用状态方程模拟注气对凝析气藏采收率的影响

提高凝析油采收率和整体开发效益是凝析气藏开发的目标，注气是防止凝析出从面提高凝析油采收率的较好方法。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凝析气藏定容衰竭不同阶段，注干气、氮气及二氧化碳对露点的影响、对注气时机、对凝析油储量和凝析油采收率的影响。研究表明不同注入气影响露点的趋势不同，随注入气增加凝析油储量下降，但凝析油采收率上升，注入时机不一定是在于高于露点压力时最好。

Recovery Study on Gas Infectioin Simulation by EOS in Gas Condensate Reservoir

Gas injection can prevent condensate oil from separating out from gas condensate reservoir. The PVTCOG application software developed by ourselves and the PR state equation were employed in a real closed condensate gas reservoir to study the depletion performance in different production stages, the influence of dry gas, the nitrogen and carbon dioxide on the dew point pressure, the gas injection time, the condensate oil reserve and the condensate oil recovery. The results showed that: different injection gas has different impact on dew point pressure; with more gas injection the condensate oil reserve will come down while the condensate oil recovery will go up; the optimum time for gas injection is not necessarily at pressure higher than dew point pressure.