利用气井动态摩阻系数预测井口流出动态

气井井下油管动态摩阻系数计算方法的提出，提高了气井垂管流动压力计算的精度，对气井生产动态分析和预测起到了很好的推动作用。借助１口干气井的多点回压法试井资料，介绍了如何利用气井稳定试井资料，确定该气井此时此刻井下油管动态摩阻系数；利用产能方程给出产量和对应的井底压力，结合油管动态摩阻系数计算井口压力，建立该井准确的井口流出动态方程并编绘井口流出动态曲线；讨论了随着地层压力递减和井下油管动态摩阻系数变化规律，井口流出动态方程或井口流出动态曲线的变化规律。气井的多点回压法试井资料的利用，可以准确地预测气井井口流出动态，从而提高采收率。

Prediction on wellhead outflow performance by dynamic friction coefficient of gas wells

With the raise of a calculation method on dynamic friction coefficient of downhole tubing, the calculating accuracy of vertical conduit flow pressure is strengthened for a gas well, which promotes the dynamic analysis and prediction on gas well production. By making use of multi points backward pressure of one dry gas well, this paper introduces how to confirm dynamic friction coefficient of downhole tubing at the exact moment through stable testing material, gives the productivity and the corresponding bottom hole pressure by using productivity equation, calculates wellhead pressure in combination with dynamic friction coefficient of tubing, establishes the correct wellhead outflow performance equation for this well, draws out wellhead outflow performance curve and discusses how wellhead outflow performance equation or wellhead outflow performance curve changes with the decrease of formation pressure or the change of wellhead outflow performance curve. It is proven that application of this multi points backward pressure method can predict outflow performance of wellhead correctly so as to raise the recovery ratio of a gas well.