Systems and methods for treating a subsurface formation with electrical conductors

1. A system for treating a subsurface formation, comprising:

a wellbore at least partially located in a hydrocarbon containing formation, the wellbore comprising a substantially vertical portion and at least two substantially horizontal or inclined portions coupled to the vertical portion;

a single, first elongated conductor extending continuously along a length of a first of the two substantially horizontal or inclined portions of the wellbore, wherein the first elongated conductor comprises electrically conductive material along a length of the first elongated conductor;

a single, second elongated conductor extending continuously along a length of a second of the two substantially horizontal or inclined portions of the wellbore, wherein the second elongated conductor comprises electrically conductive material along a length of the second elongated conductor, and wherein at least a portion of the first elongated conductor and at least a portion of the second elongated conductor are vertically displaced in the formation;

wherein the first elongated conductor and the second elongated conductor comprise substantially vertical portions positioned adjacent and non-concentric in the substantially vertical portion of the wellbore with current flow in the substantially vertical portion of the first elongated conductor approximately equal and opposite to current flow in the substantially vertical portion of the second elongated conductor; and

a power supply coupled to at least the first conductor, the power supply configured to electrically excite the electrically conductive materials of the first elongated conductor such that current flows between the electrically conductive materials in the first elongated conductor, through at least a portion of the formation, to the electrically conductive materials in the second elongated conductor, and the current resistively heats at least a portion of the formation between the two substantially horizontally oriented or inclined portions of the wellbore.

2. The system of claim 1 , wherein at least a portion of the first elongated conductor and at least a portion of the second elongated conductor are substantially parallel to each other.

3. The system of claim 1 , wherein the second elongated conductor is a ground conductor.

4. The system of claim 1 , wherein an average distance between the conductive portions of the first elongated conductor and the second elongated conductor is at least 10 meters.

5. The system of claim 1 , wherein the first elongated conductor comprises a conduit.

6. The system of claim 1 , wherein the first elongated conductor comprises a perforated conduit.

7. The system of claim 1 , wherein the second elongated conductor comprises a perforated conduit.

8. The system of claim 1 , wherein at least one of the elongated conductors comprises a first layer comprising carbon steel and a second layer comprising copper, and at least a portion of the second layer substantially surrounds or partially surrounds a portion of the first layer.

9. The system of claim 1 , wherein at least one of the elongated conductors comprises a portion positioned in an overburden section and the portion comprises one or more ferromagnetic materials.

10. The system of claim 1 , wherein at least one of the elongated conductors comprises a portion positioned in an overburden section and the portion comprises at least 15 percent by weight manganese.

11. The system of claim 1 , wherein at least one of the elongated conductors comprises a portion positioned in an overburden section and the portion comprises one or more ferromagnetic materials, and one or more of the ferromagnetic materials comprises at least 10 percent by weight manganese.

12. The system of claim 1 , wherein at least one of the elongated conductors comprises a portion positioned in an overburden section and the portion comprises one or more ferromagnetic materials, and one or more of the ferromagnetic materials comprises at least 10 percent by weight manganese, at least 5 percent by weight carbon, and at least 1 percent by weight chromium.

13. The system of claim 1 , wherein at least one of the elongated conductors is located in a portion of the wellbore comprising one or more electrical insulators.

14. The system of claim 1 , wherein at least one of the elongated conductors comprises a perforated conduit, the system further comprising a fluid injection system configured to inject fluid through at least some of the perforations and into the formation.

15. The system of claim 14 , wherein the fluid comprises a drive fluid.

16. The system of claim 14 , wherein the fluid comprises a foaming composition.

17. A method for treating a subsurface formation, comprising:

providing electrical current to a first elongated conductor in a first substantially horizontal or inclined position in a section of the formation such that electrical current flows in substantially one direction from the first substantially horizontal or inclined position to a second substantially horizontal or inclined position in the section of the formation with a second elongated conductor in the second substantially horizontal or inclined position, wherein the first elongated conductor is located in a common wellbore with a substantially vertical portion and a substantially horizontal or inclined portion extending from an end of the vertical portion, wherein the second elongated conductor is located in a substantially horizontal or inclined portion coupled to the vertical portion of the common wellbore above the end of the vertical portion, wherein the first elongated conductor and the second elongated conductor comprise substantially vertical portions positioned adjacent and non-concentric in the vertical portion of the common wellbore with current flow in the substantially vertical portion of the first elongated conductor approximately equal and opposite to current flow in the substantially vertical portion of the second elongated conductor, and wherein at least a portion of the first elongated conductor and at least a portion of the second elongated conductor are vertically displaced in the formation, wherein the first elongated conductor comprises a single, elongated conductor extending continuously along the length of the wellbore portion; and

heating a least a portion of the hydrocarbon layer between the first and second elongated conductors with heat generated by the electrical current flow.

18. The method of claim 17 , wherein the first elongated conductor extends from the vertical portion of the common wellbore, and wherein at least a portion of the first elongated conductor extends horizontally or inclined from the vertical portion and the first elongated conductor comprises electrically conductive material.

19. The method of claim 17 , wherein the second elongated conductor extends from the vertical portion of the common wellbore, wherein at least a portion of the second elongated conductor is substantially parallel to the first elongated conductor; and wherein the second elongated conductor comprises electrically conductive material.

20. The method of claim 17 , further comprising creating increased fluid injectivity in at least portion of the section between the first elongated conductor and the second elongated conductor.

21. The method of claim 17 , further comprising perforating at least a portion of the first elongated conductor and/or the second elongated conductor.

22. The method of claim 17 , further comprising mobilizing at least some hydrocarbons in the formation with the generated heat.

23. The method of claim 22 , further comprising producing at least a portion of the mobilized formation fluids from the formation.

24. The method of claim 17 , further comprising injecting a foaming composition, and injecting a pressurizing fluid at a rate sufficient to foam the foaming composition in the section.

25. The method of claim 17 , further comprising injecting a pre-foamed composition.

26. The method of claim 17 , further comprising injecting a foaming composition, wherein the foaming composition comprises a surfactant.

27. The method of claim 17 , wherein at least a portion of the first elongated conductor is positioned in a shale layer of the formation.

28. The method of claim 17 , wherein the second elongated conductor is a ground conductor.

29. The system of claim 1 , wherein the first elongated conductor extends continuously along a majority of the length of the first horizontal or inclined portion of the wellbore.

30. The system of claim 1 , wherein the second elongated conductor extends continuously along a majority of the length of the second substantially horizontal or inclined portion of the wellbore.

31. The system of claim 1 , wherein current flows between the first horizontal or inclined portion of the wellbore and the second horizontal or inclined portion of the wellbore in substantially one direction.

32. The system of claim 1 , wherein little or no current flows from either the first or the second horizontal or inclined portions of the wellbore back to the same portion.

33. The system of claim 1 , wherein substantially all current provided from the power supply flows from the first elongated conductor to the second elongated conductor.

34. The system of claim 1 , wherein the first elongated conductor comprises electrically conductive material continuously along its length.

35. The method of claim 17 , wherein the second elongated conductor comprises a single, elongated conductor extending continuously along a length of the wellbore portion.

36. The method of claim 17 , wherein little or no current flows from either the first or the second substantially horizontal or inclined position back to the same position.

37. The method of claim 17 , wherein substantially all of the provided current flows from the first elongated conductor to the second elongated conductor.

38. The method of claim 17 , wherein the first elongated conductor comprises electrically conductive material continuously along its length.