Abstract
The concept of using physics-based models for corrosion monitoring is still new although corrosion monitoring by use of hardware coupons and probes is well recognized. Corrosion models have traditionally been used for predictions in industrial applications only when need arises in instances such as a failure analysis, project design, or asset integrity reviews. As process and operating data and lab analytical data become available in real time through automation and optimization software engines, corrosion models can be automated to calculate corrosion rate or wall loss and assess corrosion threat in real time. The model results can be tracked and used for monitoring purpose through setting integrity operating window, providing rapid warning through traffic light when a key control variable (such as corrosion rate or wall thickness) breaches its limits. This monitoring through corrosion models is particularly useful for assets that may suffer large changes of corrosion rate due to small changes in operation. This is true for dewpoint corrosion in crude overhead systems. Such models are also useful where inspection access is very difficult such as subsea assets. Although the real time monitoring through using physics-based models applies to both upstream and downstream, this paper describes the application in downstream related to crude unit overhead and demonstrates how the monitoring concept can be used and its benefits.
