Local corrosion behavior of pipeline steel under deposition layer in produced water of Alkali/Surfactants/Polymers

The metal pipelines in ASP(Alkali/ Surfactants/ Polymers) flooding systems will suffer from severe under deposit corrosion. In this work, the corrosion behavior of AISI 1020 carbon steel under the deposition of SiO2 or CaCO3 was investigated in produced fluids of ASP (Alkali/ Surfactants/ Polymers) flooding. The results showed that the deposition layer inhibited the uniform corrosion of the metal and promoted the localized corrosion of the metal, and the promotion effect of the calcium carbonate deposition layer was stronger than that of the silica deposition layer. The metal corrosion product under the SiO2 deposition layer was Fe3O4 and FeOOH, and the metal corrosion product under the CaCO3 deposition layer was Fe3O4 and Fe2O3. The type and extent of localized corrosion have varied due to differences in deposited layers and corrosion products. The occurrence and development of localized corrosion of metals under deposition can be monitored by WBE. Based on the above conclusions, appropriate corrosion mitigation strategies are proposed to prevent future failures.