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Article
Publication date: 2 November 2018

Juan Du, Yuning He, Pingli Liu, Yigang Liu, Xianghai Meng and Liqiang Zhao

This paper aims to analyze the corrosion and corrosion inhibition of N80 in 10 per cent HCl + 8 per cent fluoroboric acid (HBF4) solution for acidizing operation.

Abstract

Purpose

This paper aims to analyze the corrosion and corrosion inhibition of N80 in 10 per cent HCl + 8 per cent fluoroboric acid (HBF4) solution for acidizing operation.

Design/methodology/approach

The corrosion rate, kinetic parameters (Ea, A) and thermodynamic parameters (ΔH, ΔS) of N80 steel in fresh acid and spent acid, 10 per cent HCl + 8 per cent HBF4, 10 per cent HCl and 8 per cent HBF4 solutions were calculated through immersion tests. The corrosion and inhibition properties were studied through X-ray diffraction and electrochemical measurements. The corrosion morphology of the corrosion product was examined by scanning electron microscopy (SEM).

Findings

The results demonstrated that the spent acid was the main cause of acidification corrosion, and the HBF4 would cause serious corrosion to N80 steel. The results showed that the N80 steel was more seriously corroded in the spent acid than in fresh acid, and the hydrolysis of HBF4 accelerates the dissolution process of N80 steel anode to control the corrosion reaction. The results showed that the acidification will definitely cause serious corrosion to the oil tube; therefore, necessary anti-corrosion measures must be taken in the acidification process.

Originality/value

The results showed that acidizing the formation with 10 per cent HCl + 8 per cent HBF4 will definitely cause serious corrosion to the oil tube, especially when the spent acid flows back. Therefore, necessary anti-corrosion measures must be taken in the acidification process, especially in the spent acid flowback stage.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 29 April 2014

Mahendra Yadav, Sumit Kumar and Dipti Sharma

The purpose of this investigation was to evaluate the protective ability of 2-amino-N-octadecylacetamide (AOA) and 2-amino-N-octadecyl-3-(4-hydroxyphenyl) propionamide…

Abstract

Purpose

The purpose of this investigation was to evaluate the protective ability of 2-amino-N-octadecylacetamide (AOA) and 2-amino-N-octadecyl-3-(4-hydroxyphenyl) propionamide (AOHP) as corrosion inhibitors for N80 steel in 15 per cent hydrochloric acid (HCl), which may find application as eco-friendly corrosion inhibitors in acidizing processes in the petroleum industry. Due to scale plugging in the well bore, there can be a decline in the crude production rate, and an acidization operation has to be carried out, normally by using 15 per cent HCl to remove the scale plugging. To reduce the aggressive attack of HCl on tubing and casing materials (N80 steel), inhibitors are added to the acid solution during the acidifying process.

Design/methodology/approach

Different concentrations of the synthesized inhibitors AOA and AOHP were added to the test solution (15 per cent HCl), and the corrosion inhibition efficiencies of these inhibitors for N80 steel were calculated from weight loss determinations, potentiodynamic polarization scans and alternating current (AC) impedance measurements. The influence of temperature (298-323 K) on the inhibition behavior was studied. Surface examinations were performed by means of Fourier transform infrared spectra and scanning electron microscope.

Findings

AOA and AOHP at 150-ppm concentration showed a maximum efficiency of 90.04 and 94.97 per cent, respectively, at 298 K in 15 per cent HCl solution. Both the inhibitors acted as mixed corrosion inhibitors. The adsorption of the corrosion inhibitors at the surface of the N80 steel was the underlying mechanism of corrosion inhibition.

Originality/value

This paper reports the preliminary laboratory results of inhibitors AOA and AOHP for the corrosion prevention of N80 steel casings and tubulars exposed to HCl and may be of practical help to petroleum engineers for carrying out acidization in oil wells after further investigation of the compound at higher temperature.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 23 May 2008

Dong Liu, ZhenYu Chen and XingPeng Guo

The purpose of this paper is to consider the effect of acetic acid and acetate on the anodic and cathodic reactions of carbon steel present in CO2 corrosion.

Abstract

Purpose

The purpose of this paper is to consider the effect of acetic acid and acetate on the anodic and cathodic reactions of carbon steel present in CO2 corrosion.

Design/methodology/approach

The corrosion behaviour of carbon steel (N80) in CO2‐saturated 1% NaCl solution at 50°C and 0.1 MPa was investigated by using weight‐loss tests, electrochemical methods (polarization curves and electrochemical impedance spectroscopy) and surface analysis (scanning electron microscopy).

