Simulation of cathodic protection potential distributions on oil well casings

Cathodic Protection (CP) is the most effective method for mitigating corrosion on oil well casings. CP systems are commonly designed by estimating the overall current demand and then developing an anode configuration to protect the structure. Potential and current density distributions on the casing, which determine the level of protection, are usually measured by an expensive and difficult procedure such as downhole tools. To diminish these difficulties mathematical models and computer software are used.In this study a computer software with finite element capability has been used for evaluation of the design of cathodic protection systems. The similarities between heat transfer and corrosion equations were the basis of this simulation. The effect of electrical conductivity of soil and impressed current density on the potential distribution was investigated. The results showed that the conductivity of soil and its variety strictly affected the potential distributions. Furthermore the optimum impressed current density was determined for different soil conductivities.