A method for controlling pressure of a dual well system includes drilling a substantially vertical well bore from a surface to a subterranean zone and drilling an articulated well bore from the surface to the subterranean zone using a drill string. The articulated well bore is horizontally offset from the substantially vertical well bore at the surface and intersects the substantially vertical well bore. The method includes drilling a drainage bore into the subterranean zone. The method includes pumping a drilling fluid through the drill string when drilling the drainage bore. The method includes pumping a pressure fluid down the substantially vertical well bore when drilling the drainage bore. The pressure fluid mixes with the drilling fluid to form a fluid mixture returning up the articulated well bore which forms a frictional pressure that resists fluid flow from the subterranean zone.