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ABSTRACT ABSTRACT Cases of close proximity of high voltage transmission lines and metallic pipelines become more and more frequent in high population density regions. Therefore, there is a growing concern about possible hazards resulting from the influence of electrical systems: safety of people making contact with the pipeline, damage to the pipeline and CP equipment. Hence it is not surprising that there is an industrial need for mitigating AC interference. This paper will discuss capabilities of a software tool to predict AC currents and voltages induced on metallic structures near AC power lines by electromagnetic induction, and resistive coupling effects. Situations can be studied under normal operational conditions as well as for the occurrence of fault currents. Most available computer programs limit the modeling capabilities to parallel or near parallel geometries. In addition, most of them are restricted in the number of pipelines, transmission lines and (direct) bonds that can be modeled. This is a serious restriction since in many corridors a large number of pipelines are bonded together, e.g. for cathodic protection purposes. Furthermore, handling of the software can be cumbersome and time-consuming (e.g. manual adding of routings versus being able to read in GPS coordinates) and requires a computer expert rather than a CP engineer to be able to work with it. For this reason the number of simulations done (especially in the mitigation case for fault currents) is most often very limited due to time and budget restrictions. Given the complexity of the problems dealt with nowadays it is easy to understand that this can have a negative impact on the final design since not all possible scenarios have been accounted for. In this article a software that is linked to the customers asset database will be presented. The software directly converts the complete routing in a numerical model directly taking into account all geometrical and electrical properties.
- North America > Canada (0.28)
- North America > United States > Texas (0.18)
- Energy > Power Industry (1.00)
- Energy > Oil & Gas > Midstream (0.94)
ABSTRACT ABSTRACT Electrochemical noise measurement is established as a means of estimation of corrosion rate, and methods for the identification of localized corrosion have been proposed. Many of these methods make the assumption that two electrodes used to measure current noise have similar behavior; this paper examines tests based on measured data that can be used to assess whether or not the current-measuring electrodes can be assumed to be symmetrical (i.e. they have sufficiently similar behavior). It is concluded that the mean current (which should have a value close to zero) cannot be used reliably as a test for symmetry, as even small differences in the mean current from the two electrodes (and hence minor departures from perfect symmetry) will lead to a mean current that is far larger than is expected for perfect symmetry. However, the coefficient of correlation between the potential and the current noise does appear to provide a useful test for symmetry; perfect symmetry implies that the coefficient of correlation will be zero. The significance of a non-zero coefficient of correlation depends on the nature of the departure from symmetry, but values above 0.5 suggest that there is sufficient asymmetry to lead to significant errors in estimates of electrochemical noise resistance. INTRODUCTION It is now reasonably well-established that electrochemical noise (EN) measurements are a valid way of estimating corrosion. This is achieved by a simultaneous measurement of potential and current noise, with the current noise being measured between two identical working electrodes, and the potential noise of the working electrode pair being measured with respect to a low noise reference electrode [1]. A third electrode that is identical to the two working electrodes can also be used – this configuration is not considered here, but it will be amenable to similar analysis, following the approach described by Bautista et al.[2].
Indium-Zinc And Zinc-Nickel Alloys As Cadmium Brush Plating Replacement
Berman, Elizabeth (Air Force Research Laboratory Materials and Manufacturing Directorate) | Voevodin, Natasha (Air Force Research Laboratory Materials and Manufacturing Directorate) | Schmura, Eileen M. (Concurrent Technologies Corporation (CTC)) | Blough, Shawn (Concurrent Technologies Corporation (CTC)) | Brezovec, Paul (Concurrent Technologies Corporation (CTC)) | Clark, Sarah N.L. (Concurrent Technologies Corporation (CTC))
ABSTRACT ABSTRACT As cadmium and its corrosion product (cadmium oxide) are carcinogenic and toxic, efforts are ongoing to eliminate cadmium from original equipment and repair processes such as brush plating. The objective of this project requires that the brush plating cadmium replacement meet electrical impedance and corrosion resistance requirements, defined by the customer for specific applications. Cadmium oxide is semi-conductive, while most other pure metal oxides are electrical insulators, (i.e. aluminum oxide, nickel oxide, and zinc oxide) and, therefore, fail to meet electrical impedance requirements. One potential replacement for cadmium is indium because, as it oxidizes, indium also exhibits the desired semi-conductive properties and may allow alloys of indium to be a possible cadmium replacement in brush plating applications where impedance is a critical parameter. Another possible coating system that offers suitably low electrical impedance during environmental exposure is brush-plated zinc-nickel systems. Both coating systems have the potential to meet corrosion resistance requirements and have been investigated as alternatives to cadmium. This paper discusses alloy coating development activities to replace cadmium, and electroplating approaches to overcome the insulating limitation of pure metal plating. Test results of various brush electroplated alloy coatings will be discussed. INTRODUCTION Currently, brush plated cadmium (Cd) Type I is specified as a protective coating for many United States Air Force (USAF) components and systems. However, even though Cd is been shown to be effective for this application through over 30 years of regular and constant usage, it is also a known human carcinogen. Occupational exposure and environmental impacts resulting from the use and disposal of Cd can result in chronic and acute health issues including, but not limited to, severe damage to the lungs and even death. The USAF has funded efforts to evaluate, demonstrate, and transition alternatives to inorganic coating processes that contain Cd to minimize worker exposure to hazardous materials.
