Smith International, Inc.

Richard C Lyon

William M Conn

Jerry Ensminger

A rotary cone rock bit for use in earthen formations with drilling fluid hydraulics wherein diffusion type nozzles are utilized in the outer diameters of a dome portion of the rock bit resulting in fluid, as it leaves the exit end of the nozzle, continues to diffuse outboard creating a larger surface area to entrain fluid. The diffused spray of fluid at a lesser velocity will better clean the rotary cones by moving the fluid closer to the cones without erosive damage to the cones or loss of cutter inserts or milled teeth. The diffused spray will additionally cover a larger area of a borehole bottom resulting in better bottom hole cleaning.

Rock bit nozzle diffuser

A method to back ream a borehole drilled with a roller cone drill bit is taught. Protruding hard metal cutting inserts are affixed on the upper outside diameter tapered shoulder of each of the bit legs. If the borehole closes to a smaller diameter than the bit gage diameter or loose rock rubble packs around the upper portion of the bit, the protruding cutting inserts fixed on the upper leg tapered shoulder portion back ream the borehole by lifting and rotating the bit.

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Denver, CO, United States of America

Richard C Lyon