水力振荡器流道口形状对阀前后脉冲压力幅值影响规律研究

水力振荡器流道口过流面积的周期性改变可以产生周期性压力脉冲周期性压力脉冲传到振荡短节,在蝶形弹簧的作用下,使振荡短节外壳产生周期性的轴向振动,从而使钻柱与井壁的静摩擦变为动摩擦,有效降低了摩阻,提高了钻压传递效率和钻进速度。水力振荡器的振荡效果很大程度上取决于轴向冲击力的大小和变化频率,即取决于流道口过流面积的变化规律。而在相同条件下不同形状的流道口过流面积的变化规律不同。为了获得更高效的水力振荡器,在一种涡轮式水力振荡器的研究基础上,分别采用矩形流道口、菱形流道口和圆形流道口进行流道口形状优化设计。通过对数值仿真得到的数据进行対比分析,发现菱形流道口的降摩减阻的效果优于另外两种流道口。

Study on the influence of the shape of the flow channel of the hydraulic oscillator on the pulse pressure amplitude before and after the valve

the periodic flow area of hydraulic oscillator runner changes can produce periodic pulse pressure, pulse pressure to periodic oscillation in short, butterfly spring under the action of axial vibration of the oscillating short shell produce periodic, so that the static friction of drill string and borehole wall to reduce friction. The friction and improve the transmission efficiency of the drilling pressure and drilling speed. The effect of hydraulic oscillation oscillator depends largely on the axial impact force and change of frequency variation depends on the flow orifice area. Under the same conditions, changes the flow area of different shapes and different channel in order to obtain a more efficient hydraulic oscillator, based on a hydraulic turbine type oscillator, using rectangular channel, channel of mouth shape optimization design of diamond runner and round runner. Through the numerical simulation data were compared and analyzed, and found that diamond outlet not only in the scope of application is superior to the rectangular, circular runner outlet and the reduction of friction reduction resistance effect is better than the other two channel at the mouth of the effect.