- North America > United States > Pennsylvania (0.29)
- North America > United States > Texas (0.18)
- Materials > Metals & Mining (1.00)
- Health & Medicine (1.00)
- Government > Regional Government > North America Government > United States Government (1.00)
- Government > Military > Air Force (1.00)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Health, Safety, Environment & Sustainability (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
Using Local Electrochemical Impedance Spectroscopy to Detect Coating Defects On Buried Pipelines
Shukla, Pavan K. (Center for Nuclear Waste Regulatory Analyses) | Mintz, Todd S. (Center for Nuclear Waste Regulatory Analyses) | Dasgupta, Biswajit (Center for Nuclear Waste Regulatory Analyses) | Fisher, Jay (Southwest Research Institute)
ABSTRACT: Local electrochemical impedance spectroscopy (LEIS) has been used to determine the micro- and macroscopic defect sites on coated coupons in a laboratory-scale setup. LEIS is conducted by applying a sinusoidal potential signal to a working electrode and then measuring the response of a particular location by placing two reference electrodes in the electrolyte above that location. Scale-up issues need to be resolved if LEIS is to be used for inspecting and identifying coating defects on the buried pipeline. The parameters such as the distance of the two-electrode system from the pipeline surface, distance between the two electrodes, and frequency of the applied excitation signal are important factors that need careful selection. These parameters are determined by conducting the numerical simulations of cathodic protection and LEIS models and conducting field experiments. A bielectrode probe, consisting of two reference electrodes, was developed for field experiments. Field experiments were conducted on a buried pipeline with several coating defects. The collected data were used to calculate local electrochemical impedance spectra of different test sites on the pipeline. The calculated local impedances indicate that the method is capable of identifying coating defect locations on buried pipelines. INTRODUCTION In this paper, we report on applicability of local electrochemical impedance spectroscopy (LEIS) to identify and measure the corrosion rate of a coating defect site, also called a holiday in the pipeline industry, on a buried pipeline under cathodic protection. To date, LEIS has been used to determine the micro- and macroscopic defect sites on coated coupons in a laboratory-scale setup.LEIS is a slight deviation of the traditional electrochemical impedance spectroscopy (EIS) where a test sample is perturbed from its base state electrostatic condition by applying a small amplitude sinusoidal potential or current signal.
- Energy > Power Industry (0.68)
- Energy > Oil & Gas > Midstream (0.34)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Piping design and simulation (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
Assessment Of Preferential Weld Corrosion Of Carbon Steel Pipework In CO2-Saturated Flow-Induced Corrosion Environments
Barker, Richard (Institute of Engineering Thermofluids, Surfaces and Interfaces School of Mechanical Engineering University of Leeds) | Hu, Xinming (Institute of Engineering Thermofluids, Surfaces and Interfaces School of Mechanical Engineering University of Leeds) | Neville, Anne (Institute of Engineering Thermofluids, Surfaces and Interfaces School of Mechanical Engineering University of Leeds) | Cushnaghan, Susan (Shell U.K. Limited)
Susan Cushnaghan Shell U.K. Limited 1 Altens Farm Road Nigg Aberdeen AB12 3FY United Kingdom ABSTRACT The performance of a commercially available oilfield corrosion inhibitor to control preferential weld corrosion in CO A submerged impinging jet (SIJ) was utilized to test carbon steel parent metal and a 1% Ni 0.25% Mo weld material at a temperature of 45 C. The dual nozzle arrangement of the jet allowed one parent metal and one weld material to be placed under each nozzle of the jet. The velocity over the parent metal was kept constant at 7 m/s whilst the weld material was subjected to velocities of 7, 8.8 and 11.4 m/s to simulate different severities of turbulence and shear stress. A pre-corrosion time of 2 hours was allowed before inhibitor was added to the system at a concentration of 100 ppm. The galvanic current between the parent metal and weld material was recorded by coupling the materials together. The galvanic current measurements were compared and reviewed for each case. The two materials were then assessed in their uncoupled state for each condition using AC impedance and linear polarization to help elucidate their behavior when coupled together. Requests for permission to publish this manuscript in any form, in part or in whole, must be in writing to NACE International, Publications Division, 1440 South Creek Drive, Houston, Texas 77084. The material presented and the views expressed in this paper are solely those of the author(s) and are not necessarily endorsed by the Association. INTRODUCTION Research focusing on carbon steel weld corrosion in mildly sour sea water injection systems during the 1980's concluded that up to 1% nickel weld consumables should be utilized to minimize preferential weld corrosion attack because of its improved strength and corrosion resistance. S-containing environments in oil and gas production") has also become applicable for CO Examples include seawater injection lines, topsides piping and wet gas flow lines. Figure 1: A section of welded pipework indicating preferential weld corrosion. The cycle of heating and cooling that occurs during the welding process alters the microstructure and surface composition of the weld and adjacent parent metal.
