Buried Pipeline Coating And Cathodic Protection Evaluation Method Of Corrosion Protection Posture

Based on the technology of Electromagnetism, Electrochemistry and Fuzzy Mathematics and Statistics, making researches on technologies of corrosion and protection of pipeline in this paper. The result of the research work indicated that the approaches adopted are feasible in practice and scientific in theory. We can analyze the reasons and mechanism of pipeline coating holiday from macroscopically and microcosmic point of view, and help the corrosion engineer in oil field to analyze and comprehend the corrosion trends of pipeline roundly and correctly, and then they can find anti-corrosion measure more effectively.The main tasks of this research work are as follows:(1) Based on the steady-state electric field, the mathematical models have been deduced for current and potential distribution on a pipe, which indicates that potential measured on site is resulted by metal electric-field, anticathode electric-field and cathode electric-field, i.e,△E = △Um-(△Ua+△Uc)The formula is tested on site.(2) Various investigation techniques have been discussed on coating holiday and compared these techniques' advantages and shortcomings have been compared. By virtue of electromagnetism, we make researches on current and potential distribution of underground pipeline with coating holidays and influences resulted by the shape, location and size of coating holidays.(3) An evaluation word-pinprick index have been put forward, which is used to evaluate coating quality of buried pipeline. At the same time, we established the corresponding coating evaluation criterion.(4) The synthesis appraisement has been discussed on pipeline security running based on several factors. According to some theory of Fuzzy Mathematics, expressing the fuzzy conception of common judging with fuzzy set, directly entering the calculate course with the form of fuzzy conception, we received the judging result expressed with fuzzy set by fuzzy transform, and found the mathematics model, at the same time, compiled the database and software.