Chemical Engineering
Mansoor Naderi; Ghasem Zargar; Ebrahim Khalili
Abstract
Heat EXchangers (HEX) that are used in City Gate Station (CGS) systems are modeled numerically to recover the exhaust waste heat. It was tried to find the best viscous model to obtain results in accordance with experimental results and to change the heat exchanger design. This HEX is used for recovering ...
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Heat EXchangers (HEX) that are used in City Gate Station (CGS) systems are modeled numerically to recover the exhaust waste heat. It was tried to find the best viscous model to obtain results in accordance with experimental results and to change the heat exchanger design. This HEX is used for recovering heat from exhaust flue gas with a mixture of 40% water and 60% ethylene glycol as the cooling fluid. Then, the effects of sizes and numbers of fins and tube rows on recovered heat rate were investigated under various pump speeds. As the first step in solving the problem, SST k–ω and RNG k–ε suitable viscous models were chosen for these kinds of problems. Secondly, a new HEX is designed at a fixed coolant speed, pipe and fin thickness, and shell dimension because of operational constraints. Finally, the best HEX with the minimum pressure drop (minimum fin number) is numerically analyzed, and the new HEX specifications were extracted.
Masoumeh Bashiri; Mosayyeb Kamari; Ghassem Zargar
Abstract
Water saturation and cation exchange capacity are the most significant parameters used to calculate a hydrocarbon zone potential. In clean formations, by applying the famous Archie model, which assumes that in the formation the only electric conductor is the formation water, the water saturation can ...
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Water saturation and cation exchange capacity are the most significant parameters used to calculate a hydrocarbon zone potential. In clean formations, by applying the famous Archie model, which assumes that in the formation the only electric conductor is the formation water, the water saturation can be calculated. Additionally, in shaly sand formations this assumption may not be true as the ions are associated with clay minerals and transport electricity. We attempt to utilize some logs, as well as experimental data, to improve the water saturation calculations and the cation exchange capacity within shaly sand layers for an Iranian oil field. Therefore, several shaly sand models were considered for the calculations of these values for three wells of the Ahvaz oil field. The validity of the different models was controlled through the measured values of cation exchange capacity and water saturation on core samples. The comparative results show that cation exchange capacity and water saturation calculated using Ipek-Bassiouni model are more indicative of zone hydrocarbon potential with correlation coefficients of 0.91 and 0.95 respectively. The results of this study show the requirement for the I-B model in studied reservoir and its superiority compared to other models because it is on the basis of principles reflecting the formation water and clay counter ions conductive behavior. Concerning to this model, two cement exponents are incorporated to illustrate the electric current path tortuosity in clay bound water and free water. In the current work, cementation exponent in free water (mf) and clay bound water (mc) were estimated from pure shale and clean sand respectively. The results of this study are promising and can be simply extended in other similar neighboring shaly sand reservoirs.
Edris Junaki; Shima Ghanaatian; Ghasem Zargar
Abstract
A new chemical compound is developed at Petroleum University of Technology to enhance the recovery of the free imbibition process and simultaneously hinder asphaltene precipitation. The compound is tested on heavy oil samples from Marun oil field, Bangestan reservoir. The effects of the chemical compound ...
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A new chemical compound is developed at Petroleum University of Technology to enhance the recovery of the free imbibition process and simultaneously hinder asphaltene precipitation. The compound is tested on heavy oil samples from Marun oil field, Bangestan reservoir. The effects of the chemical compound on viscosity, hydrocarbon composition, and average molecular weight of the heavy oil are investigated. It is found that the substance dramatically reduces oil viscosity and molecular weight and hinders the precipitation of asphaltene in the heavy oil. The results of free imbibition tests demonstrate a significant recovery enhancement after oil reacts with the compound and is used in water in an Amott cell. Finally, the new chemical compound causes a significant reduction in surface tension and contact angle. This is verified by the molecular analysis of heavy oil after reacting with this ionic compound.
Ahad Fereidooni; Masoud Fereidooni; Siyamak Moradi; Ghasem Zargar
Abstract
Enhanced oil recovery using nitrogen injection is a commonly applied method for pressure maintenance in conventional reservoirs. Numerical simulations can be practiced for the prediction of a reservoir performance in the course of injection process; however, a detailed simulation might take up enormous ...
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Enhanced oil recovery using nitrogen injection is a commonly applied method for pressure maintenance in conventional reservoirs. Numerical simulations can be practiced for the prediction of a reservoir performance in the course of injection process; however, a detailed simulation might take up enormous computer processing time. In such cases, a simple statistical model may be a good approach to the preliminary prediction of the process without any application of numerical simulation. In the current work, seven rock/fluid reservoir properties are considered as screening parameters and those parameters having the most considerable effect on the process are determined using the combination of experimental design techniques and reservoir simulations. Therefore, the statistical significance of the main effects and interactions of screening parameters are analyzed utilizing statistical inference approaches. Finally, the influential parameters are employed to create a simple statistical model which allows the preliminary prediction of nitrogen injection in terms of a recovery factor without resorting to numerical simulations.
