Production from multiple zones of a tar sands formation

• US 8,381,815 B2
• Filed: 04/18/2008
• Issued: 02/26/2013
• Est. Priority Date: 04/20/2007
• Status: Expired due to Fees

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Karanikas, John Michael, Vinegar, Harold J.
• Primary Examiner(s): DiTrani, Angela M
• Application Number:
  US12/106,008
• Publication Number:
  US 20090095479A1
• Time in Patent Office: 1,775 Days
• Field of Search: None
• US Class Current: 166/302
• CPC Class Codes: C09K 8/845 containing inorganic compounds
• CPC Class Codes: C09K 8/86 containing organic compounds
• CPC Class Codes: C10G 1/008 Controlling or regulating of liquefaction processes
• CPC Class Codes: C10G 1/02 by distillation
• CPC Class Codes: C10G 1/04 by extraction
• CPC Class Codes: C10G 1/042 by the use of hydrogen-donor solvents
• CPC Class Codes: E21B 36/04 using electrical heaters
• CPC Class Codes: E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: E21B 43/2401 by means of electricity
• CPC Class Codes: Y10T 29/49083 Heater type

Abstract

A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. Fluids are produced from the formation through at least one production well that is located in at least two zones in the formation. The first zone has an initial permeability of at least 1 darcy. The second zone has an initial of at most 0.1 darcy. The two zones are separated by a substantially impermeable barrier.

Claims

1. A method for treating a tar sands formation, comprising:

providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation;

allowing the heat to transfer from the heaters to at least a portion of the formation;

producing fluids from the formation through at least one production well that is located in at least two zones in the formation, the first zone having an initial permeability of at least 1 darcy, the second zone having an initial permeability of at most 0.1 darcy and the two zones are at least partially separated by a barrier with an initial permeability of at most 10 μ

darcy; and

heating such that an average pressure in the two zones is within about 20% of each other.

2. The method of claim 1, further comprising heating such that an average viscosity in the two zones is within about 20% of each other.

3. The method of claim 1, wherein the at least one production well allows fluid communication between the zones.

4. The method of claim 1, further comprising providing a drive fluid to the formation.

5. The method of claim 1, further comprising providing steam to the formation.

6. The method of claim 1, further comprising controlling an average pressure in the formation such that the average pressure remains below a selected pressure.

7. The method of claim 6, wherein the selected pressure is the fracture pressure of the formation.

8. The method of claim 7, wherein the selected pressure is between about 1000 kPa and about 15000 kPa.

9. The method of claim 6, wherein the selected pressure is a pressure below which hydrocarbon coking in the formation occurs when the average temperature in the formation is less than 300°

C.

10. The method of claim 9, wherein the selected pressure is between about 100 kPa and about 1000 kPa.

11. A method for treating a tar sands formation, comprising:

providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation;

allowing the heat to transfer from the heaters to at least a portion of the formation;

wherein heat is transferred to at least two zones in the formation, at least two of the zones being at least partially separated by a barrier with an initial permeability of at most 10 μ

darcy;

allowing fluid to flow between the zones through one or more holes that connect the zones through the barrier, wherein the fluid flow equalizes pressure between the zones such that an average pressure in the two zones is within about 20% of each other; and

producing fluids from the formation.

12. The method of claim 11, further comprising heating such that an average pressure in the two zones is within about 20% of each other.

13. The method of claim 11, further comprising heating such that an average viscosity in the two zones is within about 20% of each other.

14. The method of claim 11, wherein the holes allow fluid communication between the zones.

15. The method of claim 11, further comprising providing a drive fluid to the formation.

16. The method of claim 11, further comprising providing steam to the formation.

17. The method of claim 11, further comprising controlling an average pressure in the formation such that the average pressure remains below a selected pressure.

18. The method of claim 17, wherein the selected pressure is the fracture pressure of the formation.

19. The method of claim 18, wherein the selected pressure is between about 1000 kPa and about 15000 kPa.

20. The method of claim 17, wherein the selected pressure is a pressure below which hydrocarbon coking in the formation occurs when the average temperature in the formation is less than 300°

C.

21. The method of claim 20, wherein the selected pressure is between about 100 kPa and about 1000 kPa.