During the development process of gas reservoirs with high sulfur

when the pressure near the wellbore reduced to a critical value

the sulfur particles precipitated gradually and cloged the pores and fractures

decreasing the productivity of gas wells. Based on the fractal theory

this model for composite gas reservoirs with high sulfur

consisted of inner region and outer region

wass established. Taking wellbore fluid phase separation

wellbore storage factor

skin factor and varying permeability into consideration and by the Stehfest numerical inversion method

this model solved the bottom hole pseudo-pressure solutions in real space. Then with the assistance of Visual Basic 6.0 programming

the log-log type curves for pseudo-pressure and pseudo-pressure derivative were obtained. Finally

the influence of some factors such as skin factor

varying permeability index and mobility ratio on type curves were analyzed. The results had some essential practical significance.