HYBRID BIT WITH MECHANICALLY ATTACHED ROLLER CONE ELEMENTS

摘要

A modular hybrid bit is disclosed comprising a plurality of fixed blades and at least one rolling cutter assembly that is mechanically fastened to the bit body by a plurality of mechanical fasteners. The rolling cutter assembly can be adjusted to change the axial and radial exposure of the rolling cutter elements.

主权项

1. A hybrid drill bit comprising:
a body having a plurality of blades, each blade comprising a plurality of earth formation cutting elements; at least one rolling cutter assembly pocket formed into the body and comprising a first torque-reacting structure, wherein the pocket is disposed between adjacent blades; at least one rolling cutter assembly comprising a head onto which a cutter element is rotatably coupled; the head comprising a second torque-reacting structure configured to operatively engage the first torque reacting structure, and a plurality of mechanical fastener openings; a plurality of mechanical fasteners configured to securely and removably couple the at least one rolling cutter assembly to the pocket; a locking structure formed on a portion of at least one fastener and configured to provide an interference fit between the locking structure and an associated fastener opening in the head; a plurality of locking caps each configured to engage an exposed portion of a fastener and prevent relative rotation between the fastener and the cap; and a plurality of weldments engaging at least a portion of each locking cap and configured to prevent dislodgment of the caps from the fastener and to prevent relative rotation between the cap and the body.