Evaluation and Retrofit Optimization of Sacrificial Anode Cathodic Protection System on Submarine Pipeline

With the help of numerical simulation technology, the distributions of the cathodic potential and the remaining life of the original sacrificial anode were predicted before replacing the anode of a submarine pipeline and after using different sacrificial anode replacement schemes. The results showed that before the anode was replaced, the cathodic protection potential of the submarine pipeline reached the standard (negative -800 mV), but the sacrificial anode life was less than 10 a, which was consistent with the detection results of the underwater robot (ROV). Scheme 2 (9 massive sacrificial anodes) had the best protection effect after the anode was replaced. The results of two consecutive ROV tests indicated that the subsea pipe had been effectively protected.