- Europe (0.86)
- North America > United States > Texas > Harris County > Houston (0.36)
- Materials (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Disposal/Injection (0.54)
ABSTRACT ABSTRACT Optical shearography techniques were used for the first time to measure the surface resistivity/conductivity of different organic-thin films. Different organic coatings i.e., ACE Premium- gray, white, and beige Enamels (spray coatings), on a metallic alloy, i.e., a carbon steel, were investigated at a temperature range simulating the severe weather temperatures in Kuwait, especially between the daylight and the night time temperatures, 20–60 °C. The investigation focused on determining the in-plane displacement of the coatings, which amounts to the thermal deformation (strain) with respect to the applied temperature range. Then, the alternating current (AC) impedance (resistance) of the coated samples was determined by the technique of electrochemical impedance spectroscopy (EIS) in 3.5 % NaCl solution at room temperature. In addition, a mathematical model was derived in order to correlate between the AC impedance (resistance) and to the surface (in-plane) displacement of the samples in solutions. In other words, a proportionality constant (surface resistivity or conductivity=1/ surface resistivity) between the determined AC impedance (by EIS technique) and the in-plane displacement (by the optical interferometry techniques) was obtained. Consequently the surface resistivity (?) and conductivity (s) ??of the coated samples in solutions were obtained. Also, electrical resistivity values (?)??? from other source were used for comparison with the calculated values of this investigation. This study revealed that the measured values of the resistivity for the ACE Premium- gray, white, and beige coatings were carried out for the first time. No data on the values of (?)?? were found in literature for the same coatings, using direct current (DC) methods. However, the value range of (?) of all investigated coatings, 0.25x10 - 0.27x10 O-cm was found in the insulator range. INTRODUCTION It is well established that metrological methods utilizing coherent light such as speckle interferometry may be very useful in measuring deformation of surfaces of different objects under various conditions.
- Asia > Middle East > Kuwait (0.24)
- North America > United States > Texas (0.19)
ABSTRACT ABSTRACT The electrochemical potential and current noise generated by an array of galvanically coupled electrodes have been analysed. The individual currents flowing through each electrode are measured simultaneously with the potential of the array. For each electrode, the apparent noise resistance, Rn*, is determined from the square root of the potential variance divided by the individual current variance. Depending on the relative noise levels and resistances of electrode n and the remaining n-1 electrodes, Rn* may approach closely to the true noise resistance of electrode n, Rn, be proportional to Rn, or be unrelated to Rn. The analysis is facilitated by the introduction of “virtual electrodes”, corresponding to a convenient sub-array of real electrodes, and obtained by mathematical manipulation of the individual currents in the time or frequency domain. By using this approach, the validity of the assumptions on the relative magnitude of the noise sources and electrode resistances that are often necessary to evaluate Rn can be partially or completely verified. For example, the electrochemical noise data recorded from four identical electrodes and from two dissimilar couples of identical electrode are discussed. INTRODUCTION Electrochemical noise analysis is a mature technique that can be used in the laboratory and in the field for corrosion monitoring. Electrochemical potential or current noise arises from anodic and/or cathodic events on the surface of corroding electrodes, associated with the initiation or propagation of corrosion. A variety of methods are available for electrochemical noise analysis, ranging from techniques based on the statistical analysis of the current and/or potential signal, fast Fourier transform or wavelet transform based analyses, and others. Each of these methods has specific advantages for the study or monitoring of a particular corroding system. Whatever the approach for the analysis, if both current and potential noises need to be acquired, generally two working electrodes and a third reference electrode are employed.
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.88)