scholarly journals Corrosion Behavior in External Surface of API 5L X52 Underground Pipelines in Buzurgan Region/ Missan province

2021 ◽  
Vol 11 (1) ◽  
pp. 36-52
Author(s):  
Dr. Kadhim F. Alsultani ◽  
Zahraa Qasim Mutasher

External corrosion of underground pipeline is one of the most common damage mechanismsassociated with the soil environment particularly in ageing pipelines. This study investigatesthe external corrosion phenomenon for exporting crude oil pipeline (28'') in Buzurgan region /Missan province. Corrosion rate was measured by using weight loss method, and Tafelextrapolation. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS)were also used in this work. During the field survey, soil sample was taken from Buzurganregion (collected as close as possible to buried pipes at 1.2 m) for tests were carried out for soilthat included: pH, moisture content, resistivity and chemical composition (XRF, XRD, andsoluble salts). It was found that the environment of the areahas a low soil resistivity value(870) ohm.cm. On other hand, the samples that were immersed in Buzurgan soil showed thethat highest damage was by pitting corrosion due to the high soluble salts content particularlychlorides (7388 )ppm and sulfates (2570) ppm.

2015 ◽  
Vol 3 (1) ◽  
pp. 14-18
Author(s):  
S.R.A. Saupi ◽  
M.A. Sulaiman ◽  
M.N. Masri

This review concentrates on corrosion properties that expose to soil environment. Forms of corrosion classified with respect to outward appearance and altered physical properties are uniform attack, galvanic corrosion, erosion corrosion, stress corrosion, crevice corrosion, pitting and inter-granular corrosion. A porous soil may retain moisture for a longer period for optimum aeration and indirectly increase the initial corrosion rate. External corrosion is corrosion attack upon the outside of the pipe soil medium and the most failure mechanisms experienced by buried steel pipelines. Many systems possibly in contact with soil have risk to be corroded such as storage tanks and pipelines.


1980 ◽  
Vol 8 (1) ◽  
pp. 10-12
Author(s):  
F. C. Brenner

Abstract Tread wear rates during first wear measured by groove depth and weight changes do not always agree. Sometimes, the groove depth method shows a high rate and the weight loss method a low rate. Reported here are experiments designed to determine if grooves show depth changes without wear. Four tires were measured before mounting on a wheel, after mounting and inflation, and after inflation and storage. The mounted and inflated tires showed shallower shoulder grooves and deeper center grooves than the unmounted tires. In a second experiment, tires were measured immediately after a tread wear test and then stored mounted for two weeks before remeasuring. Each groove became deeper, and there was no change in the crown radius of any tire.


2012 ◽  
Vol 9 (4) ◽  
pp. 1746-1752 ◽  
Author(s):  
J. Wilson Sahayaraj ◽  
A. John Amalraj ◽  
Susai Rajendran ◽  
N. Vijaya

The inhibition efficiency (IE) of sodium molybdate (SM) in controlling corrosion of carbon steel in an aqueous solution containing 120 ppm of Cl-, in the absence and presence of Zn2+has been evaluated by weight-loss method. A synergistic effect exists between SM and Zn2+when the concentration of Zn2+is 25 ppm and above. Inhibition efficiencies obtained are greater than 85%. Antagonistic effect exists between SM and Zn2+when the concentration of Zn2+is 10 ppm and below. The SM-Zn2+system shows excellent IE up to third day. Above third day IE decreases. Acceleration of corrosion takes place. Excellent IE is shown at pH 5,7 and 12. At pH 9, IE decreases since Zn2+is precipitated as Zn(OH)2in the bulk of the solution. Polarization study reveals that SM-Zn2+system functions as a mixed inhibitor. FTIR spectra reveal that the protective film consists of Fe2+-SM complex and Zn(OH)2.


2014 ◽  
Vol 1073-1076 ◽  
pp. 2244-2247
Author(s):  
Hu Sun ◽  
Zhi Jun Ning ◽  
Zu Wen Wang ◽  
Zhen Li ◽  
Zhi Guo Wang

Erosion is a main failure of tubings and downhole tools in Changqing gas field. It is necessary to evaluate the erosion rate for the safety of tubing and strings. In this paper, the erosion of P110 steel, in the 0.2%wt guar gum fracturing fluid which contains sands, is investigated by weight loss method in the self-made jet experiment device. It is indicated that the erosion rate increases with the increment of slurry velocity exponentially. When the slurry velocity is in low velocity area, the electrochemical corrosion of dissolved oxygen dominates in erosion mechanism; when slurry velocity increases into middle velocity area, the weight loss is controlled by the synergism of corrosion-erosion; and when the slurry velocity increases into high velocity area, the weight loss rate is dominantly depended on erosion of particles. The results can provide guidelines for large-scale fracturing work of Changqing gas fields.


