HYBRID DRILL BITS HAVING INCREASED DRILLING EFFICIENCY

摘要

A hybrid earth-boring drill bit (611), comprising a bit body (613) having a face, wherein said hybrid earth-boring drill bit (611) comprises roller cone support arms (617, 619) and fixed blades (623, 625) extending radially outward from ends located proximate a central axis of the bit body, wherein the further comprise a saddle mount assembly (660) proximate the central axis of the bit body and the roller cones (629, 631) are rotatably mounted on spindles (670) projecting outwardly from the saddle mount assembly (660).