1. What is Important in the Reservoir for CO2 EOR/EGR and Sequestration
What is Important in the Reservoir for CO2 EOR/EGR and Sequestration? Presented by: Richard Baker
Prepared for
APEGGA Annual Conference
GHG Opportunities: Small and Large Technologies
April 22-24, 2004

2. Outline Conclusions Field CO2 EOR response
Determination of Incremental Reserves
Incremental CO2 Response RF vs. HCPVI
Typical cash flow for CO2 /EOR
CO2 sequestration
What are the most important factors?
Summary

3. Conclusions
There has been very good to excellent response on many USA/Canadian CO2 floods to date in a wide range of conditions
CO2 is a mature technology in USA and in Canada it will be mature in years
Early time response often control CO2 economics
There is wide variations in early time response between various fields. Early time response is a function of heterogeneity , current oil saturation and injection rates.

4. Conclusions
Forty plus years of EOR (CO2 + HC) miscible have shown that the controlling factors in CO2 economics are (early time response);
Reservoir heterogeneity
Remaining oil saturation
CO2 price
Infrastructure
Well bore integrity
Screening needs to include historical field response and level of depletion as well as infrastructure and mapping of current oil in place
Concerns about CO2 emissions will force action
Cooperative approach will aid implementation

5. Options for CO2 Usage/Disposal
EGR
EOR
‘Value Added’
CBM
GOB
CO2 Emission
Regulatory driven
‘Rental of pore space’

8. Response time
Peak oil rate

10. Time to peak oil rates
response
time

11. CO2 Flooding – World Wide
75 Projects worldwide
194,000 Bbl/d
66 in US
From Jarrell et al, ‘Practical Aspects of CO2 Flooding’

12. CO2 Flood Performance Total oil rate Incremental oil rate
SPE paper 26391

13. CO2 Flood Performance Total oil rate Incremental oil rate
Hansford Marmaton = secondary, low initial pressure, low permeability reservoir

14. Initial response 0.5-2 years Time to peak oil rate 4-6 years
depends on
expansion
From DOE Spraberry Doc.

15. Comparison Normalization of CO2 behaviour
Cum. oil
Vol. of original oil
Cum. injection
Vol. of reservoir
For comparison purposes

16. How Do These Floods Compare to Each Other?
SPE paper 35391, SPE monograph Stalkup, SPE paper 26391, and Epic’s interpretation

17. What’s Different between Texas and Canadian Reserves
Infrastructure
Thicker continuous net pay
General geological environment
Depth
Temperature
Some of the best Canadian have already miscible flooded
Horizontal wells
Rules of thumb

18. So What is Important ?
Initial Response drives payout time

19. Important The major objection to CO2 by oil
producers is long pay out times not
necessarily total reserves or NPV
 initial oil response
 large capital exposure

20. What’s worked in Western Canada in the Petroleum Industry?
Short pay out time
Good to excellent local knowledge of the reservoir/geology
Very good execution of plans
Using technical edges; horizontal well/3D seismic/screw pumps
Economy of scale (shallow gas or heavy oil drilling)

21. Disjoint between Government and Industry
If CO2 capture and geological storage is to play a significant role in mitigating global emissions, then the quantity of CO2 place in geological storage will need to approach 10 Gt/yr worldwide roughly 300 times the current rate of CO2 injection for EOR.
D. Keith and M. Wilson
Nov. 2002
34 Mt/yr vs. 10,000 Mt/yr
~ target
{1.79 Bcf/d} {527 Bcf/d}

22. Disjoint between Government and Industry
Global screening techniques
Research focused
Regulation focus
Specific field screening
Field experience critical
Large capital expense
CO2 flood payout
Keeping low costs ($/bbl)
SUGAR vs. SALT
GOVERNMENT
Industry ?
Pilots
Commercial Scale

23. Use the Past to Forecast the Future
What is the classical Screening Criteria?
API gravity
Current reservoir pressure
Depth
Oil saturation
But what about Heterogeneity?

24. Screening
“ The most common screening methods are reviewed and some shortcomings are pointed out. One important aspect is that more effort should be put on mapping of remaining mobile oil in the reservoirs and methods for producing these resources.”
“not taking heterogeneities into account in realistic manner”
T. Bu, I. Soreide, T. Kydland: “IOR Screening: What Went Wrong?”, Norsk Hydro E & P Norway, Steering Committee of the European IOR Symposium, This paper was prepared for presentation at the European IOR Symposium in Moscow, Russia, October 27-29, 1993

25. What is the most important for CO2 EOR?
Initial oil response (response time/peak oil rate); current oil saturations and injection rates
Permeability/Reservoir heterogeneity
CO2 price
Infrastructure

26. Some Info on CO2 Sequestration
Oil & Gas
Known
Seismic
Core
Prod
Minimizes risk
Which reservoir should I inject in?
Deep Saline
Unknowns
Long term liability increased
It is better to have the devil that you know than the one you don’t.

