Method and system for accessing subterranean deposit from the surface

• US 6,668,918 B2
• Filed: 06/07/2002
• Issued: 12/30/2003
• 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:
  US10/165,627
• Publication Number:
  US 20020148605A1
• Time in Patent Office: 571 Days
• Field of Search: 166/52, 166/50, 166/245, 166/313
• 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 subterranean drainage pattern for accessing an area of a subterranean zone, comprising:

a first well bore extending substantially horizontally from a first end of the area in the subterranean zone to a second end of the area;

a first plurality of three or more lateral well bores extending in spaced apart relation to each other from the first well bore to the periphery of the area on a first side of the first well bore;

a second plurality of three or more lateral well bores extending in spaced apart relation to each other from the first well bore to the periphery of the area on a second, opposite side of the first well bore; and

wherein the length of the lateral well bores progressively shorten on each side of the first well bore as a distance from the first end of the area increases.

2. The subterranean drainage pattern of claim 1, wherein the lateral well bores each substantially extend at an angle of between 40 and 50 degrees from the first well bore.

3. The subterranean drainage pattern of claim 1, wherein the lateral well bores each substantially extend at an angle of about 45 degrees from the first well bore.

4. The subterranean drainage pattern of claim 1, wherein the area substantially comprises a square and the ends comprise opposite ends of the square.

5. The subterranean drainage pattern of claim 1, wherein the first well bore and the lateral well bores provide substantially uniform coverage of the area.

6. The subterranean drainage pattern of claim 1, wherein the lateral well bores in each of the first and second plurality are substantially evenly spaced apart from each other.

7. The subterranean drainage pattern of claim 1, wherein the first plurality of lateral well bores mirrors the second plurality of lateral well bores.

8. The subterranean drainage pattern of claim 1, wherein the first well bore is formed sloping upwardly within the subterranean zone.

9. The subterranean drainage pattern of claim 1, wherein each of the lateral well bores comprises:

a radiused portion extending from the first well bore; and

an elongated portion extending from the radiused portion to the periphery of the area.

10. The subterranean drainage pattern of claim 1, wherein each of the first plurality of lateral well bores extend from the first well bore at a first angle, and wherein each of the second plurality of lateral well bores extend from the first well bore at a second angle, the first angle different than the second angle.

11. The subterranean drainage pattern of claim 1, wherein the lateral well bores of the first plurality of lateral well bores are disposed substantially parallel to each other.

12. The subterranean drainage pattern of claim 11, wherein the lateral well bores of second plurality of lateral well bores are disposed substantially parallel to each other.

13. The subterranean drainage pattern of claim 1, wherein the first and second plurality of lateral well bores each comprise four or more lateral well bores.

14. The subterranean drainage pattern of claim 1, wherein the first and second plurality of lateral well bores each comprise five or more lateral well bores.