My topic is investigation on the near wellbore transient flow under liquid loading conditions in gas wells. Now I use the hassler cell to simulate the reservoir conditions. And the media is air. The air flows through the core sample and I test the pressure change at different point. But I do not know how can I build the new model for transient flow. Because of the accumulated water in the well, I think darcy law can not be used any more. My target is research the gas flow behavior under liquid loading conditions. Who has experence about this research, could you give me some advices. Thank you very much!