Corrosion behavior of X65 steel in CO2-saturated oil/water environment of gathering and transportation pipeline

2019 ◽  
Vol 66 (5) ◽  
pp. 671-682
Author(s):  
Yuanpeng Cheng ◽  
Yu Bai ◽  
Shanfa Tang ◽  
Dukui Zheng ◽  
Zili Li ◽  
...  
Keyword(s):  
Weight Loss ◽  
Crude Oil ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Water Environment ◽  
Content Type ◽  
X65 Steel ◽  
Corrosion Scales ◽  
Oil Water ◽  
Water Cut

Purpose The purpose of this paper is to investigate the corrosion behavior of X65 steel in the CO2-saturated oil/water environment using mass loss method, potentiodynamic polarization technique and characterization of the corroded surface techniques. Design/methodology/approach The weight loss analysis, electrochemical study and surface investigation were carried out on X65 steel that had been immersed in the CO2/oil/water corrosive medium to understand the corrosion behavior of gathering and transportation pipeline steel. The weight loss tests were carried out in a 3 L autoclave, and effects of water cut and temperature on the CO2 corrosion rate of X65 steel were studied. Electrochemical studies were carried out in a three-electrode electrochemical cell with the test temperature was 60°C, and the CO2 partial pressure was 1 atm by recording open circuit potential/time and potentiodynamic polarization characteristics. The surface and cross-sectional morphologies of corrosion product scales were characterized using scanning electron microscopy. The phases of corrosion product scales were investigated using x-ray diffraction. Findings The results showed that due to the wetting and adsorption of crude oil, the corrosion morphology of X65 steel changed under different water cuts. When the water cut of crude oil was 40-50 per cent, uniform corrosion occurred on the steel surface, accompanied by local pitting. While the water cut was 70-80 per cent, the resulting corrosion product scales were thick, loose and partial shedding caused platform corrosion. When the water cut was 90 per cent, the damaged area of platform corrosion was enlarged. Crude oil can hinder the corrosion scales from being dissolved by the corrosive medium, and change dimension and accumulation pattern of the crystal grain, thickness and structure of the corrosion scales. Under the corrosion inhibition effect of crude oil, the temperature sensitive point of X65 steel corrosion process moved to low temperature, appeared at about 50°C, lower corrosion rate interval was broadened and the corrosion resistance of X65 steel was enhanced. Originality/value The results can be helpful in selecting the applicable corrosion inhibitors and targeted anti-corrosion measures for CO2-saturated oil/water corrosive environment.

The corrosion behavior of X65 steel in CO2/oil/water environment of gathering pipeline

2019 ◽  
Vol 66 (2) ◽  
pp. 174-187 ◽  
Author(s):  
Yuanpeng Cheng ◽  
Yu Bai ◽  
Zili Li ◽  
JianGuo Liu
Keyword(s):  
Crude Oil ◽  
Partial Pressure ◽  
Flow Velocity ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Critical Value ◽  
Corrosive Environment ◽  
Content Type ◽  
X65 Steel ◽  
Oil Water

Purpose The purpose of this paper was to investigate the corrosion behavior of X65 steel in the CO2/oil/water environment using mass loss method, potentiodynamic polarization technique and characterization of the corroded surface techniques. Design/methodology/approach The weight loss analysis, electrochemical study and surface investigation were carried out on X65 steel that had been immersed in the CO2/oil/water corrosive medium to understand the corrosion behavior of gathering pipeline steel. The weight loss tests were carried out in a 3L autoclave, and effects of flow velocity, CO2 partial pressure and water cut on the CO2 corrosion rate of X65 steel were studied. Electrochemical studies were carried out in a three-electrode electrochemical cell with the test temperature of 60°C and CO2 partial pressure of 1 atm by recording open circuit potential/time and potentiodynamic polarization characteristics. The surface and cross-sectional morphologies of corrosion product scales were characterized using scanning electron microscopy. The phases of corrosion product scales were investigated using X-ray diffraction. Findings The results showed that corrosion rates of X65 steel both increased at first and then decreased with the increase of flow velocity and CO2 partial pressure, and there were critical velocity and critical pressure in the simulated corrosive environment, below the critical value, the corrosion products formed on the steel surface were loose, porous and unstable, higher than the critical value, the corrosion product ?lms were dense, strong adhesion, and had a certain protective effect. Meanwhile, when the flow velocity exceeded the critical value, oil film could be adsorbed on the steel surface more evenly, corrosion reaction active points were reduced and the steel matrix was protected from being corroded and crude oil played a role of inhibitor, thus it influenced the corrosion rate. Above the critical CO2 partial pressure, the solubility of CO2 in crude oil increased, the viscosity of crude oil decreased and its fluidity became better, so that the probability of oil film adsorption increased, these factors led to the corrosion inhibition of X65 steel reinforced. The corrosion characteristics of gathering pipeline steel in the corrosive environment containing CO2 would change due to the presence of crude oil. Originality/value The results can be helpful in selecting the suitable corrosion inhibitors and targeted anti-corrosion measures for CO2/oil/water corrosive environment.

