Investigation of the microstructure of the oil pipeline pipes destroyed as a result of corrosion (original) (raw)
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College & Research Libraries, 2019
Crude oils are dominant earth resources since composed with large number of hydrocarbons and some of trace compounds especially with corrosive compounds such as sulfur compounds, naphthenic acids and salts. In the current research the major scope was the investigations of the impact of such corrosive compounds on the corrosion of seven different types of ferrous metals in both qualitatively and quantitatively. According to the methodology such corrosive properties of two different types of selected crude oils were analyzed and the chemical compositions of seven different types of selected ferrous metals were detected by the standard methodologies and recommended instruments. The corrosion rates of such metals were determined by the relative weight loss method after certain immersion time periods in both crude oil samples while analyzing the corroded metal surfaces through a microscope. In addition that the decays of metallic elements from metals into crude oil samples were measured ...
Investigation of Corrosion of the Pipeline Using TOEFLT in Iran Refinery
Corrosion, from long time before was a greatest problem in oil and gas industry and experts have always tried to combat this major problem. This has been given to the corrosion and inspection in oil and gas industry. Corrosion in oil and gas wells has the electrochemical mechanism, When the system reaches a temperature below the dew point, moisture is converted to liquid and many droplets occurs on the pipe's wall. In the electrochemical reaction, water plays role of the electrolyte. The water that creates was not corrosion by itself. When the acidic gases such as H 2 S and CO 2 are dissolved in water create an acidic environment which in the vicinity of the steel will cause severe corrosion. Sometimes in oil wells, oxygen is one of the corrosive gases too. In the oil and gas industries, corrosion may be localized or uniform. Localized corrosion, can be create under the insulators, sediment and bacteria, was 10 to 100 times faster than uniform corrosion lead to destruction and there are many costs and risks associated with it.
Corrosion Reviews, 2018
The present work aimed to investigate the effect of crude oil on the rate of diffusion-controlled corrosion of copper pipeline in acidified dichromate under fully developed flow. To achieve this goal, various parameters were investigated, such as crude oil percentage volume (%), flow physical properties, active height of the copper pipeline, flow velocity, and the presence of Triton X-100. The results of our study revealed that the rate of copper pipeline inner-wall corrosion increases with the increase of crude oil percentage volume and flow velocity. On the other hand, the active height of copper pipeline has no significant effect on the corrosion rate. In addition, the presence of crude oil and Triton has a synergistic effect on retarding the corrosion rate. The inhibition efficiency of Triton X-100 varied from 4.4% to 41.3% depending on its concentration and flow velocity. Polarization curves indicated that the corrosion kinetics is diffusion controlled in acidified dichromate a...
Industrial & Engineering Chemistry Research, 2002
In this paper, we attempt to correlate the rate of corrosion at the metal surface with bulk solution properties such as electrical conductance, viscosity, and density. The premise is that the process solution environment within the pipe or refinery equipment controls the severity of the corrosion at the metal surface. Furthermore, the migration of a protonated amine to the metal surface (instead of a proton in acid solutions) is the rate-determining step. For this study, the corrosion rate and solution properties of a single neutralizer salt (DEA‚HCl) plus ammonium chloride, were examined more closely at fixed temperature, pressure, and composition. The metallurgy was restricted to carbon steel. Metal coupons of the same geometry and size were used to collect corrosion rate data in a nonflowing static environment. Under such conditions, the experimental data support the hypothesis that the corrosion rate at the metal surface is strongly influenced by the diffusion of the protonated amine. Diffusion, like all transport properties (i.e., electrical conductivity, viscosity, density, and diffusion coefficients), is a function of temperature, pressure, and solution composition (Dillon, C. P. Materials Selector for Hazardous Chemicals; Materials Technology Institute: St. Louis, MO, 1997; Vol. 1, p 69). The diffusion coefficient plus the Reynolds and Schmidt numbers determine mass-transfer-limited electrochemical processes (Eisenberg, M.; Tobias, C. W.; Wilke, C. R. J. Electrochem. Soc. 1954, 101, 306). The practical significance of this study lies in its ability to define, select, and/or screen neutralizer candidates via analytical measurements of their solution properties. Any mitigation in the corrosion rate resulting from a judicious choice of the neutralizer amine can have a significant economic impact.
