Piping Corrosion Induced by High-Sulphur Natural Gas in Northeast of Sichuan Basin

Through field investigation and model experiment,the oil tube corrosion in northeast of Sichuan basin is characterized as follows.(1) The main factors affecting the oil tube corrosion are CO2,H2S and Cl-.The main corrosion types are pitting corrosion,hydrogen embrittlement and sulfide stress corrosion (SSC).(2) The reason of H2S and NaCl as main factors affecting corrosion could be explained by their good dissolubility.(3) From laboratory model test of A3 steel in well Zhong 21 the corrosion rate of oil tube at the low part reached 1.24 mm/a.