| 摘要 |
An easy break-out tool joint (10) (two embodiments) comprising a drive spindle (stem), or sub (12, 12a) having a shoulder ring (32, 32a) whose shoulder (34) is axially movable but rotatable with the sub (12, 12a) to form a conventionally shouldered (34, 58) drill pipe joint so that, upon rotation in one direction, torque is applied in the conventional manner for drilling or back reaming. The shoulder (34) is initially axially moved relative to the drive sub to disconnect the shoulder (34, 58) when the drive stem is rotated in the opposite, or break-out direction, thereby reducing the torque required for break-out to only that torque necessary to unthread the joint. In the practice of the method of triple back reaming utilizing this easy break-out tool joint, a drilling unit (140, 160) is lowered to the platform and the drive spindle or sub (12, 12a) is connected to the top drill pipe of the string, while the string is held by a spider (156) at the platform level. The string is then rotated as the drill pipe string is withdrawn from the well bore. When the last of the joints in the stand (three lengths of drill pipe) is above the spider (156), the raising and rotation of the drill pipe string is stopped and the drill pipe string is then held by spiders (156). At this, the drive stem (12, 12a) is powered to break-out the joint at the top of the stand. Thereafter, the stand is still held by the rig elevators and appropriate tongs (162, 164) are applied to break the joint at the platform level, thus freeing the stand for movement out of the rig drive axis. The above procedure is repeated until the drill pipe string has been withdrawn. |
