Method for accessing subterranean deposits from the surface

• US 6,688,388 B2
• Filed: 06/07/2002
• Issued: 02/10/2004
• 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:
  US10/165,625
• Publication Number:
  US 20020148613A1
• Time in Patent Office: 613 Days
• Field of Search: 175/61, 175/62, 166/245, 166/50, 166/52, 166/313
• US Class Current: 166/245
• 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 method for forming a subterranean drainage pattern for accessing an area of a subterranean zone, comprising:

forming 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;

forming 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; and

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

2. The method of claim 1, wherein forming the first and second plurality of lateral well bores comprises forming each of the lateral well bores extending substantially at an angle of between 40 and 50 degrees from the first well bore.

3. The method of claim 1, wherein forming the first and second plurality of lateral well bores comprises forming each of the lateral well bores extending substantially at an angle of about 45 degrees from the first well bore.

4. The method of claim 1 wherein the substantially quadrilateral area comprises a substantially square area.

5. The method of claim 1, wherein forming the first well bore and the first and second plurality of lateral well bores comprises forming the first well bore and the first and second plurality of lateral well bores to provide substantially uniform coverage of the area.

6. The method of claim 1, wherein forming the first and second plurality of lateral well bores comprises forming each of the lateral well bores substantially evenly spaced apart from each other.

7. The method of claim 1, wherein forming each of the second plurality of lateral well bores comprises forming each of the second plurality of lateral well bores to mirror one of the first plurality of lateral well bores on the opposite side of the first well bore.

8. The method of claim 1, wherein forming each of the lateral well bores comprises:

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

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

9. The method of claim 1, wherein forming the first and second plurality of lateral well bores comprises:

forming each of the first plurality of lateral well bores extending from the first well bore at a first angle; and

forming each of the second plurality of lateral well bores extending from the first well bore at a second angle, the first angle being different than the second angle.

10. The method of claim 1, wherein forming the first and second plurality of lateral well bores comprises forming the lateral well bores of each plurality of lateral well bores substantially parallel to each other.

11. The method of claim 1, wherein the first and second plurality of lateral well bores each comprise four or more lateral well bores.

12. The method of claim 1, wherein the first and second plurality of lateral well bores each comprise five or more lateral well bores.