大位移井循环压耗精确计算方法研究及应用

Precise Method of Calculating Circulating Pressure Loss in Extended Reach Wells (ERW)

对现有大量的压耗计算方法进行了研究分析,提出了适合于大位移井循环压耗计算的不同流变模式泥浆流动的流态判别和摩阻系数计算方法,建立了钻杆接头对钻杆内压耗的影响系数计算式和井下动力钻具压耗计算方法。基于传统钻井循环压耗计算方法,结合大位移井特点,提出了大位移井循环压耗的精确计算方法,验证结果表明,该方法能够较大幅度降低误差,从而能为大位移井水力参数计算和设计提供帮助。

The method to distinguish flow regime and calculate friction factor for ERW was selected based on analysis on available pressure calculating methods.The influential coefficient of joint on pressure loss in drill pipe and the way to calculate the downhole motor pressure loss were also proposed.On the base of traditional calculating methods and in combination with characteristics of ERW,the precise method to calculate circulating pressure loss in ERW was proposed.The calculating result shows that this method can reduce the discrepancy greatly and is helpful for hydraulics design and calculation in ERW.