| 摘要 |
<p>A drill pipe (10) having an elongate tubular body (12) with an interior surface enclosing a main bore (14) which extends generally parallel to a longitudinal axis (A) of the tubular body (12) from a first end to a second end of the tubular body (12), 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) at the first end thereof, the first connection portion (10a) comprising a thickened portion of the tubular body (12) in which the separation of the interior surface and the exterior surface is substantially greater than the adjacent portion of the tubular body (12), the length of the connection portion (10a) parallel to the longitudinal axis (A) of the tubular body (12) being less than 64 cm.</p> |
