Patent ID: 6595303
Filing Date: 2003-07-22
Classification: E21B

Abstract:
A rotary steerable drilling tool, comprising:(a) a mandrel; (b) a housing mounted on the mandrel for rotation in relation to the mandrel; (c) an adjustable offset mechanism on the housing, the adjustable offset mechanism being surface adjustable to move the rotary steerable drilling tool to and from a straight ahead drilling position and an offset drilling position, wherein the adjustable offset mechanism comprises plural pistons radially mounted in the housing, the plural pistons being radially adjustable by actuation of the mandrel, wherein the plural pistons comprise first and second pistons located on opposed sides of the housing, the first piston being extended and the second piston being retracted in the straight ahead drilling position, and the first piston being retracted and the second piston being extended in the offset drilling position, and wherein the pistons are actuated by a cam sleeve mounted on the mandrel; (d) wings mounted on the mandrel and operable by fluid pressure within the mandrel into a radially extended position; and (e) the wings cooperating with the cam sleeve to drive the second piston outward and retract the first piston when the wings are in the extended position.