摘要 |
A string of drill pipe, for example, is assembled with a severing sub in anticipation of a possible need to cut the string at some point in the operation. The severing sub includes a thin wall tube that links opposite end tool joint bosses. The tin wall tube is easily cut by a shaped charge cutter. Rotary drive torque is transmitted between the sub tool join bosses by a concentric external torque tube having a torque transmitting assembly at each boss. The torque tube connection to the upper boss has an inseparable circumferential shoulder engagement with the boss. The lower boss engagement of the torque tube is axially separable. When the thin wall tube is cut, the upper boss and torque tube is withdrawn from the well with the upper pipe string. |