Abstract: By linking equation of geologic equilibrium in a condensate gas reservoir,exponential equation of gas well productivity with gas reservoir's fluid characteristics,prediction of development indexes of a condensate gas reservoir at constant volume has been made, establishing individual behavior process of pressure, yielded dry gas, condensate oil as well as each pseudo-component, and determining stable rate period and declining ended time during production of a condensate gas field. Field application showed that this method is simple and reliable, and can be effectively used for comprehensive evaluation, progress selection and macroscopic decision of a condensate gas field development.

Key words: Condensate field, Development index, Prediction, Production decline