Sharif Digital Repository

Considering the wide range of applications of porous media for heat transfer enhancement in various components of industrial machineries, including solar collectors, air dryers, compact heat exchangers, electronic microchips, investigation of heat transfer characteristics in porous media has been a major concern for many researchers. On the other hand, precise understanding of the physics of porous media-flow interaction has been an open research topic for a long time. The present research however, has aimed at developing a computational method to simulate the interaction between fluid flow and porous media to investigate heat transfer from prously covered surfaces. Pore scale modeling of... 

In recent years, application of porous media is highlighted among researchers due to their wider use in micro-scale problems, such as in gas reservoirs, micro-filtering, and heat exchangers. In such applications, accurate description of flow behavior, using governing equations based on continuum assumption, is not valid, since mean free path has the same order as the characteristic length of the problem. In such cases, imposing appropriate slip condition on the fluid-solid interface of porous media (in pore-scale level), based on kinetics theory, is an appropriate approach. For this purpose, pore-scale simulation of flow inside porous media in slippery and transient regimes is carried out... 

During all operations in oil and gas reservoirs, it is possible to cause formation damage. These damages can greatly reduce the rate of production. One of the major damages that can seriously affect the performance of a reservoir is the damage caused by drilling fluid. The main purpose of this thesis is to study the main mechanisms of formation damage caused by water-based drilling fluid using a glass micromodel for the first time. An accurate understanding of the mechanisms of formation damage can provide a good understanding of the selection of the type and concentration of materials used, as well as appropriate methods to control and eliminate damages. for controlling the drilling fluid... 

Most of oil content, especially in Iran, has been reserved in fractured reservoirs, so study and modeling of production mechanism of these reservoirs are great of importance. Gravity drainage is one of these effective production mechanisms in fractured porous media which dynamic pore scale modeling of this mechanism will lead to better understanding of it. In this work, the effects of variety of parameters such as oil gravity, interfacial tension between oil and gas, pore and throat size distribution, fracture aperture, and block to block interaction (capillary continuity and reinfiltartion) have been investigated. So developed simulator in this work has two main and separated parts, which... 

Matrix acidizing aims at bypassing near wellbore damages in typical carbonate reservoirs or enhancing permeability and hydraulic conductivity in naturally fracture ones. The simulation of acidizing process at pore scale and complex geometries by LBM will lead to gain more knowledge about molecular mechanisms that govern rock dissolution, diffusion and advection of reactive fluid and help the evaluation of acidizing efficiency.In this thesis, simulation of acidizing includes the following steps:
• Multicomponent fluid convection
• Fluid diffusion into the solid
• Fluid-rock reaction
• Boundary conditions including periodic, bounceback, non-equilibrium bounceback, Dirichlet,... 

Oil composition plays an undeniable role on the low salinity water flooding (LSWF) efficiency. This property directly affects the kinetics of wettability alteration through electrostatic interactions and interfacial tension (IFT). For instance, mixing in stagnant zones through a thin water film is considered as one of the most important diffusion controlled phenomenon which is goverened by Non-Fickian solute transport model. The major two potentials controlling the solute transport in thin film are salinity gradient and electrostatic potentials, which can be affected by oil composition and surface charges. This study aims to investigate the effect of oil composition on low salinity... 

Acidizing as the most frequent stimulation technique in the field, has been extensively used to increase the production rate. Even though acidizing treatments is well established, there is still an inherent risk for self-induced formation damage through incompatibilities of the fluids involved in this process.
A main potential problem during acidizing is the incompatibility of the acid and the reservoir’s crude oil. Acid interaction with crude oil can produce two major damage mechanisms that could offset partially, if not totally the benefit of the acid stimulation. These mechanisms are the rigid film emulsion formation and the acid-sludge precipitation, result in well productivity... 

In the recent two decades Lattice Boltzmann method has been introduced as a class of computational fluid dynamic methods for fluid simulation. In this method instead of solving Navier-Stocks equation, Boltzmann equation is solved to simulate the flow of a fluid. This method originally was developed based on uniform grids which makes lattice Boltzmann a time consuming technique. This feature already exists in the case of simulation of fluid flow in porous media. To eliminate this limitation some research has been done on methods to formulate lattice Boltzmann on unstructured grids. On the basis of this research a method on non-uniform grids has been selected. Here using object oriented... 

The study of porous media, especially in pore-scales (micro and nano scales), is of particular importance in various sciences such as petroleum engineering, chemical, and civil engineering. Determine the physics of the pore scale to understand it better, identify the conditions for it to enforce the laws better, and explain some of the phenomena unknown so far, and finally obtain the parameters performed in the laboratory for specific samples are the main goals of these studies. One of the most well-known methods for analyzing porous media is pore network modeling. These models are always affected by the macroscopic structure of porous media, such as their multiscale state. In this study, an... 

Mass or large-scale storage of hydrogen, as a clean source of energy, should be conducted in underground formations in order to be used as a reliable energy source at the peak of consumption. In this regard, underground formations such as aquifers and depleted hydrocarbon reservoirs are the most favorable and secured media for hydrogen storage. However, detailed understanding of the flow dynamics of hydrogen-water in these media is critical to maximize hydrogen storage and recovery and tackle the existing uncertainities which exist in the flow functions. To fill this gap, this research aims at a detailed pore-scale investigation of the effect of flow regime, hydrogen compressibility, and...