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There is an old adage “if it is not broken, do not fix it” and this could be applicable for our day-to-day menial activities, but could prove fatally disastrous if followed by any pipeline owners globally. Although, pipelines are statistically the safest means of transporting hydrocarbon — the consequence to an event could be exponential, even if the probability of the event to occur is low. The magnitude of consequence only goes higher with the ever-burgeoning population. To this effect, Oil India Limited (OIL) owns an intensive network of spider-webbed carbon steel pipelines in Upper Assam, India geographical area with varying vintage. Understanding the associated risks of operating such critical pipeline systems, it was decided for the pipelines to undergo code-compliant integrity assessment. It is well known that non-CP protected pipelines are electrically continuous conductors without any insulation (isolation) joints to separate the above-ground station piping to the cross-country underground pipeline sections. With respect to this, OIL deployed a state-of-the-art integrated indirect inspection survey tool to assist in conducting Direct Assessment based integrity assessment. This paper provides an insight into such a scenario where the operator proactively employed the use of advanced high-resolution integrated survey technology to their non-cathodically protected, but coated pipeline assets. Due to the age and design of these “temporary” pipeline systems, there were no prior readily available records in terms of construction, drawings, maps, alignment sheets, operational or historical maintenance data for these pipelines. The advanced Integrated survey played a vital role in decluttering these extensively jumbled network of non-CP pipelines. Firstly, by actually locating the pipeline based on sub meter accuracy and secondly performing simultaneous above ground survey for coating assessment and susceptibility for corrosion. The adaptability of integrated survey as per given situation helped overcome the difficult pipeline route conditions and customize the assessment for these highly challenging pipelines and make ECDA feasible as per NACE SP0502 Standard Practice for this very complex spider web network of pipelines.

To provide cathodic protection (CP) for gas and oil underground pipelines, a direct current (DC) isolator is needed to isolate the main CP converter from the earth around the pipeline. The ...

The present study develops a nonparametric Bayesian network (NPBN) model to predict the corrosion depth on buried pipelines using the pipeline age and local soil properties. The dependence structure and parameters of the NPBN model are extracted from Velázquez’s dataset, which consists of 250 samples of corrosion depths, pipeline age, and such local soil properties as the water content, redox potential, and pH value. The NPBN models the joint distribution of the corrosion depth, pipeline age, and local soil parameters by a Gaussian copula. The five-fold cross-validation is used to examine the predictive capability of the developed NPBN model. The results indicate that the predicted mean values of corrosion depths in general agree well with the corresponding field measurements, and more than 95% of the field-measured depths are within the 5 to 95 percentile range of the predicted distribution for the corrosion depth. The NPBN and the associated model mining method provide an effective data-driven approach to develop predictive models of corrosion depths using soil parameters as predictors. The developed NPBN will benefit the corrosion management of pipelines for which direct inspections are infeasible.

Underground pipeline mapping is important in urban construction. There are few specific procedures and approaches to map underground pipelines using ground penetration radar (GPR) without knowing the number of buried pipelines. In this paper, an automatic pipeline mapping model, the Dirichlet Process Pipeline Mapping Model (DPPMM), is introduced with GPR and Global Position System (GPS) data as input. By combining the GPR and GPS the position, direction, depth and size of pipelines could be estimated. The number of buried pipelines in the detection site could be automatically estimated with the benefit of DPPMM, without any prior knowledge. By adopting this model, the probabilities of each survey point belonging to each pipeline are calculated, and the pipeline directions and locations are also estimated. The experimental results demonstrate that this model could obtain more accurate pipeline maps than other state-ofthe-art algorithms in various experimental settings.

