Method and system for enhanced access to a subterranean zone

• US 6,598,686 B1
• Filed: 01/24/2001
• Issued: 07/29/2003
• Est. Priority Date: 11/20/1998
• Status: Expired due to Term

• Current Assignee: Effective Exploration LLC
• Original Assignee: CDX Gas LLC (EnerVest Ltd.)
• Inventors: Zupanick, Joseph A
• Primary Examiner(s): TSAY, FRANK
• Application Number:
  US09/769,098
• Time in Patent Office: 916 Days
• Field of Search: 166/50, 166/52, 166/245, 166/263, 175/61, 175/69, 175/62
• US Class Current: 175/62
• CPC Class Codes: E21B 43/006 Production of coal-bed methane E21B43/243 takes precedence
• CPC Class Codes: E21B 43/305 comprising at least one inclined or horizontal well
• CPC Class Codes: E21B 47/09 Locating or determining the position of objects in boreholes or wells , e.g. the position of an extending arm; Identifying the free or blocked portions of pipes
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003
• CPC Class Codes: E21F 7/00 Methods or devices for drawing- off gases with or without subsequent use of the gas for any purpose

Abstract

A system for enhanced access to subterranean zone from the surface includes a well bore pattern having a first well bore extending from a surface well bore substantially defining a first end of the area in the subterranean zone to a distant end of the area. The pattern also includes a plurality of lateral well bores extending outwardly from the first well bore. The distance from an end of a lateral well bore to the surface well bore may be configured to be substantially equal for each of the lateral well bores to facilitate forming the lateral well bores. The system and method may also include nesting two or more well bore patterns within the subterranean zone to provide uniform coverage of the zone. Additionally, the system and method may include multiple well bore patterns in communication with a common surface well bore to reduce the surface area required for accessing the subterranean zone.

Claims

1. A subterranean well bore pattern for accessing an area of a subterranean zone from the surface, comprising:

a first well bore extending from a surface well bore substantially defining a first end of the area in the subterranean zone to a distant end of the area; and

a plurality of lateral well bores extending outwardly from the first well bore, wherein a distance from an end of a lateral well bore to the surface well bore is substantially equal for each of the lateral well bores.

2. The well bore pattern of claim 1, wherein the plurality of lateral well bores comprises:

a first set of lateral well bores extending outwardly from a first side of the first well bore; and

a second set of lateral well bores extending outwardly from a second side of the first well bore.

3. The well bore pattern of claim 2, further comprising a third set of lateral well bores extending outwardly from the first and second sets of lateral well bores.

4. The well bore pattern of claim 1, wherein the plurality of lateral well bores each extend to a periphery of the area.

5. The well bore pattern of claim 1, wherein each of the plurality of lateral well bores are substantially evenly spaced from each other.

6. The well bore pattern of claim 1, wherein at least one of the plurality of lateral well bores comprises:

a first radiused portion extending from the first well bore;

a second radiused portion extending from the first radiused portion; and

an elongated portion extending from the second radiused portion.

7. The well bore pattern of claim 6, wherein the second radiused portion extends toward the surface well bore.

8. The well bore pattern of claim 1, wherein the area substantially comprises a quadrilateral, and wherein the ends comprise distant end of the quadrilateral.

9. The well bore pattern of claim 8, wherein each of the plurality of lateral well bores extends to a periphery of the quadrilateral.

10. A method for accessing an area of a subterranean zone from the surface, comprising:

forming a first well bore extending from a surface well bore substantially defining a first end of the area in the subterranean zone to a distant end of the area; and

forming a plurality of lateral well bores extending outwardly from the first well bore, wherein a distance from an end of a lateral well bore to the surface well bore is substantially equal for each of the lateral well bores.

11. The method of claim 10, wherein forming the plurality of lateral well bores comprises:

forming a first set of lateral well bores extending outwardly from a first side of the first well bore; and

forming a second set of lateral well bores extending outwardly from a second side of the first well bore.

