Creating fluid injectivity in tar sands formations

• US 7,730,947 B2
• Filed: 10/19/2007
• Issued: 06/08/2010
• Est. Priority Date: 10/20/2006
• Status: Expired due to Fees

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Beer, Gary Lee, Stegemeier, George Leo, Zhang, Etuan
• Primary Examiner(s): SUCHFIELD, GEORGE A
• Application Number:
  US11/975,738
• Publication Number:
  US 20080217016A1
• Time in Patent Office: 963 Days
• Field of Search: 166/245, 166/256, 166/272.1, 166/272.3, 166/302, 166/303
• US Class Current: 166/272.3
• CPC Class Codes: C10G 1/02 by distillation
• CPC Class Codes: C10G 2300/4037 In-situ processes
• CPC Class Codes: E21B 36/04 using electrical heaters
• CPC Class Codes: E21B 43/243 Combustion in situ
• CPC Class Codes: E21B 43/30 Specific pattern of wells, e.g. optimising the spacing of wells
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor

Abstract

Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.

Claims

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

heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion;

controlling the heating to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone;

controlling the pressure in the portion such that the pressure is below the fracture pressure of the portion;

providing a drive fluid and/or an oxidizing fluid into the injection zone; and

producing at least some hydrocarbons from the portion, wherein the injection zone is above a portion of the formation from which the hydrocarbons are produced.

2. The method of claim 1, wherein the drive fluid and/or the oxidizing fluid moves from the injection zone to mobilize at least some hydrocarbons in the portion.

3. The method of claim 1, further comprising providing at least some heat to the portion using the drive fluid and/or the oxidizing fluid.

4. The method of claim 1, further comprising providing at least some heat outside the injection zone with the drive fluid and/or the oxidizing fluid.

5. The method of claim 1, further comprising increasing the permeability of at least part of the portion outside the injection zone with the drive fluid and/or the oxidizing fluid.

6. The method of claim 1, wherein the drive fluid and/or the oxidizing fluid is selected from a group consisting of steam, water, carbon dioxide, carbon monoxide, methane, pyrolyzed hydrocarbons, air, and mixtures thereof.

7. The method of claim 1, wherein the injection zone has little or no initial injectivity.

8. The method of claim 1, wherein increasing the permeability of the injection zone creates a fluid production network between at least one of the heaters and a production well in the injection zone.

9. The method of claim 1, further comprising providing the drive fluid and/or the oxidizing fluid to a part of the injection zone behind a heat front generated by the heaters.

10. The method of claim 1, wherein the provided heat decreases a viscosity of liquid hydrocarbons in the injection zone with an initial viscosity of above about 10000 cp, wherein the viscosity is measured at 1 atm and 5°

C.

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

heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion;

controlling the heating to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone;

controlling the pressure in the portion such that the pressure is below the fracture pressure of the portion;

providing a drive fluid and/or an oxidizing fluid into the injection zone; and

allowing at least some of the hydrocarbons to flow into a second portion of the formation;

providing heat to the second portion of the formation from one or more heaters located in the formation before and/or after allowing at least some of the hydrocarbons to flow into the second portion; and

producing at least some hydrocarbons from the second portion of the formation.

12. The method of claim 11, wherein the drive fluid and/or the oxidizing fluid moves from the injection zone to mobilize at least some hydrocarbons in the portion.

13. The method of claim 11, further comprising providing at least some heat to the portion using the drive fluid and/or the oxidizing fluid.

14. The method of claim 11, further comprising providing at least some heat outside the injection zone with the drive fluid and/or the oxidizing fluid.

15. The method of claim 11, further comprising increasing the permeability of at least part of the portion outside the injection zone with the drive fluid and/or the oxidizing fluid.

16. The method of claim 11, wherein the drive fluid and/or the oxidizing fluid is selected from a group consisting of steam, water, carbon dioxide, carbon monoxide, methane, pyrolyzed hydrocarbons, air, and mixtures thereof.

17. The method of claim 11, wherein the injection zone has little or no initial injectivity.

18. The method of claim 11, wherein increasing the permeability of the injection zone creates a fluid production network between at least one of the heaters and a production well in the injection zone.

19. The method of claim 11, further comprising providing the drive fluid and/or the oxidizing fluid to a part of the injection zone behind a heat front generated by the heaters.

20. The method of claim 11, wherein the provided heat decreases a viscosity of liquid hydrocarbons in the injection zone with an initial viscosity of above about 10000 cp, wherein the viscosity is measured at 1 atm and 5°

C.