Cavitating and structured jets for mechanical bits to increase drilling rate

The erosion and cleaning effect of jets is enhanced when the degree of cavitation occurring on or near the bottom of the hole is increased. Self-excited, acoustically resonating nozzles cause jets to be structured with large discrete vortex rings that promote cavitation to depths several times greater than for conventional jets. The new nozzle designs are shown to be suitable for existing mechanical drill bits and may even affect hole cleaning in the absence of cavitation. 16 refs.