CONTINUOUS CIRCULATION DRILLING METHOD

摘要

Apparatus for connecting or disconnecting tubular to and from a drill string while continuously rotating the drill string in a bore hole comprising: (a) first means for positioning a tubular above a drill string in axial alignment; (b) rotary gr ip means for gripping the drill string; and (c) motorized means connected to the rota ry grip means for rotating the drill string relative to the tubular and continuously rotating the drill string in the bore hole while simultaneously connecting or disconnecting the tubular to and from the drill string.