Patent ID: 7025154
Filing Date: 2006-04-11
Classification: E21B,E21F

Abstract:
1. A method for circulating drilling fluid in a well system, comprising: drilling a substantially vertical well bore from a surface to a subterranean zone; drilling an articulated well bore from the surface to the subterranean zone using a drill string, the articulated well bore horizontally offset from the substantially vertical well bore at the surface and intersecting the substantially vertical well bore at a junction proximate the subterranean zone; drilling a drainage bore from the junction into the subterranean zone; pumping a drilling fluid through the drill string when drilling the drainage bore, the drilling fluid exiting the drill string proximate a drill bit of the drill string; providing fluid down the substantially vertical well bore through a tubing, the tubing having an opening at the junction such that the fluid exits the tubing at the junction; and wherein a fluid mixture returns up the substantially vertical well bore outside of the tubing, the fluid mixture comprising the drilling fluid after the drilling fluid exits the drill string.