Petroleum Engineering
Seyed Mohammadreza Mousavi; Saeed Jafari; Mahin Schaffie; Saeid Norouzi Apourvari
Abstract
Ultrasonic irradiation is a new, economic, and environmentally friendly technique for treating asphaltene aggregation in petroleum industry. In this study, the effect of ultrasonic radiation on asphaltene formation is investigated using conventional optical microscopy, viscosity measurement, and Fourier-transform ...
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Ultrasonic irradiation is a new, economic, and environmentally friendly technique for treating asphaltene aggregation in petroleum industry. In this study, the effect of ultrasonic radiation on asphaltene formation is investigated using conventional optical microscopy, viscosity measurement, and Fourier-transform infrared spectroscopy (FTIR). To this end, five crude oil samples, collected from different reservoirs, are used, and the effect of ultrasonic radiation on the structure of the crude oils is investigated at various exposure times. The results show that, at an optimum radiation time, the ultrasonic waves can break the asphaltene clusters and shift the size distribution of the asphaltene aggregate to a smaller size. In addition, the FTIR analysis reveals structural changes in the composition of the crude oil after the ultrasonic irradiation. By increasing the ultrasound exposure time, the viscosity of the asphaltenic oil first decreases to a minimum before rising again. Moreover, the measurement of asphaltene and resin content of the crude oils indicates that at exposure times longer than the one leading to the minimum viscosity, resin molecules are broken upon exposure to ultrasound. This can be the main reason for the existence of an optimum time in the application of ultrasonic radiation, after which the percentage of asphaltene particles and the viscosity of the crude oils increase.
Chemical Engineering
Farhad Salimi; Shahab Ayatollahi; Mohsen Vafaie Seftie
Abstract
In this study, asphaltene deposition from crude oil has experimentally and theoretically been studied using a test loop and an accurate temperature monitoring during a laminar flow. The effects of oil velocity and surface temperature on the thickness of asphaltene deposition were investigated. The results ...
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In this study, asphaltene deposition from crude oil has experimentally and theoretically been studied using a test loop and an accurate temperature monitoring during a laminar flow. The effects of oil velocity and surface temperature on the thickness of asphaltene deposition were investigated. The results show that asphaltene deposition thickness increases by increasing surface temperature. As the oil velocity increased, less deposition was noticed in this experimental study. The thermal approach was used to describe the mechanisms involved in this process, and the results of data fitting showed that there was good agreement between the results of the proposed model and the measured asphaltene deposition rates. Moreover, the theoretical study of deposition process showed that the rate of asphaltene deposition was inversely related to velocity, which was proved by the experimental results.
Mahdi Kalantari Meybodi; Jamshid Moghadasi
Abstract
Onset of asphaltene precipitation is the key parameter in dealing with asphaltene problems because it is the starting point of the asphaltene separation from the solution. In this study, a new technique is provided based on the experimental observations for the determination of the onset of asphaltene ...
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Onset of asphaltene precipitation is the key parameter in dealing with asphaltene problems because it is the starting point of the asphaltene separation from the solution. In this study, a new technique is provided based on the experimental observations for the determination of the onset of asphaltene precipitation using accurate density measurements of the crude oils upon titration with precipitating agents like n-alkanes. Moreover, density measurements have been conducted for three different crude oils diluted with different ratios of precipitating agents, i.e. n-pentane, n-hexane, and n-heptane. The experimental results confirmed that, as it was expected, the density showed a decreasing trend as the dilution ratio increased, except at one point, at which the density increased with raising dilution ratio; this corresponded to the onset of asphaltene precipitation. For all the crude oils used, a sample diluted with a non-precipitating solvent (toluene) was also used as a reference system, its densities were measured upon titration with toluene, and the results were used for comparison with the other systems diluted with precipitating solvents. The measured onsets of asphaltene precipitation using this technique were confirmed with the onsets obtained by using interfacial tension approach.
Fatemeh Amin; Ali Reza Solaimany Nazar
Abstract
The Taguchi design of experiments (DOE) approach is adopted here to evaluate the impact ofeffective factors such as nanoparticles type, nanoparticles to model solution mass ratio, asphaltenestructure, and temperature on asphaltene adsorption equilibrium. Herein, the toluene-asphaltenesolution model is ...
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The Taguchi design of experiments (DOE) approach is adopted here to evaluate the impact ofeffective factors such as nanoparticles type, nanoparticles to model solution mass ratio, asphaltenestructure, and temperature on asphaltene adsorption equilibrium. Herein, the toluene-asphaltenesolution model is applied. Three commercially nanoparticles (SiO2, Al2O3, and TiO2) are used.Asphaltene characterizations are carried out by X-ray diffraction (XRD) analysis. It is found that thenanoparticle type and asphaltene structure with a respective influence of 48.5% and 3.11% have themaximum and minimum contribution on the amount of adsorbed asphaltene at the selected levelsrespectively. Aluminum oxide nanoparticle has the maximum and silicon oxide nanoparticle showsthe minimum adsorption. The temperature has no statistical significance. Asphaltenes with higheraromaticity have more tendencies for adsorption on nanoparticles.
