关键词: 合成, 缓蚀剂, 抑制作用, 钻具, 硫化氢腐蚀

Abstract: The synthesis of imidazoline derivatives as inhibitors for H₂S corrosion of the drillpipe was investigated. Experiments with weight-loss coupons in drilling muds containing 1000-3200mg/L H₂S with imidazoline inhibitors showed inhibition effectiveness of 70-90% with an addition of 0.1-0.2%. If they are used together with zinc alkali carbonate, the inhibition become more effective. A synergistic effect was found between these inhibitors and CaO. These inhibitors also showed good inhibition against O₂ corrosion and good effect on the rheological properties of drilling mud. Corrosion product of mild steel in drilling muds containing H₂S was proved to be kansite (Fe₉S₈) by X-ray diffraction, and it is found that H₂S is able to decompose FCLS (ferrous chromic lignosulfonate), and reacts with Fe to form smythite (Fe₂S₄).