scholarly journals USING WIRE BEAM ELECTRODE (WBE) TO EVALUATE THE CORROSION BEHAVIOR OF ND STEEL IN ACID MEDIUM

2020 ◽  
Vol 1 (2) ◽  
pp. 27-30
Author(s):  
Bo Zhao ◽  
Yuxin Yu ◽  
Jing Guo ◽  
Tianyu Zhou ◽  
Shiwen Zou ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Corrosion Behavior ◽  
Ring Structure ◽  
Corrosion Products ◽  
Dew Point ◽  
Co2 Corrosion ◽  
Uniform Corrosion ◽  
Corrosion Morphology ◽  
Co2 Partial Pressure ◽  
Wire Beam Electrode

In this article, wire beam electrode (WBE) was used to evaluate the corrosion behavior of ND steel in environmental acid atmosphere with different partial pressure of CO2. Meanwhile, corrosion products and surface morphology analysis also used to support this research. The results showed that the corrosion behavior began from the edge of droplet in dew point corrosion, and gradually spread to the center of it. The spread speed would be increasing with CO2 partial pressure enhance, which was 24h in 5% CO2 and 4h in 50% CO2. Corrosion current density in the edge of droplet can form the “cathode-anode-cathode ring” structure and disappears gradually as the corrosion time was going. Corrosion morphology observation results showed three ring shapes region and different elemental composition of different corrosion products, which is correspondence with the “cathode-anode We-cathode ring” structure measured in WBE experiments. The results showed that the reaction gradually transferred to the uniform corrosion on electrode surface when the dew point corrosion reaction reaching the late stage. It comes from the dissolution, diffusion and reaction of gaseous corrosion medium of CO2 and O2.

Corrosion Behavior of X70 Pipeline Steel and Corrosion Rate Prediction Under the Combination of Corrosive Medium and Applied Pressure

2017 ◽  
Author(s):  
Kaikai Li ◽  
Wei Wu ◽  
Guangxu Cheng ◽  
Yun Li ◽  
Haijun Hu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Corrosion Rate ◽  
Tensile Stress ◽  
Partial Pressure ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Applied Pressure ◽  
Chloride Concentration ◽  
X70 Pipeline Steel ◽  
Co2 Partial Pressure

Natural gas transmission pipeline is prone to internal corrosion due to the combination of corrosive impurities in the pipe (such as CO2, H2S and chlorides) and applied pressure of the pipeline, which seriously affects the safe operation of the pipeline. In this work, the corrosion behavior of a typical X70 pipeline steel was investigated by using potentiodynamic polarization and electrochemical impendence spectroscopy (EIS). The polarization and EIS data under different CO2 partial pressures (0–1 atm), H2S concentrations (0–150 ppm), chloride concentrations (0–3.5 wt%) and tensile stress (0–400 MPa) were obtained. The results show that corrosion rate increases with the increase of CO2 partial pressure and chloride concentration, respectively, while first increases and then decreases with the increase H2S concentrations. The corrosion rate is less affected by elastic tensile stress. In addition, a quantitative prediction model for corrosion rate of natural gas pipeline based on adaptive neuro-fuzzy inference system (ANFIS) was established by fitting the experimental data which maps the relationship between the key influencing factors (i.e. CO2 partial pressure, H2S concentration, chloride concentration and tensile stress) and the corrosion rate. The prediction results show that the relative percentage errors of the predicted and experimental values are relatively small. The prediction accuracy of the model satisfies the engineering application requirement.

Optimizing CAPEX and OPEX for High CO2 and H2S Field by Using Mechanistic Corrosion Modelling Approach

2021 ◽  
Author(s):  
Ahmad Fahdlam Saleh ◽  
Muhammad Zaid Kamardin ◽  
Shahrun Nizam Safiin ◽  
Mohd Farizan Ahmad
Keyword(s):  
Corrosion Rate ◽  
Partial Pressure ◽  
Gas Production ◽  
Co2 Corrosion ◽  
Original Design ◽  
Co2 Partial Pressure ◽  
Field Development ◽  
Stage Of Development ◽  
Corrosion Modelling ◽  
Modelling Approach

