CO2 EOR

The Schlumberger Perspective

Mahmut Sengul
Schlumberger Carbon Services MEA
Paris – July 17, 2006
Overview

„ Concept Development
„ Enhanced Oil Recovery Techniques
„ EOR Production
„ CO2 EOR
„ Growth Opportunities
„ Conclusions
Energy for the Coming Decades

„ 40 years of oil available with the current production rates

„ Possibly discovering another 20 years of worth reserves

„ Natural gas will be available at least 70+ years

„ There is a coal lasting up to 1000+ years

„ Fossil fuels drive the current world economy

IOR / EOR technologies will deliver most of the new oil from
existing reservoirs.

(*): BP Energy Statistics & IEA

 Petroleum
Recovery Processes

Conventional Current Methods Future Trends

Secondary Recovery of Developments
Pressure Maintenance Enhanced Recovery Possible EOR

Thermal Improved Foam & complex Explosives,

Water Gas
Recovery Fluid-injection Gas, oil, water Hypersonic
Injection Injection Methods Methods mixtures etc.

Combination
In-situ Immiscible
WAG
Combustion Displacement
• Forward • Polymer
• Reverse • Surfactant

Hot-fluid Miscible
Injection Displacement
• Steam Injection • Micro emulsion & micellar
• Hot water flooding
injection • CO2, N2, LPG, alcohol HP
enriched gas drives
Conventional Oil and EOR Potential
Oil Cost Curve (IEA)
Enhanced Oil recovery

„ EOR Contribution to global E&P (OGJ-2006) 3% of total

production
„ 13% of EOR in carbonates

„ Almost 90% of EOR in carbonates are gas injection

„ <10% of thermal EOR in carbonates

„ Total EOR production is approx. 3 million b/d

 World EOR Production 2004

Total EOR Production: 3,000 MSTB/D (est.) Source: OGJ - Shell

Five Categories of EOR Processes

Thermal
Miscible
Chemical
Mobility Control
Others (microbial, …)
Thermal Processes
Thermal EOR Processes

Hot-water floods (limited success)

Steam processes
In-situ combustion
Miscible EOR
Miscible EOR Processes

First Contact-Miscible (slug of LPG displaced by a large value

of gas with high CH4 content)
Multiple-Contact-Miscible: CO2, WAG

Miscibility is Developed in This Region

(CO2 and Oil Form Single Phase)

Pure CO2 Vaporizing CO2 Condensing Original

CO2 Oil Components Into Oil Oil

Direction of Displacement
Chemical EOR
Chemical EOR Processes

Objective: to reduce the IFT between displacing liquid and oil

Surfactant/Polymer
„ Micellar solution (10% PV) followed by polymeric buffer (1 %
PV)
Alkaline Flooding (-> in-situ
surfactant generation)
$

Chemistry
Other EOR
Factors for EOR Assessment

„ Gravity/viscous balance
„ X-layer heterogeneities
„ Microscopic Sweep
„ Minimum Miscibility Pressure (MMP)
„ Optimum reservoir pressure for miscible and immiscible gas
injection
„ Thermal stability of Chemical EOR agents
„ Stability of Crestal injection processes
Identification of Major Project Variables

Reservoir Variables:
„ Volumetric, Continuity, Lateral and Vertical Heterogeneities,
Drive (aquifer size …)
EOR variables:
„ Kro, Krg, Compositional effects …
Operational Issues:
„ Supplies, sour production …
Geographical Considerations
„ Injection Pooling, Disposal issues
EOR Screening (Miscible)
EOR API Visc (cp) Compos. Oil-Satur Formatio Thickness Perm Depth (ft) Temp (F)
Method n (md)

N2 >35 ↑ 48 < 0.4 ↓ High % of > 40 ↑ 75 Sand/Car Thin > 6000

(&Flue ↑ 0.2 ↓ C1-C7 ↑ b
Gas)

Hcarbon >23 ↑ 41 <3↓ High % of > 30 ↑ 80 Sand/Car Thin > 4000

↑ 0.5 ↓ C2-C7 ↑ b

CO2 >22 ↑ 36 < 10 ↓ High % of > 20 ↑ 55 Sand/Car >2500

↑ 1.5 ↓ C5-C12 ↑ b

Taber et al. - 1996

EOR Screening (Chemical)
EOR API Visc (cp) Compos. Oil-Satur Formation Thickness Perm Depth (ft) Temp (F)
Method (md)

Micellar/Al >20 ↑ 35 ↑ < 35 ↓ 13 Light, > 35↑ 53 ↑ Sandstone >10 ↑ > 9000 < 200
kaline ↓ intermed. 450 ↑

Polymer >15 < 40 < 35 ↓ > 70 ↑ 80 ↑ Sandstone >1000 < 9000 < 200
Flood 13 ↓

Taber et al. - 1996

EOR Screening (Thermal)
EOR Method API Visc (cp) Compos. Oil-Satur Formation Thickness Perm Depth (ft) Temp (F)
(md)

Combustion >10 ↑ 16 <5000 Asphaltic > 50↑ 72 ↑ Hi Por > 10 >50 > 11500 < 100
↑ comp. Sandstone

