METHOD AND APPARATUS FOR HYDRAULIC STEERING OF DOWNHOLE ROTARY DRILLING SYSTEMS

摘要

A technique is used to control the direction of a drill bit or bottom hole assembly via hydraulic steering utilizing a plurality of steering pads. A portion of hydraulic fluid, e.g. drilling fluid, is directed under pressure to a pad interface region proximate each pad. The hydraulic fluid provides additional force against a surrounding wall and/or reduces or eliminates contact between the pads and the surrounding wall.