Corrosion behavior of the expandable tubular in formation water
来源期刊：International Journal of Minerals Metallurgy and Materials2015年第2期
论文作者：Shu-jun Gao Chao-fang Dong An-qing Fu Kui Xiao Xiao-gang Li
文章页码：149 - 156
摘 要：The corrosion behavior of expandable tubular materials was investigated in simulated downhole formation water environments using a series of electrochemical techniques. The corrosion morphologies in the real downhole environment after three months of application were also observed by stereology microscopy and scanning electron microscopy(SEM). The results show that, compared with the unexpanded sample, the area of ferrite increases dramatically after a 7.09% expansion. The expanded material shows a higher corrosion current in the polarization curve and a lower corrosion resistance in the electrochemical impedance spectroscopy(EIS) plot at every studied temperature. The determined critical pitting temperatures(CPT) before and after expansion are 87.5°C and 79.2°C, respectively. SEM observations demonstrate stress corrosion cracks, and CO2 corrosion and H2 S corrosion also occur in the downhole environment. Due to additional defects generated during the plastic deformation, the corrosion performance of the expanded tubing deteriorates.
Shu-jun Gao1，Chao-fang Dong1，An-qing Fu2，Kui Xiao1，Xiao-gang Li1
1. Corrosion and Protection Center, Institute of Advanced Materials and Technology, University of Science and Technology Beijing2. Tubular Goods Research Institute, China National Petroleum Corporation
摘 要：The corrosion behavior of expandable tubular materials was investigated in simulated downhole formation water environments using a series of electrochemical techniques. The corrosion morphologies in the real downhole environment after three months of application were also observed by stereology microscopy and scanning electron microscopy(SEM). The results show that, compared with the unexpanded sample, the area of ferrite increases dramatically after a 7.09% expansion. The expanded material shows a higher corrosion current in the polarization curve and a lower corrosion resistance in the electrochemical impedance spectroscopy(EIS) plot at every studied temperature. The determined critical pitting temperatures(CPT) before and after expansion are 87.5°C and 79.2°C, respectively. SEM observations demonstrate stress corrosion cracks, and CO2 corrosion and H2 S corrosion also occur in the downhole environment. Due to additional defects generated during the plastic deformation, the corrosion performance of the expanded tubing deteriorates.
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