Experimental study of rock breaking by a three wing, abrasive jet assisted drill bit
Abstract：A theoretical basis for improved drilling in rock was developed through a mechanical analysis of rock breaking by a three wing, abrasive, water jet assisted drill bit. Erosion of pre- fabricated cement test samples was performed. An experimental abrasive jet with a convergent nozzle was designed for these tests. Results show that rock breaking ability of the jet first in- creases and then decreases parabolically as a function of erosion depth at a constant pump pres- sure and concentration of abrasive. There appears to be an optimum distance from target to substrate. The rate of fragmentation decreases with increasing specimen hardness. The opti- mum distance from target to substrate does not change, however. The optimum distance does increase with an increase in pump pressure and changes to the accelerating segment length within the nozzle have a strong effect on the optimum length. Drilling efficiency through com- pacted sandstone can be increased by 63.4% when using abrasive jet assisted bits.
Keywords：abrasive jetthree wing drilling bitmechanical analysisrock breakingexperi-mental study
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 212-218 )