Retrofit Cathodic Protection of Marine Pipelines Associated with Petroleum Production

Marine oil and gas transportation pipelines have been in service in the Gulf of Mexico for almost 50 years. These lines are invariably protected from external corrosion by a combination of coatings and cathodic protection (cp); however, the design life of such protection systems upon older lines has now been exceeded in many cases such that some have required, and others will soon require, cp retrofitting. In response to this, the present project was initiated in 1997 for the purpose of establishing criteria and protocols for design of marine pipeline retrofit cp systems. Five research tasks were identified and addressed as: I. Development of a New Approach to Cathodic Protection Design for New Marine Pipelines. II. Development of An Inclusive, First Principles Based Attenuation Model for Marine Pipeline Cathodic Protection. III. Verification of the Proposed Cathodic Protection Design Method and Attenuation Model. IV. Definition and Examination of Critical Issues Related to Pipeline Cathodic Protection Retrofits. V. Recommended Protocol for Retrofit Cathodic Protection Design of Marine Pipelines.