在凝析气藏衰竭式开采中，受凝析气组分、地层多孔介质、温度和压力等因素的影响，会发生PVT相态变化，并呈现双组分特性。为了尽量减少凝析油在储层中析出，保持较高产量、采收率和开采效益，用黑油模型方法和物质平衡原理建立了一套处理凝析气藏相变开采的数学模型，并对实际气藏的主要参数进行了拟合预测，结果与开采计算及实验数据吻合较好。

During the pressure-depleted exploitation of condensate gas reservoirs, PVT phase behavior transition will occur because of the changes of condensate gas composition, stratum porous media, temperature and pressure, especially the pressure decrease. According to these characteristics, this paper establishes a mathematical model that deals with the phase behavior transition exploitation of condensate gas reservoirs using the black oil model method and the mass balance principle. And it is used for the imitating and forecasting of the main parameters of an actual condensate gas reservoir, and all the parameters are close to the calculating results from the condensate gas reservoir exploitation and experiment. The aim is to avoid the appearance of retrograde condensed liquids under dew point pressure in formation near the wellbore bottom, and keep higher productivity, recovery ratio and production benefits for the condensate gas reservoir.