Cathodic Protection Of Pipelines Research Articles

A New Formulation Addressing Base Resin Challenges and Carcinogenic Concerns for Water Pipeline Cathodic Protection

Traditional epoxy coatings used for water pipeline cathodic protection have several shortcomings, including limited availability, high cost, and carcinogenic concerns. To address these challenges, a new, food-grade epoxy coating that is affordable, meets all technical requirements, and is free of carcinogenic substances was developed.The study involved testing various kinds of reinforcing fillers, non-reinforcing pigments, red pigment, and BYK additives to formulate the epoxy-based coating. Curing experiments were then conducted by formulating the coating with a fixed ratio of curing agent and spraying the resins onto mild steel panels for testing.The results demonstrated that the new formulation has good compressive strength, adequate impact resistance, and Shore D hardness in the range of 60-70, which is expected for this type of application. The abrasion resistance of the coatings increased with increasing hardness.Overall, the new food-grade epoxy coating is a promising alternative to traditional epoxy coatings for water pipeline cathodic protection. It is affordable, meets all technical requirements, and is free of carcinogenic substances.Key words: Epoxy Resin, Coating, Food Grade, TETA

Effect of DC grounding electrode currents on the corrosion interference behavior of cathodic protection of nearby pipelines

When operating a direct current (DC) transmission grounding electrode in single-pole return ground mode, transient currents traverse the soil, generating stray currents. These currents can intensify the corrosion of long-distance transmission pipelines near the grounding electrode, subsequently altering the pipeline’s cathodic protection potential. Previous investigations into the interference of grounding electrodes on pipeline cathodic protection have overlooked the cathodic protection systems themselves. Addressing this gap, we integrated COMSOL’s electrochemical module with its AC/DC module. To corroborate the accuracy of our COMSOL-based models, we devised specific validation experiments. Additionally, we crafted a COMSOL application builder interface to streamline computations. Consequently, we derived a multi-regression function to express the cathodic protection potential of the pipeline under varied factors and executed a regression tree classification for soil resistivity. To pinpoint optimal corrosion protection for pipelines, we simulated the cathodic protection of segmentally isolated pipelines, determining that potential excursions can be notably mitigated. This research offers insights into both disturbance evaluation and protective strategies for DC transmission and pipelines.

Studying and Realizing the Based-Intelligent IoT System for Pipeline Cathodic Protection

Cathodic protection (CP) emerges as the optimal approach for mitigating metal corrosion in pipeline networks. To ensure the continued efficiency of the CP system, monitoring the potential distribution throughout the network is crucial. In distribution networks, the pipeline potential is influenced by time-varying environmental factors, making it challenging to estimate the potential at locations away from the measurement point. This paper presents a proposed CP system for pipelines, utilizing an intelligent IoT system. The sensor nodes of the system designed based on the STM32 microcontroller perform the measurement of voltages from the reference electrodes, process the signal as well as perform wireless communication about the control stations via LoRa (Long Range Radio) communication. Besides, the control stations are designed to implement voltage compensation control through autotransformer and to communicate with the server through the GPRS communication. The objective is to deploy an affordable system capable of effectively monitoring and regulating the potential of the pipeline at a designated measurement location in industrial plants.

Study on the Interference of the HVDC Transmission Grounding Electrode to the Pipeline Cathodic Protection System.

Oil and gas are still largely transported by long-distance pipelines. In this study, we aimed to examine the impact of the high-voltage DC transmission grounding electrode on long-distance pipelines' cathodic protection system nearby. The writer built the interference model of the DC transmission grounding electrode on the pipeline using COMSOL Multiphysics based on the parameters of the actual project and considering the cathodic protection system within and then tested the model using experimental data. By simulating and calculating the model under different conditions of grounding electrode inlet current, grounding electrode-pipe distance, soil conductivity, and pipeline coating surface resistance, we obtained the current density distribution in the pipeline and the cathodic protection potential distribution law. The outcome presents a visual representation of the corrosion occurring in adjacent pipes as a result of DC grounding electrodes operating in monopole mode.

