Performance Assessment Of Sacrificial Anode Cathodic Protection Of Subsea Pipeline

The integrity of subsea pipeline depends mostly on the applied corrosion control. One of the corrosion control methods is using sacrificial anode cathodic protection, SACP. The performance of sacrificial anode cathodic
protection is measured by the current supply and the operational life of the anode to protect the pipeline. In order to maintain the integrity of sacrificial anode cathodic protection, frequent inspection has been taken. However, there are no further assessment or analysis towards the performance of anode. The condition protection system only relies on the subjective data provide by the inspector. This study include aluminium and zinc as the sacrificial anode and carbon steel API 5L X65 as the cathode. The Objective of this study is to analyse on the corrosion rate of aluminium and zinc as well as to determine the most effective metal as a function of sacrificial anode metal. In this study, data are gathered from PETRONAS Carigali Sdn. Bhd. Peninsular Malaysia Operation, PCSB PMO. Two of their operating pipeline with different type of anode were selected and have been analysed on the corrosion rate of the
sacrificial anode cathodic protection. Other than that, this study also includes data from laboratory simulation which are Linear Polarization Resistance test and weight loss test. As a reference, Det Norske Veritas, DNV RP B401 was
used in order to design the sacrificial anode cathodic protection. Based on the results, it has been found that the corrosion rate of aluminium is higher than the other metals that are carbon steel API 5L X65 and zinc. To conclude this
study, aluminium is found to be the most effective metal as sacrificial anode cathodic protection based on the corrosion rate, operational life and the current supplied by the metal.