The article considers the issues of underground pipeline strength, which are operated in geological or technogenic complication conditions (movements of indigenous soil in the tectonic fault zone, mutual displacements and rotations of rock blocks, etc.). The work aims at studying of a mobility limitation effect of a pipeline anchorage imposed on the stress state in the pipe wall in the site of a local damage foundation. The pipeline static was investigated in a geometrically linear formulation, modeling it with a tubular cross-section, and with a momentless cylindrical shell for straight issues. The interaction of the pipe with a dense base through soil backfill was described by the hypothesis of Winkler's elastic layer. The deformation of the anchored pipe caused by base local continuity disturbances was studied, which was modeled by the given jumps of longitudinal displacement and the block angle of rotation. This approach makes it possible to evaluate the strength of long underground communications not on the external load from the ground, which is usually unknown, but according to the observed parameters of riverside movements. The limiting state of the pipeline under the internal pressure of the transported product and under additional loading from kinematic perturbation was investigated by the energy theory of strength. The authors formulated boundary value problems for differential tensile-compression equations and torsion of a straight bar with discontinuous right-hand sides. On the basis of analytical solutions to the problems, the effect of normal separation crack damage, foundation blocks convergence and their turn around the axis of the pipe on the stress-strain state of the pipeline was studied. Plots of displacement distribution, angles of rotation and equivalent stresses of von Mises are constructed depending on the magnitude and direction of the mutual displacement and reversal of the riverside at different distances from the anchor to the base defect. It has been found that overlapping anchors in the form of anchorage leads to a significant increase in the equivalent stresses in the pipe. It has also been found that for pipes under internal pressure, the approximation of the base blocks is more dangerous than their divergence.

A new criterion of strength and a set of informative parameters have been devised for modelling the stressed-strained state (SSS) of the underground metal pipeline (UMP) taking into consideration the system of defects of the cavity type, atop of which there is a crack. We have inspected the surface of pipes made from structural carbon steel 20, which are exposed to the internal hydrostatic pressure. It has been proposed that the strength criterion of a pipe's metal, which is in contact with the soil electrolyte, should take into consideration the stages of elastic and plastic deformation. The strength criterion has been supplemented with ratios for a corrosion current (the Kaesche type) and internal pressure, which acts on a cylindrical pipe, taking into consideration the inelastic energy characteristic of the surface layer. For a pipeline, in a neutral soil environment, we have measured polarization potentials and corrosion currents using the PPM (polarization capacity meter) and CCM (contactless current meter) equipment. Results measure respective defects of the cavity type (pitting), formed at the outer surface of an underground pipeline. For five variants of internal pressure pi=5.5¸7.5MPa, the CCM and PPM devices determined currents and voltages for characteristic surface defects and, based on them, we have estimated the effective time it takes for a crack to reach critical depth (a pipe resource), as well as the reliability parameter b (a safety characteristic). By comparing results from experimental study and appropriate calculations it has been established that the relative changes in the rate of corrosion Vcoris 2.8 times, and, accordingly, the UMP resource parameter tRis 3.1times, larger, while the reliability parameter b is 6.9 times less, than the relative changes in internal pressure changes pT. Based on analysis of the parameter tR, which characterizes the UMP resource, it has been found that this dependence tRon internal pressure pTis nonlinear and tends to saturation. The specified information is important for improving the methods of control over UMP at oil and gas enterprises, specifically, procedures for correct estimation of anode current density in metal defects at the outer surface of an underground pipeline, taking into consideration changes in internal hydrostatic pressure

Protective properties of polymer coatings are mainly determined by their adhesion properties. Organosilanes represent the most commonly applied adhesion promoters; they are also capable of decelerating corrosion processes. In this study, the possibility of applying organosilanes in the function of inhibitors of cathodic peeling-off of polymer coatings has been investigated. It has been established that the introduction of vinyl silane to the coating results in the inhibition of cathodic peeling-off due to higher compatibility of vinyl with the components of the bitumen-polymer coating.

This research demonstrates a methodology to identify critical pipeline crossing locations that could have a severe impact on truck tonnage movement and detouring. A ‘critical’ underground pipeline crossing impacting a road link has been defined as the most important crossing in the network whose damage can cause the road above to close. This causes significant impacts on truck tonnage movement and detour increase for trucks. In this research, criticality of a crossing was tested using two indices namely, the Dangerousness Index (DI) and Detour Index (DTI). Pareto frontier was subsequently used to identify critical pipeline crossing in the Los Angeles (LA) County. There were 74 candidate crossings which were part of the analysis. It was observed that underground pipeline crossings that are located at Interstate-405, Interstate-110 and State Highway-91 are highly critical compared to others in the county. These three highways are also considered as major truck routes of the LA County. The research contribution primarily is in understanding risks associated with underground pipelines, particularly those that cross a major highway with heavy freight truck volume.

