Method and system for accessing subterranean deposits from the surface and tools therefor

1. A system for accessing a subterranean zone from the surface, comprising:

a substantially vertical well bore extending from the surface to the subterranean zone;

an articulated well bore extending from the surface to the subterranean zone, the articulated well bore horizontally offset from the substantially vertical well bore at the surface and intercepting the substantially vertical well bore at a junction proximate to the subterranean zone;

a substantially horizontal drainage pattern extending from the junction into the subterranean zone; and

the subterranean zone comprising shale.

2. The system of claim 1 , further comprising an enlarged cavity formed in the substantially vertical well bore at the junction.

3. The system of claim 1 , wherein the substantially horizontal drainage pattern comprises a plurality of lateral well bores.

4. The system of claim 1 , wherein the substantially horizontal drainage pattern comprises a main well bore extending from the junction and a plurality of well bores extending from each side of the main well bore.

5. The system of claim 1 , wherein the substantially horizontal drainage pattern comprises:

a substantially horizontal diagonal well bore extending from the junction defining a first end of an area in the subterranean zone to a distant end of the area;

a first set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a first side of a diagonal well bore; and

a second set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a second, opposite side of the diagonal well bore.

6. A system for accessing a shale subterranean zone from the surface, comprising:

a first well bore extending from the surface to the shale subterranean zone;

a second well bore extending from the surface to the shale subterranean zone;

the first and second well bores coupled to each other at a junction proximate the shale subterranean zone; and

a substantially horizontal drainage well bore coupled to the junction in the shale subterranean zone.

7. The system of claim 6 , further comprising an enlarged cavity formed in the first well bore at the junction.

8. The system of claim 6 , wherein the first well bore comprises a substantially vertical well bore.

9. The system of claim 6 , wherein the second well bore comprises an articulated well bore.

10. The system of claim 6 , wherein the second well bore is offset from the first well bore at the surface.

11. The system of claim 6 , wherein the drainage well bore comprises a substantially horizontal drainage pattern.

12. The system of claim 11 , wherein the substantially horizontal drainage pattern comprises a plurality of well bores.

13. The system of claim 11 , wherein the substantially horizontal drainage pattern comprises a main well bore coupled to the junction and a plurality of well bores extending from each side of the main well bore.

14. The system of claim 11 , wherein the substantially horizontal drainage pattern comprises a substantially horizontal diagonal well bore coupled to the junction defining a first end of an area in the shale subterranean zone to a distant end of the area;

a first set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a first side of a diagonal well bore; and

a second set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a second, opposite side of the diagonal well bore.

15. A method for accessing a subterranean shale zone from the surface, comprising:

drilling a substantially vertical well bore extending from the surface to the subterranean shale zone;

drilling an articulated well bore from the surface to the subterranean shale zone, the articulated well bore intercepting the substantially vertical well bore at a junction proximate to the subterranean shale zone; and

drilling a substantially horizontal drainage pattern extending from the junction into the subterranean shale zone.

16. The method of claim 15 , further comprising forming an enlarged cavity in the substantially vertical well bore at the junction.

17. The system of claim 15 , wherein the articulated well bore is spaced apart from the substantially vertical well bore at the surface.

18. The system of claim 15 , wherein the substantially horizontal drainage pattern comprises a plurality of lateral well bores.

19. The system of claim 15 , wherein drilling the substantially horizontal drainage pattern comprises drilling a main well bore extending from the junction and a plurality of well bores extending from each side of the main well bore.

20. The system of claim 15 , wherein drilling the substantially horizontal drainage pattern comprises:

drilling a substantially horizontal diagonal well bore extending from the junction defining a first end of an area in the subterranean shale zone to a distant end of the area;

drilling a first set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a first side of a diagonal well bore; and

drilling a second set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a second, opposite side of the diagonal well bore.

21. A system for accessing a subterranean zone from the surface, comprising:

a substantially vertical well bore extending from the surface to the subterranean zone;

an articulated well bore extending from the surface to the subterranean zone, the articulated well bore horizontally offset from the substantially vertical well bore at the surface and intercepting the substantially vertical well bore at a junction proximate to the subterranean zone;

a substantially horizontal drainage pattern extending from the junction into the subterranean zone; and

the subterranean zone comprising a low permeability zone.

22. The system of claim 21 , further comprising an enlarged cavity formed in the substantially vertical well bore at the junction.

23. The system of claim 21 , wherein the substantially horizontal drainage pattern comprises a plurality of lateral well bores.

24. The system of claim 21 , wherein the substantially horizontal drainage pattern comprises a main well bore extending from the junction and a plurality of well bores extending from each side of the main well bore.

25. The system of claim 21 , wherein the substantially horizontal drainage pattern comprises:

a substantially horizontal diagonal well bore extending from the junction defining a first end of an area in the subterranean zone to a distant end of the area;

a first set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a first side of a diagonal well bore; and

a second set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a second, opposite side of the diagonal well bore.

26. A system for accessing a subterranean zone from the surface, comprising:

a first well bore extending from the surface to the subterranean zone;

a second well bore extending from the surface to the subterranean zone;

the first and second well bores coupled to each other at a junction proximate the subterranean zone;

a substantially horizontal drainage pattern coupled to the junction in the subterranean zone, the substantially horizontal drainage pattern comprising a plurality of well bores; and

the subterranean zone comprising shale.

27. A system for accessing a subterranean zone from the surface, comprising:

a first well bore extending from the surface to the subterranean zone;

a second well bore extending from the surface to the subterranean zone;

the first and second well bores coupled to each other at a junction proximate the subterranean zone;

a substantially horizontal drainage pattern coupled to the junction in the subterranean zone, the substantially horizontal drainage pattern comprising a main well bore coupled to the junction and a plurality of well bores extending from each side of the main well bore; and

the subterranean zone comprising shale.

28. A system for accessing a subterranean zone from the surface, comprising:

a first well bore extending from the surface to the subterranean zone;

a second well bore extending from the surface to the subterranean zone;

the first and second well bores coupled to each other at a junction proximate the subterranean zone;

a substantially horizontal drainage pattern coupled to the junction in the subterranean zone, the substantially horizontal drainage pattern comprises:

a substantially horizontal diagonal well bore coupled to the junction defining a first end of an area in the subterranean zone to a distant end of the area;

a first set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a first side of a diagonal well bore; and

a second set of substantially horizontal lateral well bores in spaced relation to each other extending from the diagonal well bore to the periphery of the area on a second, opposite side of the diagonal well bore; and

the subterranean zone comprising shale.