Patent ID: 9004198
Filing Date: 2015-04-14
Classification: E21B

Abstract:
1. A hybrid drill bit for use in drilling through subterranean formations, the hybrid drill bit comprising: a bit body having longitudinal centerline defining an axial center of the bit, and at least one fixed blade extending in the axial direction downwardly from the bit body; at least one rolling cutter leg mounted to the bit body and extending in the axial direction downwardly from the bit body, the rolling cutter leg comprising a spindle assembly at the distal end of the rolling cutter leg; a rolling cutter coupled to each of the at least one rolling cutter legs and rotatably disposed about the spindle assembly, the rolling cutter having a plurality of interior recesses; at least one rolling-cutter cutting element arranged on the rolling cutter and radially spaced apart from the axial center; and a plurality of fixed cutting elements arranged on the at least one fixed blade; wherein the spindle assembly comprises a journal pin disposed at the base of the spindle, a pilot pin adjacent the nose end of the journal pin, and a shoulder region intermediate between the journal pin and the pilot pin, both the journal pin and the pilot pin extending along an axis of rotation of the spindle, wherein the spindle assembly further comprises a bearing assembly comprising: wherein the PDC or diamond bearing elements are arranged such that when the rolling cutter is mounted on the spindle assembly, the bearing elements are in alignment with correspondingly shaped and spaced bearing elements on at least one interior surface of the rolling cutter.