Corrosion In Underground Pipelines Research Articles

Dielectric Waveguide Filled With Particulate Media for Ultrahigh Frequency (UHF) Radio Frequency Identification (RFID) Applications

Radio frequency identification (RFID) is a wireless communication technique that has a wide variety of applications in many fields. In some cases, the read range of the RFID transponder is a limiting factor to the application; thus, it is desired that the read range of a given RFID system be maximized. This paper presents a method to extend the read range of UHF RFID signal (860-960 MHz) by using cost-effective dielectric particulate materials (e.g., dry sand) as filler in dielectric waveguides, which is useful for applications that employ UHF RFID as a sensing or communication tool that need long read ranges, e.g., underground pipeline corrosion monitoring or leak detection. Reading tests conducted in both laboratory (air) and underground showed that the transmission of the UHF RFID signal through dielectric particulate media can considerably extend the read range of passive RFID transponders, which makes it a good material choice for the manufacturing of wireless monitoring systems for underground infrastructures. Classic waveguide theories developed by Marcatili and Emslie et al. were modified to analyze the transmission of the UHF RFID signal in the waveguide filled with dielectric particulate media. Reasonably good agreement was observed between the measured and calculated power values.

3D Analysis of Pipeline with Cathodic Corrosion Protection

Abstract Natural gas is an indispensable resource for human life. Its transport is usually done through underground pipelines. Due to the environment in which they are placed, the pipelines are subjected to a continuous process of corrosion. This paper aimed a 3D numerical analysis using specialized software (COMSOL Multiphysics) to study several parameters that influence the corrosion of underground pipelines. Starting from real geometric and environmental data, a comparative analysis was performed, considering the pipeline coating (e.g., with HDPE - high- density polyethylene), the placement of the cathode protection electrode, and the soil conductivity near the pipeline. The results confirm the need to cover the pipelines and can be a starting point for choosing the final configuration of the cathodic protection system.

(Corrosion Division H. H. Uhlig Award) The Journey from Numerical Simulations to Impedance Analysis

