Calculation Method of Corrosion Rate of Long Distance Pipeline Based on CART

Evaluation of pipeline corrosion rate is an important part of pipeline integrity management. In order to obtain a more accurate corrosion rate of pipelines, the local corrosion rate of pipeline was calculated by using the data of two consecutive rounds of inline inspection (ILI). Based on the local corrosion rate, the pipeline was divided into several sections by classification and regression tree (CART), and the calculation model of pipeline corrosion rate was established by evaluating the corrosion rate of pipeline sections. Combined with an engineering example, the influence of local corrosion rate, maximum corrosion rate of pipeline sections and maximum corrosion rate of pipeline on making maintenance plan was compared and analyzed. The results showed that the model determined the most serious corrosion pipe sections as No. 1, No. 6, No. 12, No. 25, No. 38, which was convenient for the owner to monitor and maintain these pipe sections and check the effectiveness of relevant anti-corrosion facilities. The maximum corrosion rate method based on CART pipeline division was most suitable for pipeline evaluating corrosion rate . This method could not only well characterize the corrosion rate of each pipeline, but also prevented the excessive maintenance of pipeline on the premise of ensuring the safety of pipeline.