Complicated phas variation and phase state redistribution exist in condensate gas wells.This may result in considerable effect on derivative curves of well test pressure. To choosethe straight section of well test analysis accurately is the key factor in successfully interpreting well test. The effect of condensate oil must be considered in calculating the parameters ofhigh-pressure physical property. In order to avoid interpretation error

the productivities usedin well test analysis should also include condensate oil productivity. This has been proved bywell-test information of a condensate gas well in Tarim Basin.