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Performance improvement of ionic surfactant flooding in carbonate rock samples by use of nanoparticles

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Petroleum Science 2016年第4期13卷 725-736页

作者： Mohammad ali ahmadi James Sheng Department of Petroleum Engineering Ahwaz Faculty of Petroleum Engineering Petroleum University of Technology Petroleum Department Texas Tech University

Various surfactants have been used in upstream petroleum processes like chemical flooding. Ultimately, the performance of these surfactants depends on their ability to reduce the interfacial tension between oil and water. The surfactant concentration in the aqueous solution decreases owing to the loss of the surfactant on the rock surface in the injection process. The main objective of this paper is to inhibit the surfactant loss by means of adding nanoparticles. Sodium dodecyl sulfate and silica nanoparticles were used as ionic surfactant and nanoparticles in our experiments, respectively. AEROSIL~？ 816 and AEROSIL~？200 are hydrophobic and hydrophilic nanoparticles. To determine the adsorption loss of the surfactant onto rock samples, a conductivity approach was used. Real carbonate rock samples were used as the solid phase in adsorption experiments. It should be noted that the rock samples were water wet. This paper describes how equilibrium adsorption was investigated by examining adsorption behavior in a system of carbonate sample（solid phase） and surfactant solution（aqueous phase）. The initial surfactant and nanoparticle concentrations were 500–5000 and 500–2000 ppm, respectively. The rate of surfactant losses was extremely dependent on the concentration of the surfactant in the system, and the adsorption of the surfactant decreased with an increase in the nanoparticle concentration. Also, the hydrophilic nanoparticles are more effective than the hydrophobic nanoparticles.

关键词： Adsorption Hydrophobic silica nanoparticles Hydrophilic silica nanoparticles Ionic surfactant Carbonate rock

Comparison of machine learning methods for estimating permeability and porosity of oil reservoirs via petro-physical logs

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Petroleum 2019年第3期5卷 271-284页

作者： Mohammad ali ahmadi Zhangxing Chen Department of Chemical and Petroleum Engineering University of CalgaryCalgaryCanada

This paper deals with the comparison of models for predicting porosity and permeability of oil reservoirs by coupling a machine learning concept and petrophysical *** machine learning methods including conventional artificial neural network,genetic algorithm,fuzzy decision tree,the imperialist competitive algorithm(ICA),particle swarm optimization(PSO),and a hybrid of those ones are employed to have a comprehensive *** machine learning approach was constructed and tested via data samples recorded from northern Persian Gulf oil *** results gained from the machine learning models used in this paper are compared to the relevant real petrophysical data and the outputs achieved by other methods employed in our previous *** average relative absolute deviation between the approach estimations and the relevant actual data is found to be less than 1%for the hybridized *** results reported in this paper indicate that implication of hybridized machine learning methods in porosity and permeability estimations can lead to the construction of more reliable static reservoir models in simulation plans.

关键词： Machine learning Neural network Support vector machine Porosity Permeability Well logs Petro-physic

Working Mechanism of a BC_3 Nanotube Carbon Monoxide Gas Sensor

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Communications in Theoretical Physics 2013年第7期60卷 113-118页

作者： ali ahmadi Peyghan Sirous Yourdkhani anMaziar Noei Chemistry Department Central Tehran Branch Islamic Azad University Chemistry Department Garmsar Branch Islamic Azad University Department of Chemistry Mahshahr Branch Islamic Azad University

Carbon and BN nanotubes have previously demonstrated extreme sensitivity to several molecules, but they cannot be used to detect highly toxic molecules of CO. In this work, we examine the possibility of a BC3 nanotube (BC3NT) as a potential gas sensor for CO detection by using density functional theory calculations. It is found that CO molecule can be absorbed on B and C atoms of BC3 NT wall with adsorption energies in the range of 1.0 to 25.9 kcal/mol and it can donate finite charge to the tube. By comparing the HOMO/LUMO energy gaps of the bare and CO adsorbed nanotubes, we deduce that molecular CO can induce significant change in the electrical conductivity of the tube. The conductivity change can generate an electrical signal, which might be useful for CO detection.

