Improvements on De Waard-Milliams Corrosion Prediction and Applications to Corrosion Management

Abstract This paper describes corrosion rate prediction models for the main corrosion mechanisms of carbon steel in Exploration and Production service. The models succeed earlier work by De Waard, Milliams, and Lotz. The paper emphasizes that model accuracy is less of an issue than knowledge of the key corrosivity parameters and the quality of the corrosion control system. Models will be described for the following mechanisms: CO2 corrosion, CO2/H2S corrosion, H2S corrosion, organic acid corrosion, oxygen corrosion, and microbiologically-induced corrosion. Application limits will be indicated. A good comparison with high-quality lab data is only possible for the CO2 corrosion mechanism. Computer programs will be described in which the corrosion prediction models are applied for front-end design and facility integrity management. Use of these programs during the lifetime of a facility provides a way of focusing on corrosion control issues and they are therefore essential tools for pro-active corrosion management.