SOME NEW DEVELOPMENTS IN MODELING OF INTERNAL PIPELINE CORROSION IN THE OIL AND GAS INDUSTRY

摘要

Following the introduction of an integrated mechanistic model of CO2 corrosion in multiphase flow a few years ago, new advances have been made in understanding internal corrosion of mild steel pipelines. The original model was mechanistic and covered the key underlying processes such as: kinetics of electrochemical reactions at the steel surface, dynamics of coupled transient transport of multiple species between the bulk solution and the steel surface, through the turbulent boundary layer and through a porous surface film;;kinetics of chemical reactions including precipitation of iron carbonate, as well as growth and protectiveness offered by iron carbonate scales. The new model based on the latest experimental results covers previously unknown territory: corrosion at very low temperatures (as low as 1亱C) and corrosion in very high salinity brines (up to 25%wt. NaCl). However the biggest breakthrough was the development of a mechanistic H2S corrosion model which includes the kinetics of iron sulfide growth by solid state reaction. The overall model has been extensively calibrated and verified with a reliable experimental database.