12. The method of claim 10, wherein forming the plurality of lateral well bores comprises:

forming a first set of lateral well bores extending outwardly from a first side of the first well bore;

forming a second set of lateral well bores extending outwardly from a second side of the first well bore; and

forming a third set of lateral well bores extending outwardly from the first and second sets of lateral well bores.

13. The method of claim 10, wherein forming the plurality of lateral well bores comprises extending each of the plurality of lateral well bores to a periphery of the area.

14. The method of claim 10, wherein forming the plurality of lateral well bores comprises disposing each of the plurality of lateral well bores substantially evenly spaced from each other.

15. The method of claim 10, wherein forming at least one of the plurality of lateral well bores comprises:

forming a first radiused portion extending from the first well bore;

forming a second radiused portion extending from the first radiused portion; and

forming an elongated portion extending from the second radiused portion.

16. The method of claim 15, wherein forming the second radiused portion comprises extending the second radiuses portion toward the surface well bore.

17. The method of claim 10, wherein forming the first well bore and the plurality of lateral well bores comprises disposing the first well bore and the plurality of lateral well bores to form a substantially quadrilateral area, wherein the ends of the first well bore comprise distant end of the quadrilateral area.

18. The method of claim 17, wherein forming the plurality of lateral well bores further comprises extending each of the lateral well bores to a periphery of the quadrilateral area.

19. The method of claim 10, wherein forming the plurality of lateral well bores comprises:

forming a first set of lateral well bores extending outwardly from a first side of the first well bore; and

forming a second set of lateral well bores extending outwardly from a second side of the first well bore, the second side opposite from the first side.

20. The method of claim 19, wherein forming the first and second sets of lateral well bores comprises forming each of the first set of lateral well bores opposite a corresponding one of the second set of lateral well bores.

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

a first well bore pattern extending from a surface well bore, the first well bore pattern forming a first substantially quadrilateral area; and

a second well bore pattern extending from the surface well bore, the second well bore pattern forming a second substantially quadrilateral area, and wherein a first side of the first quadrilateral area is disposed substantially in common with a first side of the second quadrilateral area.

22. The system of claim 21, wherein each of the first and second well bore patterns comprises:

a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area; and

a plurality of lateral well bores extending outwardly from the first well bore.

23. The system of claim 22, wherein a distance from an end of a lateral well bore to the surface well bore is substantially equal for each of the lateral well bores.

24. The system of claim 21, wherein each of the first and second well bore patterns comprises:

a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area;

a first set of lateral well bores extending outwardly from the first well bore; and

a second set of lateral well bores extending outwardly from the first set of lateral well bores.

25. The system of claim 21, wherein each of the first and second well bore patterns comprise:

a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area; and

a plurality of lateral well bores extending outwardly from the first well bore, each of the plurality of lateral well bores substantially equally spaced apart from each other.

26. The system of claim 21, further comprising a third well bore pattern extending from the surface well bore, the third well bore pattern forming a third substantially quadrilateral area, and wherein a first side of the third quadrilateral area is disposed substantially in common with a second side of the first quadrilateral area.

27. The system of claim 21, wherein each of the first and second well bore patterns comprise:

a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area; and

a plurality of lateral well bores extending outwardly from the first well bore, a length of each of the lateral well bores decreasing as a distance from a respective lateral well bore and the surface well bore increases.

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

forming a first well bore pattern in the form of a first substantially quadrilateral area, the first well bore pattern extending from a surface well bore; and

forming a second well bore pattern in the form of a second substantially quadrilateral area, the second well bore pattern extending from the surface well bore, and wherein a first side of the first quadrilateral area is disposed substantially in common with a first side of the second quadrilateral area.

29. The method of claim 28, wherein forming each of the first and second well bore patterns comprises:

forming a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area; and

forming a plurality of lateral well bores extending outwardly from the first well bore.

30. The method of claim 29, wherein forming the plurality of lateral well bores comprises forming the lateral well bores such that a distance from an end of a lateral well bore to the surface well bore is substantially equal for each of the lateral well bores.

