Sharif Digital Repository

In many cases, oil and gas extraction from reservoirs due to damage and permeability reduction near wellbore is lower than optimum level and reduces the flow of oil into the well. In fact, formation damage is the collapse of natural condition of reservoirs, In addition to delaying production and increasing costs, it causes early desertification of wells. Well stimulation methods are used to solve this problem and increase production. One of the most effective ways to increase the production of wells is well acidizing. In this study, the acid performance of the fractured carbonate reservoirs has been investigated. In this type of reservoirs, due to the existence of high permeable paths of the... 

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... 

The assessment of fluid transport in porous media is the main subject in oil reservoirs to understand the oil recovery efficiency. The efficiency of Enhanced oil recovery (EOR) processes depends on the surface properties and wetting behavior of oil reservoir rocks which are also affected by the electrokinetic behavior of solid part of the porous rock. Streaming potential measurement is one of the techniques to determine the electrokinetic properties. The streaming potential measurements using electrodes have recently been introduced in oil field applications and there are still significant uncertainties during the measurements and interpretation of streaming potential results. The Primarily... 

In this thesis, the application of solar energy in the steam injection as a thermal enhanced oil recovery (TEOR) is evaluated. The motivations of this project are using a renewable energy, suitable solar potential of Iran, successful experience in the world, undeveloped heavy oilfield reservoirs in Iran. This application is investigated by three aspects which are:Reservoir Engineering aspect: the heavy oilfield are determined and then screening for selection good candidate of steam injection are done. One of the reservoirs is analyzed by simulation and optimization the steam injection to determine how much it’s production will be improved by using steam injection (contionous and cyclic)... 

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... 

Given the decreasing trend of light petroleum reserves and the necessity to produce heavy and extra-heavy oil resources, the challenge of dealing with existing asphaltene related problems, which is the heaviest and the most complex component of crude oil, has become increasingly tangible. Asphaltene precipitates and deposits due to pressure, temperature or composition alterations which leads to obstruction of porous media and production facilities. Set the costly methods aside, one of the available approaches to prevent asphaltene precipitation, is to apply an electric field upon the suspected zone, which is cheap and uncomplicated. Besides, utilizing nano-particles while applying electric... 

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... 

Asphaltene, known as the heaviest and the most polar component of the crude oil, can precipitate because of the changes in the fluid condition such as pressure, temperature and composition. Asphaltene deposition causes major problems during oil production, in the form of fluid viscosity changes, wellbore damage and fouling in pipelines. The remediation of these problems is very expensive and needs to halt down the crude oil production. The use of electric field has been proposed recently as clean and cheap technique that could also be applied during the production period. In this work, the effect of electric potential on asphaltene precipitation in both static and dynamic modes has been... 

Cancer has been known as one of the main reasons for disease-related deaths in the last decades. Early diagnosis could significantly reduce the level of fatality chances. Among the known cancer types, lung cancer is one of the most malignant ones. The common diagnosticmethods are expensive and using high-technology methods; therefore, the introduction of simple and cheap methods is very urgent to detect it. In this project, surface and interfacial tension measurement of cancerous and normal lung cells have been investigated as an easy detection technique. Among the common measurement methods, Pendant Drop and Capillary height techniques have been utilized in this research work. The obtained... 

Minimum miscibility pressure (MMP) is a key parameter for successful gas injection process in the oil reservoirs for more oil recovery. This parameter is critically dependent on the reservoir condition such as temperature, reservoir and injection gas composition. There are many techniques used in the literature for MMP measurement. Vanishing interfacial tension (VIT) has been proposed recently and was used successfully to predict the MMP through pendant drop technique. This technique is used in this study to measure the MMP for Nitrogen/Carbon dioxide and water in oil emulsion fluids; then compare it to the original crude oil without water droplets. This would demonstrate the effects of... 

This research was done for feasibility evaluation and understanding correct microbial enhanced oil recovery(MEOR) procedure for carbonate reservoirs. With the aim of cost reduction and possible activation of smart water mechanisms, sea water used as a base for MEOR process. Two biosurfactant producing strains were isolated from oil contaminated water and soil, and one halotolerant strain, from sea water. Optimization of biosurfactant yield was conducted and two new definitions for optimum point, by considering economical and technical facts, were proposed. Partial characterization of produced biosurfactant was carried out through FTIR and NMR analysis and the produced biosurfactant was... 