Our work in corrosion has encompassed numerical simulations and electrochemical impedance spectroscopy. This presentation provides an overview of insights gained from these endeavors.Numerical simulations train insightIn collaboration with Kevin Kennelley and Lee Bone, then from Arco, our group developed boundary-element models to simulate cathodic protection (CP) of pipelines with coating defects that exposed bare steel. Designed initially for the trans-Alaska pipeline,1 the model was extended to account for multiple pipes, multiple CP systems,2 buried tanks, and tank bottoms.3 The program could be used to simulate rectifier wars in which impressed current on one CP system can induce corrosion on adjacent or crossing systems. This program was used to demonstrate the behavior of heterogeneous anodes. For example, addition of impressed current anodes to an inadequate set of sacrificial anodes runs the risk of protecting the sacrificial anodes at the expense of protecting steel exposed by coating defects.In collaboration with Richard Woollam, then with BP, and, later, with Scott Briggs, NWMO, our group developed finite-element COMSOL models that accounted for corrosion under droplets containing dissolved oxygen.4 The models include coupled, nonlinear, conservation equations for ionic species, which account for migration, diffusion, local electroneutrality, homogeneous reactions, and formation of precipitates. The presence of anodic and cathodic regions was not assumed a priori, but was rather the result of numerical simulations, which revealed galvanic coupling caused by differential aeration cells. This work showed that, while differential aeration created nonuniform corrosion for steel covered by a deposit or droplet, corrosion of copper was largely uniform.Impedance spectroscopy can provide useful parametersWhile the use of the Stern-Geary relationship to extract corrosion current is well known, this approach applies only for systems under kinetic control. More information may be extracted from the ubiquitous constant-phase-element (CPE) behavior. In collaboration with scientists/engineers from France and Italy, our group developed the power-law model, which provides an equation that relates CPE parameters to film thickness, dielectric constant, and film resistivity at the film-electrolyte interface.5,6 This model can be augmented with the measurement model, from which capacitance may be extracted.7 Thus, if the dielectric constant is known, the measurement model can yield the corresponding film thickness and the power-law model can yield the resistivity distribution in the film.8 An early version of this approach is now in commercial use.9 Acknowledgements I am grateful for all the students and collaborators who walked part of this journey with me. These include students J. Matthew Esteban and Doug Riemer (CP models), Ya-Chiao Chang and Chen You, (droplet models), and Bryan Hirschorn (power-law model). I thank collaborators Bernard Tribollet, Vincent Vivier, Marco Musiani, and Nadine Pébère, with whom I have explored the arcane arts of impedance spectroscopy. Finally, I thank the Corrosion Division awards committee for bestowing upon me the 2022 H. H. Uhlig Award. References E. Orazem, J. M. Esteban, K. J. Kennelley, and R. M. Degerstedt, “Mathematical Models for Cathodic Protection of an Underground Pipeline with Coating Holidays: 1. Theoretical Development,” Corrosion, 53 (1997), 264-272.Liu, A. Shankar, M. E. Orazem, and D. P. Riemer, “Numerical Simulations for Cathodic Protection of Pipelines,” in Underground Pipeline Corrosion: Detection, Analysis, and Prevention, M. E. Orazem, editor, Woodhead Publishing Limited, Cambridge, UK, 2014, 85-126.P. Riemer and M. E. Orazem, “A Mathematical Model for the Cathodic Protection of Tank Bottoms,” Corrosion Science, 47 (2005), 849-868.-C. Chang, R. Woollam, and M. E. Orazem, “Mathematical Models for Under-Deposit Corrosion: 1. Aerated Media,” Journal of The Electrochemical Society, 161 (2014), C321-C329.Hirschorn, M. E. Orazem, B. Tribollet, V. Vivier, I. Frateur, and M. Musiani, “Constant-Phase-Element Behavior Caused by Resistivity Distributions in Films: 1. Theory,” Journal of The Electrochemical Society, 157 (2010) C452-C457.E. Orazem, B. Tribollet, V. Vivier, S. Marcelin, N. Pébère, A. L. Bunge, E. A. White, D. P. Riemer, I. Frateur, and M. Musiani, “Dielectric Properties of Materials showing Constant-Phase Element (CPE) Impedance Response,” Journal of The Electrochemical Society, 160 (2013), C215-C225.Liao, W. Watson, A. Dizon, B. Tribollet, V. Vivier, and M. E. Orazem, “Physical Properties Obtained from Measurement Model Analysis of Impedance Measurements,” Electrochimica Acta, 354 (2020), 136747.You, A. Titov, B. H. Kim, and M. E. Orazem, “Impedance Measurements on QLED Devices: Analysis of High-Frequency Loop in Terms of Material Properties,” Journal of Solid-State Electrochemistry, 24 (2020), 3083-3090.P. Riemer and M. E. Orazem, “Impedance-Based Characterization of Raw Materials as Used in Electrochemical Manufacturing,” The Electrochemical Society Interface, Fall 2014, 23:3 (2014), 63-67.

SEM-EDX and AFM analysis for the surface corrosion morphology structure and roughness on embedded X70 external pipeline in acidic soil (peat) environment

The corrosion of underground pipelines, especially on external surfaces, is generally influenced by soil properties and surrounding environmental conditions. Corrosion of the external oil and gas pipeline could result in a catastrophic incident in the oil refinery sectors due to friable points and corrosion prevention failure, restricting pipeline performance under high-pressure situations. Furthermore, this issue could cause substantial financial costs for the industry, notably in pipeline maintenance. In this study, an investigation was done focusing on the surface morphology change of this external pipeline under a series of exposure times (14, 30 and 60 days) at ambient and acidic peat environments. Organic peat with a pH range of 4.5–5.5 was chosen, as it can potentially induce surface deterioration on this pipeline external surface. SEM images revealed the production of dispersive corroded deposits form and tiny irregular porosity on the surface of X70 steel, while EDX proved the presence of Fe, O, and C elements associated with corrosion products. Meanwhile, AFM measurements verified that the average surface roughness value increased between 0.06 μm and 5.9 µm, indicating an acidic attack by these acidic soil particles leading to the heterogeneous formation with some defects at random positions on this pipeline surface. The intergranular corrosion mainly contributed to this phenomenon along this pipeline and resulted in a progressive induction of non-uniform and pitting corrosion products.

