1. Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering��Yangtze University��Jinzhou 434023��Hubei��China; 2. Petroleum Engineering College��Yangtze University��Jinzhou 434023��Hubei��China; 3. The Northeast Oil and Gas Company of SINOPEC��Changchun 130062��China; 4. Research Institute of Exploration and Development��Tarim Oilfield��Kuerler 841000��Xinjiang��China

Tazhong--1 gas field in Tarim Basin is a typical acidic gas field��and the shafts of production wells face serious erosion hazard. According to actual production in Tazhong--1 gas field��the authors systematically studied various factors affect shaft corrosion (content of CO₂ and H₂S��temperature and flow velocity) and determined that �� shaft corrosion was influenced by both hydrogen sulfide and carbon dioxide��and hydrogen sulfide corrosion was the mainly factor��account for 70% ± ; �� 90 �� ± is the most serious shaft corrosion temperature; �� the flow velocity of most gas wells in Tazhong--1 gas field were below 1 m/s��existed fouling corrosion��and the flow velocity of individual wells were up to 4. 9 m/s��existed flush corrosion. According to the main factors of shaft corrosion�� corresponding suggestions and methods to protect shaft corrosion were put forward.