Underground pipelines are an essential part of the transportation infrastructure. The structural deterioration of pipelines crossing railways and their subsequent failures can entail critical consequences for society and industry, resulting in direct and indirect costs for all the stakeholders involved. Therefore, continuous and accurate condition assessment is critical for the effective management and maintenance of pipeline networks within the transportation infrastructure. The aim of this study has been to identify failure modes and consequences related to pipelines crossing railway corridors. Expert opinions have been collected through interviews and two sets of questionnaires have been distributed to the 291 municipalities in Sweden, with 137 responses in total. The failure analysis has revealed that pipe deformation has the highest impact, followed by pipe rupture at locations where pipelines cross railway infrastructure. For underground pipelines under railway infrastructure, ageing and the external load were awarded a higher ranking than other potential causes of pipeline failure. Authors gratefully acknowledge the funding provided by Sweden’sinnovation agency, Vinnova, through the strategic innovation programmeInfraSweden2030. The funding was granted in a competitiveapplication process that assessed replies to an open call for proposalsconcerning “Condition Assessment and Maintenance of TransportInfrastructure (Grant No. 2016-033113)”. Authors gratefully acknowledge the technical support and collaboration(In-kind support) of Arrsleff R€orteknik at Sweden, Luleå RailwayResearch Center (JVTC), Stormwater&Sewers and the SwedishTransport Administration (Trafikverket). In addition, the authors arethankful to the anonymous referees for their constructive commentsand Dr Matthias Asplund and Dr Masoud Naseri for their support andsuggestions. Validerad;2020;Nivå 2;2020-01-28 (johcin) PipeXrail

During the construction and operation of underground pipelines, there is a need to develop projects for the engineering protection of insulation coatings from the mechanical effects of coarse soil. The task is most relevant with significant variability of the laying conditions along the length of the route. In particular, the difficult laying conditions include the passage of the route in the areas of distribution of rocky, gravelly and permafrost soils. The appropriateness of applying the methods of engineering protection of the insulation coating from mechanical stress should be justified both economically and in terms of technical and operational indicators. Therefore, the task of analyzing the conditions of support of the underground pipeline and the study of the created forces in the supporting part of the pipeline is very relevant and characterized by insufficient knowledge. The article analyzes the effect of bedding soil and backfill on the amount of force arising in the protective coating of the supporting part of the pipeline in the presence of unevenness of the base and its particle size distribution. The results of modeling the contact problem using models of a discrete (granular) medium at the base of the pipeline are presented. The wall thickness of the pipes affects the change in created force in the supporting part of the pipeline (for pipes are 1 420 mm the maximum difference is 22 %). In the presence of unevenness of the base, the force in the supporting part can increase by 3–5 times.

Underground natural gas (NG) leaks pose an urgent safety threat, motivating ongoing efforts to improve leak detection methods. The objectives of this study were to investigate how realistic environ...

Актуальность. Внутри Земли происходят термоядерные реакции, вызывающие перемещение земной поверхности. В областях сдвига тектонических плит – геодинамических зонах – происходит изменение положения подземных магистральных трубопроводов. В свою очередь изменение положения магистрального трубопровода приводит к изменению его напряженно-деформированного состояния. После активации разломов начинается движение блоков. Вначале они движутся медленно, затем темп движения возрастает, при этом в зону риска попадают трубопроводы, находящиеся в условиях длительной эксплуатации, поэтому вопрос контроля напряженно-деформированного состояния трубопроводов на пересечениях с геодинамическими зонами является актуальным. Цель: разработать и внедрить технологию выявления участков трубопроводов при их пересечении с геодинамическими зонами, предусматривающую определение потенциально опасных участков, оценку напряженно-деформированного состояния трубы. Объекты: области прохождения магистральных трубопроводов по территории Республики Башкортостан на пересечениях с геодинамическими зонами. Методы: анализ результатов внутритрубной дефектоскопии с измерением радиусов изгиба трубопроводов, выявление потенциально-опасных участков, аналитический расчет напряженно-деформированного состояния трубопроводов. Результаты. Изложена технология выявления участков трубопроводов с изгибными напряжениями при их пересечении с геодинамическими зонами. Технология предусматривает определение фактического положения магистрального трубопровода, непосредственное измерение радиуса изгиба. Располагая данными по участкам трубопроводов с ненормативными радиусами изгиба 500D и менее из отчетов по внутритрубной дефектоскопии, предлагается выявлять потенциально опасные участки, а повторный пропуск внутритрубных дефектоскопов каждые 2–3 года позволит оценивать динамику изменения радиусов изгиба, а также выявлять активные геодинамические зоны.

