Sharif Digital Repository

The delayed coking process is one of the common thermal process technique that used to improve the quality of heavy oil. In this process, heavy feeds such as vacuum residues have been heated in the furnace to temperatures up to the 480-500 °C. For the cracking reactions the heated feed have been sent to the drum that is placed after the furnace. Since the reactions begin inside the furnace and coke is one of the products, deposited on the wall of the tube. With the deposition of coke on the tube wall and the reduction of heat transfer, the temperature of the tube have been increased with the increasing of the flame temperature to save constant heat flux. Therefore, the study of thermal... 

Heavy oil reservoirs include a major part of the world’s oil reservoirs. Therefore consideration to their enhanced oil recovery (EOR) aspects has a great importance. In heavy oil reservoirs secondary and tertiary EOR methods, have an insignificant effect on oil recovery and so we’d better to use chemical methods to improve mobility and oil recovery. One of the appropriate EOR methods which has attracted a lot of attention is alkaline – surfactant – polymer (ASP) flooding which has a considerable impact on EOR from heavy oil reservoirs. In this EOR method, the low concentration of surfactant in the injecting fluid, results in a low or ultra-low interfacial tension (IFT) between residual oil... 

Most of the heavy oil reservoirs contain discontinuous shaly structures which affect fluid flow through porous media as well as oil recovery efficiency during EOR processes. However, selecting the best EOR technique which maximizes the oil recovery remains a topic of debate in the literature. In addition the effect of shale geometrical characteristics including: spacing from wells, discontinuity, orientation, number of shale streaks, shale's spacing and length on oil recovery factor are not well understood. In this work experiments have been performed on one-quarter five-spot glass micromodels. These models have been developed by a new method using laser technology. Generally, this research... 

By continuous decreasing the fossil fuel energy resources and increasing demand of such energies on the other hand with decreasing exploration of the new ones, production from these limited resources are in grate consideration. As a few percentages of the oil recovers by primary oil production and also remaining a lot of oil after water and gas injection in the secondary oil recovery process, causes that new methods to increase the oil recovery has been proposed. Water injection is a simple and common method in enhanced oil recovery process. Also water alternating gas injection and simultaneous water and gas injection causes considerable increase in oil recovery. Recently utilization of... 

Existing processes to improve the quality of heavy oil cuts catalytic converter hydroconversion can be mentioned in the slurry phase. This process is usually done in the temperature 440˚C to 470˚C be a heavy craking led to the production of light weight thermal feed can be more. With more products light, adverse reaction can also lead to the formation of coke be. Coke formation of secondary radical reactions can be feed from cracking of heavy compounds. Coke production is to eliminate or limit the ability of homogeneous catalysts (eg sulfide Molybdium) about 600-1000 ppm disposable food adds to be used. The main role of catalyst in the stable radicals fail thermal compound feed is heavy. The... 

Heavy oil reservoirs are becoming more important as the oil price increase and more light oil reservoirs are being depleted. Thermal oil recovery, especially steam flooding is considered as the most efficient EOR technique for heavy oil reservoirs that stays on the top of the recent EOR field experiences. However this method is not applicable in some reservoir conditions like deep reservoirs or reservoirs with thin pay zones.
Due to sever viscous fingering during water flooding heavy oil reservoirs, a large amount of oil would remain untouched in the reservoir. Polymer flooding could be a potential method for enhanced oil recovery by improving sweep efficiency. However there haven’t been... 

Due to the importance of enhanced oil recovery of heavy oil fractured reservoirs, in this work micromodel setup has been used to study the miscible solvent injection in five-spot fractured reservoirs with different fracture geometrical characteristics. Due to the visual nature and flexibility of the micromodel patterns it is a subject of interest to be used in different studies. Different patterns has been constructed by chemical etching and controlled laser etching and saturated with displaced fluid and flooded by constant rate injection of hydrocarbon solvent in abient temperature and pressure. At first, effect of fracture’s length, numbering, orientation, discontinuity and scattering on... 

VAPEX is a relatively new EOR process for the recovery of heavy oil. In this process solvent is used to form a vapor chamber within a reservoir. Vapor dissolves in the oil and diluted oil drains by gravity to a horizontal production well. The essential features of this recovery mechanism have been discussed in this study. Furthermore, a semi-analytical and a simulation study of VAPEX process have been performed on a specified Iranian heavy oil reservoir (such as Kuh-e-Mond). The aim of this study is to investigate an exponential functionality (correlation) witch incorporates all physical parameters that affect the production rate of VAPEX process in dimensionless form. The adjustable... 

Chemical flooding has great potential to recover significant fractions of remaining oil for medium to heavy oil reservoirs not applicable for thermal recovery techniques. Nowadays, with gradual crude oil price increase the chemical process is receiving renewed attention, however, illustration of the possibility of various chemical injection scenarios for medium to heavy oil reservoirs has not been clearly reported and these kinds of reservoirs require more investigation for the applicability of these techniques in the fields. The interfacial active molecules are responsible for providing low IFT range and water/oil emulsions which in many cases could improve the oil displacement efficiency.... 

The aim of this project was to upgrade and reduce viscosity of heavy oils by adsorbing of asphaltene on Ni-Mo/CB and converting it into lighter and more valuable gas and liquid compounds. Asphaltene has been extracted from a heavy crude oil sample of Soroush oil field in Iran. After adsorption, Asphaltene conversion to lighter components (gas/liquid) was studied through hydrocracking process. To prepare the support of catalyst, Carbon Black, initially a thermal treatment step under the argon gas atmosphere followed by acid-washing process was performed. Afterward, the catalysts was prepared through dry impregnation method. In order to activate catalyst for hydrocracking, the catalysts has... 

Steam-Assisted Gravity Drainage (SAGD) is one of the best and the most effective methods of enhanced oil recovery (EOR) which is used in the production from Heavy Oil Reservoirs which constitute large amount of oil throughout the globe. In a typical process of SAGD, steam is injected into a horizontal well and the oil is produced several meters deeper in the ground. In order to increase the Recovery of this process, it is better to review on the Pre-heating methods around the injecting and producing wells. Pre-heating is important when the viscosity of the oil is large enough to prevent oil from any motion at the beginning of the SADG operation, and makes it necessary to to use a Pre-heating... 

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...