Abstract: Since the Yuanba Gas Field was put into operation,wellbore blocking has been occurring in many wells and has seriously hindered the normal production of the gas wells.Through different studies on blockage samples from representative wells of the Yuanba Gas Field including element analysis,inorganic component XRD analysis,organic component IR analysis,the thermogravimetric analysis and solubility analysis of blockage samples in acid and ethanol,it has been found that some difference exist on the blockage compositions of various gas wells.In response to this identified difference,organic and inorganic blockage removing chemicals were developed.In addition,the team wished to remove specific wellbore blockages,so processes were developed to remove both organic and inorganic blockage that had been causing wellbore restriction and complete wellbore blockage.Such technologies have been successfully used to remove blockage in 8 wells in the Yuanba Gas Field.The results yielded remarkable economic benefits,with an increase in daily gas productivity increase of 3.16 million m3.The same kind of technologies can also be promoted in similar ultra-deep high-sulfur gas wells.