凝析气井生产系统分析方法

A METHOD FOR ANALYSING PRODUCTION SYSTEM OF GAS CONDENSATE WELLS

根据天然气和反凝析液在地层中渗流特征，结合凝析油气体系相态理论及闪蒸计算方法，考虑流体相态和组分变化，引入稳态理论计算的两相拟压力函数，建立凝析气井流入动态预测新方法，通过与系统试井的结果对比，认为该方法适用于凝析气井的流入动态预测。利用垂直管流公式，结合流体相平衡热力学闪蒸计算，运用状态方程模拟，给出凝析气井流出动态预测新方法，通过三口井１２组实测数据的实例计算，其计算精度较高且比不考虑相态变化的方法更为精确，说明适用于凝析气井流出动态预测。将凝析气井流入动态和流出动态预测方法相结合，给出更为符合实际的凝析气井生产系统分析方法，能更好地指导凝析气井的生产。

Based on the flow characteristics of gas and retrograde condensate liquid in the reservoir,this paper presents a new method for predicting inflow performance of gas condensate wells which integrates phase behavior theory and flash calculation methods of gas condensate system,consideres fluid phase behavior and component difference,and employes two phase pseudo pressure function calculated by the steady state theory.Compared with the results of systematic well testing,this method is more applicable for predicting inflow performance of gas condensate wells.By employing vertical pipeline flow equation,integrating thermal flash calculation of fluid phase equilibrium,and utilizing simulation of Equation of State,a new method for predicting outflow performance of gas condensate wells is also presented.This new method is adopted in the calculation of 12 sets of measured data in three wells,and the result is of high accuracy and is more accurate than the method without consideration of phase behavior difference. It proves that this method is suitable for predicting outflow performance of gas condensate wells.In combination of the prediction methods of inflow performance and outflow performance of gas condensate wells,the method for analysing production system of gas condensate wells is more suitable in field practice and would guide the production of gas condensate wells better.