A low-cost IMU and odometer integration system is developed in this paper for underground pipeline mapping. A tightly coupled integration between IMU and odometer is implemented to decrease the error caused by the odometer installation attitude error and scale factor error. Besides this, a novel approach to this application of using a Robust Kalman filter is developed to remove the effect of odometer measurement outliers due to the wheel-slip. Compared with the loosely coupled integration method, the use of loosely coupled integration with scale factor correction, tightly coupled integration and tightly coupled with Robust Kalman filter provide a horizontal position improvement of 11%, 41% and 43%, respectively. Similarly, the height accuracy is improved by 14%, 50% and 57%. Moreover, after applying the Robust Kalman filter, the positioning error caused by wheel-slip is reduced to 0.61 m in the horizontal plan, and 0.11 m in the height.

Ground penetrating radar (GPR) is a high-resolution geophysical non-destructive detection method, which is widely used in near surface target detection, and has been successfully applied in urban construction and geotechnical engineering. In urban life, underground pipelines undertake important missions such as energy transmission and information transmission. As the basic data of smart city, the acquisition of spatial location information of underground pipelines depends on geophysical detection data such as GPR. The traditional recognition and interpretation of GPR underground pipeline image mainly depends on and is seriously limited by the professional experience of the staff, which is very disadvantageous to the development of large-scale urban underground pipeline survey. To address this problem, according to the GPR reflection image characteristics of isolated targets such as underground pipelines, this paper proposes an intelligent recognition concept of isolated targets in GPR profile based on CBIR (Content-based image retrieval) According to Hash algorithm and improved vector K-means clustering analysis, the intelligent detection, automatic image sorting and recognition of underground pipeline target in GPR profile are realized. Finally, the pipeline material is judged by extracting the image brightness function of the middle trace in the recognition area. The application results of numerical simulation experiments and measured data show that this algorithm can effectively identify the hyperbolic characteristics of the pipeline in the GPR profile, and the identified area can accurately reflect the spatial location of the underground pipeline.

Through effective measurement and evaluation of the distribution and effect of urban infrastructure, the key tasks of urban work in Liaoning Province can be effectively implemented, weak links are improved, urban functions are optimized and urban comprehensive carrying capacity and radiation ability can be improved. In particular, specific proposals for infrastructure projects in basic cities are put forward. For example, the construction and renovation of urban roads, urban rail transit and urban underground pipeline corridors should be intensified. Strengthen the construction of municipal public facilities, build safe, efficient and convenient life services and municipal utilities network system.

The distribution of raw water in the fertilizer industry in the North Aceh area that uses pipes has been used for approximately 33 years. The majority of the pipe material is concealed under the soil which is one of many media that contributes in external corrosion on metals. This research has been conducted to see the effect of soil properties on different environments on the rate of corrosion that occurs in carbon steel materials. The corrosion rate is calculated by the weight loss method which refers to ASTM G 162. The tested specimens use SA 283 standard carbon steel pipe with the time of buried specimens for 3 months or 2160 h. This research was conducted on 5 different soil sites along the pipe buried line. The results show the highest corrosion rate (0.45 mm/yr) that occurs during the experiment. It’s believed that the soil has the highest redox potential with a high acidity level as well. In general, all land in underground pipelines has the potential to cause external corrosion of underground pipes.

