关键词: 裂缝, 凝析气藏, 循环注气, 采收率

Abstract: For fractured condensate gas reservoirs,condensate oil is separated from the condensate gas when the pressure of reservoir reduces to dew point, which leads to phase behavoir changes.Furthermore,integrating effect of driving force,gravation and capillary pressure causes imbibition and diffusion easily,
which makes the flowrage character more complex and some abnormal phenomena take place for cyclic gas injection in fractured condensate gas reservoir maitaining pressure.In this paper, we give an example about cyclic gas injection in fractured condensate gas reservoir. Recirculating ratio, gas injection occasion,period of the gas injection and the reason that causes the abnormal phenomenon have been studied. Results show that the bigger the recirculating ratio, the earlier the gas injection and the longer the period of gas injection, the lower the recovery percent of condensate oil reservoirs. But, after a while when gas injection is over, vice versa. That is, the bigger the recirculating ratio, the longer the period of gas injection and the earlier of
gas injection, the higher the recovery efficiency of condensate oil. The effect of cyclic gas injection is obviously better than that of natural depletion.

Key words: fracture, condensate gas, cyclic gas injection, recovery efficiency