凝析气井流入动态预测方法

根据天然气和反凝析液在地层中的渗流特征, 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, 建立了凝析气井油、气两相均服从达西渗流的产能方程和气相服从非达西渗流、油相服从达西渗流的产能方程以及油、气两相均服从非达西渗流的产能方程。通过实例得到: ①考虑相态变化的产能方程所得的流入动态曲线在井底压力为露点压力处均有一拐点, 符合凝析气井的特点; ②凝析气井流入动态预测应采用气服从非达西渗流、油服从达西渗流的产能方程。

Inflow Performance Prediction Method for Condensate Gas Well

Based on phase-state theory and flash calculation method for condensate oil/gas system, this paper presents the deliverability equations of oil and gas obeying Darcy's law, gas obeying non-Darcy's law, oil obeying Darcy's law, oil and gas obeying non-Darcy's law in condensate gas well according to flow characteristics of gas and retrograde condensed liquid in strata. In these equations, the phase state and composition changes are considered well and two-phase pseudo pressure function of steady state theory calculation is introduced. The case study shows that there exists a breakpoint in inflow performance curves when bottom pressure is at dew-point pressure, which is coincident with the characteristics of condensate gas well; in inflow performance prediction of gas condensate well, the deliverability equation of gas obeying non-Darcy's law while oil obeying Darcy's law should be adopted.