Economic analysis of DC power sources used in impressed current cathodic protection of underground pipelines

Objective: The objective of this study is to calculate and analyze the economic parameters of three main DC power sources i.e. Thermoelectric Generator, Transformer Rectifier, and solar photovoltaic (PV) Solar System, which are widely used in impressed current cathodic protection (ICCP) of underground pipelines. Methodology/Analysis : Initial or capital cost, operation and maintenance costs of the afore-mentioned DC sources are computed, for a practical ICCP system of high transmission underground pipeline over a period. Present worth analysis technique of economic analysis with inflation adjustment using a spreadsheet is adopted to compute these values. The analysis period of 20 years is used for present worth calculations of these DC sources. Findings: The cost efficiency of DC power sources for an ICCP system have been discussed in very few research papers. The calculations are made for either only one DC source at a time or the comparison is based on calculation without inflation adjustment. This study, in line with the currently adopted methodologies, provides a far easier and more comprehensive comparison and analysis of the most economical DC source for the ICCP system of underground metallic pipelines. Novelty/ Improvement: DC power sources play a pivotal role in an ICCP system that helps to mitigate the rate of corrosion in underground pipelines. This study contributes towards choosing the costeffective DC Power source for an ICCP system of underground pipelines. The results are drawn using practical data. This subsequently helps in mitigating the rate of corrosion in these pipelines. Keywords: Economic analysis; corrosion; DC power source; impressed current cathodic protection; underground pipelines

Corrosion of underground pipelines in clay soil with varied soil layer thicknesses and aerations

Underground pipelines suffer from corrosion in the soil. In this work, weight-loss testing, electrochemical measurements and surface analysis techniques were used to investigate the pipeline steel corrosion in a Regina clay soil with varied soil layer thicknesses and gassing conditions (i.e., aerobic, CO2-containing and anaerobic). Results demonstrate that the steel corrosion is dependent on the soil layer thickness, where a maximum corrosion rate is recorded under the 5 mm thick soil due to the competitive impact of the blocking effect of the soil layer and its moisture-retaining ability on the corrosion. In thin soil layers, the corrosion is accelerated with the increasing soil thickness due to more water contained in the soil. With the further increase of the soil layer thickness, the blocking effect of the soil on diffusion of corrosive species is dominant. The corrosion of the steel also depends heavily on the gassing condition in the soil. Under the specific soil layer thickness, the steel suffers from the highest corrosion rate in aerobic soil, which is followed by the 5% CO2/N2-containing soil. The steel corrosion is negligible (0.006 mm/y only) when the soil is purged with N2. In addition to uniform corrosion, localized corrosion occurs on the steel under soil due to its heterogeneous nature at a much greater rate than the uniform corrosion. The maximum localized corrosion rates in 5% CO2/N2-containing 5 mm thick soil layer and in the 3 mm thick soil that is open to air are 1.03 mm/y and 0.72 mm/y, respectively. As a comparison, the uniform corrosion rates are 0.05 mm/y and 0.04 mm/y under the two conditions.

