摘要 |
The invention relates to a tool having a valve (3c, 4c) for closing the tubing (100) of a well into which the tool has been placed. The valve member (4c) is controlled by means of a traction cable (17) via a hydraulic mechanism having two piston-and-cylinder assemblies (4b, 5e, 45; 1g, 4a, 41) which reduce the force applied on the valve member (4c) by the pressure of the fluid in the well and which amplify the force (f) applied thereto by the cable (17) in order to open said valve member.
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