TORQUE-BASED ELEMENT Russian patent published in 2016 - IPC E21B23/14 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a downhole tool extending in a longitudinal direction, comprising a tool housing; an arm assembly movable between a retracted position and a projecting position in relation to tool housing; an arm activation assembly arranged in tool housing for moving arm assembly between retracted position and projecting position,. Arm activation assembly comprises a piston chamber extending in longitudinal direction of downhole tool, a piston member arranged inside piston chamber and movable in longitudinal direction of downhole tool. Arm activation assembly further comprises a torque member comprising a first fluid channel for supplying hydraulic fluid from a pump to arm assembly. Torque member is connected with arm assembly and torque member is rotated by movement of piston member, whereby arm assembly is moved. Furthermore, invention relates to a tool string system comprising a plurality of downhole tools, wherein at least one of downhole tools is a downhole tool according to invention.

EFFECT: improved efficiency of a downhole tool.

14 cl, 15 dwg