Effect of pH in SRB (ATCC 7757) Growth for Oil and Gas API X 70 Steel Pipes

In the oil and gas industry, pipeline is the major transportation medium to deliver the products. According to [1] containment of pipeline loss to indicate that corrosion has been found to be the most predominant cause for failures of buried metal pipes. MIC has been identified as one of the major causes of underground pipeline corrosion failure and Sulphate Reducing Bacteria (SRB) are the main reason causing MIC, by accelerating corrosion rate. The objectives of this study is to study the SRB growth, Desulfovibrio desulfuricans ATCC 7757 due to pH and determine the optimum value controlling the bacteria growth on the internal pipe of carbon steel grade API X70. The result shows that the optimum SRB growth is at range pH 5-5 to 6.5 and the exposure time of 7 to 14 days. At pH 6.5 the maximum corrosion rate is 1.056 mm/year. Corrosion phenomena on carbon steel in the study proven had influence by pH and time. From this result pitting corrosion strongly attack at carbon steel pipe. In the future project, it is recommended to study the effect of different pipe location for example the pipeline under seawater.

HILDCAA‐Related GIC and Possible Corrosion Hazard in Underground Pipelines: A Comparison Based on Wavelet Transform

AbstractHigh‐intensity long‐duration continuous auroral electrojet activities (HILDCAAs) are recognized as the continuous (duration >2 days) auroral electrojet activities (AE > 1,000 nT) caused by interplanetary Alfvén waves driving magnetic reconnection at the Earth's magnetopause. This paper focuses on the study of geoeffectiveness of HILDCAA on the basis of associated geomagnetically induced currents (GICs) and pipe‐to‐soil voltage (PSV) observed in an underground pipeline at Finnish Natural Gas Station, Mäntsälä. In this study, 113 HILDCAAs with different interplanetary sources (72 corotating interaction region‐storm preceded, 29 interplanetary coronal mass ejection‐storm preceded, and 12 nonstorm) have been selected and their possible contributions in underground pipeline corrosion have been quantitatively compared by assessing GIC/PSV profiles for each of these events. In addition, the spectral characteristics of GIC during these events have been studied using continuous wavelet transforms. The Morlet wavelet has been applied to 10‐s modeled GIC data corresponding to each event to explore the main band structures and the periodicities found in GIC spectrum. GIC/PSV modeling is based on plane wave method and distributed source transmission line analogy between pipelines and electric circuits. HILDCAAs are found to drive a small‐amplitude, but continuous, fluctuation in GIC throughout the event duration of several days. This makes the cumulative effect of HILDCAAs in pipeline corrosion noteworthy. The spectral analysis shows that GIC possesses both short‐term, as well as continuous, power distribution with different periodicities. CIR‐preceded HILDCAAs are found to be more geoeffective while taking associated GIC and PSV into account. Possible physical explanations supporting the results have been presented.

Modelling and testing of optimum soil moisture levels in the corrosion of underground pipelines

Corrosion is one of the major factors leading to the failure of buried pipelines. Soil properties such as aeration, moisture content and level of compaction are known to cause variations in the level of corrosion of buried metallic structures. It is known that, at a particular soil moisture content, the corrosion rate reaches a maximum value. While this phenomenon is generally understood, an explanation from a soil mechanics perspective with mechanisms for soil water continuity and mass transport processes is currently lacking. This work fills this void by modelling the moisture-controlled diffusion transport and electrical conductivity in soil coupled to the electrochemical activity on the buried metal surface. Variations in the electrical conductivity and oxygen diffusion in sand at different degrees of saturation were determined experimentally. The results were used as input parameters in a finite element model. Results from the coupled finite element model were compared with experimental results from electrochemical corrosion tests. The tests were conducted on cast iron specimen buried in sand and the corrosion behaviour under various aeration regimes were studied. The presence of an optimum moisture/aeration regime, where the corrosion rate becomes a maximum was demonstrated and the mechanisms behind this phenomenological behaviour are discussed in this paper. The modelling and experimental results are expected to be useful in developing non-intrusive testing methods for underground corrosion.

