Patent ID: 7073595
Filing Date: 2006-07-11
Classification: E21B

Abstract:
1. A method for controlling pressure of a dual 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; pumping a pressure fluid down the substantially vertical well bore when drilling the drainage bore, the pressure fluid comprising a liquid and mixing with the drilling fluid to form a fluid mixture returning up the articulated well bore; wherein the fluid mixture returning up the articulated well bore forms a frictional pressure that resist fluid flow from the subterranean zone.