Design of a Cathodic Protection System for Inside of a Storage Oil Tank

Abstract

Corrosion is the most frequent type of deterioration that affects metallic materials. It is a serious problem that occurs in petroleum industry repeatedly, due, among other causes, to the presence of water formation in oil and its derivatives, which is in contact with the equipment for processing, storage and transportation of crude oil. The study of this phenomenon is based on basic knowledge about it, going on from the analysis in each system, of the influence of the characteristics of the two main components of the fluid: oil and water formation, the hydrodynamic regime, to the chemical composition of the metal. The final objective of these studies is to propose effective and economic methods to avoid or mitigate the undesirable phenomenon of corrosion. In this work, as an anticorrosive protection method for the inner bottom of a crude oil storage tank, the application, as a complementary method, of a cathodic protection system with sacrificial anodes, is proposed. Through the design of the system, the type and quantity of anodes to be used and their distribution at the bottom of the tank, are determined. An economic analysis is carried out to evaluate the feasibility of the project presented. The results obtained are applicable to other tanks of the petroleum industry.