Publications Scientifiques
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Item Modeling wax disappearance temperature using robust white-box machine learning(Elsevier Ltd, 2024) Nait Amar, Menad; Zeraibi, Noureddine; Benamara, Chahrazed; Djema, Hakim; Saifi, Redha; Gareche, MouradWax deposition is one of the major operational problems encountered in the upstream petroleum production system. The deposition of this undesirable scale can cause a variety of challenging problems. In order to avoid the latter, numerous parameters associated with the mechanism of wax deposition should be determined precisely. In this study, a new smart correlation was proposed for the accurate prediction of Wax disappearance temperature (WDT) using a robust explicit-based machine learning (ML) approach, namely gene expression programming (GEP). The correlation was developed using comprehensive experimental measurements. The obtained results revealed the promising degree of accuracy of the suggested GEP-based correlations. In this context, the newly-introduced correlations provided excellent statistical metrics (R2 = 0.9647 and AARD = 0.5963 %). Furthermore, performance of the developed correlation outperformed that of many existing approaches for predicting WDT. In addition, the trend analysis performed on the outcomes of the proposed GEP-based correlations divulged their physical validity and consistency. Lastly, the findings of this study provide a promising benefit, as the newly developed correlations can notably improve the adequate estimation of WDT, thus facilitating the simulation of wax deposition-related phenomena. In this context, the proposed correlations can supply the effective management of the production facilities and improvement of project economics since the provided correlation is a simple-to-use decision-making tool for production and chemical engineers engaged in the management of organic deposit-related issues.Item Rheological study of concentrated dispersions. Application to the drilling fluid(Institute of Physics Publishing, 2018) Ouaer, Hocine; Gareche, Mourad; Allal, AhmedIn order to understand the rheological behavior of concentrated aqueous Algerian bentonite dispersions of drilling (sodium bentonite of Mostaganem "m'zila"), rheological tests were carried out. By varying the concentration of bentonite, flow tests have allowed to estimate the yield stress and apparent viscosity for each concentration and to see their influence on the rheological behavior of these dispersions. In addition dynamic tests (oscillatory) are used to define the linear region of our samples, the state of our fluid (elastic solid or viscous liquid) and understanding the mechanisms of structuring of the particles constituting the material. In parallel, other tests coupled with rheological measurements such as x-rays diffraction to know the mineralogical composition and granulometry to estimate the bentonite particle size.Item Rheological studies and optimization of Herschel–Bulkley parameters of an environmentally friendly drilling fluid using genetic algorithm(Springer, 2018) Ouaer, Hocine; Gareche, Mourad; Rooki, RezaThe Herschel–Bulkley rheological parameters of an environmentally friendly drilling fluid formulated based on an Algerianbentonite and two polymers—hydroxyethyl cellulose and polyethylene glycol—have been optimized using a genetic algorithm.The effect of hydroxyethyl cellulose, temperature, pH and sodium chloride (NaCl) on the three-parameter Herschel-Bulkleymodel was also studied. The genetic algorithm technique provided improved rheological parameter characterization compared tothe nonlinear regression, especially in the case of drilling fluids formulated with sodium chloride making it a better choice.Furthermore, the oscillatory test offered more reliable yield stress values. The rheological parameters were found to be verysensitive to different conditions. Yield stress and consistency index increased with increasing the hydroxyethyl cellulose con-centration, reaching maximum at a temperature of 65 °C and decreased with decreasing pH and also when adding sodiumchloride to the drilling fluid. The flow index changed inversely to yield stress and consistency index. The physical origins of thesechanges in rheological parameters were discussed and correlation between variation in rheological parameters and bentonitesuspension properties were concluded. Based on these results, it is recommended to use the proposed formulation of drilling fluidat high temperature and when the formation of alkaline pH is encountered due to the gelation mechanism and to select theoptimum concentration of NaCl to avoid degradation of the rheological parametersItem Effect of non-ionic polymers on yield stress and kinetic structure of Algerian bentonite used in drilling