Basics of the Metallic Corrosion in Crude Oils
International Journal of Advanced Engineering Research and Applications, 2019
Corrosion is an often-used term regarding the ferrous metals also the general phenomenon of the formation of metal oxides, sulfides, hydroxides or any certain compound on the metal surface itself. There were found the effect of corrosive compounds in crude oils on the metallic corrosion in most of researches up to certain stage. In the current research it was expected to speculate the effect of sulfur, mercaptans, organic acids and salts in both Murban and Das Blend crude oils on the corrosion rates of seven different types of ferrous metals and variations of the hardness of such metals. The corrosive properties of both crude oils were determined by the standard methods and instruments. The chemical compositions of metals were detected by XRF detector. A batch of similar sized metal coupons was prepared, and those metal coupons were immersed in both crude oils separately. The rates of corrosion of those metal coupons were determined by the weight loss method after 15, 30 and 45 days...
Fundamentals of Corrosion Mitigations in Oil Industry
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It is unknown to many of the science of corrosion as old as history, where scientists have the Romans and Greeks like Pliny, Austin, and others, are built the first building blocks of the science of corrosion, through which has knowledge of the most important developments in the science of metals, Through this study determine with any kind of corrosion can be chosen in Oil and Gas industry so that the appropriate corrosion prevention and control measures, or so as to avoid corrosion problems in the future. This study also analyzes the causes that lead to the high volume of corrosivity such as environmental conditions and accompanying crude acids, gases, and production conditions in different stages.
Steel Research International, 2022
：Effects of cathodic polarization on corrosion fatigue life of E690 steel in simulated seawater were studied by carried out electrochemical measurements and corrosion fatigue tests under different cathodic potentials. The results show that effects of cathodic polarization on corrosion fatigue life are different with different stress levels. When the peak stress is far below the proof stress (< 0.8 σ p0.2), the corrosion fatigue life increases with decreasing cathodic potential and reaches close to the fatigue life in air after-900 mV. However, when the peak stress is close to or beyond the proof stress (≥ 0.95 σ p0.2), the corrosion fatigue life shows an trend of first increase and then decrease with decreasing cathodic potential and peaks at-850 mV. It is attributed to the synergistic effect between plastic deformation and hydrogen, which can be explained with hydrogen-promoting-plastic-deformation (HPPD) theory. Both anodic dissolution and HPPD can promote intergranular cracking. However, HPPD will not occur when the peak stress is far below the proof stress.
Model Compound Study of the Mitigative Effect of Crude Oil on Pipeline Corrosion
Corrosion, 2013
Internal corrosion of crude oil pipelines can lead to spills that can be very costly, both financially and environmentally. The corrosion is controlled mostly by mitigation methods, such as through design or by the use of corrosion inhibitors. However, it has been observed that some, but not all, crude oils can have an inhibitive effect on their own. There are different mechanisms for crude oils to mitigate corrosion, such as inhibition through the water phase by inhibitor-like molecules native to the crude oil, wettability alteration from water wet steel surface to oil wet, thereby limiting the access of the water to the surface, or by lowering the interfacial tension between oil and water and facilitating dispersion of water in oil, which reduces the likelihood of corrosion by keeping the water from being in contact with the steel surface. Model compounds representative of the naturally occurring surface-active compounds commonly found in crude oil were tested for their effect on corrosion inhibition, wettability alteration, and interfacial tension. It was found that the structure of the compound rather than the type of head group had the largest effect on its efficiency, especially for corrosion inhibition, while the type of head group had a larger effect on the surface wettability and interfacial tension.