Browsing by Author "Abdelbaki, Noureddine"

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2ème [Deuxième] colloque de la géologie de gisement Boumerdès le 16-17 décembre 2008
(Laboratoire des ressources minérales et énergétique Université M’Hamed Bougara Boumerdès, 2008) Abdelbaki, Noureddine
Analysis of predictive models of oil transportation ducts rehabilitation
(2012) Abdelbaki, Noureddine; Bouali, Elahmoun; Gaceb, Mohamed; Bettayeb, Mourad
The actions of the various phenomena of corrosion, mechanical constraints and others, contribute to the degradation of hydrocarbons transportation ducts. The combinations of th ese phenomena accelerate pipe ageing, and this results in the increase of the frequency of leaks interventions and pipe ruptures. The only way to struggle against the ageing of oil transportation pipelines is the rehabilitation. This will allow the re - serv icing of pipes whose resistance characteristics are degraded. One of the major difficulties, during the conception of a pipeline rehabilitation program, is the determination of the specific sections to rehabilitate. Indeed if there is any real risk not to do enough rehabilitation in the one hand, there is a risk to bad rehabilitation on the other. The decision to continue to maintain, renovate or replace some degraded sections of a pipeline is not an easy task, and requires development of forecasting models that will enable decision - makers to take the right decisions on the middle and long term. In this context, this study is devoted to analysis of problems associated with statistical exploitation of controls and repair files of aged pipes, establishing acti on plans and controlling the ageing of hydrocarbons transportation pipelines
Approche probabiliste au contrôle et suivi des joints de soudure des conduites
(2007) Abdelbaki, Noureddine; Bouali, E.; Bouzid, R.; Gaceb, M.
Les conduites de transport des hydrocarbures sont des constructions mécano-soudées, confrontées en exploitation à des conditions particulières de fonctionnement. Les ruptures des joints de soudure des conduites, bien que rares, ont des conséquences majeures aux niveaux humain, environnemental et économique. Ces derniers sont le siège de formation des fissures de fatigue. L'utilisation des résultats d'inspection in situ, à partir des techniques de contrôle non destructif, est une composante essentielle de la réévaluation et du maintien de l'intégrité des conduites dans leur fonction. Elle nécessite des méthodes de calcul et des outils d'aide à la décision en appui des campagnes d'inspection et de réparation. C'est dans ce contexte que la présente étude a été réalisée qui est une contribution à l'effort méthodologique d'évaluation de l'endommagement par détection de fissure et d'estimation de la durée de vie résiduelle des joints de soudure sous sollicitations en fatigue
Drill string fatigue failure and lockup risks assessment in tortuous trajectory well in Algeria
(2017) Belkacem, Lallia; Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahmoun; Bettayeb, Mourad
Failure due to fatigue and lock up risks for drilling pipes in tortuous trajectory is a very costly problem in oil and gas industry, since the cyclic loading which occurs while rotating bent drill pipes in a dog leg are more dangerous than rotating buckled drill pipes. This study is aimed to assess these risks and determine whether by integrating 2024 aluminium alloy drill pipes in drilling string, it is possible to extend the drilling operation without having detrimental impact on the drilling string integrity. Accordingly, the obtained results showed that, even though steel drill pipes have better mechanical properties, compared to 2024 aluminium alloy drill pipes, the latter have a better fatigue resistance even in the simultaneous presence of high applied torque and axial load, and severe dog-legs, beside good resistance to wear and corrosion even at high temperature, thereby reducing environmental trash and full consumption in order to minimise pollution
Effect of milling conditions on structure and magnetic properties of nanocrystalline cobalt
(2005) Fenineche, N.; Guessasma, S.; Abdelbaki, Noureddine
Milling process conditions are related to magnetic properties of nanocrystalline Co material. Experiments are carried out varying plateau rotation and vial velocities. Coercivity, crystallite size and percentage of the cubic phase are analyzed using a statistical methodology based on artificial neural network. Predicted results show that the combination of low plateau rotation velocity and high vial velocity can enhance the cubic phase formation and consequently the coercivity
Effect of shape factor on structural reliability analysis of a surface cracked pipeline-parametric study
(2019) Guillal, Abdelkader; Abdelbaki, Noureddine; Bensghier, Mohamed El Amine; Betayeb, Mourad; Kopei, Bogdan
The variation of crack shape factor (a/c) during propagation has an important role on calculation of the stress intensity factor (SIF), where imprecise estimation of this latter can lead us to an inaccurate prediction of failure probabilities. For the case of external cracked surface pipeline carried oil and gas products, such estimation can results undesired fault decisions like excessive repairs action or inspection planning. In this paper, the structural integrity analysis of pipeline with semi elliptical crack on the external surface is evaluated. Reliability calculations expressed in term of reliability index β are carried out based on Monte Carlo simulation and First Order reliability Method (FORM). The crack shape factors are varied to cover a variety of geometries from shallow to deep cracks while fatigue crack growth is assumed in depth direction. For SIF estimation, surface and deep point are considered. Results of the analysis indicate that for a constant crack depth a/t, the reliability index is strongly affected by a/c ratio and the trend is not similar in deep and surface point for different crack shapes.
