Patent ID: 8905163
Filing Date: 2014-12-09
Classification: E21B,Y10T

Abstract:
1. A rotary drill bit operable to form a wellbore in a downhole formation comprising: a bit body having one end operable for connection to a drill string; a bit rotational axis extending through the bit body; a bit face profile defined in part by a plurality of blades disposed on exterior portions of the bit body; each blade having an associated gage pad; a plurality of cutting elements disposed on exterior portions of each blade; a respective first cutting element disposed on each blade at a respective first radial distance from the bit rotational axis, wherein the respective first radial distance for at least one blade varies from the respective first radial distance for at least one other blade; a respective last cutting element disposed on each blade adjacent to the associated gage pad, each last cutting element disposed on each blade at the same height measured parallel to the bit rotational axis; the other cutting elements disposed on exterior portions of each blade between the respective first cutting element and the respective last cutting element; a gage cutter disposed on each blade in the associated gage pad immediately adjacent to the respective last cutting element; a respective gap formed between adjacent cutting elements on each blade, wherein the respective gap between adjacent cutting elements on at least one blade varies from the respective gap between adjacent cutting elements on at least one other blade; each cutting element operable to form a kerf in adjacent portions of the downhole formation in response to rotation of the drill bit; and the respective last cutting element of each blade operable to form a kerf overlapping with at least portions of kerfs formed by each of the respective last cutting elements of the other blades.