Abstract The gas contaminants especially CO2 and H2S from the well is a major threat to oil and gas production facilities and pipeline. Developing this type of reservoir cost enormous CAPEX and OPEX due the need for expensive materials or the need of continuous chemical injection. This paper outlines the opportunity of cost optimization for future field development and operational through mechanistic corrosion modelling approach. This method was embedded to an in-house corrosion prediction model that was first developed by collaboration with Ohio University in 2008 with capability to predict corrosion rate for partial pressure more than 20bar of CO2 and up to 1bar of H2S. The model validation was performed based on actual field production operated at 55°C and 22 bar of CO2 partial pressure followed the methodology as outlined in NACE paper C2012-0001449. Upon successful validation, the model has been deployed to assist an Operator of an offshore pipeline in Southeast Asia, operating at 97°C and 17 bar of CO2 partial pressure, to ascertain the risk due to CO2 corrosion and review the original pipeline design adequacy. Subsequently, the model has been utilized for an Operator of onshore facilities in Middle East to address specific issue encountered during the final stage of development for one of the wellpad in which the wells are expected to experience increase of H2S from 100ppm in original design to more than 1000ppm during actual production. This process changes raised a serious concern on the integrity of the materials as potential corrosion issue and the need for corrosion mitigation such as H2S Scavenger injection was not originally considered during early stage of engineering. The corrosion rate from the model has been validated against the intelligent pigging (IP) data and proven to be able to predict corrosion rate with +20% accuracy and more than 99% confidence level for CO2 partial pressure up to 25 bar with the presence of H2S. Based on deployment and utilization of the model, the high confidence in the model ability to accurately predict the corrosion rate will lead to potential CAPEX and OPEX optimization for the field development and during operational stage.

scholarly journals Effect of CO2/H2S and Applied Stress on Corrosion Behavior of 15Cr Tubing in Oil Field Environment

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 409
Author(s):  
Xuehui Zhao ◽  
Wei Huang ◽  
Guoping Li ◽  
Yaorong Feng ◽  
Jianxun Zhang
Keyword(s):  
Stainless Steel ◽  
Partial Pressure ◽  
Stress Corrosion ◽  
Applied Stress ◽  
Corrosion Behavior ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Oil Field ◽  
Uniform Corrosion ◽  
Field Environment

The corrosion behavior of a 15Cr-6Ni-2Mo martensitic stainless steel (15Cr stainless steel) in a CO2/H2S environment was investigated by conducting high-temperature/high-pressure immersion tests combined with scanning electron microscopy and metallographic microscopy. The presence of H2S decreased the corrosion resistance of the 15Cr tubing steel. The critical H2S partial pressure (PH2S) for stress corrosion cracking in the 15Cr tubing steel in the simulated oil field environment with a CO2 partial pressure of 4 MPa and an applied stress of 80% σs was identified. The 15Cr tubing steel mainly suffered uniform corrosion with no pitting and cracking when the PH2S was below 0.5 MPa. When the PH2S increased to 1 MPa and the test temperature was 150 °C, the pitting and cracking sensitivity increased. The stress corrosion cracking at a higher PH2S is attributed to the sulfide-induced brittle fracture.

Long-term monitoring of zinc corrosion behavior in typical hot and dry atmosphere environment in Turpan, China

2018 ◽  
Vol 65 (5) ◽  
pp. 471-483 ◽  
Author(s):  
Chunhui Kang ◽  
Decheng Kong ◽  
JiZheng Yao ◽  
Chunyun Guo ◽  
Li Wang ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Exposure Time ◽  
Corrosion Products ◽  
Corrosion Mechanism ◽  
Corrosion Morphology ◽  
Transfer Resistance ◽  
Positive Direction ◽  
Pure Zinc ◽  
Content Type ◽  
X Ray

Purpose This paper aims to investigate the corrosion behavior of zinc in a typical hot and dry atmosphere. It proposes the dynamic corrosion for different exposure periods. Results can provide the basic data and corrosion mechanism of zinc in such environment. Design/methodology/approach In this paper, the authors investigated the corrosion behavior of pure zinc exposed in the typical hot and dry environment in Turpan for one-four years, which has never been studied. Scanning electron microscopy, laser scanning confocal microscopy, electron probe micro-analyzer (EPMA), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were conducted to measure the corrosion morphology and products of zinc. Finally, combining electrochemical impedance spectroscopy and scanning Kelvin probe techniques, the corrosion mechanism of zinc in Turpan was examined. Findings The thickness loss of the zinc followed an exponential law with respect to exposure time: D = 3.17 t0.61, and both of the rust layer resistance and the charge transfer resistance increased with exposure time. The corrosion products mainly comprised ZnO, Zn(OH)2, Zn5(CO3)2(OH)6, Zn4SO4(OH)6·5H2O and Zn12(SO4)3Cl3(OH)15·5H2O. The Kelvin potentials shifted toward the positive direction from −0.380 to −0.262 V (vs saturated calomel electrode [SCE]) when the exposure time extended from one to four years and the distribution of the corrosion products became more and more uniform. Originality/value The corrosion behavior of pure zinc in the typical hot and dry environment in Turpan has not been studied. The dynamic corrosion for different exposure periods was obtained. The corrosion products were systemically investigated via energy-dispersive X-ray spectroscopy, EPMA, XPS and XRD.

