Pitting and CO2 corrosion behavior of oil and gas pipeline welds

2021 ◽  
Vol 63 (11) ◽  
pp. 1018-1024
Author(s):  
Huan Xie ◽  
Xiang Chen ◽  
Yongxin Lu ◽  
Qian Zhang ◽  
Haitao Wang
Keyword(s):  
Corrosion Behavior ◽  
Oil And Gas ◽  
Welded Joint ◽  
Oil And Gas Industry ◽  
Gas Pipeline ◽  
Co2 Corrosion ◽  
Fe Model ◽  
Gas Industry ◽  
Remaining Service Life ◽  
Pit Depth

Abstract A finite element (FE) model is presented in this work that is used to analyze the effect of pitting corrosion on the CO2 corrosion behavior of oil and gas pipeline welds. The FE model contains two parts, i. e., stress calculation of the welded joint using Abaqus software, and of the chemical reaction at the welded joint using COMSOL Multiphysics® software. The effect of transportation pressure, pit depth and welding material on the CO2 corrosion behavior of weld metal was investigated using the FE model. It turned out that the FE model is helpful to instruct the management and to assess the remaining service life prediction of pipelines in the oil and gas industry.

Manufacture and Qualification of Small Diameter / Thickwall Reelable DSAWL Linepipe

2016 ◽  
Author(s):  
Stephen Hall ◽  
Martin Connelly ◽  
Graham Alderton ◽  
Andrew Hill ◽  
Shuwen Wen
Keyword(s):  
Oil And Gas ◽  
Small Diameter ◽  
Oil And Gas Industry ◽  
Fe Model ◽  
External Diameter ◽  
Gas Industry ◽  
The North ◽  
Innovative Thinking ◽  
The North Sea ◽  
The Cost

Tough market conditions have seen the price of oil drop which with the subsequent uncertainty surrounding the industry have seen the oil and gas industry concentrate on reducing the cost of designing, installing and operating pipelines. A critical process for the industry is the procurement, manufacture and installation of appropriate linepipe. The method of installation is often dictated by the pipe size and the water depth that the pipe is to be laid in, however there are times when the choice of lay method is due to vessel availability and relative costs for each technique. In early 2014, Tata Steel successfully manufactured and delivered 16"OD × 0.875”WT X65 submerged arc welded longitudinal (SAWL) linepipe for installation via the reel lay method. Notable features about this fact were the size, which represents the thickest 16” external diameter UOE pipe yet delivered by Tata Steel, and that this was to be the first UOE pipe to be installed by the reel lay method in the North Sea. The ability to manufacture small diameter thickwall linepipe was only possible due to recent operational developments including an established tooling programme and a fully validated Finite Element (FE) model of the UOE process, along with years of experience of integrating these tools into the manufacturing process. This paper discusses the manufacturing challenges for small diameter thickwall linepipe, and how with the aid of modelling tools, innovative thinking and previous experience in supplying small diameter thickwall linepipe into two reel-installed projects, the pipe was manufactured and delivered with the properties shown to be compliant with DNV OS-F101 Supplementary Requirement P.

scholarly journals Corrosion Control, Prevention and Mitigation in Oil & Gas Industry

2019 ◽  
Vol 9 (2) ◽  
pp. 1568-1572
Keyword(s):  
Oil And Gas ◽  
Continuous Production ◽  
Oil And Gas Industry ◽  
Co2 Corrosion ◽  
Gas Industry ◽  
Well Control ◽  
Material Choice ◽  
Definition Of ◽  
The Impact ◽  
Oil Gas

The impact of corrosion within the refining industry ends up in the failure of components. This failure leads to closing down the plant to scrub the corroded components. Additionally, corrosion normally causes serious environmental issues, namely spills and releases. A vital resource for all those that are concerned within the corrosion management of oil and gas infrastructure, corrosion management within the oil and gas industry provides engineers and designers with the tools and strategies to plan and implement comprehensive corrosion-management programs for oil and gas infrastructures. Control of corrosion is important for continuous production and evading the well control losses. Materials to be used in down hole have to meet certain characteristics to avoid corrosion and provide additional mechanical strenght. It is potential to determine a logical series of steps for material choice, incorporating analysis of the surroundings, corrosion rate calculations, and final material choice based on established limits. Several developments have taken place in refinement the calculation of CO2 corrosion rates. Moreover, the definition of bitter examination has been reviewed and a way wider evaluation of the relevance of varied established and new materials for various service conditions has been created.

