Patent ID: 7621350
Filing Date: 2009-11-24
Classification: E21B

Abstract:
1. An earth boring bit, comprising: a diamond impregnated crown having an axis of rotation, a gage area, and a plurality of blades formed thereon; a first set of channels formed between some of the blades and extending outward to the gage area, each channel of the first set of channels having an enlarged width area joining a diverging width area that increases in width to the gage, the junction between the enlarged width area and the diverging width being smaller in width than a maximum width of the enlarged width area; a nozzle port formed in each of the enlarged width areas; a nozzle releasably fastened to each of the nozzle ports; a second set of channels formed between some of the blades and extending outward to the gage area; and a fixed port located in each channel of the second set of channels, each of the fixed ports being of smaller diameter than each of the nozzle ports and not having any of the nozzles therein.