Findings

The results indicated that: both HAc and Ac significantly increased the corrosion rate of carbon steel, and the surface chemical reactions of cathodic reduction were enhanced in the presence of HAc and Ac. Because adsorbed HAc could be reduced directly in the presence of Ac, the corrosion rate increased, even though the pH of the solution increased. Ac played an important role in the anodic dissolution processes, which mainly affects the formation/adsorption of intermediates, and acts to form more soluble corrosion products.

Originality/value

The results of this work clarify the role of acetic acid or acetate in the anodic and cathodic reactions of CO2 corrosion.

Details

Anti-Corrosion Methods and Materials, vol. 55 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 January 2016

Wei Yan, Yong Xiang, Wenliang Li and Jingen Deng

This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion…

Abstract

Purpose

This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion design. CO2 partial pressure is the most important parameter to the oil and gas corrosion research for these wells which contain sweet gas of CO2. However, till now, there has not been a recognized method for calculating this important value. Especially in oil well, CO2 partial pressure calculation seems more complicated. Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. A case study was presented according to the new method, and two kinds of corrosion environment were determined. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. Based on the test results, 3Cr-L80 was recommended for downhole tubing. Combined with the field application practice, 3Cr-L80 was proved as a safety and economy anti-corrosion tubing material in this oil field. A proper corrosion parameter (mainly refers to CO2 partial pressure and temperature) can ensure a safety and economy downhole tubing anti-corrosion design.

Design/methodology/approach

Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. A field application practice was used.

Findings

It is necessary to calculate the CO2 partial pressure properly to ensure a safety and economy downhole tubing (or casing) anti-corrosion design.

Originality/value

The gas and oil separation theory and corrosion theory are combined together to give a useful method in downhole tubing anti-corrosion design method.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 6 November 2017

Liqiang Zhao, Yanhua Zhu, Pingli Liu, Jian Zhang and Yigang Liu

This paper aims to describe the corrosion behavior and possibility of inhibition by corrosion inhibitor SA1-3 in acidizing solution (5 per cent hydrochloric acid [HCl…

Abstract

Purpose

This paper aims to describe the corrosion behavior and possibility of inhibition by corrosion inhibitor SA1-3 in acidizing solution (5 per cent hydrochloric acid [HCl] solution). The study aims to explain the mechanism of corrosion and inhibition of N80 steel in 5 per cent HCl solution to provide theoretical basis for expanding the range of application of N80 steel in acidification process.

Design/methodology/approach

This paper opted for a laboratory study using simulation of acidizing solution to do the experiments. The results of experiments including weight-loss method, electrochemical method and surface analysis were used to explain the mechanism of corrosion and inhibition so as to predict the dissolution progress of N80 steel in 5 per cent HCl solution with and without inhibitor SA1-3.

Findings

This paper provides theoretical insights about how to inhibit the corrosion behavior of N80 steel in 5 per cent HCl solution. It suggests that the corrosion inhibitor which can form a protective film on the steel surface should be used to expand the application of N80 steel in acidizing solution. The inhibitor SA1-3 is a kind of cathodic corrosion-controlling inhibitor which mainly inhibits cathode corrosion; it cannot change the corrosion mechanism of N80 steel.

Originality/value

This paper provides a theoretical basis for the corrosion behavior and inhibition mechanism of N80 steel in acidizing solution.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 9 August 2019

Yanhua Zhu, Liqiang Zhao, Pingli Liu and Xiao Qu

In this work, a kind of Mannich base (C21H25NO) was synthesized with cinnamal aldehyde, acetophenone and diethylamine in a condensing reflux device based on the…

Abstract

Purpose

In this work, a kind of Mannich base (C21H25NO) was synthesized with cinnamal aldehyde, acetophenone and diethylamine in a condensing reflux device based on the conventional method. Optimization of the inhibitor concentration was explored.

Design/methodology/approach

Spectral properties of this compound was investigated by FTIR, and its inhibition efficiency and mechanism on N80 steel in 20% hydrochloric acid solution were studied by weight loss measurement, electrochemical measurement (potentiodynamic polarization and electrochemical impedance spectroscopy) and surface analytical measurement (scanning electron microscope with energy dispersive spectrometer).

Findings

The results showed that the new inhibitor reduced the double-layer capacitance and increased the charge transfer resistance. The inhibition efficiency is 99.7% when the concentration of C21H25NO is 3%. The adsorption of C21H25NO on N80 steel surface in 20% HCl solution was found to be spontaneous and steady. Observed from the steel surface, an inhibition film was confirmed to be presented after adding inhibitor and successfully hindered the corrosive ions from reaching the bulk steel.