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Для надежности транспортировки жидких сред требуются коррозионно-стойкие и прочные трубы. Эффективное использование их при подземной укладке необходимо определение НДС трубы с учетом воздействия температуры, грунта, жидких сред, а также на основе компонентов материала. Композиционный материал из которого изготовляются трубы относится к сложной механической системе. Основная проблема при решении задач моделирования механических свойств гетерогенной среды состоит в определении условий процедуры осреднения корректной с точки зрения прогнозирования эффективных свойств идеализированной среды на основании данных о механических свойствах и геометрических характеристиках компонентов реальной среды. В связи с этим задача оценки влияния упругих свойств материала на НДС подземного нефтепровода имеет важное прикладное значение и является актуальной., For reliable transportation of liquid media, corrosion-resistant and strong pipes are required. Effective use of them in underground laying it is necessary to determine the VAT of the pipe taking into account the effects of temperature, soil, liquid media, as well as on the basis of the material components. The composite material from which the pipes are made belongs to a complex mechanical system. The main problem in solving the problems of modeling the mechanical properties of a heterogeneous medium is to determine the conditions of the averaging procedure that is correct from the point of view of predicting the effective properties of an idealized medium based on data on the mechanical properties and geometric characteristics of the components of the real medium. In this regard, the task of assessing the influence of elastic properties of the material on the VAT of an underground oil pipeline is of great practical importance and is relevant.

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This chapter introduces the necessary preparation work before the pipeline rehabilitation construction being carried out. It includes four parts. Firstly, the general provisions about the pipeline rehabilitation construction have been introduced briefly. Then the site investigation, underground pipeline detection and construction site preparation have been introduced in details, respectively.

During the years of operation, underground pipelines deteriorate because of aging, wear, damage, and destruction. A comprehensive inspection of the main pipeline revealed various defects on a certain pipeline route section. To identify the remaining operation life of the pipeline, a number of hydraulic tensile strength tests were performed using the cyclic loading method. The authors propose to calculate the minimum allowable wall thickness capable of withstanding the maximum internal pressure, as an alternative to cyclic hydraulic tests. The strength calculations were performed using the well-known mathematical strength criteria proposed by K.V. Zakharov and I.I. Goldenblatt and V.A. Kopnov.

Metal-loss corrosion is one of the major threats to the integrity of oil and natural gas pipelines. The Fitness-For-Service (FFS) assessment is commonly carried out to demonstrate the integrity of the corroded pipelines. The naturally occurring corrosions on the external surfaces are irregularly shaped three-dimensional features. Due to the geometric complexity of the natural corrosion features, the research of FFS assessment in the previous studies always employed the pipe segments containing artificially induced corrosion features. However, since artificial features are in general regular-shaped, e.g. cubic or semi-ellipsoidal, they do not capture geometric characteristics of naturally occurring corrosions. The thesis develops a finite element model and a random field based corrosion model to deal with five issues regarding the FFS assessment of pipe segments containing naturally occurring corrosion features. The first study develops a three-dimensional finite element model to simulate the full-scale burst tests of pipe segments containing real corrosion features. The finite element model, as well as the RSTRENG model, is used to study the impact of the depth threshold and five commonly used interaction rules on the burst capacity predictions of naturally corroded pipe segments. This study recommends the optimal depth threshold values and interaction rules to evaluate the burst capacity of corroded pipelines in the practical FFS assessment. The second study investigates the impact of corrosion anomaly classes on the predictive accuracy of the B31G, B31G-M, Shell92, PCORRC, PCORRC-M, CSA and RSTRENG models, based on 897 corrosion anomalies on 16 naturally corroded pipe specimens removed from in-service pipelines. The 897 corrosion anomalies are classified into seven classes, namely pin hole, axial slotting, axial grooving, circumferential slotting, circumferential grooving, pitting and general corrosion, based on the Pipeline Operators Forum (POF) anomaly classification system. The seven burst capacity models and finite element analyses (FEA) are employed to evaluate the burst capacities of the corrosion anomalies. The accuracies of the burst capacity models are assessed and compared based on the FEA-to-model predicted burst capacity ratios for different classes of anomalies. The third study proposed a modified RSTRENG (RSTRENG-M) model to evaluate the burst capacity of corroded pipelines by employing the riverbed profile of corrosion features. The riverbed profile consists of representative corrosion depths at a collection of circumferential profiles of the corrosion feature and takes into account the influence on the burst capacity of the maximum corrosion depth and overall metal loss associated with the circumferential profile. Based on full-scale burst tests of 16 naturally corroded pipe specimens and 44 specimens containing artificially induced corrosion features, RSTRENG-M is shown to be more accurate than the RSTRENG model, particularly for corrosion features with complex morphologies, comparable to the Psqr model in terms of accuracy but more advantageous in terms of computational efficiency. An empirical equation is also developed to estimate the representative depth for a given circumferential profile directly from the corresponding maximum depth to facilitate the application of RSTRENG-M in the context of the inline inspection data. The fourth study proposes a random field model to characterize the corrosion depth on the external surface of buried oil and gas pipelines. The model addresses the intermingling of corroded and corrosion-free areas on the pipe surface by using a latent homogeneous Gaussian random field and a spatial position-dependent threshold associated with the latent Gaussian field. High-resolution corrosion measurement data obtained from corroded pipe segments removed from in-service pipelines are used to estimate parameters of the proposed model, including the probability of corrosion at a given point, marginal distribution of the nonzero corrosion depth and correlation structure of the latent Gaussian field. A comparison of simulated and measured corrosion fields suggests that the proposed model is able to capture the characteristics of naturally-occurring corrosion field on the pipe surface. The fifth study combines the FEA model developed in the second study with the random field-based corrosion model presented in the fourth study to analyze the simulated naturally occurring corrosion features (i.e. synthetic corrosion features) in large quantity to further validate the RSTRENG-M model. For comparison, the predictive accuracies of RSTRENG, CSA, CPS, Psqr and DNV are also investigated based on the FEA results of the synthetic corrosion features. The impact of length and maximum depth of corrosion feature on the predictive accuracies of the six semi-empirical models are also presented.

