Sharif Digital Repository

Miscible displacement in fluid flowing through a porous medium plays an important role in many environmental and industrial applications; for instance, miscible displacements in enhanced oil recovery processes and pollutant spreading in groundwater. A large number of numerical approaches have been developed to solve the advection-dispersion equation that describes the behavior of miscible displacement in porous media. Most of these numerical models suffer from numerical dispersion. Random walk seems to be an effective method to overcome this problem especially in heterogeneous media. Here, a random walk model was developed and used for simulating miscible displacement in heterogeneous porous... 

In this study, single-phase and two-phase, incompressible flow in a non-deformable porous media was modeled and also simulated. The Reynolds numbers have been considered high enough to justify the use of the model including inertial terms. Afterwards, the mass conservative equations were discretized. Then, the numerical model has been developed for heterogeneous porous media. The heterogeneous porous media was comprised by several specified homogeneous regions, each having isotropic transport properties or permeability distribution with applying stochastic methods. The developed numerical model was used for predicting of saturation profile in water flooding process in one, two and... 

In this work, flow transport, distribution, and dissolution of non-aqueous phase liquids (NAPLs) in heterogeneous porous media were modeled by focusing on the dissolution process in pore-level and field scale. First, by adopting advection-diffusion and mass transfer equations, dissolution process and NAPL distribution were investigated in a heterogeneous porous media using pore network modeling. The 2-D developed model was based on observations of micromodel tests. The pore scale simulator which adopted by this work was improved in some aspects in comparison to previous models in the literatures. First, in the phase displacement, by considering more realistic geometries for pore structure... 

The aim of this work is numerical analysis of wave propagation in earth by using spectral element method for single and multi phase with application in oil industry. In this method, numerical solution has high accuracy due to using high order polynomials and appropriate integration points. Also, the mass matrix is diagonal by using this method which results in considerable decrease in computational cost with respect to finite element method.
The wave propagation in the mentioned models is studied by many researchers. The main problem in petroleum industry is large dimension of the model which results in high computational costs. Thus, using the proper numerical approach for these... 

Upscaling is an important step in hydrocarbon reservoir modeling which reduces the number of grid blocks of high detailed geological models to prepare them for flow simulation. This helps to speed up computational process, to keep the simulation (CPU) time within a reasonable range and to make future engineering analysis (history matching, comparison of production scenarios, Monte Carlo simulation and etc.) possible. The accuracy of post processing analysis heavily depends on the robustness and validation of the applied upscaling method. Although numerous methods have been proposed in the literature, overemphasizing the effect of scale on the behavior of complex governing equations has... 

In this work, a pore-scale analysis of nonaqueous phase liquid (NAPL) flow, transport, dissolution, and mobilization in heterogeneous and homogeneous porous media was presented. First, dissolution processes and distribution of NAPL phase were investigated using micromodel experiments. The tests were conducted at different injection rates in NAPL-saturated porous media using distilled water, surfactant, and nanoparticles-assisted surfactant. Changes in residual NAPL volume and interfacial area were measured using image analysis method to calculate the mass transfer coefficient, k, and the lumped mass transfer rate coefficient, K. Based on the experimental results, empirical Sherwood... 

Today, due to a massive increase in accuracy of reservoir characterization models, multiphase flow simulation on real permeability fields faces a serious challenge. Using multiscale methods in reservoir flow simulation of a heterogeneous environment has led to huge speed-up of the simulation. In multiscale methods, instead of replacing a heterogeneous medium by an equivalent homogeneous medium, used in upscaling, the problem is solved on the original resolution. In this thesis, multiscale finite volume method (MSFV) has been used to simulate flow and saturation behavior of a black oil model. Unlike the original multiscale finite volume methods that were unable to solve compressible fluid... 

Multi-Scale finite volume (MSFV) method have been developed and applied for multiphase flow in porous media. The most important advantage of MSFV method is its computational efficiency. In this thesis we apply and implement this method to porous media simulation. Then, computational parameters such as coarsening ratio, effect of threshold on adaptive computation and different boundary conditions for computing basis functions are investigated. The two difficulties of sMSFV method are problems with high permeability contrast and problems with high course grid aspect ratio which are considered. In standard MSFV (sMSFV) method reduced boundary condition is used to determine the basis and... 

Dense non-aqueous phase liquid accounts for a large share of groundwater pollution. In oil-rich countries, including Iran, the emission of this type of pollutant is mainly through leakage from concrete and steel tanks belonging to refineries and gas stations. The dissolution of these pollutants in groundwater and the vapor intrusion into residential homes increased the importance of developing efficient treatment methods. To choose the best method, it is necessary to gain sufficient knowledge of how these types of contaminants are distributed in the subsurface and how contaminants change and move over time. Heterogeneity, especially in the form of fracture, is one of the challenges to... 

The swelling phenomenon in the porous media causes many problems in various engineering issues, including foundation construction and oil and gas extraction. For this reason, in the last few decades, flow modeling in reactive porous media and investigation of coupled hydro-chemo-mechanical problems have attracted a lot of attention. On the other hand, despite the simplifications, porous media have a heterogeneous structure, and the numerical modeling of these heterogeneities directly increases the computational costs. A suitable method for modeling heterogeneous problems is the computational homogenization method. In this method, the problem is solved in two scales in a correlated manner and...