In situ conversion process utilizing a closed loop heating system

• US 7,575,052 B2
• Filed: 04/21/2006
• Issued: 08/18/2009
• Est. Priority Date: 04/22/2005
• Status: Expired due to Fees

• Current Assignee: Shell Oil Company (Shell Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Schoeber, Willen Jan Antoon Henri, Vinegar, Harold J., Fowler, Thomas David, Sandberg, Chester Ledlie
• Primary Examiner(s): SUCHFIELD, GEORGE A
• Application Number:
  US11/409,556
• Publication Number:
  US 20070045266A1
• Time in Patent Office: 1,215 Days
• Field of Search: None
• US Class Current: 166/248
• CPC Class Codes: C07C 4/02 by cracking a single hydrocarbon or a mixture of individually defined hydrocarbons or a normally gaseous hydrocarbon fraction
• CPC Class Codes: C07C 9/04 Methane production by treatment of sewage C02F11/04; natural gas, synthetic natural gas C10L3/06
• CPC Class Codes: E21B 17/028 Electrical or electro-magnetic connections
• CPC Class Codes: E21B 36/001 Cooling arrangements
• CPC Class Codes: E21B 36/04 using electrical heaters
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: E21B 43/243 Combustion in situ
• CPC Class Codes: Y10T 29/49179 by metal fusion bonding

Abstract

An in situ conversion system for producing hydrocarbons from a subsurface formation is described. The system includes a plurality of u-shaped wellbores in the formation. Piping is positioned in at least two of the u-shaped wellbores. A fluid circulation system is coupled to the piping. The fluid circulation system is configured to circulate hot heat transfer fluid through at least a portion of the piping to form at least one heated portion of the formation. An electrical power supply is configured to provide electrical current to at least a portion of the piping located below an overburden in the formation to resistively heat at least a portion of the piping. Heat transfers from the piping to the formation.

Claims

1. A method of heating a subsurface formation, comprising:

heating a heat transfer fluid;

circulating the heat transfer fluid through piping in the formation to heat a portion of the formation below an overburden, wherein the piping comprises U-shaped piping having an entrance into the formation, and an exit from the formation laterally offset from the entrance; and

applying electrical current to at least a portion of the piping to resistively heat the piping.

2. The method of claim 1, wherein the heat transfer fluid comprises carbon dioxide.

3. The method of claim 1, wherein the electrical current is time varying current.

4. The method of claim 1, wherein a portion of the piping through which heat transfer fluid is introduced into the formation has a smaller diameter than a portion of the piping below the overburden.

5. The method of claim 1, further comprising recovering heat from the heated formation by circulating water through the piping.

6. The method of claim 1, wherein circulating and/or applying electrical current heats the portion of the formation to a first temperature of at most 200°

C.

7. The method of claim 6, further comprising applying circulating heat transfer fluid to increase the temperature of the formation from the first temperature to a second temperature.

8. The method of claim 6, further comprising applying electrical current to increase the temperature of the formation from the first temperature to a second temperature.

9. The method of claim 1, wherein circulating and/or applying electrical current heats the portion of the formation to a first temperature of at most 400°

C.

10. The method of claim 1, further comprising producing formation fluid from the subsurface formation, wherein the formation fluid comprises hydrocarbons.

11. The method of claim 10, further comprising producing transportation fuel from at least a portion of the hydrocarbons.

12. A method of heating a subsurface formation, comprising:

heating a heat transfer fluid; and

circulating the heat transfer fluid through piping in the formation to heat a portion of the formation below an overburden, wherein the piping comprises U-shaped piping having an entrance into the formation, and an exit from the formation laterally offset from the entrance, and wherein a portion of the piping through which heat transfer fluid is introduced into the formation has a smaller diameter than a portion of the piping below the overburden.

13. The method of claim 12, wherein the heat transfer fluid comprises carbon dioxide.

14. The method of claim 12, further comprising recovering heat from the heated formation by circulating water through the piping.

15. The method of claim 12, wherein an entrance of piping in a first wellbore is adjacent to an exit of piping in a second wellbore so that heat transfer fluid flowing through the piping in the first wellbore travels in a direction opposite to the direction of heat transfer fluid flowing through the piping in the second wellbore.

16. The method of claim 12, wherein at least some of the piping extending through the overburden comprises insulation.

17. A method of heating a subsurface formation, comprising:

heating a heat transfer fluid;

circulating the heat transfer fluid through piping in the formation to heat a portion of the formation below an overburden, wherein a portion of the piping through which heat transfer fluid is introduced into the formation has a smaller diameter than a portion of the piping below the overburden; and

applying electrical current to at least a portion of the piping to resistively heat the piping.

18. The method of claim 17, wherein the heat transfer fluid comprises carbon dioxide.

19. The method of claim 17, further comprising recovering heat from the heated formation by circulating water through the piping.