Petroleum Engineering
Bardiya Yazdani; Amir Hossein Saeedi Dehaghani
Abstract
This research aims to investigate the effect of microwaves on the physical and chemical properties of heavy crude oil in the presence of different minerals. In this regard, the physical and chemical changes of the oil and rock powder (sand and carbonate) mixture are investigated by microwave radiation. ...
Read More
This research aims to investigate the effect of microwaves on the physical and chemical properties of heavy crude oil in the presence of different minerals. In this regard, the physical and chemical changes of the oil and rock powder (sand and carbonate) mixture are investigated by microwave radiation. Viscosity and temperature changes of two samples are measured. IP143 and elemental analysis (carbon, hydrogen, nitrogen, and sulfur) are used to extract and identify the composition changes of asphaltene. The viscosity and temperature changes show that for both samples at the beginning of microwave radiation, there is a decrease in viscosity due to heavy hydrocarbon particle cracking, such as asphaltene, and converting them into lighter ones. Light compounds evaporate by continuing the radiation and temperature increase; finally, the viscosity increases. The evaporation process in the carbonate powder sample starts earlier than in the sand powder. From elemental analysis, it is concluded that the sulfur and nitrogen in asphaltene decrease almost the same for both samples, and this decrease is more evident for sulfur; thus, the rock powder combined with oil does not have a significant effect on the reduction of these elements. The increase in IFT is also observed due to the evaporation of light oil compounds, and IFT increases further due to the higher temperature of the sample containing carbonate rock powder.
Petroleum Engineering
Yaser Ahmadi
Abstract
Using nanoparticles for adsorbing asphaltene is an efficient method for upgrading actual oil samples compared to other expensive mechanical treatments or even solvents, such as n-pentane and n-heptane, and surfactants. This study uses nickel–zeolite oxide nanoparticles for asphaltene adsorption ...
Read More
Using nanoparticles for adsorbing asphaltene is an efficient method for upgrading actual oil samples compared to other expensive mechanical treatments or even solvents, such as n-pentane and n-heptane, and surfactants. This study uses nickel–zeolite oxide nanoparticles for asphaltene adsorption and solving asphaltene precipitation problems. Although nickel–zeolite oxide nanoparticles have been used in previous studies as an asphaltene adsorbent, observing the relationship between asphaltene adsorption on their surface and asphaltene precipitation in the presence of nanoparticles during the actual process is not covered. For addressing this relation, we performed a series of experiments included Fourier-transform infrared spectroscopy (FTIR), CO2–oil interfacial tension tests, Langmuir and Freundlich isotherm models, and natural depletion tests in the presence of nickel–zeolite oxide nanoparticles. The Langmuir model better fitted the adsorption data than the Freundlich model, which shows that the adsorption occurs on a homogeneous surface with monolayer coverage. Based on the CO2–oil interfacial tension results, there are two different slope forms in interfacial tension readings as pressure increases from 150 to 1650 psi. Due to asphaltene aggregation, the second slope (900–1650 psi) is slower than the first one (150–900 psi). Three pressures of 1350, 1500, and 1650 psi and nickel–zeolite oxide nanoparticles at a concentration of 30 ppm were selected for the natural depletion tests, and the basis of selection was high-efficiency adsorption at these points. As pressure decreased from 1650 to 1350 psi, asphaltene precipitation changed from 8.25 to 10.52 wt % in the base case, and it varied from 5.17 to 7.54 wt % in the presence of nickel–zeolite oxide at a concentration of 30 ppm. Accordingly, nickel–zeolite oxide nanoparticles adsorbed asphaltene on their surface correctly, and the amount of asphaltene precipitation decreased in the presence of nickel–zeolite oxide nanoparticles.
Petroleum Engineering
Mohsen Mansouri; Mehdi Parhiz; Behrouz Bayati; Yaser Ahmadi
Abstract
One of the critical issues in the oil industry is related to asphaltene precipitation during different stages, and using nanoparticles is known as a standard method for solving this problem. Although nickel oxide and zeolite have been addressed in previous research to solve the asphaltene precipitation ...
Read More
One of the critical issues in the oil industry is related to asphaltene precipitation during different stages, and using nanoparticles is known as a standard method for solving this problem. Although nickel oxide and zeolite have been addressed in previous research to solve the asphaltene precipitation problem, using NiO/Na-ZSm-5 (the primary goal of this study) has not been developed to solve relevant asphaltene precipitation problems. The crystalline structure and morphology of the synthesized nanoparticles were analyzed with the help of X-ray diffraction spectrometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDXS). The results show that the nanoparticles were well synthesized and preserved their crystalline structure with a diameter of 13.6 nm after synthesis. The EDXS analyses also proved that the sorbent adsorbed an amount of asphaltene. In the next step, asphaltene adsorption experiments were carried out at various concentrations of asphaltene and temperatures, and the effect of different variables, including the initial concentration of asphaltene, temperature, and the ratio of heptane to toluene, on the asphaltene adsorption rate was evaluated. The results indicate that with an increase in the initial asphaltene concentration from 25 to 2000 ppm, the asphaltene adsorption rate in zeolite increases. At concentrations less than 500 ppm, a rise in the temperature reduces the asphaltene adsorption, while at concentrations higher than 500 ppm, raising the temperature from 25 to 55 °C increases asphaltene adsorption capacity on zeolite. Further, more significant adsorption is observed at a heptane-to-toluene ratio of 0.4 with q = 25.17 mg/g. Evaluating the effects of kinetic adsorption molecules of asphaltene on these nanoparticles shows that the adsorption process reaches equilibrium in less than 2 h. The experimental data were adapted according to Lagrangian pseudo-first-order and pseudo-second-order models to determine the kinetic mechanism of this process. The Langmuir and Freundlich adsorption isotherms were evaluated, and the isotherms resulting from the Langmuir isotherm model were of good conformity, indicating that adsorption at the homogenous level occurred with a single-layered coating. In the final step, after evaluating the thermodynamic conditions, the spontaneity of the asphaltene adsorption process was proved.
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 ...
Read More
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 ...
Read More
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 ...
Read More
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 ...
Read More
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.
