在复杂结构井的钻进工作中,水力振荡器能大幅降低井壁摩阻、提高机械钻速,脉冲压力发生单元是该工具的重要组成部件.采用CFD仿真技术基于端面密封式旋转阀系统的端面开口角α、开口圆弧内外径R和r及安装间隙h等3种结构参数对脉冲压力进行了数值模拟,研究了其结构参数对脉冲压力波形和幅值的影响规律,并应用回归分析的方法建立了脉冲压力与阀系过流面积之间的回归方程.结果表明:该阀系的结构参数及安装间隙通过改变液体在流道内的流通性,进而影响脉冲压力峰值和高压带宽范围,且基本不改变脉冲压力波形的变化规律;端面开口角α对高压脉冲宽度影响显著,开口圆弧内外径R和r对脉冲压力的极值影响较大,且会使脉冲压力曲线局部发生不规则波动;安装间隙h主要影响阀系高压幅值.提供了一种水力振荡器脉冲压力设计的经验公式,对水力振荡器的研究具有重要的参考及应用价值.%During the drilling of structurally complex wells, hydraulic oscillator can reduce the wall friction significantly and in-crease the rate of penetration (ROP). And pulse pressure generating unit is one of its important components. In this paper, pulse pressure was numerically simulated using CFD simulation technology based on three structural parameters of end-face sealed rotary valves, i.e., end-face open angle (α), inner and outer radius of open arc (R and r) and installation clearance (h). Then, the effect laws of structural parameters on the form and amplitude of pulse pressure wave were investigated, and the regression equation between pulse pressure and valve open area was established by means of regression analysis. It is indicated that the structural parameters and installation clearance of this series of valves affect the peak pulse pressure and the range of high-pressure band width by changing the flowability of fluid in flow channels, while the change laws of pulse pressure wave form is basically unchanged. The effect of end-face open angle (α) on the width of high pressure pulse is obvious. Inner and outer radius of open arc (R and r) have stronger effect on the extreme pulse pressure, and lead to irregular fluctuation locally in the pulse pressure curve. Installation clearance (h) mainly affects the high pressure amplitude.Finally, an empirical formula for the design of pulse pressure of hydraulic oscillator was provided, and it can be used as the reference and guidance for the study on hydraulic oscillators.
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