Verification and Optimization of Cathodic Protection Design of Fully Buried Pipeline in Submarine Mud

Aluminum alloy anode was screened and optimized by electrochemical test in brackish water and sea mud as testing mediums, aiming at the requirement of 50 years service period of steel pipelines buried in sea mud. And the optimized anode was used in the optimal design of sacrificial anode cathodic protection scheme for a 21 km subsea pipeline. The results show that the electrochemical performance of the preferred component aluminum alloy anode had little difference compared with that of DNV standard component aluminum alloy anode in the brackish water. But in the sea mud, the preferred aluminum alloy anode had better electrochemical performance, showing more negative potential, higher capacitance and more uniform dissolution, compared with the standard aluminum alloy. In the design of cathodic protection scheme, the consumption of preferred aluminum alloy anode was 25% less than that of standard aluminum alloy anode, which greatly improved the economy of cathodic protection scheme.