US Patent 10989004 Shock and agitator tool

A shock and agitator tool assembly vibrates a drill string to overcome stick slip and other friction-based problems that may occur during directional drilling. The agitator tool portion of the assembly, which can be used without the shock tool, allows for controlled activation and deactivation of the agitator tool by the use of one or more darts pumped downhole. The darts can be retrieved with a wireline tool. When activated, the agitator portion creates alternating pressure pulses. These pulses cause axial movement of the drill string above the agitator. A shock tool is described which utilizes a telescoping mandrel to amplify the axial movement created by the agitator tool.