Steam >8 < 200,000↓ > 40 ↑ 66 ↑ Hi Por > 20 >200 < 4500
Sandstone

Taber et al. - 1996

Quick Screening Criteria of Main EOR Methods
by Oil Gravity

API gravity range of oil that is most effective for EOR methods. Relative production
(b/d) is shown by size of type.
−From Taber, Martin, and Seright (1996)
Remaining gas reserves with CO2>2% and/or H2S>10ppm
(Excluding North America)

40% of remaining reserves are sour

FSU
641 Tcf

EUROPE
40 Tcf
2576 Tcf
MIDDLE-EAST
1552 Tcf

AFRICA FAR-EAST
35 Tcf 249 Tcf
SOUTH AMERICA
59 Tcf

CO2
H2S
CO2 + H2S
Reserves with >10% H2S represent 333 Tcf
Source: Iris 21 database from IHS Energy -June 2004
CO2 Capture and utilize for EOR

Environmental
Protection

Increased More
Oil Production Natural Gas for sale
CO2 EOR
Carbon Capture and Storage Process

CO2 SOURCE GAS PROCESSING CO2

Oil & Gas - Power
Separation Compression
Ammonia - H2 Transportation
Capture Dehydration INJECTION
Cement - Others
Well

Can greenhouse gas emissions be reduced?

Can CO2 Enhance Oil Recovery in Carbonates?

INJECTION ZONE
What are the technology gaps? Disposal
EOR - Storage
 CO2 for Enhanced Oil Recovery

Some CO2 dissolves in the oil, some hydrocarbons in the oil transfer to the CO2.
If pressure is high enough (depends on reservoir temperature and oil composition), oil can be
displaced very efficiently (in the zones invaded by CO2.)
Mechanisms which contribute to
Oil Displacement in CO2 Flooding

1. Swelling the crude oil

2. Reducing oil viscosity
3. Reducing oil density
4. Reducing the gas-oil interfacial tension
5. Solubility process
6. Vaporizing (extracting) lighter hydrocarbon in
crude oil
7. Generating miscibility by the multiple contact
process if the pressure is sufficiently high
CO2 EOR Scope

„ Reservoir characterization
– Geological
– Rock fluid interactions, IFT, wetability
– Permeability, pore size distribution
„ Field development plan
„ Well Construction
„ Reservoir recovery
„ Monitoring / Verification
„ Process optimization
Geochemical reactions
Reactive Fluid Transport in
Carbonate Reservoirs
CO2 - Rock interactions CO2 - Well interactions
Diffusion Interfaces
Hydraulic fracturing Escape through cement
Fault crossing Corrosion
Migration along fault

Storage

L
SEA
S. 1
RE
S. 2
RE
CO2 - Fluid interactions • •• ••
•
Diagenetic front • •••• • •
•
••
•• • • • • •
T

Hydrodynamism / Dispersion
UL

•
• • • •
FA

Spill points
CO2 HC gas Oil Aquifer [Total]
Reservoir Flow Mechanics

„ Injected gas has low viscosity

„ Flow at reservoir is dominated by heterogeneity and gravity

„ Gas follows the least resistant path

„ Cycling gas from injection wells to production can be an issue

Displacement Behavior : CO2 - Oil

„ During the EOR stage, convection and gravity dominate the

flow, High K paths between wells determine gas cycling
„ CO2 dissolved in remaining oil, water near swept zones.
„ Low permeability zones swept poorly
„ After shut-in, long period of diffusion, gravity drainage of oil
„ Driving force for upward migration probably remains
indefinitely, so an intact seal is required
 CO2-EOR Screening

Average reservoir pressure and MMP

Well Patterns and Stage of Depletion
Residual oil saturation to Waterflooding
Reservoir Wettability
Reservoir Heterogeneity and Inter-well continuity
Ability to inject and produce fluids at economical rates
Gravity effects
EOR API Visc (cp) Compos. Oil-Satur Formation Thickness Perm Depth (ft) Temp (F)
Method (md)

CO2 >22 ↑ 36 ↑ < 10 ↓ High % of > 20 ↑ 55 ↑ Sand/Carb >2500

1.5 ↓ C5-C12

Taber et al.
Project Screening Criteria for CO2-EOR

„ Can CO2 recover incremental oil?

„ Rates and Volumes to be recovered
„ Estimated Investment and Operating Costs
„ CO2 Purchase Cost
„ Analysis of ROI for Different Scenario
„ Investment Portfolio Fit
„ QHSE
 US EOR Production
1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006
Thermal
Steam 468,692 455,484 444,137 454,009 415,801 419,349 439,010 417,675 365,717 340,253 286,668
Combustion In situ 10,272 6,525 6,090 4,702 2,520 4,485 4,760 2,781 2,384 1,901 13,260
Hot Water 705 2,896 3,985 1,980 250 250 2,200 306 3,360 3,360 1,776
Total Thermal 479,669 464,905 454,212 460,691 418,571 424,084 445,970 420,762 371,461 345,514 301,704

