Abstract: According to the actual production conditions, the mathematical model of nodal system analysis of the gas wells is established and the mathematic expressions are proposed.It can be used to calculate the gas yielding amount of different tubing diameters and the pressure loss for each segment and to predict the gas productivity based on the performance curves of gas wells.It can also be applied to do many other works for gas wells such as system's index prediction and parameter optimization, etc.The calculation and analysis are conducted by means of the field data from gas well Wen-23 in Zhongyuan oilfield.The calculated results accord basically with the real indices and parameters.

Key words: gas well, production, system, prediction, mathematical model