Overview of the Use of CO 2 as Applied to Enhanced Oil Recovery (EOR) Projects EGRC 6 th Session Geneva, Switzerland April 2015
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