Asphaltene precipitation and deposition are sources of a number of problems for petroleum industry. Thus, solving the problem of precipitation and deposition is very important. In order to measure deposition level, study of other asphaltene flocculation is vital; since there is a time interval between precipitation and deposition. Use of chemical inhibitors is one of the best methods for prevention of asphaltene precipitation that could postpone precipitation point and prevent formation of huge flocculations. In this study, effects of asphaltene flocculation size on deposition with or without using inhibitors were investigated. In this regard, QCM was used for measuring the amount of... 

Low-salinity waterflooding (LSWF) is a promising EOR approach that decreases the oil-wetness of reservoir rocks, hence increasing the recovery factor. Despite the importance of the pore-geometry on the performance of LSWF, especially in 3D simulations being affected by corner-flow and roughness, it is not yet investigated, thus in this thesis we aim at studying the aforementioned effects on LSWF. According to the preceding studies, during the drainage phase, the brines in the corners of pores cannot be displaced by oil because of requiring very high capillary pressure; thereby rendering a mixed-wet system. Hence considering this type of wettability is necessary for two-phase flow... 

Water injection, as one of the conventional methods to increase the oil recovery factor has always been at the center of research works for Enhanced Oil Recovery (EOR). The conducted studies show that by controlling the amount and type of ions in the injected water, the recovery efficiency can be improved. In the meantime, most of the investigations are focused on the interaction between water/rock/oil to trace the wettability alteration. However, these interactions especially between the injected water and the oil phase, would lead to change of surface charge distribution of the reservoir rock. Besides, this effect can change some of the characteristics of the fluid phases, especially in... 

Inorganic scale deposition has been found to affect many industrial processes,including water injection into the oil reservoirs. Major formation damage because of incompatibility of high sulfate ion content of seawater with formation water containing calcium ion results in formation damage and production decline.In this study, several simultaneous techniques are utilized for qualitative and quantitative analysis of calcium sulfate scale to get more insight into the damage of formation during smart water flooding at micro and Nano scales. In the experimental section, calcium sulfate deposition due to the mixing of the formation water and seawater samples was investigated using the dynamic... 

During the Acidizing process in oil and gas reservoirs, the injected acid reacts with the rock grains, changes the rock pore structure and affects the flow conditions. Due to the presence of a large concentration gradient at the vicinity of the rock grains and the continuous changes in rock-fluid interfaces of the porous medium, the continuum assumption has been remained debatable for the effective local mass transport and effective molecular diffusion coefficients and the porosity-permeability relation in the continuum scale modeling of this process. Therefore, the need for pore scale modelling is evident. The novelty of this study relies in adapting the grid refinement method on the... 

As many oil fields are reaching their final stage of production, new technologies are required in order to maintain production and increase recovery of hydrocarbons. Among these techniques of enhanced oil recovery (EOR), chemical injection method focuses on increasing the effectiveness of waterflooding. Due to the relatively high costs and considerable adsorption on the rock formations, this method is no longer used. In Recent years nanofluids (nanoparticles dispersed in brine) have been used as a cheap, efficient and environmentally friendly alternative more than any other chemicals. It has been stated that the Smart Water method and enhanced oil recovery by SiO2 nanoparticles are effective... 

The Low salinity water flooding is one of the important methods of secondary and tertiary oil production in which many expert petroleum-production engineering working on it in recent two decades. There are some basis mechanisms for low salinity method presented in the literatures including fine migrations, alkaline flooding, multicomponent ionic exchange, electrical double-layer expansion and pH-driven wettability alteration. The main approach is generating low salinity mechanism especially wettability alteration in OpenPNM framework. OpenPNM is a python base framework developed by Jeff Gostick for porous media modeling. OpenPNM has paved the way for extracting pore network models (PNM) from... 

Petrophysical properties of reservoir rocks are of the most important parameters in fluid flow simulation and reservoir characterization. Although in core laboratories some well-known procedures for determination of these parameters are applied, in almost all of them the rocks are assumed to be homogeneous and their properties are taken up as identical in all directions. To eliminate these unrealistic assumptions, an accurate, non-destructive technique with appropriate degree of resolution is required for recognition of internal heterogeneity of cores. Medical “CT Scanner” is one of these techniques whose information in conjunction of conventional experiments could reduce their limitations...