Theory and Simulation Analysis of FSM Used in Internal Corrosion Monitoring for Oil&Gas Pipeline

Field signature method (FSM) is used today by many of the world's major oil companies in a wide range of monitoring applications, with advantages of high degree of reliability and accuracy, non-intrusive, reflecting wall thickness visually. In this paper, the theory of FSM used in inner corrosion monitoring was analyzed and the expression of defects evaluation parameter (F-c) was deduced based on the corresponding relation between wall thickness (T-t) and potential drop (E-t) of plate model. Numerical simulations with a finite element (FE) model were used for current conduction analysis, the models with defect of various depths were simulated, the relation between F-c and defects was summarized, and the validity of model formula was verified. The correction formulas was given by data fitting and proved to be effective by examples.