Corrosion behavior of Si-DLC film in simulant solutions containing CO2-H2S-Cl-

Tubing and casing failure due to corrosion is a common problem in the oil industry. The Si-DLC film deposited by plasma enhanced chemical vapor deposition (PECVD) technology is expected to protect the pipeline during oil and gas exploitation. Corrosion tests were carried out in different Na2S & sdot;9H2O concentrations and temperatures in order to evaluate the corrosion resistance and stability of Si-DLC film. The results show that the Si-DLC film significantly improves the corrosion resistance of the SS304 substrate. There is no significant change on the surface of Si-DLC film with the increase of temperature, and the XPS spectrum and Raman spectrum of DLC film after corrosion possess no obvious change, which indicates that Si-DLC film possesses a great high temperature stability. The Si-DLC film is denser and it possesses excellent protective effect on the substrate compared to the corrosion product layer. The as-deposited Si-DLC film possesses excellent corrosion resistance in CO2-H2S-Cl- environment and this study provides a promising protective material for the inner surface of the pipeline during oil and gas exploitation.