Effect of the Damage Area of Coating on IR Drop of Cathodic Protection for Oil and Gas Pipeline

Breakpoint test and indoor simulated experiment were used to investiguate the effect of damaged area of coating on IR drop of cathodic protection. The results showed that IR drop increased when potentiostat output voltage increased for the pipeline with cathodic protection. Meanwhile, in the same voltage, IR drop increased when the damage area increased, and defect size and cathodic protection efficiency was negatively correlated.