关键词： sensor boron carbide nanotubes DFT carbon monoxide

First Principles Study on Encapsulation of Alkali Metals into ZnO Nanocage

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Chinese Journal of Chemical Physics 2012年第6期25卷 671-675,I0003页

作者： Mohammad T. Baei ali ahmadi Peyghan Zargham Bagheri Department of Chemistry Azadshahr Branch Islamic Azad University Azadshahr Golestan Iran Young Researchers Club Islamic Azad University Islamshahr Branch Tehran Iran Physics Group Science Department Islamic Azad University Islamshahr Branch P.O. Box: 33135-359 Islamshahr Tehran Iran

Encapsulation of alkali metals （Li, Na, K, and Rb） into Zn12O12 nanocage has been inves- tigated using density functional theory. Encapsulation of Li and Na atoms is found to be thermodynamically favorable at 298 K and 100 kPa, with negative Gibbs free energy change AG of about -130.12 and -68.43 kJ/mol, respectively. By increasing the size of encapsu- lated atom the process become less favorable so that in the cases of K and Rb encapsulations the AG values are positive. The results indicate that the LUMO, Fermi level, and specially HOMO of the cluster are shifted to higher energies so that the HOMO-LUMO gap of the cluster is significantly narrowed in all the cases. After encapsulation of the alkali metals the work function of cluster is decreased due to the shift of the Fermi level to higher energies. Therefore, the emitted electron current density from the Zn12O12 cluster will be increased.

关键词： Density functional theory Nanocluster Nanostructure Adsorption

Low-cost fault tolerance in evolvable multiprocessor systems:a graceful degradation approach

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 922-926页

作者： Shervin VAKILI Sied Mehdi FAKHRAIE Siamak MOHAMMADI ali ahmadi School of Electrical and Computer Engineering University of Tehran

The evolvable multiprocessor (EvoMP), as a novel multiprocessor system-on-chip (MPSoC) machine with evolvable task decomposition and scheduling, claims a major feature of low-cost and efficient fault tolerance. Non-centralized control and adaptive distribution of the program among the available processors are two major capabilities of this platform, which remarkably help to achieve an efficient fault tolerance scheme. This letter presents the operational as well as architectural details of this fault tolerance scheme. In this method, when a processor becomes faulty, it will be eliminated of contribution in program execution in remaining run-time. This method also utilizes dynamic rescheduling capability of the system to achieve the maximum possible efficiency after processor reduction. The results confirm the efficiency and remarkable advantages of the proposed approach over common redundancy based techniques in similar systems.

关键词： Fault tolerance Multiprocessor system-on-chip (MPSoC) Genetic algorithm (GA) Adaptive task scheduling

A computational study of AlN nanotube as an oxygen detector

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Chinese Chemical Letters 2012年第8期23卷 965-968页

作者： Mohammad T.Baei ali ahmadi Peyghan Zargham Bagheri Department of Chemistry Azadshahr BranchIslamic Azad UniversityAzadshahrGolestanIran Young Researchers Club Islamic Azad UniversityIslamshahr BranchTehranIran Physics group Science departmentIslamic Azad UniversityIslamshahr BranchP.O.Box:33135-369TehranIran

Interaction of O2 molecule and a zigzag aluminum nitride nanotube（AlNNT） was studied based on the density functional *** O2 molecule is adsorbed on the surface of AlNNT with the adsorption energies in the range of 11.0 to 12.1 kJ/*** structure of the AlNNT remains intact in the presence of oxygen molecule while its electronic structure dramatically changes so that its HOMO（or SOMO）-LUMO gap is approximately reduced to half of its original *** suggests that the AlNNT may be used as a gas sensor for the O2 detection.

