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.
JIEEMUSU ENU SUTORITSUKURANDO
CHIYAARUZU II RANKASUTAA
RICHIYAADO RII PAAMAA
