مهندسی عمران - ژئوتکنیک
دانشگاه صنعتی خواجه نصیرالدین طوسی،
اینجانب احسان طاهری دکتری عمران-مکانیک خاک و پی هستم. تخصص اینجانب مدلسازی مخازن نفتی، مدلسازی چند مقیاسی و مدل های رفتاری خاک و سنگ می باشد.
Reservoir formations exhibit a wide range of heterogeneity from micro to macro scales. A simulation that involves all of these data is highly time consuming or almost impossible; hence, a new method is needed to meet the computational cost. Moreover, the deformations of the reservoir are important not only to protect the uppermost equipment but also to simulate fluid pattern and petroleum production strategy. In this regard, multiscale multiphysic mixed geomechanical model (M 3 GM) is recently developed. However, applications of petroleum reservoirs through gas or water injection in the depleted reservoir are in concern. In the present paper, a multiscale finite volume framework and a finite element method are employed to simulate fluid flo
Fluid transport in petroleum reservoirs occurs on at a wide range of scales that involve multiple physics. Flow simulation with respect to all scales and interactions with the solid phase is computationally expensive, if not impossible. The recently developed Multiscale Multiphysic Mixed Geomechanical Model (M 3 GM) overcomes this deficiency with respect to porous media deformation. However, its application to practical problems requires extensions that enable it to deal with surrounding strata and actual geomechanical boundary conditions. This paper discusses first the combination of multiscale finite-volume (MSFV) and finite-element frameworks for simulation of fluid transport and soil deformation. Then it describes the interaction of mul
Reservoir formations typically display high degrees of spatial variations over multiple length scales. Moreover, several physical phenomena affect the flow pattern in different hierarchies. However, a full description of flow and deformation that includes all these scales exceeds the current computational capabilities. To overcome this deficiency, each physical effect should be treated separately on its area of influence. In the present article, the fluid transport and deformation of porous media are determined through separate frameworks in different scales. The finite element method is combined with multiscale finite volume (MSFV) to solve the solid equilibrium and fluid flow equations. Interactions between soil and fluid multiscale frame
The Multiscale Finite Volume (MSFV) has been recently utilized in order to solve elliptic and parabolic equations. Oil transport in porous media is the major topic of this field. In multiscale framework pressure and saturation equations are managed separately. In order to have complete property of pressure distribution parabolic nature of pressure equation is considered. In this paper the advanced features of Multiscale is cleared in compare with other computational methods. This model is applied for both isotropic and anisotropic media. New trend of Progressive Parabola Strategy (PPS) technique is introduced to solve anisotropic media or domain with high aspect ratio. Finally the model is compared with fine scale reference solution and rea
Polycyclic aromatic hydrocarbons (PAHs) are types of hazardous contaminants, which their ingestion could cause severe consequences on human health. Leakages from storage tanks, underground pipelines, and evaporation ponds are the main sources of soil and groundwater contaminations at the Tehran Oil Refinery area (TOR site), located in south of Tehran, Iran. In this study, soil samples were collected from different locations at and adjacent to a polluted stream in the south of the refinery. The samples were analyzed for two hazardous PAH compounds, namely benzo[a]anthracene and acenaphthene. The clean up levels due to the accidental ingestion of contaminated soils at the site were also investigated in accordance to the U.S.EPA guidelines. C
Â Stock Return Volatility and the factors that affect on it are the controversial subjects in financial research. Institutional Investors as a group of investors, who access to huge financial resources, have an important role in economic and capital market development. On this basis, study about institutional investor's role in stock returns volatility is necessary. This paper is tended to find evidence in support of relationship between institutional investors and stock return volatility. This relationship is examined based on two theories in Tehran Stock Exchange: Efficient monitoring and convergence of interests. This study is descriptive-correlation based on cross sectional data. The final sample includes 121 of listed companies in T
Stock Return Volatility and the factors that effect on it are the controversial subjects in financial research. Institutional Investors as a group of investors, who access to huge financial resources, have an important role in economic and capital market development. On this basis, study about institutional investor's role in stock returns volatility is necessary. This paper is tended to find evidence in support of relationship between institutional investors and stock return volatility. This relationship is examined based on two theories in Tehran Stock Exchange: Efficient monitoring and convergence of interests. This study is descriptive-correlation based on cross sectional data. The final sample includes 121 of listed companies in Tehran
Leakage of petroleum compounds from Tehran Oil Refinery (TOR) has caused soil contaminations in this area. These compounds can enter the groundwater and cause direct or indirect hazardous effects.
Polyaromatic hydrocarbons (PAHs) are types of hazardous and carcinogenic compounds that their inhalation could have adverse effects on human health. Leakage from oil refinery facilities such as storage tanks, underground oil pipelines and evaporation ponds are the means of contaminants leaking to the environment, particularly to soils and groundwater. In this research, due to the widespread oil's leakages occurring in Tehran oil refinery in Shahre-Ray, Iran, soil samples were collected from different contaminated locations in the south of the refinery. The samples were analyzed for two PAH compounds, namely benzo (a) pyrene and benzo (k) fluoranthene. Physical and hazardous characteristics of the contaminants were evaluated based on geotech
Leakage of petroleum compounds around the Tehran Oil Refinery (TOR) for the past 30 years has caused oil pollutants to spread in a large area around this refinery, Therefore, remediation of the soil in this area is on the priority necessity. In the present paper, in order to obtain a better site perception, gas chromatography analysis and permeability tests were conducted on soil samples. Measurement shows the present concentrations of Benzo [a] Pyrene between 108 to 638 ppm that is 800 to 5000 times higher than the clean up level (120 ppb). Due to clayey texture and low permeability of the soils that ranges between 5.5? 10-6 to 7.3? 10-6 (cm/s), the low volatility of Benzo [a] Pyrene with Henry’s constant equal to 4.63? 10-5 (dimless) an
Leakage of petroleum constituents in the areas around Tehran Oil Refinery (TOR) has caused the hydrocarbon constituents to spread around this site. Poly aromatic hydrocarbons (PAHS) are a large group of petroleum compounds, which could be harmful for human if they are inhaled, ingested, or absorbed by the skin. In this research, 16 soil samples were collected from the south of TOR around the polluted stream with grid sampling method and 3 samples from the center of the stream. The research followed by gas chromatography analysis of the PAHs contaminants. Analyses indicate high concentration of pollutants in this area. Two hazardous PAH compounds namely; naphtalene and fluoranthene were evaluated. Physical and hazardous characteristics of th
In present paper Multiplane unified model for clay and sand incorporating strain anisotropy is presented. This model is relied on critical state concept. Bounding surface plasticity is also applied due to better prediction of cyclic behavior of soil. In order to consider anisotropy, 17 planes are adopted in related directions. Considering 17 planes not only satisfy stress equilibrium but also meet compatibility condition. The result shows good agreement between experimental results and Multiplane model. Present model is also capable of predicting shear band and fracture direction in soil with cyclic loading. Moreover regarding its unified nature it can be applied for highly heterogeneous soil via considering different parameters in differen
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