| 摘要 |
A hydraulic well packer for releasable setting within a well casing is disclosed. The packer includes a hydraulic actuator assembly mounted between annular packing seal elements and anchor slips, with the seal elements, hydraulic actuator assembly and anchor slips being mounted for sliding movement along the packer mandrel. Premature retraction of the setting cylinder relative to the piston is prevented by interlocking action of a shear screw lock and a transfer lug against the piston, setting cylinder and a tubular setting wedge. The piston is locked against the anchor slips and the slip housing so that seals mounted on the piston head which engage the mandrel and the setting cylinder cannot be dragged and worn out prematurely in response to hydraulic pressure fluctuations imposed after the packer has been set and sealed. The setting piston and setting cylinder are locked together during run-in by the shear screw and by interlocking engagement of the transfer lug. The transfer lug is shifted to provide a direct interlocking engagement between the setting piston and the setting wedge assembly after hydraulic pressurization has been initiated to a level sufficient to cause separation of the shear screw. According to this arrangement, the shear screw lock is substantially isolated with respect to the weight of the well packer and any production equipment connected to the packer and can only be sheared in response to the application of a hydraulic setting force developed by introduction of hydraulic pressure through a tubing string.
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