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 …
Probabilistic Model for Internal Uniform / Pitting Corrosion of Gas pipelines
CO2/H2S corrosion is a major threat to gas pipelines because it often leads to loss of life and property when explosions happen as a result of corrosion. Corrosion inspection is one of the best ways to mitigate the potential risk, however, it is often costly in money and time if inline inspection is not done efficiently. This paper presents a probabilistic corrosion model that is able to predict the internal corrosion rate of gas pipelines in an aqueous CO2/H2S environment. Firstly, the corrosion type between uniform and pitting corrosion is determined for each pipeline by the extreme value analysis. Then, the proposed model for uniform corrosion and the Papavinasam model for pitting corrosion, respectively, are applied to predict the corrosion rate. Monte Carlo simulation is used for the calculation to include uncertainties of operating and basic design variables of gas pipelines. The results show good agreement between the observational corrosion rates and the predicted corrosion rates on eight wet gas gathering pipelines in Sichuan province, China. In addition, it is found that gas gathering pipelines tend to suffer uniform and pitting corrosion depending on ages when they are under similar operating conditions with the presence of chloride ions.
Incorporating Vapor Corrosion Inhibitors (VCIS) in Oil and Gas Pipeline Additive Formulations
Two new oil and gas pipeline additives were formulated utilizing volatile corrosion inhibitors (VCIs). These products provide a very high level of protection for steel subjected to different types of corrosive petrochemicals due to surface adsorption and vapor phase action environments. The formulation work was based on fatty acid imidazoline chemistry combined with different organic acids. Different surfactants were used to provide maximum wetting properties to the inhibitor and faster transport of inhibitor from the oil or gas phase to the water. Vapor corrosion inhibitors were introduced in the formulation. A Windowscompatible software was used to identify the vital factors that affect the quality of the product. The protective properties of newly developed inhibitors were evaluated in various types of corrosive mediums.