Self-anchoring device with force amplification
AssigneeSchlumberger Technology Corporation
InventorsTodor K. Sheiretov, Dwight C. Chilcoat, Robin A. Ewan, Carl J. Roy, Matthew Billingham, Franz Aguirre
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Abstract
A downhole tool is provided that includes a grip assembly for contacting a well formation. The grip assembly includes a gripper body; and a centralizer that is attached to and radially expandable with respect to the gripper body and that has a geometry which is lockable by a locking device. The grip assembly also includes a force amplifier in force transmitting relation with the centralizer, wherein the force amplifier transfers a force in a first direction to a much larger force in a second direction when the centralizer is locked by the locking device.
Claims23
A downhole tool comprising a grip assembly for contacting a well formation, the grip assembly comprising:
- a gripper body;
- a centralizer that is attached to and radially expandable with respect to the gripper body and that has a geometry which is lockable by a locking device;
- a force amplifier in force transmitting relation with the centralizer, wherein the force amplifier transfers a force in a first direction to a much larger force in a second direction when the centralizer is locked by the locking device.
The downhole tool of claim 10, wherein the force amplifier is a hydraulic force amplifier.
A downhole tractor comprising:
- first and second grip assemblies each having a power stroke and a return stroke;
- wherein the first grip assembly comprises a plurality of first engagement members, each for contacting a well formation;
- wherein the second grip assembly comprises a plurality of second engagement member, each for contacting a well formation;
- wherein the plurality of first engagement members each remain in contact with the well formation during both the power stroke and the return stroke of the first grip assembly;
- and
- wherein the plurality of second engagement members each remain in contact with the well formation during both the power stroke and the return stroke of the second grip assembly.
Dependencies are inferred from the claim text.