| 摘要 |
A drilling apparatus includes a drill string, a drilling head located at a first end of the drill string, a drilling fluid pump located at a second end of the drill string, wherein the drilling fluid pump pumps a drilling fluid along the length of the drill string to the drilling head, and a traveling wave generator coupled to the drill string at a location downstream of the drilling fluid pump, wherein the traveling wave generator generates a series of ramped pressure pulses that are applied to the drilling fluid. The ramped pressure pulses are compressed by a reduction of the cross-sectional area of the drill string, and further by time compression caused by varying propagation rates of different portions of the pressure pulses pressure pulse if substantially formed at a surface of a drilling substrate. A shock wave associated with the compressed pressure pulse is generated substantially at the location of a surface of a drilling substrate. The traveling wave generator includes a gas chamber, a heating element located in the gas chamber, and a control unit for controlling the operation of the heating element to generate the ramped pressure pulses. A drilling rate detection mechanism is also provided to supply drilling rate data to the control unit, which adjusts the timing of the ramped pressure pluses based on the drilling rate data to control the formation point of the shock wave.
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