Search for: permeability-and-porosities
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    Experimental investigation of asphaltene-induced core damage during miscible CO2 injection

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Vol. 36, issue. 13 , 2014 , pp. 1395-1405 ; ISSN: 15567036 Bolouri, H ; Ghoodjani, E ; Sharif University of Technology
    In this article, dynamic core flood experiments in miscible CO2 condition were carried out to investigate core damage due to asphaltene deposition. Carbonate and sandstone cores were used to study of effect of core characteristic on permeability and porosity reduction. The experimental results show asphaltene deposition preferentially in sandstone core type takes place in the first half of the core while in the carbonate one it occurs in the second half. In spite of asphaltene content measurement results (IP-143) that show higher asphaltene deposition in sandstone cores, permeability impairment compared to the carbonate one is severe. Also, permeability-porosity reduction models are affected... 

    Application of artificial neural network for estimation of formation permeability in an iranian reservoir

    , Article 1st International Petroleum Conference and Exhibition, Shiraz, 4 May 2009 through 6 May 2009 ; 2009 Yeganeh, M ; Masihi, M ; Fatholahi, S ; Sharif University of Technology
    European Association of Geoscientists and Engineers, EAGE  2009
    The permeability is one of the most important reservoir parameters and its accurate prediction is necessary for reservoir management and enhancement. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs [1], these correlations cannot be modified accurately in carbonate reservoir for the wells which are not cored and there is no welltest data. Therefore estimation of these parameters is a challenge in reservoirs with no coring sample and welltest data. One of the most powerful tools to estimate permeability from well logs is Artificial Neural Network (ANN) whose advantages and disadvantages have been discussed by several authors [2]. In this... 

    Investigation of asphaltene adsorption in sandstone core sample during CO2 injection: Experimental and modified modeling

    , Article Fuel ; Vol. 133 , 2014 , Pages 63-72 ; ISSN: 00162361 Jafari Behbahani, T ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
    In this work, asphaltene adsorption in a sandstone core sample under dynamic conditions and during miscible CO2 injection was studied using live oil sample which is close to real conditions in petroleum reservoirs. In order to investigate of damage in sandstone core sample by the deposited material such as asphaltene, the morphology analysis of sandstone core sample using scanning electron microscopic method was studied. Also analyses of the adsorbed material in sandstone core sample by Soxhlet extraction using an azeotrope mixture and with SARA method were performed. The experimental results show that by increasing the flow rate of injected CO2, the amount of asphaltene in retained material... 

    Specific surface and porosity relationship for sandstones for prediction of permeability

    , Article International Journal of Rock Mechanics and Mining Sciences ; Vol. 71, issue , October , 2014 , p. 25-32 Rabbani, A ; Jamshidi, S ; Sharif University of Technology
    Porosity and specific surface are two prominent factors in describing the hydraulic properties of porous media. Determination of these two important parameters leads to identify the capability of porous media to conduct the fluids. In the present study, a new relationship between porosity and specific surface of sandstones has been developed. Micro-CT data from 10 types of sandstones has been utilized in order to present a porosity-specific surface correlation. This correlation also contains the average grain radius of each rock obtained by image processing algorithms. Finally, the correlation is tested on the provided data to evaluate its precision. The simplicity and applicability of the... 

    Production of drinking water from seawater using membrane distillation (MD) alternative: Direct contact MD and sweeping gas MD approaches

    , Article Desalination and Water Treatment ; Vol. 52, issue. 13-15 , Apr , 2014 , p. 2372-2381 Shirazi, M. M. A ; Kargari, A ; Bastani, D ; Fatehi, L ; Sharif University of Technology
    In this work, two-membrane distillation (MD) modes, direct contact MD, and sweeping gas MD were investigated for synthesized and real (Persian Gulf) seawater desalination. A commercial PTFE membrane with 0.22 μm pore size was characterized (using atomic force microscopy and scanning electron microscopy) and was used for experiments. A multipurpose plate and frame MD module was used for desalination experiments. The effects of various operating conditions and MD module design, as well as feed type on the permeation flux have been studied. The feed temperature was found to be the most effective operating parameter. The flow rate in both sides of the MD module was found to be effective;... 

    Comparison of the membrane morphology based on the phase diagram using PVP as an organic additive and TiO2 as an inorganic additive

    , Article Polymer (United Kingdom) ; Volume 97 , 2016 , Pages 559-568 ; 00323861 (ISSN) Mohsenpour, S ; Safekordi, A ; Tavakolmoghadam, M ; Rekabdar, F ; Hemmati, M ; Sharif University of Technology
    Elsevier Ltd 
    The morphology of symmetric and asymmetric membranes obtained by precipitation can be rationalized by thermodynamic and kinetic parameters. Such parameters which the former relates to thermodynamic effect and the latter controls the time of separation of the cast solution film immersing in the non-solvent bath from the glass plate were calculated as dimensionless parameters for further analysis. Phase diagram was used to consider the role of thermodynamic. The kinetic properties of the membranes could be investigated by the rate of mass transfer between solvent and non-solvent. By adding additives to the polymer solution the desire for becoming two phase and also viscosity of the solution... 

