1. SOFREGAZ US
REQUIREMENTS FOR CAVERN
STORAGE
Paul Bieniawski
SPE Appalachian Storage Group
February 19, 1997

2. SOFREGAZ US
OUTLINE
• History
• Comparisons
• Cavern Storage Requirements
• Cavern Storage Operations
• Effect of Variables
• Questions

3. SOFREGAZ US
HISTORY
• 1961 Southeastern Michigan Gas converts abandoned
brine caverns in bedded salt to gas storage.
• 1963 Saskatchewan Power Corporation commences
operations of first caverns designed specifically for gas
storage in bedded salt.
• 1964 First cavern storage in Armenia.
• 1966 First cavern storage in West Germany.
• 1968 First cavern storage in France.
• 1970 Transcontinental Gas Pipe Line Corporation commences
operations of first caverns designed specifically for gas
storage in a salt dome.
• 1974 First cavern storage in United Kingdom.
• 1981 First cavern storage in Denmark.

4. SOFREGAZ US
COMPARISONS
RESERVOIR AQUIFER REEF MINE CAVERN
BASE GAS
59% 67% 40% 28% 29%
CAPACITY
PER
WELL 470 785 1,225 165 1,890
DELIVERABILITY
PER
WELL 3,320 3,395 20,930 10,940 72,715

5. SOFREGAZ US
REQUIREMENTS
• Location
• Salt
• Caprock
• Raw Water
• Brine Disposal

6. SOFREGAZ US
LOCATION
• Acreage
• Proximity to Pipelines
• Proximity to Markets
• Proximity to Raw Water Supply
• Proximity to Brine Disposal
• Proximity to Utilities

7. SOFREGAZ US
SALT
• Salt Purity
• Existence and Nature of Caprock
• Existence and Nature of Interbeds
• Distribution of Interbeds

8. SOFREGAZ US
ADVANTAGES OF SALT
• Impervious to Hydrocarbons
• Very High Compressive Strength
• Ability to Yield and Divert Stresses
• Ability to Flow and Heal Fractures

9. SOFREGAZ US
LOCATION OF SALT BASINS

10. SOFREGAZ US
CAPROCK
• Not Present in Bedded Salts
• Exact Origin Unknown
• Believed to be Accumulation of Insolubles
Originally Transported in the Salt
• Usually Comprised of Anhydrites, Gypsum,
and Dolomite
• May be Highly Fractured with Numerous Lost
Circulation Zones

11. SOFREGAZ US
RAW WATER
• Fresh, Brackish, or Unsaturated Brine
• Sources
• Aquifers
• Rivers
• Canals
• Lakes
• Municipal Supplies

12. SOFREGAZ US
BRINE DISPOSAL
• Wells
• Chemical Feedstock
• Evaporation Plants
• Solar Evaporation
• Surface Waters
• Displacement

13. SOFREGAZ US
LEACHING OPERATIONS

14. SOFREGAZ US
DIRECT CIRCULATION

15. SOFREGAZ US
REVERSE CIRCULATION

16. SOFREGAZ US
CAVERN SHAPING
Top of Insolubles
Raw Water Injection
Brine Return
Blanket Level
Production Casing
Brine Return
Raw Water Injection
SUMP DEVELOPMENT CAVERN DEVELOPMENT

17. SOFREGAZ US
CAVERN MECHANICS
Sump Building Partially Cavern
BRINE
RETURN
INSOLUBLES
WATER INJECTION
BLANKET
LEVEL
BRINE
RETURN
WATER
INJECTION
BOTTOM
OF CAVERN
BRINE RETURN
BLANKET LEVEL
BOTTOM OF
CEMENTED CASING
BRINE
RETURN
DEPTH OF
ORIGINAL HOLE
BLANKET
LEVEL
INSOLUBLES
INSOLUBLES
Near Completion Developed Cavern Near Completion
WATER
INJECTI
ON

18. SOFREGAZ US
CAVERN OPERATIONS.
Injection
Facilities
Withdrawal
Facilities
Brine Pond
GAS
EXPANSION
BRINE
DISPLACEMENT
Gas
Heater
PCR
GLYCOL
ABSORBER

19. SOFREGAZ US
OPERATIONS (cont’d)
M
STORAGE
CAVERN
STORAGE
CAVERN
Injection
Facilities
Withdrawal
Facilities

20. SOFREGAZ US
EFFECT OF VARIABLES
• Minimum Pressure
• Maximum Pressure
• Insolubles Percentage
• Bed Thickness

21. SOFREGAZ US
MINIMUM PRESSURE
GRADIENT
0
0.4
0.8
1.2
1.6
0.1 0.15 0.2 0.25 0.3
Minimum Pressure Gradient, psi/ft
BaseGas,Bcf

22. SOFREGAZ US
MAXIMUM PRESSURE
GRADIENT
2.5
2.7
2.9
3.1
3.3
3.5
3.7
0.6 0.65 0.7 0.75 0.8 0.85 0.9
Max Pressure Gradient, psi/ft
TotalCapacity,Bcf

23. SOFREGAZ US
INSOLUBLE CONTENT
0
0.2
0.4
0.6
0.8
1
0 5 10 15 20 25 30
Insoluble Content, % vol
CavernVolume,MillionBarrels

24. SOFREGAZ US
BED THICKNESS
0
0.5
1
1.5
2
2.5
100 150 200 250 300 350 400
Bed Thickness, ft
CavernVolume,MillionBarrels

25. SOFREGAZ US
QUESTIONS ????