Drilling rig and method for introducing one or more drilling pipes into an underbalanced well using same

Abstract

A drilling rig includes a mast to be placed above or close to a well and a device connected to the mast for carrying drill pipes to be lowered into the well, which carrying device includes at least three carriers which are connected at different heights to the mast and displaceable in height direction therealong and which are adapted to exert a pulling force or a pressing force as required on the drill pipes. The upper carrier can have a device for rotatingly driving the drill pipes, while the lower carrier, which can be connected releasably to the mast, can have a flexible device for connecting thereof to a blowout preventer placed on the well. A method for introducing one or more drill pipes into an underbalanced well while making use of such a drilling rig includes suspending the drill pipe(s) from the carrying device and urging the pipe(s) downward into the well while exerting a pressing force.

Dependencies are inferred from the claim text.