    Optimal input experiment design and parameter estimation in core-scale pressure oscillation experiments

    , Article Journal of Hydrology ; Volume 534 , 2016 , Pages 534-552 ; 00221694 (ISSN) Potters, M. G ; Mansoori, M ; Bombois, X ; Jansen, J. D ; Van den Hof, P. M. J ; Sharif University of Technology
    This paper considers Pressure Oscillation (PO) experiments for which we find the minimum experiment time that guarantees user-imposed parameter variance upper bounds and honours actuator limits. The parameters permeability and porosity are estimated with a classical least-squares estimation method for which an expression of the covariance matrix of the estimates is calculated. This expression is used to tackle the optimization problem. We study the Dynamic Darcy Cell experiment set-up (Heller et al., 2002) and focus on data generation using square wave actuator signals, which, as we shall prove, deliver shorter experiment times than sinusoidal ones. Parameter identification is achieved using... 

    Characterization and estimation of reservoir properties in a carbonate reservoir in Southern Iran by fractal methods

    , Article Journal of Petroleum Exploration and Production Technology ; Volume 8, Issue 1 , 2018 , Pages 31-41 ; 21900558 (ISSN) Rahimi, R ; Bagheri, M ; Masihi, M ; Sharif University of Technology
    Springer Verlag  2018
    Reservoir heterogeneity has a major effect on the characterization of reservoir properties and consequently reservoir forecast. In reality, heterogeneity is observed in a wide range of scales from microns to kilometers. A reasonable approach to study this multi-scale variations is through fractals. Fractal statistics provide a simple way of relating variations on larger scales to those on smaller scales and vice versa. Simple statistical fractal models (fBm and fGn) can be useful to understand the model construction and help the reservoir structure characterization. In this paper, the fractal methods (fGn and fBm) have been applied to characterize and to estimate of reservoir properties.... 

    Analysis of MEOR efficiency to increase recovery in an Iranian reservoir

    , Article Scientia Iranica ; Volume 14, Issue 2 , 2007 , Pages 161-168 ; 10263098 (ISSN) Biria, D ; Roostaazad, R ; Darouneh, E ; Izadi, H ; Sharif University of Technology
    Sharif University of Technology  2007
    Rock samples from the Asmary outcrop formation of the Ahwaz oil rich zone with a porosity of 16% and permeability of 1 md and MIS crude oil with an API value of 42.5 and moderate asphaltene content of 3%, were used to study the effect of the incubation time and flow rate of the displacing fluid in MEOR operations. Five species of rod shaped, gram positive, thermophile and facultative bacteria were isolated and purified from the crude. Due to the high sweep efficiency prevailing in the core flooding system, the effect of the displacing brine flow rate on the oil recovery efficiency was found not to be significant. On the other hand, a 100% increase in incubation time from 7 to 14 days... 

    Experimental study and mathematical modeling of asphaltene deposition mechanism in core samples

    , Article Oil and Gas Science and Technology ; Volume 70, Issue 6 , Nov , 2015 , Pages 1051-1074 ; 12944475 (ISSN) Jafari Behbahani, T ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
    Editions Technip  2015
    In this work, experimental studies were conducted to determine the effect of asphaltene deposition on the permeability reduction and porosity reduction of carbonate, sandstone and dolomite rock samples using an Iranian bottom hole live oil sample which is close to reservoir conditions, whereas in the majority of previous work, a mixture of recombined oil (a mixture of dead oil and associated gas) was injected into a core sample which is far from reservoir conditions. The effect of the oil injection rate on asphaltene deposition and permeability reduction was studied. The experimental results showed that an increase in the oil injection flow rate can result in an increase in asphaltene... 

    An unsteady state retention model for fluid desorption from sorbents

    , Article Journal of Colloid and Interface Science ; Volume 450 , July , 2015 , Pages 127-134 ; 00219797 (ISSN) Bazargan, A ; Sadeghi, H ; Garcia Mayoral, R ; McKay, G ; Sharif University of Technology
    Academic Press Inc  2015
    New studies regarding the sorption of fluids by solids are published every day. In performance testing, after the sorbent has reached saturation, it is usually removed from the sorbate bath and allowed to drain. The loss of liquid from the sorbents with time is of prime importance in the real-world application of sorbents, such as in oil spill response. However, there is currently no equation used for modeling the unsteady state loss of the liquid from the dripping sorbent. Here, an analytical model has been provided for modeling the dynamic loss of liquid from the sorbent in dripping experiments. Data from more than 60 sorbent-sorbate systems has been used to validate the model. The... 

