Sharif Digital Repository

Naturally Fractured Reservoirs (NFRs) play an important role in petroleum industry and the global economy.. The reservoirs of the most complex geological structures in petroleum engineering science, on the other hand the largest sources of hydrocarbons are considered throughout the world and especially in our country. Therefore, characterization and modeling them frst step to develop best practices for hydraulic fracturing gap, optimal design of production Method and evaluate potential reservoirs. Physics of the present work is 2D two-phase immiscible flow under gravittational effect through fractured porous media and the most practical formulas for transfer function in dual porosity-dual... 

Quadrotors have limitation in performing fast descending maneuver due to entering a dangerous region in velocity space called Vortex Ring State(VRS) which cause considerable loss of lift that may lead to fall. The purpose of this project is to reduce time of fast descending maneuver without entering VRS region by using model predictive control. First, appropriate nonlinear dynamic model of quadrotor obtained by considering important aerodynamics effect. Then by considering velocity constraints in order to avoid entering the VRS region, a nonlinear model predictive controller(NMPC) has designed. This controller successfully reduce the time of the maneuver up to than ordinary descending.... 

The gamma cameras, based on scintillation crystal followed by an array of photomultiplier tubes (PMTs), play a crucial role in nuclear medicine. The use of square PMTs provides the minimum dead zones in the camera. The camera with squared PMTs also reduces the number of PMTs relative to the detection area.In this thesis, we introduced a new read-out method whereby the total cost of the read-out board will be decreased by a factor of 2.4; in return, the energy and spatial resolution of the system will be reduced by 0.3% and 0.4% respectively. We also implemented a positioning module in the FPGA chip via that the transmission rate between FPGA and the computer will be tripled, and the... 

In recent years, carbon dioxide is used for enhanced oil recovery of heavy oil. Steam Huff and Puff is one of the enhanced oil recovery methods used for heavy oil. In this study liquid CO2 was used as an injecting fluid instead of steam. In this paper a series of experiments were performed to demonstrate the effect of carbon dioxide injection pressure on huff and puff process. The experimental data are used in lab scale model simulated with commercial simulator Eclipse 300 to investigate the effect of soaking time, injection pore volume and rate of injection on the heavy oil recovery. Result of experiments showed that huff and puff process under miscible pressure condition gives the most... 

Polymer flooding is a famous enhanced oil recovery method and is used to reduce mobility ratio of displacing fluid to displaced fluid by forming a stable front in displacing process. Due to high costs, polymer flooding faces economical risks and from this point of view, performance investigation of polymer flooding in laboratory scale was concerned. In this project, performance of 7 types of polymers which have different rheological properties were investigated in fractured/non-fractured carbonated and sandstone reservoirs. These polymers consists of 4 commercial polymers, one branched polymer, one synthetic polymer and one polymer composite which have different molecular weight,... 

Low salinity/smart waterflooding is simple to apply and a promising enhanced oil recovery method in which ion-tuned saltwater is injected into subsurface oil reservoirs. Many aspects of this operation, in particular those pertaining to nano-scale, are not yet fully understood. The present dissertation is an attempt to shed light on the microscopic properties and behavior of rock/brine/oil interfaces throughout low salinity/smart waterflooding. Several simulations were carried out for oil/brine and calcite/brine categories each containing various ions and hydrocarbons compounds. The surface contribution of non-functional oil compounds (aromatics and aliphatics) near brine medium was... 

Nowadays, different processes are designed in order to convert raw materials to value added products. One of these is the Bentonite sulfur production process. The most important equipment in this process are stirred tanks where mixing operation of molten sulfur with some additives such as functionalized Bentonite and oxides of iron, zinc and manganese are performed.
In this thesis, following the design and making of a laboratory scale glass baffled stirred tank, the viscosity of molten sulfur and additive suspension has been measured at different temperature (125, 130 and 135oC) and several formulations. Concentration profile of Bentonite has also been obtained by means of local sampling... 

PMMA bone cement lacks biodegradability and the ability to bond with surrounding bone tissue. Therefore, the development of a new generation of bioactive bone cements that are biodegradable and possess adequate mechanical properties as well as desirable setting time is receiving remarkable interest.In this study, we have developed novel mineral-based bioactive bone cements. Our mineral bioactive bone cements were composed of Calcium Sulfate Hemihydrate, Bioactive Glass, and Tricalcium Silicate. Firstly, a binary system composed of Calcium Sulfate Hemihydrate and Bioactive Glass was optimized based on mechanical and setting behavior. Secondly, Tricalcium Silicate was added to the powder phase... 

Various studies have confirmed that water salinity and its composition significantly affect the efficiency of the waterflooding process. Field-scale operation of low-salinity water injection has been proven to be a cost-effective enhanced oil recovery (EOR) method which is also compatible with the environmental regulations. Although this method has satisfactory results, it faces some challenges, such as in-situ mixing of the injection low-salinity water with the saline water in the host reservoir. The salinity of the injected water increases, as it contacts the high-salinity reservoir brine in the pores. This phenomenon significantly impairs the efficiency of this technique, and increases... 

One of the most important challenges in drilling horizontal and directional wells is the optimization of hydraulics and hole cleaning and ECD management. In these wells, poor hole cleaning can lead to formation of cutting bed on the low side of the annulus and cause problems such as stuck pipe or increase in torque and drag. Also poor hydraulic design can lead to decrease in rate of penetration and thus, increase in costs. Mud weight should be placed inside the range of mud window (more than pore pressure and less than formation fracture pressure) in order to prevent kick of reservoir fluid or mud loss.In this thesis, the main goal is to optimize hydraulics and hole cleaning and manage ECD...