2002 ◽  
Vol 67 (11) ◽  
pp. 777-782 ◽  
Author(s):  
Dragutin Drazic ◽  
Jovan Popic

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1M Na2SO4 + H2SO4 (pH1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II):Cr(III)?7:1. This process was stable over 4h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, "anomalous" dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process.


2016 ◽  
Vol 12 (1) ◽  
pp. 27
Author(s):  
Maria Erna ◽  
Emriadi Emriadi ◽  
Admin Alif ◽  
Syukri Arief

The thermodynamic properties and characterizations of corrosion inhibition of chitosan nano-particles on the surface of mild steel in peat water media had been studied using weight loss method at temperatures of 30 - 50 <sup>o</sup>C. Steel surfaces were characterized by FT-IR spectra and SEM-EDS morphology photos. The research found that the value of DG<sup>o </sup>approaching -40 kJmol<sup>-</sup><sup>1</sup>. The negative value of Gibbs free energy shows that the adsorption of inhibitor molecules on the surface of mild steel was achemisorption and it occurred spontaneously. Meanwhile, the values of DH<sup>o </sup>is also negative confirming that the adsoprtion of inhibitor molecules is an exothermic process. The value of DS<sup>o </sup>obtained is positive, it indicates hat the inhibitor molecules were adsorbed spontaneously on the mild steel surface. The analysis on mild steel surfaces hows that the nano-particle chitosan was adsorbed on the steel surface to form the complex compounds.


2014 ◽  
Vol 11 (4) ◽  
pp. 1577-1582
Author(s):  
Baghdad Science Journal

The corrosion behavior of copper and carbon steel in 1M concentration of hydrochloric acid (HCl) and sulphuric acid (H2SO4) has been studied. The corrosion inhibition of copper and carbon steel in 1M concentration of hydrochloric acid (HCl) and sulphuric acid (H2SO4) by Ciprofloxacin has been investigated. Specimens were exposed in the acidic media for 7 hours and corrosion rates evaluated by using the weight loss method. The effect of temperature (from 283 ºK to 333 ºK), pH (from 1to 6), inhibitor concentration (10-4 to 10-2) has been studied. It was observed that sulphuric acid environment was most corrosive to the metals because of its oxidizing nature, followed by hydrochloric acid. The rate of metal dissolution increased with increasing exposure time. Corrosion rates of carbon steel in the acidic media found to be higher.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Fang Wang ◽  
Jichuan Xing ◽  
Jinxin Li ◽  
Feng Zhao ◽  
Shufeng Zhang

With the development of technology, the total extent of global pipeline transportation is also increased. However, the traditional long-distance optical fiber prewarning system has poor real-time performance and high false alarm rate when recognizing events threatening pipeline safety. The same vibration signal would vary greatly when collected in different soil environments and this problem would reduce the signal recognition accuracy of the prewarning system. In this paper, we studied this effect theoretically and analyzed soil vibration signals under different soil conditions. Then we studied the signal acquisition problem of long-distance gas and oil pipeline prewarning system in real soil environment. Ultimately, an improved high-intelligence method was proposed for optimization. This method is based on the real application environment, which is more suitable for the recognition of optical fiber vibration signals. Through experiments, the method yielded high recognition accuracy of above 95%. The results indicate that the method can significantly improve signal acquisition and recognition and has good adaptability and real-time performance in the real soil environment.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
O. Sotelo-Mazón ◽  
C. Cuevas-Arteaga ◽  
J. Porcayo-Calderón ◽  
V.M. Salinas Bravo ◽  
G. Izquierdo-Montalvo

Corrosion resistance of pure Fe, Cr, and Ni materials exposed in NaVO3molten salt at 700°C was evaluated in static air during 100 hours. The corrosion resistance was determined using potentiodynamic polarization, open circuit potential, and lineal polarization resistance. The conventional weight loss method (WLM) was also used during 100 hours. The electrochemical results showed that Fe and Cr have a poor corrosion resistance, whereas pure Ni showed the best corrosion performance, which was supported by the passive layer of NiO formed on the metallic surface and the formation of Ni3V2O8during the corrosion processes, which is a refractory compound with a higher melting point than that of NaVO3, which reduces the corrosivity of the molten salt. Also, the behavior of these materials was associated with the way in which their corresponding oxides were dissolved together with their type of corrosion attack. Through this study, it was confirmed that when materials suffer corrosion by a localized processes such as pitting, the WLM is not reliable, since a certain amount of corrosion products can be kept inside the pits. The corroded samples were analyzed through scanning electron microscopy.


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