Sharif Digital Repository

Additive manufacturing technology (AM) is one of the new methods of rapid prototyping. Experts claim that using this process can produce a prototype of the product with any complex geometry in the shortest possible time. Among the methods of metal additive fabrication, the direct metal layering method with the powder coaxial nozzle has different capabilities and has received much attention by researchers. In this research, we intend to find a relationship between device parameters and the geometry of samples made by direct metal layer method. According to the research, many parameters affect the quality of the samples made by this method, the most effective of which are the three parameters... 

A significant amount of research in self-consolidating concrete technology is being placed in evaluating the suitability of the material for use in structural applications. However, research is needed to confirm the ability of self-consolidating concrete structural elements to adequately resist vertical and lateral loads. In a reinforced concrete building subjected to earthquake type loading, the beam to column connections constitute one of the critical regions and they must be designed and detailed to dissipate large amounts of energy without a significant loss of stiffness or strength. In the experimental part of this study, four full size interior beam-column subassemblages with 3.0 m... 

Asphaltenes are a polydisperse mixture of the heaviest and most polarizable fractions of the crude oil. They are defined according to their solubility properties as being soluble in aromatic solvents but insoluble in light paraffin solvents. Asphaltenes are usually responsible for many problems like wettability changes of the reservoir rock, pore clogging in the reservoir porous matrix and fouling in wellbore tubing and production surface facilities. Most of the studies in the literature, addressing the asphaltene precipitation and deposition (APD), are investigating natural depletion or gas injection process such as CO2 flooding. These studies show that asphaltene deposition and... 

One of the main purposes of this project is to propose an efficient and stable algorithm of a semi-discretized formulation for compositional simulation of oil reservoirs. In this algorithm, all the equations including both mass balances and equilibrium equations are solved simultaneously. The gradient terms are discretized by the Finite Volume Method (FVM). The resulting Differential Algebraic Equation, the so-called DAE, are solved by MATLAB functions. Another novel technique developed, handles each block equations set, separately. In this block-by-block scheme, there are two set of equations; the primary (mass balance) and secondary (equilibrium) equations. In the primary ones, the... 

As the reservoir matures, especially in fractured reservoirs, oil production is usually accompanied by the production of some unwanted water. Water production causes environmental problems and imposes high costs on the production system, including the cost of separating water and oil, corrosion of facility, and sometimes, leading to abandoning well. One way to solve this problem is to use gels as a blocking agent. Today, preformed particle gels are used as an alternative to in situ gels, which can solve some issues of in-situ gels, such as uncertainty in gelling time and penetration depth.This research comprises three main parts. In the first part, four samples of preformed particle gels... 

Low salinity water flooding (LSWF) as an efficient enhanced oil recovery (EOR) technique is proved to affect both, fluid-fluid and rock-fluid interactions to potentially release the trapped oil from the porous rock. Despite more than one decade of extensive research works on the low salinity water effect (LSWE), there are still many parameters to be studied for very complex cases. Therefore, in the first part of the experimental study of the dissertation, a systematic investigation on the effect of the initial wetting state (water-wet or oil-wet) of pure calcite is conducted to study the importance of fluid/fluid and fluid/rock interactions for LSWE investigation. In the case of initially... 

One of the main purposes of this study is to present a robust and yet efficient semi-discretized algorithm for compositional simulation. All the equations including both the mass balance and the phase equilibrium equations are solved simultaneously which forms a Differential-Algebraic set of Equations and is solved by utilizing an efficient MATLAB solver. Furthermore, another formulation and algorithm is proposed which is consisted of two sets of equations, the primary equations (differential mass balance equations) and the secondary equations (the algebraic phase equilibrium equations). The gradient terms in the primary equations are discretized by using finite element method (Galerkin... 

Major parts of Iran's oil reservoirs are fractured carbonates, which need time to produce oil due to their much lower permeability than sandstone reservoirs. Molecular diffusion mechanism is an efficient mechanism in oil recovery from fractured reservoirs under gas injection conditions. The main subject of this work is to investigate the role of molecular diffusion mechanism in the non-equilibrium gas injection project and its role in increasing the oil recovery rate in two southern fractured reservoirs located in the west of Iran, taking into account the capillary pressure, as well as the change of interfacial tension closely miscible conditions is also investigated through simulation. The... 

Excessive water production in highly heterogeneous mature reservoirs (water flooded or affected by water zones) leads to increased production costs. Water production causes sediment formation, creation of corrosion, water treatment and disposal, and finally due to the inefficiency of production, it leads to closure of the well.Among the methods introduced to reduce water production, the use of polymers and gels as an affordable and effective method has been widely used in enhanced oil recovery processes. The main mechanism in this method is blocking or limiting the major paths of water flow (fractures or high permeability zones) and thereby increasing sweep efficiency in water injection.... 

Two-phase fluid flow physics in porous media is applied in various fields. Studies have shown that wettability and surface tension, which represent fluid-rock and fluid-fluid interactions, have a significant effect on the dynamics of the immiscible displacement. Although the effects of wettability and surface tension on the macroscopic behavior of fluid flow are known, there is less understanding of it at the micro scale. Considering the essential role of wettability and surface tension in various fields, this project seeks to investigate the effects of wettability and surface tension on the movement and distribution of fluids and the dominant displacement mechanisms within the porous media... 

Water production from high permeability regions such as fractures and channels in the reservoir can be considered as one of the problematic issues in oil production. In order to control water production, chemical methods such as polymer injection, surfactant injection, and foam injection are widely used, among all of them, Preformed Particle Gel (PPG) is the most efficient method.By injecting the preformed particle gel into the reservoir and blockage of fractures and high permeable regions, Injected water bypasses to the target zone. In this study, preformed gel with a unique formulation was synthesized by free radical polymerization method in the laboratory.Nano-Clay and Nano-Silica were...