rotary bit

The impact-rotary drilling technique and its tendency;

液动冲击旋转钻井技术及其发展趋势

The developing trend and inherent drive force for rotary drilling are pointed out.

对油气钻井的关键技术、理论基础及多学科的交叉特点进行了阐述 ,指明了旋转钻井的发展趋势与内在动力 ,并对 2 1世纪油气钻井技术进行了展望。

Based on analysis of application prospects of rotary drilling in petroleum drilling, this paper presents the structure and working principle of the new hydraulic kicker.

在分析了冲击旋转钻井技术在石油钻井中的应用前景的基础上，介绍了新型液动冲击器结构及工作原理；并根据往复泵的能量方程推导了液动冲击器的单次冲击功、能量利用率和冲击频率的计算公式，并利用实测数据进行了验证。

Drilled caisson pile construction technology by rotary drill;

旋转钻机钻孔灌注桩施工技术

Based on the principle of conversation of energy,the energy for rotary drilling has been analyzed.

旋转钻进是岩土工程钻探的主要钻进方式,从能量守恒原理出发,对旋转钻进的能量进行分析。