| 摘要 |
A single piece, tubular mandrel extends centrally through a closely surrounding composite outer body. The outer body includes metal anchoring slips and resilient packers to respectively anchor the outer body and supporting central mandrel to a surrounding well pipe and to seal the annular space formed between the mandrel and the surrounding well pipe. The outer body includes setting components which are moved axially by hydraulic setting pressure introduced through the mandrel into expandable chamber means formed in the outer body. The setting components wedge under the anchoring slips and axially foreshorten the packer, forcing the slips and packer radially outwardly into engagement with the surrounding well conduit. Reverse axial movement of the setting components is prevented by a one-way acting friction lock which retains the anchoring slips and packer in engagement with the well conduit even after reduction of the hydraulic setting pressure. The anchoring slips and packers are released from their set position by moving the mandrel axially with respect to the expanded slips and packer in the outer body. Undesired relative movement of the mandrel is prevented by a pressure expanded, normally retracted mechanical hold-down linkage extending between the mandrel and the set outer body. In the absence of a pressure differential across the set packer, the mechanical linkage returns to a normally retracted position which provides no obstacle to relative movement between the mandrel and outer body.
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