Electrical Conductivity of Pipeline Deposits Under Pressure and Their Impacts on Sales-Gas Pipeline Cathodic Protection Systems

Summary Natural gas pipelines are critical for safe and efficient energy transport across large distances. To maintain operational safety, pipelines use cathodic protection systems that minimize the rate of external corrosion. This work characterizes the effects of black powder deposits, a widely experienced operational hazard across the natural gas industry, on the failure of pipeline cathodic protection systems due to electrical “shorting” of isolation devices. Black powder sludgy deposits from coal seam gas (CSG) pipelines were analyzed, revealing electrical conductivity values within the range of 580 to 5400 µS/cm when under pipeline pressure. These values were used to calculate the internal resistances of monolithic isolation joints (MIJs), a type of electrical isolation device, to show that electrical shorting (internal resistance of < 100 Ω) can occur for black powder sludgy deposit thicknesses in the range of millimeters. To reduce the frequency of such shorting events, it is recommended that upstream dehydration systems be designed to reduce carry-over of triethylene glycol (TEG), that internal nonconductive coatings be applied to isolation devices, and that these devices are installed in ways that facilitate regular cleaning.

Study on the Interference Law of AC Transmission Lines on the Cathodic Protection Potential of Long-Distance Transmission Pipelines

Through inductive coupling, AC transmission lines can generate large amounts of voltage to buried oil and gas pipelines in areas with common corridors, posing a threat to the cathodic protection effect of pipelines. Therefore, this paper investigates the effect of AC transmission lines on the cathodic protection of long-distance pipelines through inductive coupling. COMSOL Multiphysics finite element simulation software is used to calculate the distribution of cathodic protection potential of long-distance pipelines under different voltage levels, parallel spacing, conductor-to-ground height, conductor arrangement and pipeline burial depth for normal operation of AC transmission lines. Comparison and analysis of the AC transmission line on the pipeline cathodic protection potential interference law is conducted. The results show that: 1. AC transmission lines cause serious electromagnetic interference with the pipeline cathodic protection system, which will cause the pipeline cathodic protection potential to shift out of the effective protection area. 2. The maximum value of the induced voltage of the pipeline will appear at the two ends of the pipeline, and the induced voltage of the pipeline in the middle position is 0. 3. The shift of the pipeline cathodic protection potential increases with the increase of voltage level and decreases with the increase of parallel spacing, conductor height and burial depth. The pipeline cathodic protection potential shift is highest when the wires are arranged horizontally and lowest when they are arranged in an umbrella shape.

Determination of Soil Corrosion Potential for Gas Pipeline Cathodic Protection System Planning

Research has been carried out to identify the potential for soil corrosion for the design of the cathodic gas pipeline protection system. The research location is in Cimanggis - Bitung, West Java, which is located at coordinates 6°19’00 “- 6°28’00” South Latitude and 106°43’00 “- 106°55’30” East Longitude. Measurement of soil resistivity using the Wenner method which refers to ASTM G37, with variations in distance of 0.75m, 1.50m, 2.50m and 6.00m at each point. The number of measurement points is 185 points. DC electric current is injected into the ground, then the current and potential values between the electrodes are read on the device. Then the soil resistivity is calculated using the equation ρ = 2πAR. The results of the measurements are soil type resistance which is then categorized according to the level of corrosion. Based on the results of data processing and interpretation of soil resistivity, some locations have low to extreme corrosion rates. The degree of soil corrosion will affect the corrosion of buried pipes. Therefore, for these locations, planning and technical calculations are needed for the protection of the pipes to be installed.

A New Risk Assessment Model to Check Safety Threats to Long-Distance Pipelines

Abstract With the number of long-distance pipelines increasing in China, risk management has become important for controlling pipeline leakage. However, all the current assessment technologies are semiquantitative and do not include inspection data. To address this problem, a new quantitative risk assessment model is proposed to guide decision-making on excavation inspection and maintenance. Based on previous failure cases, the model includes data about the surrounding soils as well as about the pipeline's protective layer, cathodic protection (CP), and pipe wall thickness readings. Testing of the proposed model on previous failure cases shows that the new model can correctly assess the real leakage risk of a long-distance pipeline and support the quantitative integrity management of a long-distance pipeline during its whole service life.