scholarly journals Corrosion Failure Mechanism of Associated Gas Transmission Pipeline

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1935 ◽  
Author(s):  
Weimin Zhao ◽  
Timing Zhang ◽  
Yonglin Wang ◽  
Jianhua Qiao ◽  
Zerui Wang
Keyword(s):  
Corrosion Rate ◽  
Gas Pipeline ◽  
Corrosion Products ◽  
Oxygen Absorption ◽  
Co2 Corrosion ◽  
Uniform Corrosion ◽  
X Ray Diffraction ◽  
Corrosion Failure ◽  
Associated Gas ◽  
Transmission Pipeline

Corrosion has been responsible for several gas pipeline leakage accidents; thus, clarifying its failure mechanisms is a precondition to prevent such accidents. On the basis of failure analysis of corroded pipe sections, laboratory exposure tests were conducted by simulating three possible corrosion environments inside a gas pipeline. The corrosion rate indicated by depth change was adopted in this study. Scanning electron microscopy and X-ray diffraction were used to analyze corrosion products. Results showed that the specimens completely immersed in condensate water were generally corroded and that the specimens exposed to gas were locally corroded. However, the corrosion rate of the latter was slightly lower; hence, no autocatalysis of occluded corrosion cell occurred in the formation of corrosion pit, and uniform corrosion occurred in the precipitation location of condensate water. The areas in the range of 5 mm below the waterline indicated severe corrosion, and the rate could reach twice that of other areas. The corrosion products were mainly FeO(OH) and FeCO3, thereby proving that the corrosion failure of pipelines was caused by oxygen absorption corrosion and CO2 corrosion. Suggestions were presented to control corrosion failure of associated gas pipelines.

scholarly journals Fundamental aspects of the corrosion of N80 steel in a formation water system under high CO2 partial pressure at 100 °C

RSC Advances ◽  
2019 ◽  
Vol 9 (21) ◽  
pp. 11641-11648 ◽  
Author(s):  
Huixin Li ◽  
Dapeng Li ◽  
Lei Zhang ◽  
Yang Bai ◽  
Yun Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Carbon Steel ◽  
Partial Pressure ◽  
Corrosion Behavior ◽  
Water System ◽  
Formation Water ◽  
High Co2 ◽  
Co2 Partial Pressure ◽  
N80 Steel

The corrosion behavior of N80 carbon steel in a simulated formation water system saturated with CO2 under high pressure at 100 °C was investigated.

Fractal characteristics of AC corrosion morphology of X80 pipeline steel in coastal soil solution

2019 ◽  
Vol 66 (6) ◽  
pp. 868-878
Author(s):  
Yu Fu ◽  
Jie Kou ◽  
Cuiwei Du
Keyword(s):  
Fractal Dimension ◽  
Soil Solution ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Three Dimensional ◽  
Uniform Corrosion ◽  
X80 Pipeline Steel ◽  
Corrosion Morphology ◽  
Content Type ◽  
X80 Steel

Purpose Pipelines are seriously corroded due to the close distance between pipelines and high voltage transmission lines. The purpose of this paper is to study the influence of alternating current (AC) on corrosion behavior of X80 pipeline steel in coastal soil solution. Design/methodology/approach The corrosion behavior of X80 steel under different AC densities in coastal soil solution was investigated by electrochemical measurements and image processing technology. Furthermore, a quantitative description model of AC corrosion through fractal dimension of corrosion image was established. Findings The results show that under low AC density the X80 steel is mainly uniform corrosion, and once AC density reaches 150 A/m2, the corrosion morphology gradually turns to pitting corrosion with irregular circle. For another aspect, the fractal dimension of corrosion images shows that the two/three-dimensional fractal dimension increase with the increase of AC density, presenting a linear and an exponential relationship respectively. In addition, the variation of the three-dimensional fractal dimension is the same as that of average corrosion rate. The threshold of the increasing trend of fractal dimension as well as corrosion type is 150 A/m2. Originality/value The investigation provides a quantitative method to describe AC corrosion morphology through fractal dimension. Furthermore, the method is of benefit to process corrosion images automatically.