Effect of main controlling factor on the corrosion behaviour of API X65 pipeline steel in the CO2/oil/water environment

2017 ◽  
Vol 64 (4) ◽  
pp. 371-379 ◽  
Author(s):  
Yuanpeng Cheng ◽  
Zili Li ◽  
Yalei Zhao ◽  
Yazhou Xu ◽  
Qianqian Liu ◽  
...  
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosion Behaviour ◽  
Pipeline Steel ◽  
Corrosion Morphology ◽  
Content Type ◽  
Api X65 Steel ◽  
Oil Water ◽  
Water Cut

Purpose The purpose of this paper was to investigate the corrosion behaviour of API X65 pipeline steel in the simulated CO2/oil/water emulsion using weight loss technique, potentiodynamic polarization technique and characterization of the corroded surface techniques. Design/methodology/approach The weight loss analysis, electrochemical study and surface investigation were carried out on API X65 pipeline steel that had been immersed in the CO2/oil/water corrosive medium to understand the corrosion behaviour of gathering pipeline steel. The weight loss tests were carried out in a 3L autoclave, and effects of temperature, CO2 partial pressure, water cut and flow velocity on the CO2 corrosion rate of API X65 pipeline steel were studied. Electrochemical studies were carried out in a three-electrode electrochemical cell with the test temperature was 60°C, and the CO2 partial pressure was 1 atm by recording open circuit potential/time and potentiodynamic polarization characteristics. The surface and cross-sectional morphologies of corrosion product scales were characterized using scanning electron microscopy. The phases of corrosion product scales were investigated using X-ray diffraction. Findings The results showed that water cut was the main controlling factor of API X65 steel corrosion under the conditions of CO2/oil/water multiphase flow, and it had significant impact on corrosion morphology. In the case of higher water cut or pure water phase, general corrosion occurred on the steel surface. While water cut was below 70 per cent, corrosion morphology transformed into localized corrosion, crude oil decreased corrosion rate significantly and played a role of inhibitor. Crude oil hindered the corrosion scales from being dissolved by corrosive medium and changed dimension and accumulation pattern of the crystal grain, thickness and structure of the corrosion scales; thus, it influenced the corrosion rate. The primary corrosion product of API X65 steel was ferrous carbonate, which could act as a protective film at low water cut so that the corrosion rate can be reduced. Originality/value The results can be helpful in selecting the suitable corrosion inhibitors and targeted anti-corrosion measures for CO2/oil/water corrosive environment.

Effect of Water Cut on the Localized Corrosion Behavior of P110 Tube Steel in Supercritical CO2/Oil/Water Environment

CORROSION ◽  
10.5006/1926 ◽  
2016 ◽  
Vol 72 (11) ◽  
pp. 1470-1482 ◽  
Author(s):  
Jianbo Sun ◽  
Chong Sun ◽  
Guoan Zhang ◽  
Weimin Zhao ◽  
Yong Wang
Keyword(s):  
Corrosion Behavior ◽  
Supercritical Co2 ◽  
Water Environment ◽  
Localized Corrosion ◽  
Tube Steel ◽  
Effect Of Water ◽  
Oil Water ◽  
Water Cut

Effects of the Dispersed Phase on Oil/Water Wax Deposition

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pengyu Wang ◽  
Wei Wang ◽  
Jing Gong ◽  
Yuanxin Zhou ◽  
Wei Yang
Keyword(s):  
Particle Size ◽  
Crude Oil ◽  
Dispersed Phase ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Wax Content ◽  
Oil Water ◽  
Water Cut

In the study of the foundation of the oil / water wax deposition experiment, the emulsification characteristics of crude oil emulsion with high wax content have gradually become the hot research area. In the current research of emulsification characteristics of oil/water emulsion, the attention has been focused on the study of the effects of water cut, stirring speed, particle size distribution on the viscosity of waxy crude oil emulsion in the experiment, in which heavy oil and simulated oil are adopted as the working fluids. In this study, the emulsion with different water cut and stirred by different speed was prepared under three different temperature conditions, the temperature above the wax appearance temperature (WAT), near the WAT, and below the WAT. The polarization microscope and rotary viscometer were applied to measure the effects of the particle size of the dispersed phase and waxy crystal distribution on the oil/water emulsion viscosity. The results suggest that preparing the temperature for crude oil emulsion with high wax content has an important influence on the emulsion microstructure. This study lays the foundation for further study of oil/water two phase dynamic wax deposition experiments.

scholarly journals Corrosion Behavior of 3% Cr Casing Steel in CO2-Containing Environment: A Case Study

