Patent ID: 6962216
Filing Date: 2005-11-08
Classification: E21B

Abstract:
1. An underreamer for forming cavity from within a well bore, comprising: a housing adapted to be disposed within the well bore; at least one cutter, each cutter having a first end and a second end, the first end of each cutter pivotally coupled to the housing; an actuator positioned in the housing, the actuator having a first end and a second end; an enlarged portion of the actuator proximate the second end of the actuator; wherein a first force applied to the actuator is operable to move the actuator relative to the housing causing the enlarged portion to contact each cutter and extend the second end of each cutter radially outward relative to the housing from a retracted position to a first position; and wherein an axial force applied to the underreamer is operable to further extend the second end of each cutter radially outward relative to the housing from the first position to a second position.