Possibility of High Phosphorus Pig Iron as Sacrificial Anode

Cathodic protection is an effective method to control the corrosion of underground pipelines and submerged structures. In the present work, high phosphorus containing pig iron was utilized as sacrificial anode for cathodic protection of underground mild steel plates and the results were compared with that of a commercially pure magnesium sacrificial anode. Driving potential and current between the galvanically coupled sacrificial anodes and mild steel plates were continuously monitored in real time for one month. Microstructure and morphology of the corrosion products formed on the surface of pig iron, magnesium sacrificial anodes and mild steel plates were observed with the help of optical microscope and scanning electron microscopy, and phase identification were performed using x-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. The distribution of phosphorus in the pig iron matrix and soluble rust formation on the surface of pig iron under buried condition were critical from the point of sacrificial effect, indicating the possible scientific reasons for high phosphorous pig iron to be used as sacrificial anode.

Influence of soil microorganisms on metal corrosion of underground pipelines

Abstract There have been revealed and summarized the regularities in biocorrosion of steel 17G1S-U, which is traditionally used for manufacturing oil and gas mains. The basic regularities of biocorrosion processes in the 17G1S-U pipe steel under the influence of SRB Desulfovibrio Sp. strains Kyiv-10 was obtained by weight-loss testing and surface analysis techniques. Effective inhibitors are proposed, which allow protecting steel 17G1S-U against the development of anaerobic corrosion under the influence of sulfate-reducing bacteria (SRB). The effectiveness of inhibitors is estimated by the degree of their protective effect. The porous structure of the surface film contributes to the initiation of localized corrosion. Damage analysis of the specimen surface corroded under different test conditions was performed.

Evaluation of corrosion factors and determination of their influence on underground pipeline corrosion defects growth (Russian)

Evaluation of corrosion factors and determination of their influence on underground pipeline corrosion defects growth (Russian)

Effects of Soil Physical Properties to the Corrosion of Underground Pipelines

Corrosion of metals in soil be able to change from comparatively fast material loss to insignificant effects, depending on soil environment. Corrosion is a process of deterioration of metal surfaces degraded into another compound. Soil is one of the medium known to have constituted to corrosion of metals. The soil creates an environment for the corrosion to react. The buried pipelines are exposed to the soil that may experience corrosion attack. The study of the soil as corrosion environment is important to mitigate the problem due to the environment and economy. There are factors that contribute to the corrosion process. This study concentrates on corrosion properties that expose to soil environment particularly underground pipelines. The mild steel coupons taken from actual pipelines, stimulating and analyzing the physic-chemical characteristics of the soil environment. The soil is sandy clay in natural. A total summed index of 2 numerical scale, thus, indicates that the soil tested was mildly to non-corrosive. The corrosion rate increase with increasing of moisture content and pH value. The observations on the coupon surface also did in order to study the morphology.

Effect of Temperature in SRB Growth for Oil and Gas Pipeline

In the oil and gas industry, pipeline is the major transportation medium to deliver the products. MIC has been identified as one of the major causes of underground pipeline corrosion failure and Sulphate Reducing Bacteria (SRB) are the main reason causing MIC, by accelerating corrosion rate. The objectives of this paper is to study the SRB growth namely, Desulfovibrio desulfuricans ATCC 7757 correlating to one of the important environment parameter which is temperature. Thus, a determination of the optimum value for the parameter influencing the corrosion process on the internal pipe of carbon steel grade API X70 is unveiled. This research conducted via laboratory works and One-Factor-at-A-Time (OFAT) method is used for the analysis. The result shows that the SRB growth well at temperature ranging from 20°C to 37°C with the maximum exposure time of 28 days which produce the maximum Cr value of 3.746 mm/year at 37°C. The results in this study prove that the corrosion phenomena on carbon steel by the environment parameter such as temperature and time plays a role in the corrosion process. Furthermore, the study identified that the pitting type of corrosion is detected and accelerated at carbon steel pipe.

Effects of Soil Properties to Corrosion of Underground Pipelines: A Review

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.