31. The method of claim 28, wherein forming each of the first and second well bore patterns comprises:

forming a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area;

forming a first set of lateral well bores extending outwardly from the first well bore; and

forming a second set of lateral well bores extending outwardly from the first set of lateral well bores.

32. The method of claim 28, wherein forming each of the first and second well bore patterns comprises:

forming a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area; and

forming a plurality of lateral well bores extending outwardly from the first well bore, each of the plurality of lateral well bores substantially equally spaced apart from each other.

33. The method of claim 28, further comprising forming a third well bore pattern in the form of a third substantially quadrilateral area, the third well bore pattern extending from the surface well bore, and wherein a first side of the third quadrilateral area is disposed substantially in common with a second side of the first quadrilateral area.

34. The method of claim 28, wherein forming each of the first and second well bore patterns comprises:

forming a first well bore extending from the surface well bore, the first well bore extending from a first end to a distant end of a respective quadrilateral area; and

forming a plurality of lateral well bores extending outwardly from the first well bore, a length of each of the lateral well bores decreasing as a distance from a respective lateral well bore and the surface well bore increases.

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

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

a plurality of well bore patterns disposed within the subterranean zone each extending in a different direction from the surface well bore, the plurality of well bore patterns symmetrically disposed about the surface well bore.

36. The system of claim 35, wherein each of the plurality of well bore patterns comprises:

a first well bore extending outwardly from the surface well bore; and

a plurality of lateral well bores extending outwardly from the first well bore.

37. The system of claim 36, wherein the lateral well bores are disposed substantially evenly spaced apart from each other.

38. The system of claim 36, wherein a length of a respective lateral well bore decreases as a distance from the respective lateral well bore to the surface well bore increases.

39. The system of claim 36, wherein a distance from each of the lateral well bores to the surface well bore is substantially equal.

40. The system of claim 35, wherein each of the plurality of well bore patterns forms a substantially quadrilateral shape.

41. The system of claim 35, wherein each of the well bore patterns comprises:

a first well bore extending from the surface well bore;

a first set of lateral well bores extending outwardly from a first side of the first well bore; and

a second set of lateral well bores extending outwardly from a second side of the first well bore.

42. The system of claim 41, wherein each of the first set of lateral well bores is disposed opposite a corresponding one of the second set of lateral well bores.

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

forming a surface well bore extending from the surface to the subterranean zone; and

forming a plurality of well bore patterns disposed within the subterranean zone each extending in a different direction from the surface well bore, the plurality of well bore patterns symmetrically disposed about the surface well bore.

44. The method of claim 43, wherein forming each of the plurality of well bore patterns comprises:

forming a first well bore extending outwardly from the surface well bore; and

forming a plurality of lateral well bores extending outwardly from the first well bore.

45. The method of claim 44, wherein forming the lateral well bores comprises disposing each of the lateral well bores substantially evenly spaced apart from each other.

46. The method of claim 44, wherein forming the lateral well bores comprises forming each lateral well bore such that a length of the lateral well bore decreases as a distance from the respective lateral well bore to the surface well bore increases.

47. The method of claim 44, wherein forming the lateral well bores comprises forming each of the lateral well bores such that a distance from each of the lateral well bores to the surface well bore is substantially equal.

48. The method of claim 43, wherein forming each of the plurality of well bore patterns comprises forming each of the plurality of well bore patterns having a substantially quadrilateral shape.

49. The method of claim 43, wherein forming each of the well bore patterns comprises:

forming a first well bore extending from the surface well bore;

forming a first set of lateral well bores extending outwardly from a first side of the first well bore; and

forming a second set of lateral well bores extending outwardly from a second side of the first well bore.

50. The method of claim 49, wherein forming the first and second sets of lateral well bores comprises forming each of the first set of lateral well bores opposite a corresponding one of the second set of lateral well bores.

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

a first well bore pattern disposed within the subterranean zone extending from a first surface well bore; and

a second well bore pattern disposed within the subterranean zone extending from a second surface well bore, the first and second well bore patterns configured to nest adjacent each other within the subterranean zone.