Determination Transition Resistance of Cathode-Polarized Main Pipeline on Magnetometery Data

The article deals with the inverse problem of determining the transient resistance of the main pipeline insulating coating. For this, UAV measurements of the magnetic induction vector modulus of the magnetic field excited by the system of electrochemical cathodic protection of pipelines are used. The solution method is based on Tikhonov's method for finding the extremal of the regularizing functional. The developed algorithm is implemented in software. The results of computational experiments are presented.

Mathematical Modelling of Electric and Magnetic Fields of Main Pipelines Cathodic Protection in Electrically Anisotropic Media

A mathematical model is constructed and computational experiments are performed to study the effect of anisotropy of the specific electrical conductivity of the soil on the distribution of electric and magnetic fields generated by cathodic electrochemical corrosion protection stations of the underground main pipeline (MP). The variation of electric and magnetic fields depending on the azimuth angle of rotation of the specific electrical conductivity tensor of the soil containing the pipeline is analysed.

Modeling of electromagnetic fields of pipelines cathodic protection systems in horizontally layered medium

Design of cathodic protection systems of the trunk pipeline is regulated by current standards, based on the condition of uniformity and constancy of the electric conductivity of the multilayered half-space surrounding the pipeline. The current mathematical models of such systems also use an average value of the medium electric conductivity, which does not fully reflect the actual characteristics of the soil, in which the pipeline is laid. The authors present a method that accounts for the thickness and electrical conductivity of individual beds in a vertically-inhomogeneous, horizontally layered medium (the most practically appropriate case). Using method of computational experiment, the authors showed the importance of accounting for the effect of the medium layers structure and electrical resistivity on the protective voltage of the electric current in the cathodic protection system for underground trunk pipeline and studied the magnetic field sensitivity dependence on the insulation resistance of the pipeline defect-containing segments and on the altitude of data acquisition.

Long-Term Sour Corrosion of Carbon Steel in Anoxic Conditions

Coatings and cathodic protection of pipelines can fail leading to exposure of underlying steel substrate to environmental conditions. In Canada, these conditions are typically alkaline and can contain dissolved sulfides. Sulfides are known to accelerate corrosion of steel, however, the corrosion behavior may differ if a preformed oxide or oxyhydroxide is present on the steel surface. This study investigates the change in corrosion behavior of steel in anoxic alkaline conditions that is directly exposed to sulfide or has a preformed surface oxide. The electrochemical response (corrosion potential and polarization resistance) were monitored for 90 d and 120 d, while simultaneously monitoring the film composition and morphology by Raman spectroscopy and scanning electron microscopy, respectively. In the absence of a preformed oxide the mackinawite film was able to undergo anoxic aging to greigite and pyrite whereas the electrodes with a preformed film had only mackinawite present on the surface. The interconversion of mackinawite to greigite and pyrite lead to a higher relative polarization resistance than the electrode with the preformed oxide.

Моделирование электромагнитных полей систем катодной защиты трубопроводов в горизонтально-слоистых средах

Моделирование электромагнитных полей систем катодной защиты трубопроводов в горизонтально-слоистых средах

Main trends in increasing technical and economic efficiency of underground power pipelines cathodic protection

The analysis and systematization of the main factors determining the parameters of the electrochemical protection of underground metal communications (UMC) is carried out in the article. Reasons influencing current consumption and power losses in the DC circuit of the cathodic corrosion protection are discussed in detail, and practical recommendations for their reduction are given. Preparatory measures have a significant impact on anticorrosive protection of power pipelines, namely, measures to improve the quality of insulation (increasing the electrical resistance of coatings and ensuring their integrity), measures to ensure high longitudinal conductivity of pipelines, and removal of contacts of underground metal structures with other earthed structures. On the basis of the research, practical recommendations for reducing power losses and reducing current consumption in cathodic protection systems are given.

A Networked Control System for Gas Pipeline Cathodic Protection

Cathodic protection (CP) is the most suitable technique to limit metal corrosion in pipeline networks. To preserve the effectiveness of the CP system, the monitoring of the potential distribution along the net is essential. In distribution networks, the pipeline potential is affected by environmental time-variant phenomena, which make it difficult to estimate the potential away from the measurement point. In this paper, a novel networked control system, based on fuzzy logic and an existing wM-Bus at 169-MHz infrastructures for gas metering, is proposed. The aim is the implementation of a low-cost system able to monitor and control the pipeline potential in a suitable measurement point.