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.

scholarly journals Inlet pressure simulation of pigging in uphill gas pipeline

2019 ◽  
Vol 20 (4) ◽  
pp. 406 ◽  
Author(s):  
Honggang He ◽  
Zheng Liang ◽  
Yishan Guo
Keyword(s):  
Gas Flow ◽  
Oil And Gas ◽  
Pressure Rise ◽  
Oil And Gas Industry ◽  
Gas Pipeline ◽  
Inlet Pressure ◽  
Gas Industry ◽  
Flow Equations ◽  
Pipeline Inspection ◽  
Common Operation

Pipe cleaning is a common operation in the oil and gas industry. In this paper, the governing equation of the pipeline inspection gauge (PIG, lowercase pig is commonly used) speed is combined with the gas flow equations. The method of characteristics (MOC) is used to solve the transient equations of gas flow. And the process of a pig passing over an uphill section of a gas pipeline is simulated. The results indicate that a pig may get stuck in uphill gas pipeline, due to the coupling of the gas and the pig. Under these circumstances, a higher pressure of the upstream could be helpful for driving the pig in motion. Additionally, the ratio of inlet pressure rise during the pigging process is primarily determined by the inclination of the uphill section. In addition, a formula to predict the inlet pressure during pigging in an uphill pipe is presented. Furthermore, the proposed method and solution can be utilized to predict the speed and position of the pig, as well as the gas pressure and the stoppage of the pig in hilly gas pipelines.

Investigation of the Hydrogen Stratification of the Metal of the Active Gas Pipeline

2018 ◽  
Vol 284 ◽  
pp. 1302-1306 ◽  
Author(s):  
O.A. Nasibullina ◽  
A.G. Gareev ◽  
Rif G. Rizvanov
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Pipeline ◽  
Negative Effects ◽  
Local Zone ◽  
Gas Industry ◽  
Hydrogen Corrosion ◽  
Metal Structures ◽  
Metal Microstructure ◽  
Free Metal

One of the most common types of metal destruction in the oil and gas industry is hydrogen embrittlement. Hydrogen corrosion is a complex of negative effects of hydrogen on steel, leading to the destruction of metal structures. Hydrogen passes through a defect-free metal, without lingering in it. In the presence of defects, hydrogen is retained in the metal forming a brittle solid solution, metal stratification along the segregation streamer, blistering. Studies of the metal of a gas pipeline made of steel 09G2S are presented in the article. The sample was selected from the local zone of destruction in the condensate collector, the metal of the pipe had typical for hydrogen corrosion stratifications. The scope of the study was identification of the most dangerous part of hydrogen corrosion on the sample taken from the local zone of destruction. Studies on the chemical composition and mechanical properties of 09G2S steel were also carried out. Stress-related characteristics of the metal microstructure of the failed gas pipeline were obtained and the character of the destruction progress was revealed. The presence of sulfides cluster in the metal of studied pipe was determined applying metallographic method for determining nonmetallic inclusions.

