Abstract: An optimal model is proposed for predicting the pressure drop of two-phase flow in gas well tubing and annulus,based on the measured data from the gas field of southwest Sichuan,China.The liq-uid holdup in tubing is modeled as a function of dimensionless gas and liqiuid velocity numbers,as well as liquid viscosity number.And the liquid holdup in annulus is modeled as functions of ratio of gas and liquid superficial velocity,density and viscocity.Absolute error as goal function,the coefficients in the liquid holdup correlation and the modification factor of absolute roughness are optimized,based on the field flowing data and the minimum pressure drop.This model is evaluated by using 37 wells field data,23 in tubing and 14 in annulus,and compared with five commonly applied empirical correlation.The results of this model are satisfied and made closerto actually one.Sensitivity of the model to liquid/gas ratio is also presented.

Key words: liquid gas well, artificial lift, annulus flow, two-phase flow, pressure gradients, optimal model

摘要： 根据川西南威远气田大水量气井现场测试数据,建立了举升油管和油套环空气液两相流压降优化模型.将油管内的持液率模化为气相、液相无因次速度和液相无因次粘度的函数;环空流动的持液率模化为气相与液相折算速度、密度和粘度三个相对量的函数.以最小计算压降与实测值的平均绝对误差作为目标函数,优化持液率关系式的参数值和管壁粗糙度修正系数.经综合评价表明,对于大水量气井条件下,新模型的计算结果与现场数据十分吻合,其性能明显优于所比较的5个常用经验相关式.文中还对此模型进行了水气比敏感性分析.

关键词: 产液气井, 人工举升, 环空流动, 两相流动, 压力梯度, 优化模型