New Friction Coefficient Explicit Equation of Annular Flow with Polymer Drag Reducer

Author of the article:LiLei1 ， Dai Xiaodong1,2 ,Hao Yongchao1

Author's Workplace：1.College of Petroleum Engineering， Shengli College， China University of Petroleum， DongYing， Shandong， 257000 China; 2.Post-Doctoral Working Station of National University Science Park， China University of Petroleum ( EastChina) ， DongYing， Shandong， 257100， China

Key Words：Poiymer drag reducer; Annular flow; Friction coefficient; Curve fitting; Least square method

Abstract：Adding polymer drag reducer in to the oil pipeline is an effective method to achieve the goal of reducing the resistance and consumption.In order to predict the friction coefficient of the annular flow with polymer drag reducer， the dimensional analysis and curve fitting were carried out through the previous experimental data， and the new explicit equation was derived based on the logarithmic velocity distribution and power law distribution of the boundary layer.Then， the equation was calibrated by the 1east square method， and the friction coefficient was predicted for the gas-liquid mixture with polymer drag reducer.Taking the drag reduction rate as scale standard， the calculation results were compared with the experimental data and the results of Al-Sarkhi， and it was found that the explicit equation had better experimental data fitting and the mean absolute percentage error is reduced to 0.062 .The results also showed the predicted  va1ue of drag reduction rate decreased with the increase of superficial gas velocity.