Abstract
Flow induced corrosion has been studied under liquid full water/oil pipe flow conditions. It appeared that whereas an oil/water dispersion gave a strong reduction in corrosion rate in smooth pipe flow, localised attack occurred under disturbed flow conditions. The leading edge of a sudden step-wise contraction was severely attacked and mesa attack was observed just after the contraction. Inhibition of the corrosion of the critical geometry under the impinging flow conditions appeared extremely difficult. The leading edge of the constriction always showed signs of localised attack, even at inhibitor concentrations much higher than used commonly. A model for mesa attack is proposed.
Inhibition of corrosion due to impingement of water droplets in a gas flow was also investigated. These tests have been carried out in a newly built apparatus. The unique equipment allows for inhibitor testing as a function of impact (i.e. gas production) velocity, among other parameters. Results show a strong dependence of the performance of the inhibitors tested on temperature. The apparatus enables screening of inhibitors for use in high production gas systems. The resistance towards mechanical deterioration of protective corrosion products layers can be tested as well.
