External corrosion prevention of sea lines in offshore and onshore section

Optimum selection and application of protective coating and CP systems are importance especially for pipelines which contains sour fluids. Each wellhead platform is connected to plant through a sea line which includes onshore section (Sub Sea, from platform up to beach )and offshore section (underground, from beach to the plant).Coatings are often used in conjunction with cathodic protection systems to minimize the effect of corrosion on the pipelines. This Paper is a study on different methods for external corrosion mitigation of sea lines .for protection offshore section proper coating and installation of sacrificial anodes, such as aluminum and zinc is used. But for onshore section, three layer polyethylene coating and the most cost effective CP system means impressed current anodes.

Keywords:

CP (cathodic protection) , ICCP (impressed current cathodic protection) , Sacrificial anodes , Coating