fluids(2019) Ouaer, Hocine; Gareche, MouradItem Review of recent advances in polyethylenimine crosslinked polymer gels used for conformance control applications(Springer, 2019) Ghriga, Mohammed Abdelfetah; Grassl, Bruno; Gareche, Mourad; Khodja, Mohamed; Lebouachera, Seif El Islam; Andreu, Nathalie; Drouiche, NadjibItem Relationship between the fractal structure with the shear complex modulus of montmorillonite suspensions(Elsevier, 2016) Gareche, Mourad; Allal, A.; Zeraibi, Noureddine; Roby, F.; Azril, N.; Saoudi, L.Item Colloidal behavior of aqueous montmorillonite suspensions in the presence of non-ionic polymer(2015) Gareche, Mourad; Azri, N.; Allal, A.; Zeraibi, NoureddineIn this paper we characterized at first, the rheological behavior of the bentonite suspensions and the aqueous solutions of polyethylene oxide (PEO), then we were investigated the influence of this polymer in a water-based drilling fluid model (6% of bentonite suspension). The objective is to exhibit how the non ionic polymer with molecular weight 6×103 g/mol. of varying concentration mass (0.7%, 1%, 2% et 3%) significantly alter the rheological properties (yield stress, viscosity, loss and elastic modulus) of the bentonite suspensions. The rheological measurements made in simple shear and in dynamic on the mixture (water-bentonite-PEO), showed rheological properties of bentonite suspensions both in the presence and absence of non-ionic polymer. The PEO presents an affinity for the bentonite particles slowing down their kinetic aggregation. The analysis by X-rays diffraction also allowed understanding the structure of this mixture. It had revealed the intercalation between of the clay platelets on one hand, and the links bridges assured by the chains of polymer between bentonite particles beyond a critical concentration in PEO on the other hand. The Herschel- Bulkley rheological model is used for the correlation of our experimental resultsItem Numerical study of a thermodependent non-Newtonian fluid flow between vertical concentric cylinders(Elsevier, 2007) Zeraibi, Noureddine; Amoura, M.; Benzaou, A.; Gareche, MouradIn this paper, we present a numerical investigation of the thermal convection for a thermodependent non-Newtonian fluid in an annular space between two coaxial rotating cylinders. The rheological behaviour of the fluid can be expressed through the Ostwald-De-Waele power law: View the MathML sourceτ=Kγ˙n; all fluid properties except consistency index K are constant. K–T relation used is K = K0e−bT. The problem is studied when the heated inner cylinder is rotating around the common axis with constant angular velocity and the cooled outer cylinder is at the rest. The horizontal endplates are assumed adiabatic. The governing equations are solved using mixed finite elements method. The influence of the temperature on the structure of the dynamic and thermal fields is examinedItem Modélisation du module complexe de cisaillement des suspensions de bentonite = Modelling of complex shear modulus of bentonite suspensions(Groupe français de rhéologie, Sophia Antipolis, FRANCE, 2009) Allal, A.; Gareche, Mourad; Dupin, J. C.; Roby, F.; Zeraibi, NoureddineDans ce travail, nous avons étudié le comportement rhéologique de suspensions de bentonite pour diverses concentrations massiques (2, 4, 5, 6 et 8 %). Nous nous sommes intéressés plus particulièrement à la viscoélasticité linéaire, avec pour objectif de faire le lien entre la structure fractale des ces suspensions et le module de cisaillement complexe. A partir de la dimension fractale des gels formés par les particules d'argile en interaction dans les suspensions de bentonite, nous avons modélisé la variation de leurs modules complexes de cisaillement en fonction de la fréquenceItem Finite element study of mixed convection for non-Newtonian fluid between two coaxial rotating cylinders(2006) Amoura, Mourad; Zeraibi, Noureddine; Smati, A.; Gareche, MouradIn this work, we present a numerical simulation of the flow characteristics and the heat transfer mechanism of a non-Newtonian fluid in an annular space between two coaxial rotating cylinders. The Carreau stress–strain relation was adopted to model the rheological fluid behaviour. The problem is studied when the heated inner cylinder rotates around the common axis with constant angular velocity and the cooled outer cylinder is at the rest. The horizontal endplates are assumed adiabatic. The governing equations are solved using mixed finite elements method. The effects of the different parameters on the heat transfer and on the flow are examined. These parameters are the Reynolds (Re), the Grashof (Gr) and the Weissenberg numbers (We), and the flow index (n). The results of the natural, forced and mixed convections are presented and discussed. © 2006 Elsevier Ltd. All rights reserved