Investigation of the influence of protecting grounding parameters of electric installations on the extent of screening of pipeline cathodic protection current

Investigation of the influence of protecting grounding parameters of electric installations on the extent of screening of pipeline cathodic protection current

Fuel Cell Based Power-Generating Installations: State of the Art and Future Prospects

Specific features of power-generating installations constructed using different types of fuel cells are considered. Problems and trends of their development in Russia and abroad are analyzed. Fuel cell commercialization lines, their application niches, and the most well-known projects of constructing and exploiting fuel cell-based power-generating installations are described. Special attention is paid to analyzing the specific features pertinent to the domestic market of fuel cells and prospects of different lines of their application taking into account competition from other energy sources. Conclusions about the most topical development lines of the considered technologies under the conditions of Russia are drawn with due regard to the available groundwork as well as technical and economic aspects. It is pointed out that the main application field of fuel cells in Russia may be distributed generation of electricity, including off-grid supply of power to consumers on the basis of network and liquefied natural gas, liquefied hydrocarbon gases, and also renewable energy sources. In this regard, installations involving combined generation of electricity and heat, including small ones with a capacity of a few tens or hundreds of kilowatts, are of special interest. Prospective market niches for using fuel cells may include pipeline cathodic protection stations, utilization of biogas obtained, e.g., in reprocessing domestic waste, emergency and uninterruptible power supply systems, propulsion power installations of air drones, auxiliary power installations with a capacity of 1–3 kW, and utilization of hydrogen rejected from chemical production facilities. In view of existing groundwork and cooperation, concentration of efforts aimed at developing solid oxide, solid polymeric, and alkaline fuel cells in Russia seems to be the most topical issue. The use of molten carbonate fuel cells may be of considerable practical interest for reclaiming landfill gas at solid domestic waste landfills and at aeration fields, a problem that is an issue for many cities in the country; such cells can also be used for concentrating and extracting CO2 from fuel gases.

Pipelines cathodic protection design methodologies for impressed current and sacrificial anode systems

Several inadequate designs of cathodically polarized offshore and onshore pipelines have been reported in Nigeria owing to design complexity and application of the cathodic protection system. The present study focused on critical and detailed approach in impressed current and sacrificial anode design calculation methodologies for 0.5m diameter and 100000m length of X65 steel pipeline in onshore and 1.2m diameter and 120000m length of X42 steel pipeline in offshore of Niger Delta region of Nigeria. The impressed current design calculation showed 2592150mA of current demand and voltage of 1127585mV required to adequately protect the X65 pipeline with external surface area of 86405m2. The current and voltage requirements were achievable by installing six transformer rectifiers with minimum direct current output of 500amperes and direct voltage output of 200volts. But the sacrificial anode design calculation indicated direct current output of 2262240mA was needed to marginally polarize the X42 pipeline with total external surface area of 226224m2. The computation further showed the current requirement was attainable with connection of 3620 anodes to set up a natural potential between sacrificial anode and pipeline.http://dx.doi.org/10.4314/njt.v36i4.12

Measuring and understanding the critical duration and amplitude of anodic transients

ABSTRACTAnodic transients are known to affect buried pipeline cathodic protection (CP) systems; however, their actual effects on pipeline corrosion have not been sufficiently quantified due to the lack of direct experimental evidences. In this work, a novel methodology developed based on an electrochemically integrated multi-electrode array has been used to visualise the dynamic effects of anodic transients on localised corrosion processes occurring on buried steel surfaces. It is shown that anodic transients do not necessarily cause steel corrosion, as long as their amplitude and duration are below critical values. The electrode array is able to determine these critical values accurately due to its ability to detect localised corrosion initiation, while the conventional coupon electrode is only able to estimate these values. The critical anodic transient duration has been explained as the incubation period for the breakdown of passivity formed on the steel surface exposed to CP-generated high pH conditions.

Independent power supply source for the station of cathodic protection of pipelines against corrosion

Independent power supply source for the station of cathodic protection of pipelines against corrosion