Sharif Digital Repository

Enhanced Oil Recovery (EOR) techniques have become of the main priorities of the oil industry during the high oil price era. It is interesting to note that the common method to increase production from reservoirs is the water injection method, which recovers a very low amount of oil from the oil-wet matrices due to the lack of water imbibition. Previous studies have shown that changing the wettability of rock would critically increase the oil recovery efficiency. This could be achieved by the low-salinity water injection method. In recent years, extensive studies have been conducted on this technique to evaluate its effectiveness for various types of oil reservoirs. Simultaneous injection... 

From previous years, water injection was considered as one of the most common methods for enhanced oil recovery. But recently much attention has been paid on the use of low salinity water (LSW) as an enhanced oil recovery fluid. The main mechanism that causes improve oil recovery is wettability alteration to a more water wet state. The change observed in recovery factor during LSW flooding induced from changes in relative permeability and capillary pressure when different levels of salinity are used. However, a few researchers tried to evaluate how macroscopic flow functions depend on the salinity of injected water. To this end, a series oil displacements by water performed on sandstone rock... 

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... 

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... 

In this study, membrane distillation process was used for treatment of high salinity waters. The focus of this study is to simulate and build a setup of membrane distillation process. Since the membrane distillation process is based on the driving force of the temperature difference, the required temperature is provided by both the use of heaters and the use of solar energy. To increase the feed temperature by solar energy, a black polymer coating on the main membrane is used. The main membrane used in this process is PVDF polymer and the polymer coated on the surface is the PAN polymer. After simulating and constructing the laboratory setup, the influence of a variety of parameters on the... 

So far, many studies have been carried out on the core-scale regarding the effects of hysteresis on the macro-scale properties of systems including fluids and porous rock, however, many issues related to the physics of the problem (especially regarding the way fluids are distributed and the trapping of the non-wetting phase) at the pore-scale need further investigation. In the process of multiphase fluid flow in porous media, hysteresis refers to the dependence of the results of the fluids’ displacements on the history of fluid saturation and the direction of saturation changes (increasing or decreasing). The first step to investigate the hysteresis effect is to determine the amount of fluid... 

Due to population growth, per capita change and heterogeneous distribution of water resources, forecasts demonstrate that more than 66% of the world's population will experience water scarcity by 2025. The major concern of desalination is their management of brine, with concentrations and their associated components more than twice the input concentration. Also, when extracting oil, per 1 oil barrel, about 7 to 10 barrels of high saline water are produced. One of the most common methods for disposing of brine is direct discharge into the environment, which, due to its destructive effects, creates serious threats to marine ecosystems. Therefore, it is necessary to desalting these high saline... 

Water injection is known as one of the most efficient and affordable techniques to displace the oil in the reservoirs. To increase oil recovery efficiency through water injection operation, recently low salinity water injection or water containing a certain amount of effective ions (engineered/low salinity water) is proposed. Besides, improving this technique is also adopted in the oil industry using certain chemicals like surfactants to change the interfacial tension or rock wettability for more oil recovery. In order to study and model the mechanisms involved during surfactant flooding, molecular dynamics simulation is utilized here as a novel technique. The advantage of this method over...