Pipeline is a valuable asset transporting very dangerous materials, so it has been safe and reliable, Tradition methods of maintenance are not enough. Applied failure predicting techniques is the important for environment and economy. Modeling is constructed for the failure frequency of underground pipelines per kilometer year, as a function of pipe and environmental characteristics. The parameters in the model were quantified, with uncertainty, using historical data and structured expert judgment. Fifteen experts from institutes in the Netherlands, the United Kingdom, Italy, France, Germany, Belgium, Denmark and Canada participated in the study.

In order to test the deep-learning YOLOv4 target detection algorithm's effect on excavator target detection in aerial photography environment, a fast target detection method for excavators in aerial photography environment was simulated. Based on the Pytorch deep learning framework and the deep learning YOLOv4 (You Only Look Once version 4) target detection algorithm, through the production of excavator aerial photography data sets, the simulation realized the rapid target detection of excavators in the aerial photography environment, and its target recognition AP value reached 0.72. Based on the same data set, its detection accuracy and speed exceeded Traditional algorithms such as Faster RCNN are used. The simulation results can provide a certain reference for the research of aerial inspection and maintenance of underground pipeline facilities.

Large standoff magnetometry (LSM) as a non-intrusive NDE technology has been used many years in commercial trials for above-ground detection of underground pipeline anomalies associated with stress concentration zones (SCZs). As a passive geo-magnetization flux leakage measurement method, it has been mainly targeting common anomalies such as corrosion, gouges/dents and cracks that are often very localized in small scale. Insufficient consistency and reliability are still the major concern due to technical challenges in getting high resolutions and signal strength at large standoff distance. In comparison, geohazard related external forces induce much large-scale elevated stresses/strains with stronger stress-magnetization signals. Lack of economically viable solutions for pipeline screening and monitoring under geohazard conditions provides a good opportunity to establish LSM’s market position. This work is part of Pacific Gas and Electric Company’s effort in better fundamental understanding of the state-of-the-art LSM technology and its potential to enhance the current industrial practices of pipeline assessment under geohazard conditions. Specifically, 3D mapping of pipelines including depth of cover (DOC) measurement, locating girth welds and peak stresses/strains with risk rating, verification of strain relief operation and continuous monitoring afterwards. Inline inspection (ILI) and geotechnical analysis data together with field excavation and strain-gauge data are utilized as references to cross-check the LSM results. The outcomes indicate geohazard application is very likely a viable application for LSM technology in near future.

In this paper, we solved the problem of liquid transporting in underground pipeline. The Fourier-Kirchhoff equation is used for receiving solution of the problem. We used the following methods: Alternating Direction Method, Cyclic Sweep Method.

This article is devoted to the calculation and optimization of the engineering protection of cold underground condensate pipelines using heat-tracing cable in frost-susceptible soils in We...