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
Taleb Eidy; Seyed Ali Hosseini; Ghasem Marandi
Abstract
The separation of naphthenic acids from crude oil is difficult, and the presence of such materials in crude oil reduces its value. In this work, using catalytic esterification with methanol, naphthenic acids of crude oil were removed to reduce their harmful effects. SnO2/γ-Al2O3 nanocatalyst was ...
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The separation of naphthenic acids from crude oil is difficult, and the presence of such materials in crude oil reduces its value. In this work, using catalytic esterification with methanol, naphthenic acids of crude oil were removed to reduce their harmful effects. SnO2/γ-Al2O3 nanocatalyst was synthesized and used to convert naphthenic acids of crude oil in a fixed bed catalytic reactor. The nanocatalyst was characterized by the X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) surface area techniques. The XRD revealed the formation of rutile SnO2 on alumina, and the FESEM approved that the catalyst is comprised of nanoparticles with a diameter in the range of 50 to 90 nm. The BET indicated that the catalyst has a mesopore structure with a surface area of 213.4 m2·g–1. The optimal conditions for the catalytic esterification process of naphthenic oil were determined. The temperature of the reduction of the total acid number (TAN) of crude oil ranged from 250 to 360 °C, and the TAN was reduced to less than 0.5 mg KOH/g in this temperature range. A methanol-to-oil ratio (M/O) of 2 wt %, a velocity space of 2.5 h–1, a reaction temperature of 300 °C, and atmospheric pressure were selected as the optimal conditions for the removal of naphthenic acids. Under these conditions, 83% of naphthenic acids was removed. The study indicated that SnO2/γ-Al2O3 could be a promising nanocatalyst for the reduction of total acid of crude oil under mild conditions.
Petroleum Engineering – Reservoir
Abiodun Ogbesejana; Oluwadayo Sonibare; Zhong Ningning; Oluwasesan Bello
Abstract
Crude oils and source rocks from the northern and offshore Niger Delta basin, Nigeria, have been characterized by gas chromatography-mass spectrometry in terms of their origin and thermal maturity based on the distribution of chrysene and its derivatives. The crude oils and source rocks were characterized ...
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Crude oils and source rocks from the northern and offshore Niger Delta basin, Nigeria, have been characterized by gas chromatography-mass spectrometry in terms of their origin and thermal maturity based on the distribution of chrysene and its derivatives. The crude oils and source rocks were characterized by the dominance of chrysene over benzo[a]anthracene. 3-methylchrysene predominated over other methylchrysene isomers in the oils, while 3-methylchrysenes and 1-methylchrysenes were in higher abundance in the rock samples. The abundance and distribution of chrysene and its derivatives allow source grouping of the oils into three families. However, this grouping disagrees with the results obtained from well-established aromatic source grouping parameters. The maturity-dependent parameters computed from chrysene distributions (MCHR and 2- methylchrysene/1-methylchrysene ratios) indicated that the oils have a similar maturity status, while the rock samples are within an immature to early oil window maturity status, which was further supported by other maturity parameters computed from the saturate and aromatic biomarkers and vitrinite reflectance data. The abundance and distribution of chrysene and its derivatives were found to be effective in determining the thermal maturity of crude oil and source rock extracts in the Niger Delta basin, but they may not be a potential source-dependent biomarker in the crude oils and rock extracts from the basin.
