低渗多孔介质低含凝析油型凝析气衰竭开发饱和度研究

常规PVT筒衰竭中没有考虑多孔介质和束缚水的影响，文章采用超声波测饱和度测试技术，对桥白低渗低含凝析油型凝析气藏在衰竭开采中凝析油饱和度变化进行测试。实验研究表明，在岩心中随压力降低凝析油饱和度增大,但凝析油饱和度未能达到临界流动值，而在PVT筒中衰竭, 露点压力以下凝析油饱和度值是先增加后降低；３块实验岩心中最大油饱和度均比PVT中最大油饱和度大；无束缚水岩心的凝析油饱和度比有束缚水岩心中的凝析油饱和度大得多；在衰竭开发中，多孔介质、束缚水对凝析油饱和度的影响不容忽视。

A STUDY OF SATURATION DURING NATURAL DEPLETION OF CONDENSATE GAS RESERVOIR WITH LOW CONDENSATE OIL CONTENT IN LOW-PERMEABILITY POROUS MEDIA

Influences of porous media and irreducible water are not considered in conventional PVT cylinder depletion experiment. Ultrasonic technique is used to test the change of condensate oil saturation during natural depletion of Qiaobai condensate gas reservoir with low-permeability and low content of condensate oil. Experiment study shows that condensate oil saturation increases with lowering pressure of core, but cannot reach critical flow value. While in PVT cylinder depletion experiment, saturation of condensate oil first increases and then decreases when pressure is lower than dew point pressure; the maximum values of condensate oil saturation of the 3 core samples are all larger than conventional PVT experiment; condensate oil saturation of core without irreducible water is much higher than that with irreducible water. The influences of porous media and irreducible water on condensate oil saturation are not negligible in natural depletion.