Elaboration et qualification d'une procédure de réparation par soudage tig d'aube de turbine a gaz en superalliage à base de nickel-inconel 738
(2007) Yahmi, Youcef; Abdelbaki, Noureddine
L'Inconel ure 738, un superalliage à base de Nickel durci par précipitation, a été utilisé avec succès pour la fabrication des aubes de turbines à gaz pendant des années. Il possède une bonne résistance au fluage et une bonne stabilité à haute température, mais il est susceptible à la fissuration à chaud dans la zone affectée thermiquement pendant le processus de soudage. La progression impressionnante des installations de turbines à gaz associée aux coûts sans précédent des aubes sont des facteurs fondamentaux qui ont conduit à un besoin croissant de procédures de réparation par soudage des aubes. Dans ce travail, nous avons développé une procédure de réparation par soudage TIG qui utilise un superalliage à base de Nickel durci par précipitation (le Waspaloy) et un deuxième superalliage à base de Nickel durci par solution solide (l’Inconel 625) aisément soudable. Les essais mécaniques ont prouvé que le Waspaloy présente des soudures aux caractéristiques mécaniques acceptables. En effet les propriétés de traction à chaud et de résistance à la rupture sous contrainte à haute température du Waspaloy sont plus proches de celles du métal de base que celles du superalliage à solution solide (IN 625)
Establishment of data base and a classification of defects in the metal of pipes according to their severity
(Elsevier, 2012) Bettayeb, M.; Bouali, E.; Abdelbaki, Noureddine; Gaceb, M.
Given the distances between areas of production and consumption of hydrocarbons, transport by pipeline is the most competitive means. These pipelines made of metal pipes can contain several types of defects of different origins. These defects can lead to pipeline failures that may have serious consequences resulting in ecological or financial disasters. The causes of these failures can be of various kinds. To assess the integrity and study the ageing of hydrocarbons transport pipelines is a current problem in the world which must be solved. The degraded state of thousands of kilometers of pipeline in the world requires the elaboration of rehabilitation by repair or replacement programs of sections in poor condition. If on one hand rehabilitation operations do improve the safety of hydrocarbons transport pipelines and prolong their remaining life, they are very expensive on the other. Therefore they must be carried out according to a previously well established plan, which determines the priority given. This priority must be defined by a multi-criteria evaluation, which also includes the criterion of severity of the defects located in the pipes metal according to the result of previous inspections of the pipelines towards the importance and the integrity of each section of the pipe.In this context the elaboration of a database and a classification of the defects in the metal of the hydrocarbons transportation pipes according to their severity are essential in this study
Evaluation and Control of the reliability of Weld Joints in Petroleum Products Transportation Pipelines
(AIDIC SERVIZI SRL, 2015) Abdelbaki, Noureddine; Bouali, Elahmoune; Gaceb, Mohamed; Bettayeb, Mourad; Bouzid, Rachid
The economic performance of petroleum products transport companies is dependent on the reliability of their equipment. Ruptures of the weld joints of petroleum products carriage pipelines have major consequences at the human, environmental and economic levels. Weld joints are potential sites of dangerous cracks. The management of reliability of weld joints in pipelines is useful to integrate the quality planning and risks throughout their life cycle and to systematically track their characteristics all along their life cycles. The use in situ of inspection results from non-destructive control techniques is an essential component of evaluation and control of reliability of pipes in their function. It requires calculation methods and tools to assist in the decision-making in support of inspection and repair campaigns. It is in this context that the present study was conducted, which is a contribution to the efforts of methodological assessment of the reliability of petroleum products transport pipelines.
