Subterranean drainage pattern

• US 6,575,235 B2
• Filed: 04/15/2002
• Issued: 06/10/2003
• 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., Rial, Monty H.
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): KRECK, JOHN J
• Application Number:
  US10/123,556
• Publication Number:
  US 20020117297A1
• Time in Patent Office: 421 Days
• Field of Search: 166/52, 166/50, 166/245
• US Class Current: 166/50
• CPC Class Codes: E21B 43/006 Production of coal-bed methane E21B43/243 takes precedence
• CPC Class Codes: E21B 43/305 comprising at least one inclined or horizontal well
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003

Abstract

A method and system for accessing subterranean zones from the surface includes a substantially vertical well bore extending from the surface to a target zone, and an articulated well bore extending from the substantially vertical well bore to the target zone. The articulated well bore diverges from the substantially vertical well bore between the surface and the target zone. The system also includes a well bore pattern extending from the articulated well bore in the target zone operable to collect resources from the target zone. The system also includes a subsurface channel operable to communicate resources from the well bore pattern to the substantially vertical well bore. The system further includes a vertical pump disposed in the substantially vertical well bore and operable to lift resources collected in the substantially vertical well bore to the surface.

Claims

1. A substantially horizontal subterranean drainage pattern for accessing an area of a subterranean zone from the surface, comprising:

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

a first set of substantially horizontal lateral well bores extending in a spaced apart relation to each other from the diagonal well bore to a periphery of the area on a first side of the diagonal well bore;

a second set of substantially horizontal lateral well bores extending in a spaced apart relation to each other from the diagonal well bore to a periphery of the area on a second side of the diagonal well bore opposite the first side; and

wherein a first lateral of the first set and a first lateral of the second set each include a short reversal of radius proximate to the substantially horizontal diagonal well bore.

2. The subterranean drainage pattern of claim 1, wherein a length of the lateral well bores progressively decreases as a distance from the lateral well bores to the surface well bore increases.

3. 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 diagonal well bore.

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

5. The subterranean drainage pattern of claim 1, wherein the area comprises a substantially quadrilateral area, and wherein the first and second ends comprise distant corners of the substantially quadrilateral area.

6. The subterranean drainage pattern of claim 1, wherein the area comprises a substantially square area, and wherein the first and second ends comprise distant corners of the square area.

7. The subterranean drainage pattern of claim 1, wherein the substantially horizontal diagonal well bore and the first and second sets of lateral well bores provide substantially uniform coverage of the area.

8. The subterranean drainage pattern of claim 1, wherein each of the lateral well bores of the first and second sets are disposed in a substantially uniform spaced apart relationship to each other.