Performance of Corrosion Inhibitors Under Different Flow Regimes

A widely used method to control corrosion in oil and gas pipelines is the use of corrosion inhibitors. However, their performance can be affected by their chemical composition, concentration, flow pattern, and flow regime. This investigation presents the comparison of two types of a water-soluble and an oil-based inhibitor, at concentrations of 0 ppm, 20 ppm, 40 ppm and 80 ppm, mixed in a 5% NaCl solution (electrolyte) at different electrolyte-to-oil ratios (2:8, 2:3, 8:2). A carbon steel rotating cylinder electrode was used to assess the inhibitors under different flow regimes with fluid velocities of: 0.32, 0.64, 0.97 and 1.29 m/s (1.05, 2.1, 3.18, and 4.23 ft/s). The water-based inhibitor presented the best performance, with efficiencies of up to 80%.