Research and Application on Corrosion Inhibitor of CO_2/Foam Flooding in Honghe 156 Well Group

摘要

Aiming at the corrosion problem of CO_2/Foam Flooding in Honghe 156 well group, the corrosion inhibiting performance of a synthesized amphoteric imidazoline corrosion inhibitor HGC2-2 was evaluated by rotary coupon test, and the corrosion inhibition mechanism was studied through the electrochemical tests. The results showed that, under the condition of optimum concentration 500 mg/L, the corrosion inhibiting effect of HGC2-2 could reach 90% on N80 steel. The corrosion inhibitor HGC2-2 had an excellent compatibility with the foaming agent. The corrosion inhibitor HGC2-2 also had a good adaptability to temperature and CO_2 partial pressure. The electrochemical tests results showed that, the corrosion inhibitor HGC2-2 could inhibit both the anodic reaction and the cathodic reaction. The adsorption of HGC2-2 molecule on the surface of metals was in conformity with the Langmuir adsorption isotherm, and the adsorption between HGC2-2 molecule and the surface of metals had strongly chemical interaction. The field test results showed that, the corrosion inhibitor HGC2-2 could decrease the corrosion rate of injection process to below 0.076 mm/a, meanwhile could decrease the corrosion the production process greatly. The content of iron ion in the production water from two gas channeling wells got a reduction of 79.1% and 80.9% respectively.