Productivity of gas wells in Songnan volcanic gas reservoir is difficult to predict as high CO

2

content has great influences on PVT of natural gas

resulting in large difference between the measured and predicted productivity.Based on laboratory experiments

this paper studied the effects of temperature

pressure and CO

2

content on PVT of gas with high CO

2

content and established the relational expressions of gas viscosity and Z-facto to pressure for gas with different CO

2

contents.A new prediction model considering PVT variations of gas with high CO

2

content was built based on gas percolation theory.The case study results indicate that the productivity reduces with the CO

2

content increasing;the effect of μZ factor changes on productivity prediction should be considered when CO

2

content is above 20%;and the impacts of CO

2

content on productivity lowers to a level that can be neglect in late production period.The new method is accurate and practical for the high CO

2

-content gas reservoirs.