Originality/value

A new Mannich base (C21H25NO) was synthesized by cinnamal aldehyde, acetophenone and diethylamine for the corrosion prevention of N80 steel in 20% hydrochloric acid solution.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 25 July 2019

Zhichao Qiu, Chunming Xiong, Zhengrong Ye, Xiang Zhou, Rui Wang, Xueqiang Lin and Pengfei Sui

This paper aims to explore the influence of CO2 partial pressure, flow rate and water cut on N80 steel corrosion behaviors in the displacement process of oil in glutenite…

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Abstract

Purpose

This paper aims to explore the influence of CO2 partial pressure, flow rate and water cut on N80 steel corrosion behaviors in the displacement process of oil in glutenite reservoir by CO2 injection.

Design/methodology/approach

A self-made 3 L high-temperature and high-pressure autoclave was used to conduct corrosion simulation experiments of N80 steel in different CO2 partial pressures, flow rates and water cut (the independently developed oil and water mixing approach can ensure the uniform mixing of oil and water in experiments). Techniques like weight loss and surface analysis were used to analyze the corrosion behaviors of N80 steel under different conditions.

Findings

Results showed that the average corrosion rate of N80 steel accelerated at varying degrees with the increase of CO2 partial pressure, flow rate and water cut. Excluding that the samples showed uniform corrosion under the two conditions of 0.5MPa CO2 partial pressure and static corrosion, they displayed mesa attack corrosion under other conditions. Besides, with the increase of CO2 partial pressure, the pH value of solution dropped and the matrix corrosion speed rose, hence leading to the increased Fe2+ and CO32− concentration. Meanwhile, a lowered pH value improved the FeCO3 critical supersaturation, thereby leading to an increased nucleation rate/growth rate and ultimately causing the decrease of the dimension of FeCO3 crystallites formed on the surface of the samples.

Originality/value

The results can be helpful in targeted anti-corrosion measures for CO2/oil/water corrosive environment.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 7 March 2016

Yuan Pan, Fengtao Zhan, Zhifeng Lu, Yan Lin, Zhen Yang and Zheng Wang

The purpose of this paper is to set out a study of a Mannich base, which was synthesized and used as an acidizing corrosion inhibitor first, and to the corrosion inhibitor…

Abstract

Purpose

The purpose of this paper is to set out a study of a Mannich base, which was synthesized and used as an acidizing corrosion inhibitor first, and to the corrosion inhibitor mechanism.

Design/methodology/approach

A Mannich base, 1-phenyl-3-(1-pyrrolidinyl)-propanone (PHPP), was synthesized with acetophenone, pyrrolidine and formaldehyde at pH = approximately 2-3. The structure of PHPP was characterized by elemental analysis and Fourier transform infrared spectroscopy (FTIR). The corrosion inhibition of PHPP on N80 steel in 15 per cent hydrochloric acid (HCl) was studied by weight loss method, scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX), and the adsorption behavior of PHPP on the surface of N80 steel was discussed.

Findings

The results showed that the inhibition efficiency reached to 99.8 per cent and corrosion rate was 2.65 g·m-2·h-1 at 0.6 per cent of PHPP concentration in 15 per cent HCl, which indicated that PHPP presented excellent corrosion inhibition performance. The results of SEM and EDAX analysis showed that PHPP could be absorbed on the surface of N80 steel. The adsorption process of PHPP on the surface of N80 steel was chemisorption. This process was spontaneous and obeyed Langmuir adsorption isotherm.

Originality/value

It was found that PHPP presented excellent corrosion inhibition performance, and it is practicable to enhance oil production in oilfield development as a oil-well acidizing inhibitor. The study results can provide theoretical guidelines for the development of the inhibitor.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 22 May 2009

S. Vishwanatham and P.K. Sinha

The purpose of this paper is to evaluate the protective ability of mixtures of aniline and phenol as corrosion inhibitors for N80 steel in 15 per cent hydrochloric acid…

Abstract

Purpose

The purpose of this paper is to evaluate the protective ability of mixtures of aniline and phenol as corrosion inhibitors for N80 steel in 15 per cent hydrochloric acid, which may find application as corrosion inhibitors in acidization jobs in the petroleum industry. Owing to scale plugging at well bore there will be a decline in the crude production and acidization operation has to be carried out in the oil wells, normally by using 15 per cent hydrochloric acid to remove the scale plugging and enhance crude production. If the acid alone is poured in the oil wells through tubular and casing, corrosion of the metal (N80 steel) structures takes place for which an inhibitor is also is used along with the acid.

