Patent ID: 6725922
Filing Date: 2004-04-27
Classification: E21B,Y02C

Abstract:
A subterranean drainage pattern for accessing an area of a subterranean zone comprising:a main well bore extending from a surface well bore located at a first end of the area to a second end of the area, the main well bore traversing a substantially horizontal plane; a first plurality of lateral well bores extending in spaced apart relation to each other from the main well bore to the periphery of the area on a first side portion of the main well bore, wherein the length of each of the lateral well bore progressively shortens as a distance between a respective lateral well bore and the surface well bore increases; a second plurality of lateral well bores extending in spaced apart relation to each other from the main well bore to a periphery of the area on a second, opposite side portion of the main well bore, wherein the length of each of the lateral well bore progressively shortens as a distance between a respective lateral well bore and the surface well bore increases; and a first plurality of ramping well bores extending in spaced apart relation to each other from an upper portion of the main well bore, the first plurality of ramping well bores extending in a substantially vertical plane toward an upper boundary of the subterranean zone; and a second plurality of ramping well bores extending in spaced apart relation to each other from a lower portion of the main well bore, the second plurality of ramping well bores extending in a substantially vertical plane toward a lower boundary of the subterranean zone.