Research and Application of a Corrosion Inhibitor for CO₂/Foam Flooding in Honghe Oilfield

To alleviate the corrosion of CO2/foam flooding in Honghe oilfield, the corrosion inhibition performance of a synthesized amphoteric imidazoline corrosion inhibitor HGC2-2 was evaluated by rotary coupon test. The results showed that, under the condition of optimum concentration 500 mg/L, the corrosion inhibiting effect of HGC2-2 could reach 90% for N80 and J55 steels. 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 CO2 partial pressure. 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, and decrease the corrosion of the production process greatly. The content of iron ions in the production water from two gas channeling wells got a reduction of 78% and 85% respectively. The corrosion inhibitor HGC2-2 could alleviate the corrosion of CO2/foam flooding in Honghe oilfield effectively and meet the corrosion inhibiting requirement of CO2/foam flooding in Honghe oilfield.