Design/methodology/approach

Different concentration ratios of the inhibitor mixtures of aniline and phenol were added to the test solution (15 per cent HCl) and corrosion inhibition of N80 steel in hydrochloric acid medium containing the inhibitor additives was tested by weight loss and potentiodynamic polarization measurements. Influence of temperature (ambient temperature to 333 K) and exposure period (6‐24 h) on the inhibition behaviour was also studied. Corrosion products on the metal surface were analyzed by fourier transform infrared (FTIR) and a possible mechanism of inhibition by the compounds is suggested.

Findings

Provides information about the protective ability of inhibitor mixtures containing aniline and phenol against corrosion of N80 casing steel in 15 per cent HCl medium. The results in the present study have shown synergistic effect of all the formulations tested. The formulation of the mixture containing 0.1 per cent AL with 0.7 per cent PH has shown a maximum efficiency (75 per cent at ambient temperature) among other tested combinations in the acid medium. The inhibition efficiency exhibited by the inhibitor mixture (0.1 per cent AL with 0.7 per cent PH) in 15 per cent HCl medium at 333 K and after 24 h – test was found to be 43 and 31 per cent, respectively. The inhibitors, in appropriate combinations may find some usefulness at still higher temperatures. Electrochemical measurements indicate that the additives are active towards both sides, i.e. cathodic and anodic. FTIR results of the inhibition product film (formed on the metal surface after the corrosion test) reveal the presence of the inhibitor molecules in the surface film on the metal. Aniline and phenol molecules of the inhibitor mixture undergo condensation after their addition to the acid solution and may result in formation of protective surface film on the metal consisting of diphenylamine (as also revealed by FTIR spectroscopy) which may also contribute to the corrosion inhibition apart from the inhibition offered by aniline and phenol separately.

Research limitations/implications

Normal temperatures of oil wells will be about 363 K. The results presented in this paper refer to temperatures up to 333 K, which perhaps limits its usefulness in actual field conditions. However, further research work to test the inhibition potentiality of the compounds at higher temperatures (363 K and above) is in progress, and will be communicated at a later stage.

Practical implications

The tested inhibitor mixtures containing aniline and phenol exhibited synergistic effect and a significant inhibition (75 per cent) at ambient temperature that also shows good inhibitive properties after longer exposure period (24 h) and higher temperature (333 K). Appropriate formulations of the compounds may also be effective at still higher temperatures and that may be worked out for possible application in oil wells as corrosion inhibitors for acidization job.

Originality/value

This paper offers preliminary laboratory results of some inhibitor formulations on corrosion prevention of N80 steel casing and tubular in hydrochloric acid that may be of practical help to petroleum engineers for carrying out acidization jobs in oil wells after further investigations of the compounds at higher temperatures and actual field conditions.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 4 August 2021

Qingchao Cheng, Guangsheng Cao, Congyu Sang, Yujie Bai, Dan Li and Ruixuan Bu

This paper aims to clarify the corrosion inhibition effect of different corrosion inhibitor systems on the corrosion of metal pipe string by potassium persulfate plugging…

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Abstract

Purpose

This paper aims to clarify the corrosion inhibition effect of different corrosion inhibitor systems on the corrosion of metal pipe string by potassium persulfate plugging agent, so as to improve the injection capacity of polymer plugging well and reduce the corrosion of steel by oxidant plugging agent.

Design/methodology/approach

The effect of different corrosion inhibitors on the corrosion inhibition of N80 carbon steel in 1% potassium persulfate solution was studied by electrochemical experiment and weight loss experiment. The corrosion inhibition mechanism of potassium persulfate inhibitor and the synergistic mechanism among different inhibitors were analyzed.

Findings

The results indicated that when the temperature was 50°C, the inhibition effect of 0.2% sodium molybdate with a single inhibitor was the best at pH 8.5, and the inhibition rate was 70.17%. The inhibition efficiency of 0.2% sodium molybdate + 0.3% sodium silicate in the composite inhibition system can reach 94.38%. In the temperature range of 20°C–60°C, with the increase of system temperature, the inhibition effect of corrosion inhibitor will gradually weaken.

Originality/value

The corrosion inhibition system of N80 steel in potassium persulfate oxidant was mainly studied, and it clarified the influence of temperature and pH value on the corrosion inhibition effect, which provided guidance and suggestions for the corrosion inhibition of tubular string in the oilfield.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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