Reliable corrosion inhibition in the oil and gas industry RR 1023 Research Report
The objective of the work was to undertake a literature review on the subject of corrosion inhibition in the offshore oil and gas industry to understand the current issues. The application of chemical corrosion inhibitors can significantly reduce the rate of corrosion of carbon steel pipelines due to the presence of CO2 and/or H2S. An inhibited corrosion rate of 0.1 mm/year can typically be achieved, which is largely independent of the uninhibited corrosion rate. The report covers the main factors affecting the effectiveness of chemical corrosion inhibitors; they are not effective against corrosion due to the presence of oxygen or microbacterial corrosion. High flow rates, high temperature, solids (either dissolved or suspended) and pre-existing corrosion can all have a negative effect on corrosion inhibitor effectiveness. The role of Key Performance Indicators (KPIs), the main factors affecting the performance of inhibition injection systems, and the levels of inhibitor availability that can be assumed at the design stage and achieved in practice are also discussed. This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy. You may reuse this information (not including logos) free of charge in any format or medium, under the terms of the Open Government Licence. To view the licence visit Some images and illustrations may not be owned by the Crown so cannot be reproduced without permission of the copyright owner. Enquiries should be sent to Objectives To undertake a literature review on the subject of corrosion inhibition in the oil and gas industry to understand the current issues. Main Findings • The application of chemical corrosion inhibitors can significantly reduce the rate of corrosion of carbon steel pipelines due to the presence of CO 2 and/or H 2 S. An inhibited corrosion rate of 0.1 mm/year can typically be achieved, which is largely independent of the uninhibited corrosion rate; • Various factors can affect the effectiveness of chemical corrosion inhibitors; they are not effective against corrosion due to the presence of oxygen or microbacterial corrosion. High flow rates, high temperature, solids (either dissolved or suspended) and pre-existing corrosion can all have a negative effect on corrosion inhibitor effectiveness; • The main Key Performance Indicator (KPI) used for assessing effectiveness of corrosion inhibitors is based on the proportion of time that …
Development of Corrosion Inhibitors for Prevention of Top of the Line Corrosion (TLC)
Inhibition of Top of the Line Corrosion (TLC) in the multiphase natural gas pipelines remains unsolved in spite of numerous researches. The majority of studies in the area are still at the laboratory testing and screening phase. It is assumed that the effectiveness of the injected corrosion inhibitor strongly depends on its volatility. On the other hand, the harsh conditions of top of the line (TOL) application, including low pH of freshly condensed water and elevated temperature and pressure, require a strong affinity between the inhibitor molecule and the material of the pipe. A variety of compounds were selected based on their physical-chemical properties and the available data on the mechanisms of corrosion prevention. Testing includes the evaluation of corrosion inhibition of carbon steel at 70°C with pH4 condensate, with and without the flow of carbon dioxide. It was found that azoles, certain acetylene alcohol, and a “green” volatile aldehyde provided the best potential for TLC prevention.
Joint strength of aluminum ultrasonic soldered under liquidus temperature of Sn–Zn hypereutectic solder
Abstract In order to obtain high-strength aluminum joints, ultrasonic soldering of 1070 aluminum was conducted under liquidus temperature of Sn–Zn hypereutectic solder. A device for ultrasonic soldering was assembled, which propagated ultrasonic vibrations in a direction perpendicular to joining surfaces. This device joined 1070-Al using quasi-melting Sn–Zn hypereutectic solder without using any artificial spacers. The strength of the solder joints was evaluated by tensile tests. The optimum joining conditions were determined, and the effects of solder compositions and soldering temperature on the joint strength and the solder layer thickness were examined. In this ultrasonic soldering process, the highest tensile strength was obtained for the solder joints fabricated at 220 °C for the Sn–23Zn and Sn–40Zn solder compositions. The joint strength was equivalent to that of 1070-Al heat treated at 220 °C. The sound joints were obtained at 300 °C using Sn–82Zn solder, the liquid phase volume fraction of which was theoretically only 0.24. The present work also revealed that the thickness of retained solder layer in the joint after ultrasonic soldering could be estimated. Accordingly, ultrasonic soldering under the liquidus temperature of Sn–Zn hypereutectic solder could be a spacer-free soldering method to obtain high-strength aluminum joints.