This paper describes the performance of film persistent corrosion inhibitors that are effective at fairly high temperatures and in systems that see large amounts of carbon dioxide (CO2). Use of batch treatment with the correct chemical, at the proper frequency resulted in substantial decrease in operating cost.
Application of corrosion inhibitors confer many advantages for combatting internal pipeline corrosion in the upstream oil and gas industry. It is known that the associated costs for using corrosion inhibitors are low compared to other mitigation techniques . For continuous injection procedures, water-soluble inhibitors are not expected to form long-lasting films, so they must be continuously injected to maintain their effectiveness. Batch inhibitors are usually higher molecular weight species and oil soluble. They tend to be more tenacious, providing a protective barrier between the water and the metal over a long period of time.
Corrosion inhibitors is commonly used to combat internal corrosion of mild steel pipelines in oil and gas production and transmission systems. Since the corrosive environment and flow conditions could vary in different fields, small scale laboratory testing is essential to determine the effectiveness of inhibitors in specific corrosive environments. To ensure the accuracy of inhibitor dosage in a small-scale lab setup, the inhibitor often needs to be pre-diluted before addition to the test electrolyte. This pre-dilution has the potential to lead to experimental errors. However, little information can be found about pre-dilution steps, and their influence on inhibition phenomena, in the open literature.
In recent years the oil and gas industry has made significant commitments to carbon reduction.1 Aligned with the goal of decreasing carbon emissions the authors have developed a corrosion inhibitor (CI-1) that is intended to protect scCO2 systems that are wet or water contaminated (1000 ppm).2 The development and composition of this corrosion inhibitor (CI) for dry scCO2 is reported elsewhere.2,3 While chemical companies have been treating high water cut, production enhanced, CO2 floods (i.e. enhanced oil recovery [EOR]) for several decades there were no inhibitors designed specifically for CO2 disposal systems or wet scCO2 systems producing CO2 for sale.4