDULE

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0 10 20 30 40

Fo

recaste

d R

eco

very

(F

rac O

OIP

)

Year

ALTERNATINGALTERNATING

Oil Production CO2 Production

Continuous CO2 Yields Fastest Oil Response

Water Alternating Gas (WAG) Needed to Control Gas Production

Tapered WAG Used to Maximize Oil and Manage Gas

7

CO2 EOR in the United States

~375 mmcfpd

~1750 mmcfpd

>1100 mmcfpd

~125 mmcfpd

8

Permian Basin Miscible CO2EOR Production is Growing

Source: Oil and Gas Journal Biannual EOR Surveys

0

25

50

75

100

125

150

175

200

225

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

Pro

du

cti

on

-T

ho

us

an

d B

OP

D

9

CO2 EOR Summary• Increases oil recovery 15-25%

• The process is a closed loop system since CO2 produced with the oil is recovered & recycledo Net utilization 5-20 thousand cubic feet/barrel oil produced (mcf/bo),

depending on the geology and petrophysicso Losses <1%

• CO2 is treated as an expensive, scarce commodity

• Proven technology: Industry has 35+ yrs of experience

• Vast majority of projects are in the USA due to naturally occurring sources of CO2

• Non-USA opportunities are expanding, as examples:o Natural

o Brazil (Lula)o Anthropogenic

o Canada (Weyburne/Midale via US-based Dakota Gasification Plant)o Saudi Arabia (Ghawar/Uthmaniyah Gas Plant) 10