Sharif Digital Repository

Nowadays, application of ultrasonic wave technology as a novel method of enhancing oil recovery and also gas and oil well stimulation is prevailing. Not only this method is environment friendly, but also it is economic. Although the application of this method is proved to be of outstanding positive influences in field operations. In this study, it is intended to investigate the effect of ultrasonic waves on the rate and final recovery of miscible and immiscible injection of fluids as Enhanced Oil Recovery (EOR) methods by using the Micro model apparatus and Although the effect of the waves on fluid flow through the porous media can be studied. The results of this work are a good guidance to... 

Gas injection is a well-known enhanced recovery method which can improve recovery using two different displacement processes, miscible and immiscible. Typical non-hydrocarbon gases which have been utilized in these processes are carbon-dioxide and nitrogen. These gases are usually injected separately and have been rarely utilized together as a tertiary recovery process.
In this paper, we have focused on sequential carbon-dioxide and nitrogen gas injection as a novel EOR method. The periodic injections of carbon-dioxide and nitrogen have been repeated for six injection pore volumes. Sensitivity analysis of injection pressure, injection volume and injection rate have been also investigated... 

The production of oil is challenging in the fractured reservoirs due to the large transmissibility contrast between matrix and fracture, and primary recovery is often low. The recovery efficiency depends on the relationship between the fracture and matrix permeability, and is strongly dependent on the wettability of the matrix, which reflects the imbibition potential of the reservoir. Among these parameters the multiphase fluid flow in gas invaded zone is the point of interest in this project. Gas injection in naturally fractured reservoirs maintains the reservoir pressure, and increases oil recovery primarily by gravity drainage and to a lesser extent by mass transfer between the flowing... 

Increasing the global demand for energy and decreasing the production rate of oil reservoirs have forced the oil companies to focus on enhanced oil recovery (EOR) extensively. This paper summarizes the design, reservoir simulation, and results of different gas injection scenarios in one of the Iranian complex oil reservoirs. This complex reservoir is located in the south west of Iran and is made up of sandstone, limestone, and dolomite layers. It is an under saturated reservoir with no gas cap but with a strong aquifer. Oil production has started in 1977, but due to strong aquifer the production is still in the plateau period. In this study, by simulation, it is estimated that natural... 

In most of the commercial and academic multiphase flow simulators, the numerical method in use is based on finite difference methods which can lead the solution toward numerical dispersions or even oscillations. These methods are very sensitive to the size of computational grid blocks. Even if we change the numerical method from finite difference to linear finite element (hFEM), still there will be such problems and size of grid blocks will be crucial in getting proper results which can lead to millions of computational grid blocks. One way to deal with this problem is using nonlinear finite element methods (pFEM) also known as higher-order finite element methods, Also compositional... 

Asphaltenedeposition is a major problem during natural depletion and EOR processes due to formation damage issues. It is necessary to reveal asphaltene deposition mechanisms and its effective parameters to prepare an acceptable prevention strategy. Therefore, different natural depletion and EOR experiments must performed on core samples. In this research, Effect of CO2 injection on asphaltene deposition phenomena has been surveyed. Two carbonate core samples and one sandstone core sample was used in experiments. The oil used in these experiments was recombinedoilfrom one of Iranian offshore oilfield.In order to estimate permeability reduction during experiment, injection of oil and CO2 was... 

A simultaneous water and CO2 injection study using sandstone cores with 21°API Sarvak (Azadegan field) oil has performed to evaluate oil recovery under four injection modes: secondary immiscible, secondary near-miscible, tertiary immiscible, and tertiary near-miscible. It is demonstrated that swag injection (secondary and tertiary) is an effective method for the recovery of significant amount of oil or residual oil from water-flooded porous media, but there is always some bypassing (at the pore level) of the oil due to topological effects, water-shielding and dead-end pores. In non-homogeneous porous medium, oil recovery is depending to SWAG ratio in immiscible and near-miscible conditions.... 

The gas injection is one of the most common methods of increasing recovery from oil reservoirs, especially when a suitable source for gas is available. For example, available sources of carbon dioxide or associated gas produced from the reservoir or adjacent reservoirs. In general, the gas injection may be miscible or immiscible, which is a function of the type and composition of the gas-oil and the reservoir conditions in terms of temperature and pressure. In miscible gas injection, different mechanisms such as molecular diffusion of gas in oil or evaporation of lighter components of oil in gas and condensation of heavier components of gas in the oil phase can be shown. To occur of such...