Integrity of Small Angle Mitered Joints

2016 ◽  
Author(s):  
Gavin (Guowei) Zheng ◽  
Iain Colquhoun ◽  
Joe Paviglianiti
Keyword(s):  
Sensitivity Analysis ◽  
Small Angle ◽  
Thermal Loading ◽  
Oil And Gas ◽  
Strong Dependence ◽  
Oil And Gas Industry ◽  
Gas Pipeline ◽  
Theoretical Development ◽  
Gas Industry ◽  
Cyclic Service

Miter bends are permitted for use in the oil and gas industry in a variety of configurations. This paper addresses small angle miter joints used to correct minor misalignments. The CSA Z662-15 standard (Oil and Gas Pipeline Systems) states in the construction section (Clause 6.2.3(g)) that “mitred bends shall not be used”. However, a note accompanying the clause states that “deflections up to 3 degrees caused by misalignment are not considered to be mitred bends.” Nonetheless, concerns continue to be raised that stresses introduced due to this misalignment can affect safety and operation of pipelines. This paper reviews literature of failures associated with mitered joints and the theoretical development of stresses in miters, and presents results from a linearized sensitivity analysis of buried mitered joints under pressure and thermal loading based on ASME B31.1 and B31.3 criteria. The paper contains an analysis of the origins of CSA-Z662 Clause 6.2.3(g). Recognizing that the stresses introduced by miters are discontinuity stresses, the paper discusses the effects of such stresses, including the use of miters in cyclic service. Recognizing also the strong dependence of D/t ratio on the discontinuity stress, the paper suggests a modification to the Z662 approach to account for this effect. This modification would provide guidance to the use of miters to effect small deflections both during design and construction of piping.

Mitigating CO2 Corrosion of Natural Gas Steel Pipelines by Thermal Spray Aluminum Coatings

CORROSION ◽  
10.5006/3797 ◽  
2021 ◽  
Author(s):  
Zineb belarbi ◽  
Joseph Tylczak ◽  
Margaret Ziomek-Moroz
Keyword(s):  
Thermal Spray ◽  
Surface Characterization ◽  
Oil And Gas ◽  
Electrochemical Impedance ◽  
Oil And Gas Industry ◽  
Co2 Corrosion ◽  
Gas Industry ◽  
Co2 Partial Pressure ◽  
Aluminum Coatings ◽  
Spray Coatings

Internal pipeline corrosion due to CO2 is a major challenge facing the oil and gas industry. To protect the pipelines and equipment from the ravages of CO2 corrosion, novel sacrificial coatings can be used. The objective of this study was to investigate the corrosion behavior of Al-based alloys as sacrificial coatings to protect pipelines in a CO2-saturated aqueous electrolyte (3.5 wt.% NaCl) at 4 bar CO2 partial pressure (3 barg) and 40 oC. The corrosion resistance of Al-based alloys and thermal spray coatings was evaluated in an electrochemical reaction autoclave using electrochemical methods (potentiodynamic polarization, linear polarization resistance, and electrochemical impedance spectroscopy). Post-corrosion surface characterization was performed by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The obtained data show Al-based alloys demonstrated promising protection against CO2 corrosion with no breakaway degradation issues.

scholarly journals Speed Simulation of Pig Restarting from Stoppage in Gas Pipeline

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Honggang He ◽  
Zheng Liang
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Pressure Change ◽  
Gas Pipeline ◽  
Maximum Speed ◽  
Gas Industry ◽  
Pipeline Inspection ◽  
Common Operation

Pigging is a common operation in the oil and gas industry. Because of the compressibility of the gas, starting up a pipeline inspection gauge (pig) from a stoppage can generate a very high speed of the pig, which is dangerous to the pipe and the pig itself. Understanding the maximum speed a pig achieves in the restarting process would contribute to pig design and safe pigging. This paper presents the modeling of a pig restarting from a stoppage in gas pipeline. In the model, the transient equations of gas flow are solved by method of characteristics (MOC). Runge-Kutta method is used for solving the pig speed equation. The process of a pig restarting from a stoppage in a horizontal gas pipe is simulated. The results indicate that the maximum speed a pig achieves from a stoppage is primarily determined by the pressure of the pipe and the pressure change caused by the obstructions. Furthermore, response surface methodology (RSM) is used to study the maximum speed of pig. An empirical formula is present to predict the maximum speed of a pig restarting from a stoppage in gas pipeline.

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