关键词： Ab initio Electronic structure DFT Sensor

Sensing behavior of BN nanosheet toward nitrous oxide: A DFT study

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Chinese Chemical Letters 2015年第8期26卷 1042-1045页

作者： Marjaneh Samadizadeh ali ahmadi Peyghan Somayeh F.Rastegar Department of Chemistry Islamic Azad University Central Tehran Branch Young Researchers and Elite Club Central Tehran Branch Islamic Azad University

In order to develop a sensor for the detection of toxic N2O molecules, the interaction of pristine and Aldoped BN nanosheets with an N2O molecule was investigated using density functional theory calculations. It was found that unlike the pristine sheet, the Al-doped sheet can effectively interact with the N2O molecule so that its electronic properties and conductivity are dramatically changed. We believe that replacing a B atom of the BN sheet with an Al atom may be a good strategy for improving the sensitivity of these nanosheets toward N2O, which cannot be trapped and detected by the pristine sheet.

关键词： toward sheet trapped reserved unlike interact dramatically doping Wales adsorbed

Robust correlation to predict dew point pressure of gas condensate reservoirs

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Petroleum 2017年第3期3卷 340-347页

作者： Mohammad ali ahmadi Adel Elsharkawy Department of Petroleum Engineering Ahwaz Faculty of Petroleum EngineeringPetroleum University of TechnologyAhwazIran Department of Petroleum Engineering College of Engineering&PetroleumKuwait UniversityKuwait

When the bottom-hole flowing pressure in a gas condensate reservoir drops below the dew point pressure,liquid starts to build up around the well bore resulting in gas productivity *** this reason it is important to be able to accurately either measure or estimate the dew point *** condensate formed in the reservoir will not flow until its saturation reaches the critical saturation and in many cases it might not be entirely *** order to maximize gas production and condensate recovery,the reservoir pressure must be maintained close to the dew point *** attempts have been made to predict the dew point pressure in case the gas sample becomes unavailable or measured value is ***,most of these attempts have minor success rates and are based on limited *** this paper we present a robust,cheap,and easy model for predicting the dew point pressure for gas condensate *** new model is an intelligent based model called“Gene Expression Programming”that is carried out to generate a precise and accurate correlation to estimate the dew point pressure in condensate gas *** new model has been trained and tested using a large data bank collected for the *** of the suggested correlation has been compared to published *** validity of this model has also been compared to experimental data and other published correlations.

关键词： Dew point pressure Gene Expression Programming Condensate gas Modeling

A predictive model of chemical flooding for enhanced oil recovery purposes:Application of least square support vector machine

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Petroleum 2016年第2期2卷 177-182页

作者： Mohammad ali ahmadi Maysam Pournik Department of Petroleum Engineering Ahwaz Faculty of Petroleum EngineeringPetroleum University of TechnologyAhwazIran Department of Petroleum Engineering Mewbourne School of Petroleum and Geological EngineeringUniversity of OklahomaOklahomaUnited States

Applying chemical flooding in petroleum reservoirs turns into interesting subject of the recent *** strategies of the aforementioned method are more robust and precise when they consider both economical point of views(net present value(NPV))and technical point of views(recovery factor(RF)).In the present study huge attempts are made to propose predictive model for specifying efficiency of chemical flooding in oil *** gain this goal,the new type of support vector machine method which evolved by Suykens and Vandewalle was ***,high precise chemical flooding data banks reported in previous works were employed to test and validate the proposed vector machine *** to the mean square error(MSE),correlation coefficient and average absolute relative deviation,the suggested LSSVM model has acceptable reliability;integrity and ***,the proposed intelligent based model can be considered as an alternative model to monitor the efficiency of chemical flooding in oil reservoir when the required experimental data are not available or accessible.

关键词： Chemical flooding Enhanced oil recovery(EOR) Polymer Surfactant Least square support vector machine (LSSVM)