Corrosion Behavior of Novel Cr2MoNbTi Pipeline Steel in CO2 Environment

2012 ◽  
Author(s):  
Wenliang Zhang ◽  
Lining Xu ◽  
Shaoqiang Guo ◽  
Lei Zhang ◽  
Minxu Lu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Corrosion Behavior ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
Oil And Gas Industry ◽  
Carbon Steels ◽  
Co2 Corrosion ◽  
Uniform Corrosion ◽  
High Temperature High Pressure

CO2 corrosion is frequently encountered in oil and gas industry. The search for new sources of oil and gas has pushed the operational activities to harsher environment and this requires new tubing and pipeline materials which can endure tough circumstances. Low alloy steel containing Chromium, which fills the gap between carbon steels and corrosion resistant alloys in terms of cost and corrosion resistance, has aroused significant interest from steel enterprises and scholars. At present, these studies mainly focus on 3%–5%Cr steel, and little study concerns the 2%Cr steel, which is more economic and weldable. In this paper, novel Cr2MoNbTi steel was developed and the microstructure and mechanical properties were studied. Corrosion behavior of the Cr2MoNbTi steel immersed in the CO2-containing solutions, which corresponded to the environment of bottom-of-line corrosion (BLC), was studied using high temperature-high pressure autoclave. In addition, dynamic high temperature-high pressure condensation autoclave was employed to simulate the top-of-line corrosion (TLC) environment and the corrosion behavior of the Cr2MoNbTi steel under wet gas environment was investigated. The composition and morphology of the corrosion scale were characterized by energy dispersive spectroscopy and scanning electron microscopy analyses. The results show that the Cr2MoNbTi steel exhibited uniform corrosion and presented good resistance to CO2 corrosion compared with X65 pipeline steel.

Influence of Thermal Effect on Electrochemical Corrosion Behavior of T2 Copper in Simulated Seawater Environment

2013 ◽  
Vol 470 ◽  
pp. 128-131
Author(s):  
Ji Nan Li ◽  
Gang Chen ◽  
Peng Zhang ◽  
Qian Su ◽  
Dong Luan ◽  
...  
Keyword(s):  
Water Quality ◽  
Thermal Effect ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Sample Surface ◽  
Corrosion Products ◽  
Solution Temperature ◽  
Corrosion Morphology ◽  
Electrochemical Corrosion Behavior ◽  
Simulated Seawater

This paper has designed electrochemical corrosion experiment of T2 copper in 3.5% NaCl solution to investigate influence of thermal effect on electrochemical corrosion behavior of copper in simulated seawater. Solution temperature was 20°C, 30°C, 40°C and 50°C. The water quality parameters and polarization curve have been measured and analyzed. Corrosion morphology and composition of corrosion products have been observed and analyzed. Thermal effect would lead to water quality variation which influenced the corrosion behavior of copper samples and corrosion potentials would fluctuate with temperature rising. Sample surface of 30°C was neatly covered with fine, uniform and granular corrosion products. There're Cu2O and CuCl on both samples of 20°Cand 30°Cand trace corrosion product of CuC2O40.5H2O and CuCl2 of only 30°C.

Corrosion Behaviors of 25CrMnVA Steel in CO2 Flooding Enhanced Oil Recovery System

2013 ◽  
Vol 816-817 ◽  
pp. 1243-1249
Author(s):  
Chong Sun ◽  
Jian Bo Sun ◽  
Yong Wan ◽  
Xin Su ◽  
Yong Zhang
Keyword(s):  
Corrosion Rate ◽  
Partial Pressure ◽  
Oil Recovery ◽  
Oil Field ◽  
Uniform Corrosion ◽  
Corrosion Morphology ◽  
Corrosion Rates ◽  
Corrosion Scale ◽  
Corrosion Behaviors ◽  
Local Defects

Influences of temperature and CO2 partial pressure on CO2 corrosion behaviors of 25CrMnVA steel were investigated in the simulated oil field environments. The corrosion rates were measured under high temperature and high pressure condition. SEM, EDS and XRD were used to analyze the morphologies and characteristics of corrosion scales on the steels. The results shows that the corrosion rates of 25CrMnVA steel change little below 65°C, the corrosion feature is uniform corrosion. The corrosion rates increase rapidly after 65°C, mesa corrosion is found on the surface of steel. The corrosion rates decrease firstly and increase subsequently with the rising of CO2 partial pressure, and the minimal corrosion rate presents near CO2 critical pressure. The compactness of corrosion scale improves with the increase of CO2 partial pressure below 8MPa, which causes uniform corrosion rate reduced. Under supercritical CO2 condition, the local defects in the surface of corrosion scale increase, and the compactness of corrosion scale reduces,which cause the increase of corrosion rate sharply. The corrosion rate and corrosion morphology are closely related to the state of corrosion scale.

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