Predicting the serving life of P110S steel in Tarim oilfield by using the multi-degree of freedom of mechanistic-chemometrics model

The P110S pipelines suffer from frequent serious problems in various stages of their working life in Tarim oilfield. The serving life was difficult to predict accurately through the empirical models and mechanism models. In this work, the life of P110S steel was predicted by using the semi-empirical and semi-mechanistic mechanistic-chemometrics model under multi-factor analysis and verified with the field data. The results showed that there was no inoculation process of the pitting for the P110S steel in such an aggressive environment. The serving life was mainly controlled by the uniform corrosion and the pitting growth. Moreover, the temperature/CO2 pressure/H2S pressure, stress, and their interactions were identified as the most significant factors in terms of serving life. Compared with the field data, the predicting results calculated by using the mechanistic-chemometrics model was also accurate and highly reliable. It was concluded that the model was still applicable in the activation dissolution system.