Development of new corrosion and scale and salt inhibitors and research on the effect of field application

Abstract Several puncture leaks and perforation failures occurred in the water injection pipeline outside a joint station in a western oilfield, seriously affecting the pipeline’s integrity. By analyzing the clogging in the pipeline, it was found that the corrosion caused by salt and scale inside the pipeline was the main reason for the perforation failure of the water injection pipeline outside the station. Given the serious corrosion and scaling of the water injection pipeline outside the station, the multi-functional agent of corrosion inhibitor, scale inhibitor, and salt suppressant was developed. It was determined that the agent had the best effect when the ratio of the single-agent additive corrosion inhibitor, scale inhibitor, and salt suppressant was 2:3:5. The sum of the three is 87% of the formula. At 40°C, when the addition amount was 150 mg/L, the corrosion rate of P110 steel was only 0.0307 mm/a, the scale inhibition rate for CaCO 3 can reach 83.5%, and the salt inhibition rate can get 4.5%. Field corrosion monitoring test piece evaluation test results show that the uniform corrosion rate of the coupons monitored by the three monitoring points is greatly reduced after the corrosion and scale and salt inhibitor are added, and the higher the injection concentration is, the lower the uniform corrosion rate is. When the concentration is high, there are almost no salt crystals on the surface of the monitoring coupon, and a small amount of salt crystals are precipitated after the concentration is reduced.