A mechanistic chemical dispersion model was developed to aid in optimizing corrosion inhibitor injection. The mechanism of corrosion inhibition is attributed to the adsorption of inhibitor to the pipe wall to create a hydrophobic layer. The mechanistic corrosion inhibitor dispersion model, which is linked to a commercial flow simulator, was developed to account for the mechanisms governing the distribution of corrosion inhibitor including the gross distribution of oil/water/gas in the pipeline, turbulent dispersion in the free water phase, partitioning of inhibitor between oil and water phases, and the adsorption/desorption of inhibitor on the pipe wall. This model can be used to calculate the inhibitor concentration in the liquid phases as well as on the wall in the flow line. Therefore, this mechanistic model should be a useful tool in the design of optimal corrosion inhibitor injection for corrosion control, i.e., determining the minimum inhibitor concentration required to provide the maximum inhibition protection. The model was tested by conducting numerous simulation runs using different scenarios including injection rates, number and location of injection points, and inhibitor partition characteristics based on the flowing characteristics of the pipeline. Major factors, which can affect the treatment optimization methodology, are identified.
Keywords: Corrosion Inhibitor, Distribution, Adsorption/Desorption, Mechanistic Model, Numerical Method