凝析气井产能和储量计算新方法

凝析气藏存在复杂的相变与相态分布，当地层压力下降到露点压力以下时，凝析油会在地层和井筒中分别析出，导致井口产气量、产油量与井底产气量、产油量之间存在质量转换，但仍遵循质量守恒定律。因此利用质量守恒建立考虑油、气两相的渗流微分方程，通过引入两相拟压力函数，推导凝析气井不稳定产能方程。在此基础上，结合物质平衡方程，利用生产动态数据拟合整个历史生产过程，不但可以获得气井目前的产能，还可以获得地层压力及各种地层参数。实例分析表明，计算结果准确可靠，有利于在凝析气井中推广使用。

The New Calculation Method of Condensate Gas Well Production and Reservoirs

Complex phase change and re-distribution exist in gas condensate reservoir.It will produce gas condensate in formation and the wellbore,respectively,when the pressure drop to below dew point pressure,resulting in the conversion of mass between wellhead and bottom hole in gas production and oil production,but still follows the law of conservation of total mass.Therefore,according to mass conservation principle,we established the oil and gas two-phase flow equations.By introducing the two-phase pseudo-pressure function,unstable deliverability equation was derived.On this basis,we fit the entire history of production by taking material balance equation and production data into consideration.With this method we not only get the current gas production,but a variety of formation pressure and formation parameters.An example is then analyzed to verify the accuracy and reliability,the method is conducive to the promotion the use of gas condensate.