2018 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Lin Xu ◽  
Jie Xu ◽  
Ming-biao Xu ◽  
Si-yang Li ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Exposure Time ◽  
Corrosion Products ◽  
Localized Corrosion ◽  
Internal Corrosion ◽  
Tafel Polarization ◽  
Water Cut ◽  
Increasing Temperature

Introduction: The production casing of 3% Cr steel has encountered severe internal corrosion in Huizhou Oilfield. To disclose corrosion behavior of inner casing, a series of corrosion exposure tests were systematically conducted on 3% Cr coupons in terms of in-field conditions. Material and Methods: Influence of exposure time, temperature, and water-cut on the CO2 corrosion of 3% Cr steel was investigated, and analyses on weight loss, composition and morphology of corrosion product, and Tafel polarization curves were further carried out. Result: The results showed that the corrosion rate of 3% Cr steel increased with increasing temperature, but such trend descended when the temperature exceeded 65°C due to formation of an compact and adherent corrosion product film on the surface of 3% Cr coupons. While varying exposure time from 7 days to 14 days, the corrosion rate decreased, and the Cr and O enrichment was determined in the corrosion products. The corrosion rate of 3% Cr steel increased with a continuous increment of water-cuts, especially when the water-cut was larger than 40%. Conclusion: The localized corrosion can happen at the lower water-cut due to the presence of amorphous films. The main corrosion products were FeCO3, Cr5O12, Fe2O3, and Fe-Cr. Entry of CO2 to the simulated formation water caused an increase in the anodic Tafel slope, and accelerated dissolution of 3% Cr steel.

Corrosion behavior of X80 pipeline steel in oilfield injection water in Eastern China

2021 ◽  
Vol 68 (5) ◽  
pp. 438-448
Author(s):  
Haoping Peng ◽  
Zhaolin Luan ◽  
Jun Liu ◽  
Yun Lei ◽  
Junxiu Chen ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Eastern China ◽  
Immersion Test ◽  
X80 Pipeline Steel ◽  
Content Type ◽  
Corrosion Product Film ◽  
Product Film ◽  
Injection Water

Purpose This paper aims to under the laboratory environment, the corrosion behavior of X80 pipeline steel in oilfield injection water in eastern China was studied by immersion test. Design/methodology/approach First, the corrosion product film was immersed in oilfield injection water and the effect on the corrosion behavior and the corrosion reaction mechanism were constantly observed during this period. The effect was displayed by potentiodynamic polarization curve and electrochemical impedance spectrums (EIS) measurements. Second, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to observe and test the corrosion product film immersed in the oilfield water for 30 days. Findings The results indicate that the tendency of metal corrosion becomes weaker at an early stage, but strengthened later, which means the corrosion rate is accelerating. Besides, it is indicated by impedance spectroscopy that with the decreasing of the capacitance arc radius, the reaction resistance is reducing in this progress. Meanwhile, the character of Warburg impedance could be found in EIS, which means that the erosional components are more likely to penetrate the product film to reach the matrix. The corrosion product is mainly composed of the inner Fe3O4 layer and outer shell layer, which contains a large number of calcium carbonate granular deposits. It is this corrosion under fouling that produces severe localized corrosion, forming many etch pits on the metal substrate. Originality/value The experiment chose the X80 steel, the highest-grade pipeline steel used in China, to conduct the static immersion test in the injection water coming from an oilfield in eastern China. Accordingly, the corrosion mechanism and the effect of corrosion product film on the corrosion of pipeline steel were analyzed and discussed.

Effects of crude oil-water emulsions at various water-cut on the performance of the centrifugal pump

2017 ◽  
Vol 16 (1) ◽  
pp. 71
Author(s):  
Sayed A. Bellary ◽  
Md. Hamid Siddique ◽  
Abdus Samad ◽  
Jitendra S. Sangwai ◽  
Bohyun Chon
Keyword(s):  
Crude Oil ◽  
Centrifugal Pump ◽  
Oil Water ◽  
Water Cut

Effect of Elemental Sulfur on Corrosion Behavior of Super 13Cr Martensitic Stainless Steel

2014 ◽  
Vol 556-562 ◽  
pp. 162-165 ◽  
Author(s):  
Shi Dong Zhu ◽  
Hai Xia Ma ◽  
Jin Ling Li ◽  
Zhi Gang Yang
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Elemental Sulfur ◽  
Martensitic Stainless Steel ◽  
Chemical Elements ◽  
Different Temperatures ◽  
Corrosion Scales

Effects of elemental sulfur on corrosion behavior of super 13Cr martensitic stainless steel were investigated by utilizing weight loss test, and the micro morphologies and chemical elements of corrosion scales were characterized by using SEM and EDS. The results showed that corrosion resistance of super 13Cr stainless steel was aggravated by the hydrolytic action of sulfur, the corrosion rate of super 13Cr stainless steel increased with the increasing of sulfur content, and firstly increased and then decreased with the increasing of temperature due to the activated adsorption and existential state of sulfur at the different temperatures.

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