Publications Internationales

Now showing 1 - 6 of 6

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
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
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
Tensile and torsional loads stress distribution along the drill string for deep wells
(Springer, 2015) Belkacem, Lallia; Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahmoun; Hedjaj, Ahmed; Bettayeb, Mourad
Common knowledge and rule of thumb tell us that tensile failures will mostly occur in the pipe body, while torsion failures will occur in the tool joints. The total stresses on the drill string should be considered which are induced by combined bending, torsion and tensile stresses. The latter can usually be operating up until 80 % of the pipe body yield stress, a level which is considered as a safe working limit. Moreover, torque and drag are caused by the lateral forces and the friction between the borehole wall and the drill pipe. The lateral forces depend on the weight of the drill string. Torque and drag are sometimes overlooked when drilling simple wells. In deep well this is not acceptable. Proper decision made using correct torque and drag can make all the difference between TD drilling and suspended drilling. Therefore the over pull load plus the torque are the most important points to be considered in deep well drilling, since the resistance of the drill string body to the combined efforts will probably limit its tensional limit. By this I mean, exerting both a tension and torsion load on the drill string of this later will weaken its yield stress consequently applying a high tension effort combined with a significant torque lead to plastifying of the drill pipe body thus reducing its fatigue life. This problem is well observed in back-reaming operation. The results show that fatigue damage from rotation in dogleg during backreaming operation is a significant problem if the severity is greater than the critical value. So the position of drill pipe in the string will influence the amount of fatigue damage it sustains. Furthermore, back reaming can reduce the fatigue life of the drill pipe significantly because of the stress reversal of the drill string under tension in a dogleg
Pipeline test finds Monte Carlo superior to FORM
(2015) Bettayeb, Mourad; Abdelbaki, Noureddine; Gaceb, Mohamed; Bouali, Elahmoune
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

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