Chemical
Micellar-polymer 1,403 1,509 617 254 64 0 0 0 0 0 0
Polymer 15,313 20,992 11,219 1,940 1,828 139 139 1,598
Caustic/Alkaline 185
Surfactant 20 60 60 60
Total Chemical 16,901 22,501 11,856 2,194 1,892 139 139 1,658 60 60 0

Gas
HC Miscible/Immiscible 33,767 25,935 55,386 113,072 99,693 96,263 102,053 124,500 95,300 97,300 95,800
CO2 Miscible 28,440 64,192 95,591 144,973 161,486 170,715 179,024 189,493 187,410 205,775 234,420
CO2 Immiscible 1,349 420 95 95 66 66 102 2,698
Nitrogen 18,510 19,050 222,660 22,580 23,050 28,017 28,117 14,700 14,700 14,700 14,700
Flue Gas 26,150 21,400 17,300 11,000
Other 6,300 4,400 4,350 4,350
Total Gas 108,216 130,997 391,032 298,020 288,629 299,345 313,544 328,759 297,476 317,877 347,618

Other
Carbonated waterflood
Microbial 2 2
Total Other 0 0 0 2 2 0 0 0 0 0 0

Grand Total 604,786 618,403 857,100 760,907 709,094 723,568 759,653 751,179 668,997 663,451 649,322
US CO2 EOR Production

250000

200000
EOR (BPD)

150000

100000

50000

0
1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006
CO2 EOR Production in Texas

GROWTH OF CO2 EOR PRODUCTION IN TEXAS AS A

PERCENTAGE OF STATEWIDE PRODUCTION
20%
PRODUCTION IN BBLS/DAY
CO2 EOR AVE. YRLY

16%

12%

8%

4%

0%
1970 1975 1980 1985 1990 1995 2000 2005
YEAR
 US CO2 EOR Projects, Sources and Distribution

Source: Denbury Resources, Inc., 2004

Response to CO2 Injection at Weyburn

Source: Eliason, http://www.gasification.org/

US CO2 EOR Technically Recoverable Reserves

US DOE – April 2005

 CO2 Economics in US Market

Source: Advanced Resources International, 2005

JAF2004075.XLS
US Land EOR
2006 Planned EOR Projects

CO2 Immiscible
CO2 Miscible
Steam
Polymer
Combustion
Surfactant Polymer
Denver Unit Production/Injection History

Shell
West Texas Ultimate Recovery Efficiencies

Shell
CO2 Flooding – Effective Use of Water Injection
CO2 Utilization in EOR Projects
Impact of New Technology on
Oil Production – Norway
Needs/Solutions

„ Characterization/Imaging/Modeling

„ Mobility Control

„ Operations/Monitoring

„ Supply/Recycle
Current Research Activities
• Time lapsed 3D Seismic CO2
• Eclipse for CO2 Service
• Geochemical Simulator
• Geomechanical Simulator
• CO2 resistant cement
• ESP / HPS for CO2
• Next generation reservoir
simulator
• Risk Assessment
Schlumberger CO2 Projects

Sleipner
Alberta Weyburn

Frio
Lost Hills In Salah

CS
Gorgon Energy

Otway
In summary

EOR projects will deliver considerable amount of the

sustainable oil production in global scale,
Enabling technologies and resources yet to be developed
CO2 EOR is providing dual benefit to industry while reducing
environmental impact and maximizing reservoir recovery
Schlumberger is well positioned to be a leader in the era of
EOR
A Way Forward

„ The state of the art technologies in EOR

„ The Field Screening studies for EOR

„ Address research of technologies issues Æ JIP

„ Integrate multiple asset development projects

„ Natural gas & declining field CO2 EOR

Thank you,
Questions?
Gas Injection
„ CO2,
„ N2 (Mexico in fractured reservoir)
„ Sour Acid Gas Injection
„ MiscibleH2S in Kashagan

Limitations of gas injection:

„ Gas availability
„ Air injection could be an option / HSE issues
„ N2 is an option however costly one
„ Gas compression cost
„ Technical limitations, gravity override
„ Mobility control in reservoir conditions
Gas Flooding

„ Immiscible
„ Miscible gas flooding

Microscopic displacement efficiency

„ Pressure support
„ Increase microscopic displacement efficiency
„ Gas Gravity

Macroscopic displacement efficiency

„ Accessing bypassed oil
„ Re-cycling of produced gas
WAG

„ WAG

„ Under saturated WAG

„ FAWAG – Foam Assisted WAG

„ SWAG - Simultaneous WAG

„ GAW

„ Miscible WAG RF up to 60% achieved in carbonates

Issues
„ Early breakthrough
„ Injection issues
„ Corrosion problem
„ Deposits (scale, hydrate, asphaltine deposition)
„ Performance prediction and design is still a challenge
„ Only 50% prediction successful
„ How to design WAG Slug size?
„ Which one to start with water or gas?
„ Three phase relative permeability do not represented properly
„ Pore network modeling is an issue
„ Established technology does not apply to fractured carbonate
reservoirs
How to increase reserves base and EUR

Enhancing oil recovery of existing fields

Pursuing development of marginal fields,
Commercialization of high CO2 content gas reservoirs
Continuing exploration in traditional acreages and unexplored
areas, deep water