Multi-well structure for accessing subterranean deposits

• US 6,732,792 B2
• Filed: 02/20/2001
• Issued: 05/11/2004
• Est. Priority Date: 11/20/1998
• Status: Expired due to Fees

• Current Assignee: Effective Exploration LLC
• Original Assignee: CDX Gas LLC (EnerVest Ltd.)
• Inventors: Zupanick, Joseph A.
• Primary Examiner(s): Shackelford, Heather
• Assistant Examiner(s): Kreck, John
• Application Number:
  US09/788,897
• Publication Number:
  US 20020148647A1
• Time in Patent Office: 1,176 Days
• Field of Search: 166/245, 166/50, 166/52, 175/61, 175/62
• US Class Current: 166/50
• CPC Class Codes: E21B 43/006 Production of coal-bed methane E21B43/243 takes precedence
• CPC Class Codes: E21B 43/13 specially adapted to dewatering of wells of gas producing reservoirs, e.g. methane producing coal beds
• 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

Improved method and system for accessing subterranean deposits from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a horizontal cavity well. The drainage patterns provide access to a large subterranean area from the surface while the vertical cavity well allows entrained water, hydrocarbons, and other deposits to be efficiently removed and/or produced.

Claims

1. A structure for accessing a region of a subterranean zone, comprising:

a first substantially vertical well bore substantially defining an end of a first area in the region;

a second substantially vertical well bore substantially defining an end of a second area in the region adjacent to the first area;

a first articulated well bore intersecting the first substantially vertical well bore at a first junction;

a second articulated well bore intersecting the second substantially vertical well bore at a second junction;

a first substantially horizontal diagonal well bore extending from the first junction in line with the first articulated well bore to a distant end of the first area;

a second substantially horizontal diagonal well bore extending from the second junction in line with the second articulated well bore to a distant end of the second area; and

each diagonal well bore comprising a plurality of substantially horizontal lateral well bores extending from the diagonal well bore to a periphery of the area containing the diagonal well bore.

2. The structure of claim 1, wherein the lateral well bores extending from each of the diagonal well bores comprise:

a first set of lateral well bores extending from the diagonal well bore to the periphery of the area on a first side of the diagonal well bore; and

a second set of lateral well bores extending from the diagonal well bore to the periphery of the area on a second, opposite side of the diagonal well bore.

3. The structure of claim 2, wherein the lateral well bores are substantially evenly spaced from each other.

4. The structure of claim 2, wherein the lateral well bores are progressively shorter as they progress away from the substantially vertical well bore of the area.

5. The structure of claim 1, further comprising:

a third substantially vertical well bore substantially defining an end of a third area;

a fourth substantially vertical well bore substantially defining an end of a fourth area;

a third articulated well bore intersecting the third substantially vertical well bore at a third junction;

a fourth articulated well bore intersecting the fourth substantially vertical well bore at a fourth junction;

a third substantially horizontal diagonal well bore extending from the third junction in line with the third articulated well bore to a distant end of the third area; and

a fourth substantially horizontal diagonal well bore extending from the fourth junction in line with the fourth articulated well bore to a distant end of the fourth area.

6. The structure of claim 5, wherein the first, second, third, and fourth articulated well bores extend from a common location at a surface above the subterranean zone.

7. The structure of claim 1, wherein the first and second articulated well bores extend from a common location at a surface above the subterranean zone.

8. A structure for accessing a region of a subterranean zone, comprising:

a first well bore substantially defining an end of a first area in the region;

a second well bore substantially defining an end of a second area in the region adjacent to the first area;

a third well bore intersecting the first well bore at a first junction;

a fourth well bore intersecting the second well bore at a second junction;

a fifth well bore extending from the first junction in line with the third well bore to a distant end of the first area;

a sixth well bore extending from the second junction in line with of the fourth well bore to a distant end of the second area; and

a plurality of lateral well bores extending from each of the fifth and sixth well bores to a periphery of the respective first and second areas.

9. The structure of claim 8, wherein the lateral well bores extend from opposite sides of each of the respective fifth and sixth well bores.

10. The structure of claim 8, wherein the lateral well bores are substantially evenly spaced from each other.

11. The structure of claim 8, wherein the lateral well bores progressively shorten as a distance between a respective lateral well bore and the respective first and second junction increases.

12. The structure of claim 8, further comprising:

a seventh well bore substantially defining an end of a third area;

an eighth well bore substantially defining an end of a fourth area;

a ninth well bore intersecting the seventh well bore at a third junction;

a tenth well bore intersecting the eighth well bore at a fourth junction;

an eleventh well bore extending from the third junction in line with the ninth well bore to a distant end of the third area; and

a twelfth well bore extending from the fourth junction in line with the tenth well bore to a distant end of the fourth area.

13. The structure of claim 8, further comprising an enlarged cavity disposed in each of the first and second well bores at the respective first and second junctions.

14. The structure of claim 8, wherein each of the lateral well bores comprises:

a radiused portion extending from a respective fifth and sixth well bore; and

an elongated portion extending from the radiused portion to the periphery of the corresponding first and second area.

15. The structure of claim 8, wherein the first and second areas comprise substantially quadrilateral areas.

16. The structure of claim 8, wherein the fifth and sixth well bores are disposed substantially within a horizontal plane of the subterranean zone.

17. The structure of claim 8, wherein the fifth and sixth well bores are disposed sloping upwardly within the subterranean zone.

18. The structure of claim 8, wherein the third and fourth well bores extend from a common location at a surface above the subterranean zone.

19. The structure of claim 12, wherein the third, fourth, ninth, and tenth well bores extend from a common location at a surface above the subterranean zone.