Experimental and finite element analyses on the corrosion of underground pipelines

Underground pipelines, on which a city relies for survival and development, have become an important part of lifeline engineering. Underground pipelines are utilized for conveying liquid, gas or loose solid, pipeline leakage and damage occasionally resulting from corrosion. Corrosion monitoring of underground pipelines is aimed at ensuring their normal operation and preventing loss of life and property. In this paper, a new method to monitor corrosion of pipelines has been proposed to solve the mentioned problem. Under the influence of internal pressure and corrosion, the pipeline wall becomes thinner and the circumferential deformation increases. The method is to indirectly investigate pipeline corrosion by monitoring the circumferential deformation. Numerical simulation confirms that the circumferential strain curve of the pipeline wall measured by using the proposed method to describe the corrosion is feasible. The proposed method provides a new way for real-time and long-term monitoring and management of underground pipelines.

Polarization Behavior of Steel Corrosion in Laterite, Yellow Soil and Kaolin

Corrosion of buried pipelines caused by aging process has taken serious problems. Pitting corrosion in underground pipelines may yield material damage causing great loss of economic value and therefore, this study has emphasized on carbon steel corrosion in three types of soil (laterite, yellow soil and kaolin). Yellow soil solution performed remarkable polarization behavior compared to laterite and kaolin solutions on the basis of Tafel plot. Corrosion potentials of – 0.36V, – 0.47V and – 0.35V were showed by carbon steel corrosion in laterite, yellow soil and kaolin solutions. Yellow soil solution also performed the most corrosive effect on carbon steel due to temperature effect (30o – 90oC). In addition, the corrosion of carbon steel in yellow soil solution posed the lowest enthalpy with regard to thermodynamic effect. This study also showed that the carbon steel corrosion in laterite solution referred to pitting corrosion based on linear adsorption isotherm. This investigation gives valuable information with respect to underground pipelines corrosion.

Bayesian Modeling of External Corrosion in Underground Pipelines Based on the Integration of Markov Chain Monte Carlo Techniques and Clustered Inspection Data

AbstractIn this study, a model is developed to assess external corrosion in buried pipelines based on the unification of Bayesian inferential structure derived from Markov chain Monte Carlo techniques using clustered inspection data. This proposed stochastic model combines clustering algorithms that can ascertain the similarity of corrosion defects and Monte Carlo simulation that can give an accurate probability density function estimation of the corrosion rate. The metal loss rate is chosen as the indicator of corrosion damage propagation, obeying a generalized extreme value (GEV) distribution. Bayesian theory was employed to update the probability distribution of metal loss rate as well as the GEV parameters in order to account for the model uncertainty. The proposed model was validated with direct and indirect inspection data extracted from a 110‐km buried pipeline system.

Markov Chain Models for the Stochastic Modeling of Pitting Corrosion

The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure birth) Markov process is used to model external pitting corrosion in underground pipelines. A closed-form solution of the system of Kolmogorov's forward equations is used to describe the transition probability function in a discrete pit depth space. The transition probability function is identified by correlating the stochastic pit depth mean with the empirical deterministic mean. In the second model, the distribution of maximum pit depths in a pitting experiment is successfully modeled after the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time is simulated as the realization of a Weibull process. Pit growth is simulated using a nonhomogeneous Markov process. An analytical solution of Kolmogorov's system of equations is also found for the transition probabilities from the first Markov state. Extreme value statistics is employed to find the distribution of maximum pit depths.

Modelado del crecimiento de picaduras en tuberías enterradas que transportan hidrocarburos utilizando técnicas estadísticas

New deterministic and stochastic predictive models are proposed for external pitting corrosion in underground pipelines. The deterministic model takes into consideration the local chemical and physical properties of the soil as well as the pipeline coating to predict the time dependence of pitting depth and rate in a range of soils. This model, based on results from a field study, was used to conduct Monte Carlo simulations that established the probability distribution of pitting depth and growth rate in the studied soils and their evolution over the life of the pipeline. In the last stage of the study, an empirical Markov chain-based stochastic model was developed for predicting the evolution of pitting corrosion depth and rate distributions from the observed properties of the soil.