Fiabilist and economic approaches to optimisation of the renewal of hydrocarbons transporting pipelines
(2013) Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahhmoune; Bettayeb, Mourad; Bouzid, Rachid
Problems of hydrocarbons transporting pipelines agi ng and rehabilitation are currently a major concern for operators of such installations. Rehabilitating and insuring hydrocarbons transporting pipelines, require interventions, such as the renovation of existing lines, the replacement of some pipelines with new ones, in order to meet the growing demand of consumers and improve the supply reliability. In this context, a decision to repair or replace a section of pipe must co mbine both a technical analysis of failures and sound economic analysis of the choice of possible interventions , which is the purpose of this study, dedicated to research and policy determination of repair and replac ement of aged pipe sections, taking into account the factors mentioned above, and based on significant feedback
Influence of properties of large pipes on the reliability of pipelines
(2008) Abdelbaki, Noureddine; Bouali, E.; Gaceb, M.; Bouzid, R.
Integrating Superficially Treated 2024 Aluminum Alloy in Steel Drill String to Deal with Fatigue Problem in Crooked Trajectory for Vertical Deep Well
(Springer International Publishing, 2017) Belkacem, Lallia; Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahmoun; Hedjaj, Ahmed; Bettayeb, Mourad
Drilling deep HPHT wells is the most compelling reason for drilling companies to look for alternative drill pipes that meet their requirements. Currently, with the emergence of drill pipes made of materials other than steel, a thorough study of superficially treated 2024 aluminum alloy combined with steel drill pipe in crooked well trajectory is presented in this study. Basically; this study is built on several parameters that affect fatigue resistance of a drill pipe such as fatigue endurance limit of the drill pipe material, drill pipe specification, torque and drag loads applied, dog leg severity, besides crooked trajectory. Chiefly, this paper shows a full study about 2024 aluminum alloy drill pipe and analyzes the prospect of using aluminum drill string for deep wells while the fatigue, torque and drag as well as drilling efficiency and drill string integrity stay acceptable. It also gives a better comprehension of the mechanical behavior of lightweight material for drill pipe, which can significantly improve well planning in order to drill wells with an increasing depth, length and complexity. Additionally, even though steel drill pipe has better mechanical properties in terms of density, Young’s modulus, yield and tensile strength, than 2024 aluminum alloy drill pipe, the latter has a good fatigue resistance even in the simultaneous presence of high applied torque and axial load, and severe doglegs, which makes the use of other options (Steel Drill Pipe and Titanium Drill Pipe) impractical from the fatigue failure standpoint. Finally we can assume that, there is significant cost saving with the use of Aluminum Drill Pipe compared to steel drill pipes, because the ratio of the engine power needed to supply the drilling fluid at the required pressure for ADP versus steel drill pipe is lower, leading to a reduction in fuel consumption.
Methods of the rational choice of a labyrinth seal design for gas pumping units
(2013) Bellaouar, A.; Kopey, B. V.; Abdelbaki, Noureddine
This present paper describes a method of improving the labyrinth seal design by the development of three-dimensional parametric computer of its model and an anal-ysis of its work for gas pumping units (GPU) using the finite-element method. The authors have improved design labyrinth seal of the GPU according to the criterion of minimum pressure in the last gap by Gauss-Seidel method of optimization, which will increase GPU operational efficiency by reducing flowing medium at various operating modes of GPU. It is shown that change of geometrical sizes and form of creating more compact part of labyrinth seal with inclination them toward greater pressure for an angle of 80° decrease leakages of gas, that in same time considerably influences on the expense of working environment on the output of labyrinth seal
Pipeline test finds Monte Carlo superior to FORM
(2015) Bettayeb, Mourad; Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahmoune
Probabilistic investigation on the reliability assessment of mid- and high-strength pipelines under corrosion and fracture conditions
(Elsevier, 2020) Guillal, Abdelkader; Ben Seghier, Mohamed El Amine; Abdelbaki, Noureddine; Correia, José A.F.O.; Zahiraniza, Mustaffa; Nguyen-Thoi, Trung
In order to reduce the economic costs of pipeline construction projects and for offering a good combination of strength and toughness for efficient transportation of large quantities of hydrocarbon products under high pressure, High Strength Steels (HSS) such as API 5L X70 to X120 are used recently in the construction of pipeline systems for the large oil and gas projects. The commonly utilized models for the reliability evaluation of the HSS pipelines may lead to some conservatism regarding the used data. This paper aims to evaluate the system reliability of HSS pipelines with combined corrosion and cracks defects. Therefore, two failure modes as the plastic collapse and fracture are considered. The effect of different correlations under the term of the strain-hardening exponent that depends on the yield to ultimate tensile strength (Y/T) ratio is investigated. The reliability index of HSS pipelines is evaluated separately for each failure mode using the subset simulation technique. Herein, the tensile strength proprieties of the HSS pipelines are taken into consideration, while the applied methodology utilizes novel probabilistic models to predict the burst pressure for the plastic collapse failure mode. The steels toughness is taken as equal to the minimum requirement for both the ductile and the brittle fracture arrest applied in the HSS pipelines. Moreover, the reliability of the system with multiple failure modes is evaluated to show the mutual existence effect of crack and corrosion defects on pipeline safety
Reliability approach to the choice of dimensions and materials of tubes used in hydrocarbons transport networks
(Italian Association of Chemical Engineering - AIDIC, 2014) Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahhmoune; Bettayeb, Mourad; Bouzid, Rachid
Reliability of an unstable pipeline used for natural gas transportation
(2007) Abdelbaki, Noureddine; Bouali, E.; Bouzid, R.; Gaceb, M.
