Patent ID: 9637976
Date: 2017-05-02
CPC Classifications: E21B

Claim:
1. A drilling tool assembly for use in a drill string, the drilling tool assembly comprising: a motor comprising an eccentrically-driven rotor; a flow head comprising a plurality of ports permitting fluid communication therethrough, the flow head being coupled to a rotor of the motor to be driven thereby in eccentric rotational motion; a flow restrictor in fluid communication with the flow head, the flow restrictor comprising a plurality of ports permitting fluid communication therethrough, the flow restrictor being stationary with respect to the rotational motion of the flow head, wherein rotation of the flow head with respect to the flow restrictor causes the plurality of ports of the flow head to enter into and out of alignment with the plurality of ports of the flow restrictor such that fluid flow through the ports of the flow head and the flow restrictor is varied in an irregular pattern, the irregular pattern comprising a pattern in which an orientation of the flow head at a defined position in a cycle of the rotor is different between consecutive cycles of the rotor.