27. Summary
Early time response (<5 yrs) is critical to CO2 flood economics
Early time response is a function of heterogeneity, current oil saturation and CO2 injection rates
Because of point 2 above; screening needs to include historical dynamic reservoir performance
Screening needs to include historical field response and level of depletion as well as infrastructure and mapping of current oil in place
Beware of averages
There is a large disjoint between expectation and reality between oil producers and government, in term of
CO2 volumes and rates
Cost and economics
Historical trend (timing/phasing of projects)

28. #Reservoirs vs. screening criteria
9067 Pools (Alberta 2000 Oil Reserves Database)
ROIP>10 MMSTB
ROIP > 5 MMSTB
743 pools
1218 pools
API Gravity > 25 º
391 pools
723 pools
Reservoir Temperature < 93ºC
376 pools
694 pools
Mean Formation Depth > 610 m
374 pools
691 pools
Current Recovery Factor > 25%
125 pools
213 pools
Exclude pools with previous miscible floods
85 pools
164 pools

29. Infrastructures: CO2 Sites & Sources

30. Source: Bachu, 2001 (EUB)

31. Source: Waldie, 2003 (Combustion News)

32. Source: Bachu, 2003 (AGS)

33. CO2 Flood:Tools Available
PRIze
CO2 Prophet
Kinder Morgan Predictive Tool
Epic CO2 Analysis Package

34. Epic CO2 Analysis Package: Technical Analysis
Preliminary Screening
Data Collection
Develop Injection Patterns
Input Reservoir, Fluid & Production/Injection Data
Calculate & Evaluate Production Forecasts
Proceed To Economic Analysis

35. Input Production & Injection Profiles Evaluate economics results
Economic Analysis
Input Production & Injection Profiles
Input Capital Costs &
Economic Parameters
Calculate Economics
Evaluate economics results

36. Salient Features Uses current water saturation
Uses current reservoir pressure
Can model WAG floods
Program can be validated where CO2 flood history exists
Screening, technical analysis & economic evaluation tied-in

37. Base Case Example Economics
Describe the base case
ROIP = 10 MMBBl
CO2 price: Cdn $1.50/Mscf
Oil price: Cdn $30/bbl
CO2 Recycling Cost: Cdn $ 0.40/Mscf
Percent CO2 Recycled: 90%
Discount factor: 15%
Royalty rate: 16.7%
What areal size does this correspond?
Assume OOIP = 15 MMSTB (30% RF)
h = 6 m (20 ft)
Porosity = 15%
Swi = 30%
Areal extent 1,050 acres ( 1¾ section)

38. Validation (Joffre Viking, AB)

39. Validation (North Cross, TX)

40. Production/Injection Profiles

41. Payout versus CO2 & Oil Prices
t > 5 yrs
t < 1 yr

42. Payout versus CO2 & Oil Prices

43. NPV versus CO2 & Oil Prices (Capital = MM$11)

44. ROR versus CO2 & Oil Prices

45. Effect of Royalty (1%)

46. Sensitivity To ROIP
ROIP increased 10 times; 100 MMSTB

47. ROIP 100 MMSTB; Royalty 16.67%

48. Highlights – Economic $creening
Royalty reduction will be beneficial to small size pools
Following economic parameters emerged out of this study:
Oil price: $30
CO2 price: $1 – 1.50/MSCF
Payout: 5 – 10 years
ROR: 15 – 30 years
CO2 should be attractive for small size pools (ROIP  10 MMSTB)

49. Some Recent Developments
Streamline modeling of miscible
Compositional modeling
Sector Model
40,000 cell sector model
Run time ~ 10 hours
475,000 cell model, ~600 wells
Run time ~70 minutes
FDP delivered in <5 months

50. Summary Concerns about CO2 emissions will force action
CO2 flooding is a mature process used successfully worldwide for >35 years
CO2 infrastructure to be developed in Alberta
Cooperative approach will aid implementation
Approximately reservoirs are good candidates from initial screen
Generic economics positive - Site specific economics the next step