APPLICATION OF INTERNAL CORROSION MODELING IN THE RISK ASSESSMENT OF PIPELINES

摘要

A unique model for prediction of corrosion profiles in oil and gas pipelines has been created. The model is based on multiphase flow modeling, water wetting predictions, pH calculations and models of CO_2 and H_2S corrosion. The input data are typically the pipeline profile, fluid composition data, production rates and data on injected chemicals. It is possible to combine the model with inspection or monitoring data. Based on the uncertainty related to the model and the available data, a probability distribution for the corrosion predictions is established. The result is combined with existing codes for the allowable corrosion attack in pressurized pipes and used to assess the need for pipeline inspection based on the risk of pipeline failure. Detailed examples are given for a gas/oil multiphase pipeline, a crude oil pipeline and a pipeline carrying dried gas under upset conditions.