CUTTING STRUCTURE FOR CASING DRILLING UNDERREAMER

摘要

An underreamer earth-boring tool is connected to a bottom hole assembly for casing drilling applications. The underreamer has a tubular body with a longitudinal axis. Arms are pivotally mounted to the body and movable between retracted and extended positions. An array of cutting elements is mounted to each of the arms. Each of the arrays is swept back so that the cutting elements farther from the axis than others rotationally lag the others.