| 摘要 |
A drilling module includes a rotary drill-bit; an oscillator configured to apply high frequency axial oscillatory loading to the rotary drill-bit, a vibro transmission section connecting the rotary drill-bit and the oscillator, for transmiting the high frequency axial oscillatory loading from the oscillator to the rotary drill-bit; a vibrational isolation unit for connecting the drilling module to a drill-string, which isolates the high frequency axial oscillatory loading from the drill-string; sensors for taking downhole measurements; and a controller configured to operate downhole under closed loop real-time control by utilizing the downhole measurements from the sensors to control the oscillator by varying the high frequency axial oscillatory loading responsive to conditions of material through which the rotary drill-bit is passing to establish and maintain oscillation system resonance between the oscillator, the rotary drill-bit and the material through which the rotary drill-bit is passing whereby the high frequency axial oscillatory loading is sufficient to initiate cracks in the material through which the rotary drill-bit is passing. -- ~ ~ ~ ------------------ Figure |
