Sulphur Corrosion Research Of Oil Pipeline

In recent years, our country is increasing the import and intestine output of crude oil with high sulphur content year by year. The perforation phenomenons of pipeline occur frequently, and pipeline's using life is cut down seriously. The sulphur corrosion research of oil pipeline contributes to assesse pipeline's using life, decrease energy dissipation and environmental pollution, which has high research value.The high temperature high pressure reaction still was used in laboratory to simulate the scene operating mode condition. The corrosion rate of 16Mn pipe steel was measured in different typical sour crude oil under different transportation conditions. A corrosion rate database of pipeline was built when different kind of oil with different sulphur content and different acid number under different transportation temperature, different pressure and different speed of flow. The specimen surface appearance was observed through the scanning electronic microscope (SEM), and the ingredient of corrosion product on the test specimen surface was appraised through X-Ray Fluorescence Spectrometer(XRF). The qualitative analysis of corrosion product film was got through electro-chemical means and weight loss method in order to compare the corrosion product film under different situations. The pipeline's corrosion disciplinarian was revealed combined with corrosion rate. The research shows that sulphur content and acid value was the main reasons of the internal corrosion, temperature and flow velocity was the secondary cause, and pressure had little influence on the corrosion rate; the more sulphur content was, the stronger the crude oil was within the limit of experimental condition; the pipeline's corrosion rate increased obviously with the acid value increasing; the higher temperature was, the stronger corrosion product's protectiveness became, and the bigger diffusion rate of all kinds of corrosive materials, and the latter effort fact was stronger than the former, so the pipeline's corrosion rate increased with the temperature increasing; the dynamic crude oil had stronger corrosivity than static oil, and there was a maximum value according to certain flow velocity.On the base of the corrosion rate database, a predict software for the remaining lifetime of pipeline was programmed using BP neural network. The corresponding economic loss of transportation sour crude oil was calculated according to related expense about pipeline's construction, operation and so on. The economic loss computation function was also developed in the software.