Corrosion Failure Causes of Down-hole Tubing in a Sour Gas Well

The corrosion of tubing used in a sour gas well was found and the tubing was penetrated from outer to inner. Chemical composition analysis, mechanical test and, metallurgical microscopy test were carried out, and corrosion products were analyzed by SEM, EDS and XRD to find reasons of failure. The results indicate that H2S/CO2 corrosion was the primary cause of corrosion failure, and protection measures were proposed based on 10 years experience about tubing corrosion investigation and corrosion management.