| 摘要 |
PURPOSE: To easily remove and repair a wellhead part by selectively suppressing a longitudinal motion of a mandrel relative to a sleeve assembly and installing a locking ratchet device to unlock the setting of a packer. CONSTITUTION: When a repair unit is disposed in a well hole with a moving tool 20 and a hydraulically-operated telescoping device is operated, a towing block 30 is engaged with a casing wall part 14 and provides a tension to an outer sleeve assembly 26. Next, the mandrel 22 is moved downward, and a ratchet surface 62 of the mandrel 22 is forced to be engaged with a lower ratchet nut 64 so as to set a packer 16 preliminarily. When an upward tension is given to the mandrel 22 by a tool 20, an assembly 26 is pulled up. Then, a tension bolt is broken and a releasing/tightening support sleeve 98 becomes detachable from the mandrel 22. In addition, the engagement of a J-hooking assembly 104 and the tool 20 is disengaged to remove the sleeve 98 from the packer 16 and the well hole 14, and then the wellhead operation is performed. |
