| 摘要 |
A double shoulder tool joint, whose a sealing surface (including a pin sealing surface and a box sealing surface) is less subject to damages so that the tool joint has excellent liquid sealability when the drill pipes are interlocked and used, is provided. A double shoulder tool joint includes a box having a box access sleeve including a first contact surface perpendicular to a pipe axis, a female threaded portion having a taper relative to the pipe axis, a box backward sleeve including a second contact surface perpendicular to the pipe axis, and a pin having a pin base including a third contact surface to contact the first contact surface, a male threaded portion to be screwed and engaged to the female threaded portion, a pin nose including a fourth contact surface perpendicular to the pipe axis to contact the second contact surface. The double shoulder tool joint further includes a guard portion including a fifth contact surface provided in a tip portion of the box extended forward from the first contact surface or a sixth contact surface provided in a tip portion of the pin extended forward from the fourth contact surface. |
