جستجوی مقالات مرتبط با کلیدواژه "کشش بین سطحی" 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.

One of the effective methods in the process of enhanced recovery of oil reservoirs is applying the nanotechnology to alter the wettability of the reservoir rock. In this study, the wettability alteration was investigated using synthetic graphene oxide-Hexamethyldisilazane (GO-HMDS). For this purpose, XRD and FTIR analyzes were used to identify the synthesized structure. In the present study, the effect of concentration (0.05, 0.1 and 0.2 wt% GO-HMDS) were investigated using the zeta potential analysis, Interfacial Tension (IFT), and contact angle. Subsequently, the concentration of 0.2% was determined as a powerful sample in altering the wettability of the reservoir rock through the zeta potential analysis. This sample was used for tests of contact angle and interfacial tension. In addition the zeta potential of the sample was measured by -36 mv. Moreover, the contact angle between the reservoir rock and the graphene oxide- (Hexamethyldisilazane) solution for 0.2 wt.% GO-HMDS solution decreased from 161 to 44 degrees. On the other hand, it is in agreement the results of the zeta potential and Interfacial Tension (IFT) examines. Therefore, the synthesized nanofluid reduces the and Interfacial Tension (IFT), contact angle, and wettability alteration toward the water-wet of the carbonate core.

In recent years, smart water injection as an efficient method of oil extraction has received particular attention from different researchers. Concentration and salt type are important and influential factors in the thermodynamic equilibrium properties such as interfacial tension (IFT) and wettability. In this study, salt type performance on the physical and chemical properties of reservoir rock, changing the balance into the desired direction, and increasing oil production have been investigated in the smart water process injection. IFT and contact angle measurements and core flood test were performed to achieve the goal. Initially, rocks from the Baba Koohi outcrop in Fars province were prepared. Then, scanning electron microscopy (SEM) and X-ray fluorescence (XRF) spectroscopy were performed. The effect of NaCl, KCl, Na2SO4, and MgCl2 salts and the combination of MgCl2 / NaCl salts with the same ionic strength of 0.7 on the wettability alteration of water-wet dolomite carbonate rock has been investigated. The effect of the above salts on the IFT reduction has also been investigated. In addition, with the help of IFT and contact angle values, the spreading coefficient was calculated to select the appropriate injection salt for the core flooding tests. Finally, flooding experiments were performed with the cores with close permeability and porosity. According to the results obtained from the measured contact angle, the type of salt does not significantly affect changing the wettability of water-wet carbonate rocks. Despite the IFT reduction in the presence of salt, this effect on the spreading coefficient was insignificant. However, the injection of an aqueous solution containing MgCl2 salt resulted in the extraction of 6.1% of the original oil in place (OOIP) in the tertiary stage, which indicates the complexity of the dominant mechanism during smart water injection into the carbonate reservoirs. Besides, the results of this study show that aging time is a practical and useful parameter in oil extraction.

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.

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.

This study presents a new thermodynamic equation for interfacial tension at the organic phase/water interface in the presence of anionic surfactant. The anionic Sodium Dodecyl Sulfate (SDS) is selected to check the validity of the derived equation. The temperature and pressure from the reference are considered as 25°C and 1atm, respectively. It is shown that the newly derived equation can properly describe the organic phase/water interfacial tension in the presence of a single surfactant. In this study, hydrocarbons including n-heptadecane, n-decane, n-nonane, n-octane, n-hexane, 1-octane, 1-hexene, n-cyclohexane, n-cyclohexene, n-butylbenzene, and benzene are considered as the organic phase. By curve-fitting of the experimental data, the following two parameters are obtained: 1) molar surface area, and 2) bulk-surface distribution coefficient of surfactant. In all cases investigated, errors for the proposed equation of this study are less than one of the latest previous works in the literature. The Mean Squared Error (MSE) ranges for the proposed equation and the previous work are 0.5-5.1 (mN/m)2 and 1.8-23.9 (mN/m)2, respectively. The results show a good agreement with the experimental data in the concentration region below and near the Critical Micelle Concentration (CMC).