Publications Scientifiques
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Item Effect of concentration and temperature on the rheological behavior of hydroxylethyl cellulose solutions(2022) Remli, Samia; Benyounes, Khaled; Benmounah, AbdelbakiThe knowledge of the rheological properties of polymers makes their use interesting in various fields of applications, such as food industry, cosmetics, enhanced oil recovery or construction materials. Whatever the application, the effect of temperature and concentration on these properties is of great importance. This study covered a wide range of concentrations from 0.2 w/% to 1 w/%, and temperatures from 10 °C to 80 °C. The results obtained provide interesting information regarding the effects of the temperature and concentration of the aqueous solutions of the polymer since they reveal that the rheological properties remained practically unchanged in the temperature range considered. The impacts of shear rate, temperature and concentration on the flow behavior were analyzed. Small-amplitude oscillatory shear measurements were performed, and the results obtained show that the apparent viscosity is strongly influenced by the concentration of the aqueous solution of HEC, exhibiting a marked non-Newtonian shear-thinning behavior at different temperatures. The flow behavior is well described by several rheological models. The effect of temperature on the kinematic viscosity was fitted with the Arrhenius model; the behavior of this model in relation to experimental viscosity values was suitable and the linear fit showed good regression coefficients. The dynamic state was well described with the generalized Maxwell modelItem Rheological behavior of cement-based grout with Algerian bentonite(Springer Nature, 2019) Benyounes, Khaledhe rheological parameters, yield stress, flow index, consistency, and plastic viscosity of cement grouts are important parameters for the quality control of these materials. These parameters are assessed from the rheogram using a rheo-logical model. Cement slurries without additive indicated a non-Newtonian type of rheological behaviour with yield stress. On the other hand, the mixtures containing a viscosifying agent exhibit a shear-thinning rheological behaviour which is much more important than the mixtures without a viscosifying agent. In this work, we formulated non-hydrated Algerian bentonite cement slurry in the presence of a superplasticizer. Cement was replaced cement by bentonite in five different substitution rates (2%, 4%, 6%, 8%, and 10%) and the water/binder ratio was fixed at 0.5. For this, various rheological tests were realized by using a controlled stress rheometer. In order to show the influence of bentonite on the rheological behaviour of the different grouts, several flow tests were carried out for a range of shear rates between 0.01 and 200 s−1. To properly adjust the different rheograms, various rheological models were used such as the models of Bingham, Herschel–Bulkley, modified Bingham, Casson, De Kee, Vom Berg, Yahia and Papanastasiou. For the correct choice of the rheological model, it was based on the calculation of the standard error. It was found that the rheological models of Herschel–Bulkley and Papanastasiou made it possible to better describe the flow curves compared to the other rheological models. It has been found that as the content of bentonite increases, the yield stress and the consistency evolve drastically, by cons the flow index decreases progressivelyItem Characterization and modeling of rheological behavior of a mud system for reverse emulsion(2016) Mellak, Abderrahmane; Benyounes, Khaled; Kherfellah, N.; EL Heit, K.Item Rheological and electrokinetic characterization of bentonite particles in aqueous phase in presence of KCl(2015) Benyounes, Khaled; Benmounah, AbdelbakiItem Modeling and rheological characterization of sludge based drilling oil(2014) Mellak, Abderrahmane; Benyounes, KhaledWhen the drilling mud is in contact with more or less permeable walls of the well, the liquid filter part in the formation by depositing on the walls of the solid part is called the cake (silty clay film). Among the main functions of drilling fluid include keeping the walls of the well due to the hydrostatic pressure exerted by the flowing fluid. Also, the mastery of the rheological properties of the mud used is required. . The rheological characterization focus on the drilling mud used for drilling the 121/4 phase in the well AY (Hassi Messaoud) is an invert emulsion mud with oil report / water 85/15 and its density is 2.04, consisting essentially of gas oil, organophilic clay, two emulsions, sodium chloride and barite. It would define the rheological model of drilling fluid used and seek the most suitable rheological model. The rheological tests were carried out using a Fann viscometer 6-speed (3, 6, 100, 200,300 and 600 rpm) to determine the rheological properties of the mud as the yield value or yield stress, the plastic viscosity and apparent viscosity. Other rheological parameters such as the consistency index (k) and the behavior index (n) of the mud were estimated. The results show that the Herschel-Bulkley model is a minimal deviation from other models (model Bingham and Ostwald de Waele or Power)Item The effect of carboxymethylcellulose and xanthan on the rheology of bentonite suspensions(Taylor & Francis, 2010) Benyounes, Khaled; Mellak, A.; Benchabane, A.Item Rheological and electrokinetic properties of carboxymethylcellulose-water dispersions in the presence of salts(2012) Benyounes, Khaled; Benmounah, A.The purpose of this work is to investigate the effect of the addition of salts in the form of calcium chloride, sodium chloride and potassium chloride on the rheological and electrokinetic properties of diluted sodium carboxymethylcellulose (Na-CMC) dispersions (0.50%). The rheological data of a water-CMC-salt system were obtained using coaxial cylinder viscometer covering a wide range of shear rate (0 to 600 s-1). Ostwald–de Waele power law was used for fitting flow curves of various samples. The presence of salts in CMC aqueous solutions leads to the reduction of the consistency index and the increase of flow index as salinity increases. When the concentration of salts is greater than 3%, the rheological parameters of CMC solutions in saline medium are quasi stable. The electrokinetic measurements show an increase of the zeta potential of CMC dispersions when the concentration of salts in solution increases. Calcium chloride caused the greatest increase in zeta potential. Excluding the monovalent cations, the divalent cation is able to reverse the sign of the zeta potential from negative to positive