جستجوی مقالات مرتبط با کلیدواژه « Interfacial tension » در نشریات گروه « شیمی »

The importance of hydrocarbons in the production of various materials, as well as the supply of most part of the world's energy in the last century and the inability to replace renewable energy due to the rapid growth of global energy demand, on the other hand, has led to the extraction of hydrocarbon reserves should not be out of the focus of researchers and experts in this industry. One of the most important methods of Enhanced Oil Recovery (EOR), especially in carbonate reservoirs, is wettability alteration of the rock using chemical flooding, which has recently been considered by many researchers and research centers. Since most of the world's reservoirs, as well as our beloved country, are made of carbonates, changing the wettability of reservoir rock from oil to water wet have a significant effect on increasing the final recovery factor of the reservoir. The present study is an overview of the latest achievements of EOR through chemical flooding in carbonate reservoirs aimed at changing the wettability towards hydrophilicity. Despite extensive research on the mechanism of chemical flooding, not all aspects of it have been clarified so far. Obviously, without a comprehensive and accurate knowledge of the mechanism of this process, it will not be possible to control and improve it.in the work at hand mechanism of chemical flooding using low salinity, surfactants, polymers, nanoparticles or Nano fluids has been reviewed and an attempt is made to investigate the interactions of surface rock minerals, ions in the injection fluid, crude oil and formation brine be reviewed.

Keeping constant and reasonable production from oil reservoirs which are in the second half of their life has pushed scientists to consider enhanced oil recovery (EOR) methods and novel methods in this field are presented. Magnetized water flooding as a green and compatible method with the environment is one of the novel methods besides polymer flooding which has been applied many years ago. The main purpose of this paper is to combine the two mentioned methods to increase the efficiency of flooding operations. Therefore, magnetized water is utilized as a solvent for polymer powder, then surface phenomena including interfacial tension and contact angle were studied. Somehow the effects of four factors including; magnetization time, magnetic field intensity, time after magnetization, and polymer concentration on mentioned surface phenomena were evaluated. The results showed that all of the aforementioned factors except magnetization time have a great impact on interfacial tension and just magnetic field intensity has a significant effect on contact angle. These results prove that flooding of magnetized water-based polymer solution has a great impact not only on macroscopic efficiency but also on microscopic efficiency and can improve the efficiency of polymer flooding.

In this study, the effect of anionic sodium dodecyl sulfate surfactant on the InterFacial Tension (IFT) of water and oil that is important in the Enhanced Oil Recovery (EOR) was studied using an experimental method and molecular dynamics simulation. For this purpose, the interfacial tension between the water solution and droplet decane was investigated in two conditions. In the first case, the solution consists of pure water molecules and chimneys, and in the second case, sodium dodecyl sulfate surfactant was added to the solution. In the SDS1 system, interfacial tension decreased from 54.83 mN /m to 7.32 mN /m and in the SDS2 system, the interfacial tension of 59.06 mN /m decreased by 8.28 mN /m. The results showed that the addition of anionic sodium dodecyl sulfate surfactant reduces interfacial tension in the second case. On the other hand, the number of molecules was evaluated and the molecular ratio was affected in the process of decreasing surface tension. The larger the number of water molecules and decane, the greater the ability to reduce the interfacial tension. According to the results, the higher  the number of surfactant molecules with respect to water and alkanes, the more interfacial tension reduction is observed. Also, molecular simulations were performed to investigate the effect of surfactant concentration on interfacial tension at constant water and alkane (16 surfactant molecules, 120 molecules of dihydrates, and 800 molecules of water) (SDS3). The results showed that the interfacial tension decreased to 12.66 mN / m which has a lower performance than the SDS1 mode.

It is well known that asphaltene molecules play a significant role in stabilizing the emulsion of water and oil. Molecular dynamics simulation was employed to investigate the aggregation and orientation behaviors of asphaltene molecules in a vacuum, toluene, and water interface. It was found that the simulation results have a good agreement with available data. In order to investigate the effect of asphaltene structures on the self-assembled behavior of them, six different types of asphaltene structures are selected which are different in the terms of molecular weight, carbon-chain size, and heteroatoms in the asphaltene structure. At first, the behavior of asphaltene molecules was studied purely and it was found that the hydrogen bond plays a significant role in asphaltene molecule aggregation. In addition, the interfacial tension results show that the presence of OH and NH groups, as well as hetero atoms in the asphaltene molecules, cause they have hydrogen bonding with water molecules, so the interfacial tension compare to the pure toluene reduces. But on the other hand, if the asphaltene molecules do not have any O and N atoms, they have little tendency to be present at the water surface and they were dispersed inside the toluene solvent.

Smart water flooding is an enhanced oil recovery (EOR) technique which has gained more attention in research activities, recently. Despite many efforts on the study of fluids interaction in this process, most of the presented results are sparse, as they are not probing to the basics of transport phenomena between the involved phases. This work is aimed to bring new understanding of fluid-fluid interaction during smart water flooding through a series of organized experiments in which a crude oil sample with known properties was preserved in contact with different smart water composition for 45 days. Measuring brine pH illustrates the strong effect of the contact time and brine composition on partitioning of crude oil polar components. By increasing the concentration of divalent ions the dissociation of Naphthenic Acids (NAs) increase. To verify this important finding, ultraviolet-visible (UV-Vis) spectroscopy on aged brine samples were performed. Besides, the interfacial tension (IFT) measurements were conducted to identify the impact of the dissociation of crude oil polar components on interfacial interactions. Results show that the sulfate ion has the maximum effect on not although dissociation of polar components, but also on smart water-crude oil IFT reduction. Presence of a divalent cation is necessary for improving the effect of sulfate ion. Also the results show that presence of monovalent ions may affect the adsorption of polar components toward the interface, hence reduces the brine-crude oil IFT.