REAMING SHOE FOR INCREASED BOREHOLE CLEARANCE

摘要

An articulated reaming tool is provided in casing or liner drilling on or through the tubular wall with the articulation occurring from within the tubular. Outer limit travel stops are contemplated to optionally be used to retain the elements or blades to the tubular. In the case of liner drilling the drill string has an exterior protrusion to engage the movable components that ream and extend them to increase the clearance for the tubular as the tubular advances when more hole is made.