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34 APRIL 2017 MATERIALS PERFORMANCE NACE INTERNATIONAL: VOL. 56, NO. 4 CATHODIC PROTECTION S The influence of a sacrificial anode ca- thodic protection (CP) system de- signed for corrosion protection of a marine platform jacket was modeled using the finite element method. A numerical model was applied to cal- culate the distributions of potential and protective current density (CD) on the jacket and to evaluate anodic CD output from the anodes in the two en- vironments of the Persian Gulf and the Caspian Sea. The optimum design for the CP system was determined. The results indicated uniform potential distribution and mass loss rate of an- odes in this optimized design. The modeling results were verified by field measurements. Sacrificial anodes are commonly used in cathodic protection (CP) systems for fixed of f s h o re p l a t f o r m s . S a c r i f i c i a l a n o d e system design in accordance with various i n t e r n a t i o n a l s t a n d a rd s i s s i m p l e . 1 - 3 Sacrificial anodes should be well distrib- ut ed to prov i d e a uniform p ot enti al . 4 Focusing on areas not fully protected at the design stage is vital since the subsea repair costs may be more expensive than the additional cost of a more elaborate design. Po ssi bl e pro bl em s can b e re c og ni z ed during continuous monitoring. 5-6 The feasibility of the galvanic corrosion modeling of sacrificial anodes in contact with steel has been studied. 7-9 With the development of computer hardware and Modeling the Cathodic Protection System for a Marine Platform Jacket Masood Hajig H ola M i, Keyvan Raeissi, and Ha M id R eza s ali M i j azi, Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran s aeid s H abani, Subsea R&D; Center, Isfahan University of Technology, Isfahan, Iran numerical modeling software, the finite ele- ment method (FEM) has become a powerful tool for studying galvanic corrosion and CP systems. 10-12 The boundary element method (BEM) has been used for modeling with mixed results. 13-14 To simulate distributions of local potentials inside corrosion defects of a pipeline, Xu, et al. 15 developed a FEM model using commercial software that pro- vides convenient computation techniques. This study is a continuation of that work using COMSOL Multiphysics 4.2a † software to assess the performance of sac- rificial anode systems designed for plat- forms in the Persian Gulf and the Caspian Sea. With the distribution of the anodes optimized, a physical platform model was placed in a real marine environment in order to verify the simulated results. The correlations between the potential and cur- rent density (CD) obtained from experi- mental potentiodynamic polarization mea- surements were applied as the boundary conditions. Finite Element Method Modeling The electrochemical corrosion phe- nomenon is described through the mathe- matical formulation for an electroneutral, isotropic electrolyte solution in a steady state condition. 10 For this electrolyte sys- tem, the potential is subject to the Laplace equation, Equation (1): = „ w 0 2 (1) † Trade name.