DRILL PIPE

摘要

A drill pipe (10) having an elongate tubular body (12) with an interior surface enclosing a main bore (14), a side port (16) provided in an exterior surface of the tubular body (12), a side bore (18) extending through the body (12) from the main bore (14) to the side port (16), and a valve assembly (20, 22) which is operable to substantially prevent flow of fluid along the main bore (14) and to substantially prevent flow of fluid along the side bore (18), wherein the valve assembly (20, 22), side port (16) and side bore (18) are provided in a first connection portion (10a) of the drill pipe (10), the length of the connection portion (10a) being less than 64 cm.