Browsing by Author "Souas, Farid"

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Comparative flow behavior of oil sludge and crude oils from algerian storage tanks
(CNESE, 2025) Souas, Farid; Safri, Abdelhamid; Gueciouer, Abderazak
This study investigates the flow behavior of tank bottom sludge and two crude oil samples by analyzing the variation of viscosity and shear stress with shear rate and temperature. The flow curves reveal that all samples exhibit non-Newtonian, shear-thinning behavior characterized by a distinct yield stress, particularly prominent in the sludge due to its high content of heavy fractions such as asphaltenes, resins, and solid particulates. Viscosity and shear stress consistently decrease with increasing temperature, a result of the thermal disruption of intermolecular forces and breakdown of microstructural networks. At low shear rates, sludge displays more pronounced shear-thinning behavior than crude oils, while at high shear rates, all samples approach Newtonian flow regimes due to molecular alignment and structural degradation. Model fitting shows the Herschel-Bulkley model best describes the sludge's rheology, whereas the Casson model better fits the crude oils under specific temperature conditions. Temperature sensitivity analysis (10–40 °C) indicates that crude oils experience greater viscosity reduction than sludge, with crude 1 showing the highest response due to its thermally labile composition. Yield stress also diminishes with temperature, reflecting the weakening of internal structural rigidity. These findings underscore the critical influence of composition and temperature on the flow properties of petroleum-derived fluids, with implications for pipeline transport and sludge management
Experimental investigation of the rheological behavior of algerian crude oils from the quagmires
(Taylor & Francis, 2019) Souas, Farid; Safri, Abdelhamid; Benmounah, Abdelbaki
A review on the rheology of heavy crude oil for pipeline transportation
(ELSEVIER, 2020) Souas, Farid; Safri, Abdelhamid; Benmounah, Abdelbaki
Given the combination of rising global energy demand and the decline in conventional crudes, heavy crudes are generally considered to be the future energy resource. In many regions of the world, heavy crude oil must be transported through pipelines from the point of production to storage facilities or refineries. The transportation of heavy crude oil by pipeline poses serious problems related to the high viscosity and flow difficulties, particularly in cold climates or offshore conditions. Indeed, the viscosity of crude oil is an important physical property that influences and controls crude oil flow in pipelines. Viscosity introduces resistance to movement by causing a shear or frictional force between the fluid particles and the boundary walls. This high viscosity means that the pumping power requirements for crude oil in a long-distance pipeline are very high in order to overcome the increasing shear and friction forces. Therefore, in order to facilitate the pumping of these viscous oils and reduce operating expenses and the negative impact of pressure drops in pipelines during flow and processing, their viscosity must be reduced. Various techniques are used to increase pumping efficiency and improve the flow of crude oil through the pipeline, which may present logistical, technical or economic disadvantages for a given application. The main ones are the addition of surfactants or polymers, dilution with lighter crudes, use of water as annular fluid, thermal remediation and emulsification with surfactant (O/W). This review highlights the methods currently used to enhance the fluidity of heavy crude oil in pipelines behind rheology improvement, in particular the addition of additives and the use of water and surfactants to create a stable emulsion of heavy crude oil in water have been considered.
Rheological behavior of Algerian crude oil: effect of temperature and refined product
(Taylor and Francis Online, 2018) Souas, Farid; Safri, Abdelhamid; Benmounah, Abdelbaki; Djemiat, Djamal Eddine
The rheological behavior and its variation with temperature and refined product concentration of a crude oil sample coming from a quagmire of the separation station of Tin Fouye Tabankort oilfield/southern Algeria were investigated experimentally. The experiments were carried out at various temperatures (20, 30 and 50 °C) over the shear rate range of 0 to 700 s−1 by using a controlled stress rheometer (AR 2000, TA Instrument). The results showed that the crude oil exhibit non-Newtonian of shear thinning behavior at low shear rate and Newtonian behavior at high shear rate and was adequately described by Casson and Herschel–Bulkley models. The rheological measurements through the steady flow test and viscoelastic behavior, including the storage modulus (G′), loss modulus (G″), and complex modulus (G*), has indicated that the rheological properties of the crude oil were greatly influenced by the temperature and the additive concentration.
Rheological behavior of oil sludge from Algerian refinery storage tanks
(Elsevier, 2022) Souas, Farid
Rheological behavior of oil sludge from Algerian refinery storage tanks Farid Souas a, b, * a LEGHYD Laboratory, Faculty of Civil Engineering, University of Science and Technology Houari Boumediene (USTHB), Bab Ezzouar, Alger, Algeria b Research Unit Materials, Processes and Environment (UR-MPE), Faculty of Engineering Science, University M’Hamed Bougara, Boumerdes, Algeria a r t i c l e i n f o Article history: Received 15 August 2021 Received in revised form 20 December 2021 Accepted 28 January 2022 Available online xxx Keywords: Crude oil Rheology Sludge Storage tank Temperature Viscosity a b s t r a c t The consumption and demand for petroleum are increasing dramatically with the rapid development of industry and energy sector. As a result, petroleum refineries produce the greatest amount of oily sludge formed at the bottom of storage tanks during oil storage operations, which has a severely negative impact on the storage capacity and the operational safety of the storage tank. The present study focuses on the rheology of this complex fluid from Algerian crude oil storage tanks. Rheological measurements were performed at different temperatures under steady shear and dynamic oscillometry using AR-2000 Rheometer. The results obtained show that the sludge exhibits yield-pseudoplastic flow behavior at low shear rates, which is adequately described by the Herschel Bulkley model based on the standard error and correlation coefficient values. However, quasi-Newtonian flow behavior occurs at very high shear rates. The increase in temperature had positive effects on the rheological properties of the sludge, including dynamic viscosity, shear stress, yield stress, complex modulus, elastic modulus and viscous modulus. The dynamic rheology studies have shown that the sludge material behaves more like a solid than a liquid under all experimental conditions studied
Using Machine Learning Algorithms for the Analysis and Modeling of the Rheological Properties of Algerian Crude Oils
(Taylor and Francis Ltd., 2024) Souas, Farid; Oulebsir, Rafik
Our research described in this report investigated the rheological behavior of crude oils from the Tin Fouye Tabankort oil field in Southern Algeria, focusing on their viscosity under varying temperatures (10 °C–50 °C). The results show that the oils exhibited non-Newtonian shear-thinning behavior at low shear rates, with the viscosity decreasing as the temperature was increased. At higher shear rates, the Herschel–Bulkley model accurately described the oils’ transition to Newtonian behavior. Machine learning models, including CatBoost, LightGBM, and XGBoost, were trained on the experimental data to predict the viscosity, with CatBoost and XGBoost showing superior performance. We suggest these findings are valuable for improving the efficiency of oil transportation and processing.