Patent ID: 6098728
Filing Date: 2000-08-08
Classification: E21B

Abstract:
A rotary bit for drilling a wellbore, comprising:a bit body to receive drilling fluid under pressure, said bit body having a plurality of depending legs extending from an outer periphery of its lower end, each leg spaced from the other legs:a plurality of roller cutters, one for each leg, comprising a generally conical cutter body rotatably mounted on the respective leg and a plurality of cutting elements on the cutter body engageable with a bottom of the wellbore;said bit body formed having at least a first and second opening between at least one pair of said legs and located near said periphery;said first opening positioned on said bit body in a location where it can accept a first nozzle for directing drilling fluid directly at the borehole bottom;said second opening is positioned on said bit body in a location where it can accept a second nozzle for directing drilling fluid initially toward an adjacent roller cutter.