The Preparation, Evaluation and Application of a New Complex Corrosion Inhibitor with High Temperature Resistance at 200 ℃ for Acidizing

A new complex corrosion inhibitor was developed, which includes mannich base quaternary ammonium salt as the main agent, alkyne alcohol derivative and inorganic salt as the synergistic agent, alcohol solvent and dispersant as the auxiliary agent. By introducing alkynol derivatives to replace propargyl alcohol, the toxicity of corrosion inhibitor is reduced to a low level, and the corrosion inhibitor has the characteristics of good dissolution and dispersion, low corrosion rate at 200 ℃, and no (or a small amount) coke. With the addition of 5.5% corrosion inhibitor, the laboratory evaluation corrosion rate under the condition of 15% HCl is lower than 60 g/m2•h at 200 ℃, and lower than 70 g/m2•h under the condition of 20% HCl. Under the condition of 15% concentration of hydrochloric acid at 200 ℃, the compatibility of acid solution is good, and the corrosion rate of the system is still lower than 70 g/m2•h, which is suitable for the acidizing under the condition of high temperature and high acid concentration, to achieve level-1 industry standard. It has been successfully applied in TT1 well (temperature 202 ℃).KeywordsCorrosion inhibitorAcid corrosionMannich base quaternary ammonium saltSynergistCorrosion rateApplication