52. The method of claim 51, wherein each of the first and second well bore patterns comprises:

a first well bore extending from a respective surface well bore; and

a plurality of lateral well bores extending outwardly from the first well bore.

53. The system of claim 51, wherein each of the first and second well bore patterns comprises:

a plurality of main well bores extending outwardly from a respective surface well bore; and

a plurality of lateral well bores extending outwardly from each of the plurality of main well bores.

54. The system of claim 53, wherein the plurality of main well bores are symmetrically disposed about the respective surface well bore.

55. The system of claim 53, wherein a length of each of the lateral well bores decreases as a distance between the respective lateral well bore and a respective surface well bore increases.

56. The system of claim 51, wherein each of the first and second well bore patterns comprises:

a plurality of main well bores extending outwardly from a respective surface well bore;

a first set of lateral well bores extending outwardly from a first side of each of the plurality of main well bores; and

a second set of lateral well bores extending outwardly from a second side of each of the main well bores.

57. The system of claim 56, wherein each of the first set of lateral well bores is disposed opposite a corresponding one of the second set of lateral well bores.

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

forming a first well bore pattern extending from a first surface well bore and disposed within the subterranean zone; and

forming a second well bore pattern extending from a second surface well bore and disposed within the subterranean zone, the first and second well bore patterns arranged to nest adjacent each other within the subterranean zone.

59. The method of claim 58, wherein forming each of the first and second well bore patterns comprises:

forming a first well bore extending from a respective surface well bore; and

forming a plurality of lateral well bores extending outwardly from the first well bore.

60. The method of claim 58, wherein forming each of the first and second well bore patterns comprises:

forming a plurality of main well bores extending outwardly from a respective surface well bore; and

forming a plurality of lateral well bores extending outwardly from each of the plurality of main well bores.

61. The method of claim 60, wherein forming the plurality of main well bores comprises forming the plurality of main well bores symmetrically disposed about the respective surface well bore.

62. The method of claim 60, wherein forming the lateral well bores comprises forming each of the lateral well bores having a length that decreases as a distance between the respective lateral well bore and a respective surface well bore increases.

63. The method of claim 58, wherein forming each of the first and second well bore patterns comprises:

forming a plurality of main well bores extending outwardly from a respective surface well bore;

forming a first set of lateral well bores extending outwardly from a first side of each of the plurality of main well bores; and

forming a second set of lateral well bores extending outwardly from a second side of each of the main well bores.

64. The method of claim 63, wherein forming each of the first set of lateral well bores comprises forming each of the first set of lateral well bores opposite a corresponding one of the second set of lateral well bores.

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

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

forming a second well bore extending from the surface to the subterranean zone, the second well bore intersecting the first well bore at a junction proximate the subterranean zone;

forming a well bore pattern within the subterranean zone extending from the junction using a drill string extending downwardly through the second well bore;

supplying drilling fluid downwardly through the drill string to remove cuttings generated by the drill string; and

minimizing down-hole pressure within the subterranean zone by pumping the drilling fluid and the cuttings to the surface through the first well bore.

66. The method of claim 65, wherein forming the second well bore comprises forming the second well bore offset from the first well bore at the surface.

67. The method of claim 65, wherein forming the second well bore comprises forming the second well bore extending from the first well bore at a location between the surface and the subterranean zone.

68. The method of claim 65, wherein forming the well bore pattern comprises:

forming a main well bore extending from the junction; and

forming a plurality of lateral well bores extending outwardly from the main well bore.

69. The method of claim 65, wherein forming the well bore pattern comprises:

forming a main well bore extending from the junction;

forming a first plurality of lateral well bores extending outwardly from the main well bore; and

forming a second plurality of lateral well bores extending from the first plurality of lateral well bores.

70. The method of claim 65, wherein forming the well bore pattern comprises:

forming a main well bore extending from the junction; and

forming a plurality of lateral well bores extending outwardly from the main well bore, a length of each of the lateral well bores decreasing as a distance from the respective lateral well bore and the junction increases.

71. The method of claim 65, further comprising forming an enlarged cavity at the junction of the first and second well bores.