Wellbore pattern for uniform access to subterranean deposits

• US 6,439,320 B2
• Filed: 02/20/2001
• Issued: 08/27/2002
• 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): Bagnell, David
• Assistant Examiner(s): Kreck, John
• Application Number:
  US09/791,033
• Publication Number:
  US 20010010432A1
• Time in Patent Office: 553 Days
• Field of Search: 166/245, 166/50, 166/52, 166/313, 175/61, 175/62
• US Class Current: 175/61
• 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 substantially horizontal subterranean drainage pattern for accessing a substantially quadrilateral area of a subterranean zone, comprising:

forming a substantially horizontal diagonal well bore extending diagonally from a first corner of the substantially quadrilateral area to a distant corner of the quadrilateral area;

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

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

2. The method of claim 1, wherein the length of the lateral well bores progressively decreases as the distance from the first corner of the quadrilateral area increases.

3. The method of claim 1, wherein the lateral well bores each substantially extend at an angle of between 40 and 50 degrees from the diagonal well bore.

4. The method of claim 1, wherein the lateral well bores each substantially extend at an angle of about 45 degrees from the diagonal well bore.

5. The method of claim 1, wherein the area substantially comprises a square and the corners comprise opposite comers of the square.

6. The method of claim 1, wherein the substantially horizontal diagonal and lateral well bores provide substantially uniform coverage of the area.

7. The method of claim 1, wherein the lateral well bores in each of the first and second plurality of substantially horizontal lateral well bores are substantially evenly spaced from each other.