不同注入气对凝析气相态的影响

凝析气藏开发过程中最大的问题是由于地层压力低于露点压力以下而造成凝析油损失,注气是防止凝析油析出并提高采收率的较好方法,但目前不同注入介质对凝析气相态影响还未进行系统研究,以一个真实的凝析气藏为例,使用自行开发的PVTCOG软件和PR状态方程,研究和对比了在凝析气藏定容衰竭不同阶段,注干气、氮气及二氧化碳气对凝析气相态的影响。研究表明不同种类的气体对凝析气露点、凝析油饱和度及采收率有明显不同的影响。

Effect of Different Injection Gas on Condensate Gas Phase State

The biggest problem in the development process of condensate gas reservoirs is the condensate loss resulted from the fact that the formation pressure is lower than the dew point. Gas injection is a good method of preventing the condensate from precipitating and improving the oil recovery factor. However, so far there has been no systematic investigation on the effect of different injection media on the condensate gas facies. Taking an example from a true condensate gas reservoir and using the self-developed PVTCOG program and PR state equation, this paper studied and correlated the influence of dry-gas injection,nitrogen injection and CO₂ injection on the condensate gas factes at different constant drainage stages in condensate gas reservoirs. The study showed that different gases can significantly affect the dew point of condensate gas, condensate saturation and recovery factor.