Patent ID: 9546536
Date: 2017-01-17
CPC Classifications: E21B

Claim:
1. A vibrating tool for use with a casing string in finishing a wellbore, the tool comprising: a housing having an inlet and an outlet, the housing being installable in the casing string; and a variable flow resistance device in the housing, the device comprising a flow path with a vortex chamber and a switch to alternate the direction of flow in the vortex chamber between clockwise and counterclockwise; wherein the variable flow resistance device is configured so that, when the vibrating tool is installed in the casing string and fluid is pumped through the casing string, the device will cause repetitive interruptions of fluid flow through the vibrating tool to generate cyclic hydraulic loading on the casing string, thereby causing repeated extension and contraction of the casing string sufficient to reduce the drag force on the casing string thereby facilitating advancement of the casing string down the wellbore.