percussion drilling

Jamming often takes place during percussion rotary drilling.

用冲击回转式凿岩机凿岩时卡钎是经常发生的.

According to the field applications of jet type hydraulic percussion tools, the main problems which affect the development rotary percussion drilling technology are put forward. At last several opinions are concluded about how to improve the efficiency of rotary percussive drilling tools.

并根据射流式液动冲击器现场试验应用，阐述了影响冲击旋转钻进技术发展的的主要问题，提出了提高冲击旋转钻井工具应用效果的几点看法。

CZ-1200 percussion drill was developed to improve and perfect the performances and structures of CZ-22 cable percussion Rig used in diaphragm wall, bored pile and water well drilling engineering in China.

针对目前国内防渗墙、灌注桩桩孔施工及水井钻凿的主要设备CZ-22型钢绳冲击式钻机在使用过程中的一些不足之处，研制开发了CZ-1200型冲击钻机。

For a long time, they used percussion drilling-which basically means they hammered away at the ground to get as deep as they could get.

很长时间里他们用冲击钻井&基本上就是不停地砸地面，直到砸不动。

It is difficult to calculate the penetration rate ( ROP ) of percussion drilling.

钻井机械钻速预测是难题.

Diamond drilling replaced percussion drilling.

金钻探取代了冲击钻探.