A laboratory experimental program is being carried out in order to predict current requirements for CP design and the performance of sacrificial anodes under conditions of deep water oil production systems. Field and laboratory experience related to requirements for cathodic protection (CP) in deep water are reviewed with emphasis on identification of the major variables that need to be specified for successful deep water CP designs for offshore structures and laboratory simulation of service conditions.
Three main subjects are discussed: (1) Environmental Factors -dissolved oxygen, temperature, slinity, pH, water velocity and fouling, (2) Calcareous Deposits and difference in shallow and deep waters (3)
Application of existing industry standards suchasNACE RP0176 and the new NACE document 7L198. The validity of accepted design criteria and systems for deep water applications are assessed including initial polarization, use of coatings and anode materials. The results from laboratory tests will be compared with available documented service experiences and field tests results. A methodology is presented incorporating a numerical model than can be used to assess, evaluate and optimize CP design variables,
Keywords: cathodic protection, deep waters, sacrificial anodes, offshore structures, desigp requirements, industry standards, environmental factors, calcareous deposits, initial polarization, field experience,
laboratory simulation.