Semi-probabiliste approach of hydrocarbons canalization
(2007) Abdelbaki, Noureddine; Bouali, E.; Bouzid, R.; Gaceb, M.
Study of defect admissibility in gas pipelines based on fracture mechanics
(School of Engineering, Taylor’s University College, 2009) Abdelbaki, Noureddine; Bouali, E.; Gaceb, M.; Bettayeb, M.
Bearing in mind the considerable distances between natural gas fields and consumers’ appliances, transport by gas pipelines remains the most competitive means. These gas pipelines which are generally made of steel pipes may contain however several types of defects of various origins and which are susceptible to initiate cracks which may grow under some circumstances to such extent as to lead to fracture. Failures of gas pipelines may have serious consequences and may lead to catastrophes from ecological and financial viewpoints. It is therefore interesting to study the defect admissibility so as to maximize safety and minimize exploitation costs through a simplified method based on the Failure Assessment Diagram (FAD). The latter is used in conjunction with Finite Element Analysis (FEM) applied to fracture mechanics to help decision making as to whether a given defect present in a pipe is acceptable or not
Study of life and mechanical properties of welded joints of big diameter pipelines
(2005) Abdelbaki, Noureddine; Fenineche, N.; Bouali, E.; Bouzid, R.; Gaceb, M.
The increase in transportation capacities of pipe-lines necessitates the introduction of new construction tubes and new production technologies. Tubes should be produced according to pipe-lines service parameters. It is therefore useful to produce tubes which vary in diameter, in construction and mainly in the type of steel used for their production. For pipe of great diameter, destined to support high pressure, we use welded tubes made of controlled rolled steel and low alloyed improved steel. Tubes are the main constituents of pipe-lines. Their quality, the properties of their material and their welded joints determine to a high degree the possible deficiencies, stoppages and failures of pipe-lines. This is the reason why it is important to determine the requirements on tube steel and welded joints in terms of the service parameters of pipe-lines in order to avoid their rupture. The welded joints of tubes are subjected to complex static and dynamic loading, which takes place during pipe transportation, and during realization and exploitation of pipelines. The welding process of big diameter pipes is characterized by a great volume of melted metal and a large heat affected zone of the parent metal. The temperature in the vicinity of the weld joints varies from the melting temperature at the joint to lower temperatures in adjacent zones. In the region of the parent metal subjected to this temperature variation important alterations in the structure and in properties of the material take place. This is why it is estimated important to study this zone in which there is a reduction in the plasticity and the resilience of the metal and consequently there will be an increase in the probability of crack formation. The creation of a mechanical non-homogeneity in this zone reduces the work capacity of the weld joints and the reliability of pipe-lines reduces. It is in this context that the paper presented includes two parts: The first part is concerned with the hardness distribution and the resilience variation as a function of the temperature distribution in the heat affected zone of pipe. The second part considers the influence of the weld joint shape and the loading regime of the pipe-lines on their weld joints life in the big diameter pipes. This work shows how the bearing capacity of the weld joints wary with the mechanical non-homogeneity of weld properties and quality with their weld shape and with the relative thickness of the diameter layer in the welding. On the other hand this study shows the resilience variations in weld joints and in the parent metal of the pipes in the as bought state and after their mechanical ageing. The stress and strain concentration resulting from irrational configuration of welded joints cause the strength of weld subjected to cyclic loading to be diminished. This has lead to finish this work by the determination of the life specimens taken from weld joints in tubes and subjected to cyclic loads during testing