Abstract
Long-distance transportation of oil is usually carried out in large-diameter steel pipelines. However, water present in the oil may cause severe corrosion of inner pipe walls, resulting in compromised asset integrity and potentially catastrophic failure. Consequently, understanding the corrosion phenomena involved is of key importance to the industry. A complicating factor is that oil and gas production involves the flow of a mixture of hydrocarbons and water in a variety of flow patterns: stratified smooth, stratified with globules, stratified with mixing layer, semi-dispersed, and fully dispersed. Due to the variety of flow patterns, intermittent surface wetting often occurs. An effective method of corrosion control used in practice is to inject corrosion inhibitors, however, how intermittent wetting can impact this mitigation method is poorly understood. In this research, inhibition characteristics of corrosion inhibitor tetradecyltetrahydropyrimidinium (THP-C14) during intermittent wetting were investigated at 25°C via linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic sweep measurements. Results indicated that LVT 200 model oil did not influence the corrosion behavior of carbon steel without corrosion inhibitors in the intermittent wetting experiments. However, when THP-C14 was present in the aqueous phase, the presence of oil promoted corrosion inhibition for intermittent wetting. At higher THP-C14 concentration, the potentiodynamic sweep of intermittent wetting showed a shift for the limiting current of hydrogen evolution reaction compared with the experiment without any oil. EIS and wettability results showed that after the oil-wet stage, the inhibitor might interact with the hydrocarbon, thus causing an increase in the thickness of the surface film and affecting the limiting current.
Keywords:
chemical engineering, corrosion inhibition, intermittent wetting, electrochemical measurements, wettability
Status
G
Department
Chemical and Biomolecular Engineering
College
Russ College of Engineering and Technology
Campus
Athens
Faculty Mentor
Singer, Marc
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Effect of Intermittent Wetting on Corrosion Inhibition in Oil/Water Systems
Long-distance transportation of oil is usually carried out in large-diameter steel pipelines. However, water present in the oil may cause severe corrosion of inner pipe walls, resulting in compromised asset integrity and potentially catastrophic failure. Consequently, understanding the corrosion phenomena involved is of key importance to the industry. A complicating factor is that oil and gas production involves the flow of a mixture of hydrocarbons and water in a variety of flow patterns: stratified smooth, stratified with globules, stratified with mixing layer, semi-dispersed, and fully dispersed. Due to the variety of flow patterns, intermittent surface wetting often occurs. An effective method of corrosion control used in practice is to inject corrosion inhibitors, however, how intermittent wetting can impact this mitigation method is poorly understood. In this research, inhibition characteristics of corrosion inhibitor tetradecyltetrahydropyrimidinium (THP-C14) during intermittent wetting were investigated at 25°C via linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic sweep measurements. Results indicated that LVT 200 model oil did not influence the corrosion behavior of carbon steel without corrosion inhibitors in the intermittent wetting experiments. However, when THP-C14 was present in the aqueous phase, the presence of oil promoted corrosion inhibition for intermittent wetting. At higher THP-C14 concentration, the potentiodynamic sweep of intermittent wetting showed a shift for the limiting current of hydrogen evolution reaction compared with the experiment without any oil. EIS and wettability results showed that after the oil-wet stage, the inhibitor might interact with the hydrocarbon, thus causing an increase in the thickness of the surface film and affecting the limiting current.