Patent ID: 7726415
Filing Date: 2010-06-01
Classification: E21B

Abstract:
1. An earth-boring bit comprising: a bit body having one end configured for connection into a drill string, a generally opposite cutting end, and defining a longitudinal axis; a plurality of pilot section blades arranged in rows on the cutting end of the bit body, such that each pilot section blade opposes another pilot section blade; a plurality of pilot section cutting elements arranged in rows on the pilot section blades such that each pilot section cutting element on one pilot section blade occupies the same radial and longitudinal position on the pilot section blade as a corresponding pilot section cutting element on the opposing pilot section blade; a plurality of shock studs arranged on the pilot section blades rotationally trailing the pilot section cutting elements, the shock studs protecting the pilot section cutting elements against over-engagement with the formation; a plurality of reaming section blades arranged longitudinally above the pilot section blades such that each reaming section blade opposes another reaming section blade, the reaming section blades defining a gage diameter larger than that of the pilot section blades; a plurality of reaming section cutting elements arranged in rows on the reaming section blades such that each reaming section cutting element on one reaming section blade occupies the same radial and longitudinal position on the reaming section blade as a corresponding reaming section cutting element on the opposing reaming section blade; and at least one fluid nozzle arranged in the bit body such that upon disintegration of at least a portion of the plurality of reaming section blades, fluid flow through the fluid nozzle is restricted, indicating bit failure.