    A pore-level screening study on miscible/immiscible displacements in heterogeneous models

    , Article Journal of Petroleum Science and Engineering ; Volume 110 , 2013 , Pages 40-54 ; 09204105 (ISSN) Mohammadi, S ; Hossein Ghazanfari, M ; Masihi, M ; Sharif University of Technology
    A comprehensive understanding of the role of reservoir heterogeneities induced by flow barriers and connate water on sweep efficiency of different EOR scenarios is rarely attended in the available literature. In this work, different miscible/immiscible EOR processes were conducted on various one-quarter five-spot glass micromodels incorporating small-scale flow barriers. Microscopic and macroscopic observations revealed the reduction of sweep efficiency, premature breakthrough of displacing fluids, the severity of fingering at displacement front which leaves a large amount of oil behind the flow barriers untouched, and significant increasing trend of oil recovery after breakthrough in the... 

    Influence of additives on the morphology of PVDF membranes based on phase diagram: thermodynamic and experimental study

    , Article Journal of Applied Polymer Science ; Volume 135, Issue 21 , 2018 ; 00218995 (ISSN) Mohsenpour, S ; Khosravanian, A ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    In the present study, the morphology of asymmetric poly(vinylidene fluoride) blend membranes which were prepared by the phase inversion method is rationalized by comparing two non-dimensional number represent thermodynamic and kinetic properties of the prepared membrane. These two parameters change phase diagram and demixing rate between solvent and nonsolvent. TiO2 nanoparticles and polyvinylpyrrolidone were used as additives. Hansen solubility parameters of the components are calculated by Van Krevelen method. Furthermore, kinetic and thermodynamic properties of the prepared solutions are determined by drawing phase diagrams and controlling mass transfer rate during precipitation of... 

    Integrated image processing and computational techniques to characterize formation damage

    , Article SPE International Conference and Exhibition on Formation Damage Control 2018, 7 February 2018 through 9 February 2018 ; Volume 2018-February , 2018 Ezeakacha, C. P ; Rabbani, A ; Salehi, S ; Ghalambor, A ; Sharif University of Technology
    Society of Petroleum Engineers (SPE)  2018
    Filtrate and solid invasion from drilling fluids are two key sources of formation damage, and can result in formation permeability impairment. Typically, spurt invasion of mud solids causes the evolution of an external mud cake which tends to reduce further solids and filtrate influx. However, uncontrolled spurt and filtrate invasion are detrimental because they reduce the permeability of the formation. Mud composition, formation rock's permeability and porosity, and temperature can influence both spurt and filtrate invasion. The sizes of mud solids relative to the average pore size of a rock are also important in predicting the extent of mud invasion and permeability impairment. In this... 

    Experimental study of the effect of water to cement ratio on mechanical and durability properties of Nano-silica concretes with Polypropylene fibers

    , Article Scientia Iranica ; Volume 26, Issue 5 A , 2019 , Pages 1-18 ; 10263098 (ISSN) Rahmani, K ; Ghaemian, M ; Hosseini, S. A ; Sharif University of Technology
    Sharif University of Technology  2019
    In the present paper, the effect of Nano silica on mechanical properties and durability of concrete containing polypropylene fibers has been investigated. Here, the length and length to diameter ratio of used polypropylene fibers were considered to be fixed and equal to 18 mm and 600 respectively and the cement content was 479 kg/m3. The effect of fibers and Nano silica in four different percentages for each one at 0.1, 0.2, 0.3 and 0.4 percent by volume for fibers and 3 percent for Nano silica in concrete with water to cement ratio of 0.33, 0.36, 0.4, 0.44 and 0.5 have been compared and evaluated. In total, more than 425 cubic and cylindrical specimens were made according to ASTM standards.... 

    Numerical simulation of proppant transport and tip screen-out in hydraulic fracturing with the extended finite element method

    , Article International Journal of Rock Mechanics and Mining Sciences ; Volume 128 , 2020 Hosseini, N ; Khoei, A. R ; Sharif University of Technology
    Elsevier Ltd  2020
    In this paper, a numerical model is developed based on the X-FEM technique to simulate the proppant transport and tip screen-out in hydraulic fracturing. The governing equations are based on the momentum balance and mass conservation of the fluid. The hydro-mechanical coupling between the fracture and surrounding porous medium is fulfilled through the weak form of the governing equations. The fluid inflow within the fracture is modeled using the one-dimensional mass conservation of the injected slurry and proppant along the fracture, in which the viscosity of the slurry is dependent on the proppant concentration. The transition from the Poiseuille to Darcy flow regime is incorporated into... 

    A meta-model analysis of a finite element simulation for defining poroelastic properties of intervertebral discs

    , Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 227, Issue 6 , 2013 , Pages 672-682 ; 09544119 (ISSN) Nikkhoo, M ; Hsu, Y. C ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
    Finite element analysis is an effective tool to evaluate the material properties of living tissue. For an interactive optimization procedure, the finite element analysis usually needs many simulations to reach a reasonable solution. The metamodel analysis of finite element simulation can be used to reduce the computation of a structure with complex geometry or a material with composite constitutive equations. The intervertebral disc is a complex, heterogeneous, and hydrated porous structure. A poroelastic finite element model can be used to observe the fluid transferring, pressure deviation, and other properties within the disc. Defining reasonable poroelastic material properties of the...