Magnitude Of Interfacial Tension Research Articles

Design and synthesis of a new ionic liquid surfactant for petroleum industry

This study is intended to synthesize and assess a new pyridinium-based Ionic Liquid (IL) surfactant, 1-octadecyl-pyridinium bromide, in terms of crude oil–water Interfacial Tension (IFT) reduction and wettability alteration. The synthesized IL surfactant is firstly characterized through proton Nuclear Magnetic Resonance (1H NMR). Then, the pendant-drop and sessile drop techniques are employed to study crude oil–water IFT and the wettability of carbonate rocks. Based on the IFT results, the synthesized IL has a Critical Micelle Concentration (CMC) of 200 ppm, at which crude oil–water IFT reduces by 95.9 %, from an initial value of 23.7 mN/m to 0.97 mN/m. Increasing the salinity up to 100,000 ppm could not make the synthesized IL less effective than that of free from salinity, as the magnitude of IFT is obtained to be 0.938 mN/m at CMC. Based on the wettability investigation phase, the synthesized IL changes the wettability of carbonate slices from oil-wet to intermediate-wet (140.47°–90.97°). It is also observed that the synthesized IL can tolerate harsh salinity conditions as no appreciable change in the contact angle is noticed after increasing the salinity even up to 150,000 ppm (84.54° at CMC). It should be noted that an optimal salinity of 50,000 ppm is found based on the results of IFT and contact angle measurements. The introduced surfactant is expected to exhibit a significant positive impact on the oil recovery factor while implementing chemical flooding.

Wettability and Interfacial Tension Alteration of Rare-Earth Doped Yttrium Iron Garnet under Influence of Electromagnetic Waves

Yttrium Iron Garnet (YIG) doped with rare-earth elements have shown to alter the magnetic properties of garnet nanoparticles (NPs), which is believed to have direct influence on the wettability, interfacial tension and viscosity alteration of garnet nanofluids. In this study, Y2.8R0.2Fe5O12 (R = Lanthanum (La), Neodymium (Nd) and Samarium (Sm)) NPs were synthesized by using the sol gel auto-combustion method followed by annealing treatment at 1000°C for 3 hours. The Y2.8R0.2Fe5O12 nanoparticles synthesized had grain size ranging from 100 to 200nm with high crystallinity properties. X-ray Diffraction peaks showed varying shifting with the size of the rare-earth ions in the Y2.8R0.2Fe5O12 crystal system, suggesting that structural distortion is due to replacement of bigger ions. Sm-YIG exhibited the highest magnetization saturation among all samples, with the value of 23.54 emu/g. Wettability data of Y2.8R0.2Fe5O12 (RE-YIG) nanofluids showed that oil-wetting contact angle has an overall reduction under the influence of electromagnetic wave. Whereas the interfacial tension and viscosity data showed that doped garnet nanofluids has lower value than that of garnet nanofluids, but the magnitude of interfacial tension and viscosity value decreased with the rare-earth ionic size. Sm-YIG also has the highest interfacial tension across all samples, as the stronger magnetization saturation may contribute to higher surface tension exerted on the oil-nanofluid interface.

A Pore-level Investigation of Surfactant-crude Oil Displacements Behavior in Fractured Porous Media Using One-quarter Five Spot Micromodels

Despite numerous studies, there is a lack of fundamental understanding about the displacement behavior of surfactant-crude oil systems under the influence of different fractures' geometrical properties in five-spot systems. In this work, a series of flow visualization experiments were carried out on one-quarter five spot glass micromodels at various fractures' geometrical properties, such as fracture density and fracture continuity, under oil-wet condition. The influences of injection of Linear Alkyl Benzene Sulfonate and Sodium Dodecyl Sulfate surfactants as well as the effect of fracture geometrical parameters, on macroscopic and microscopic displacement behavior have been investigated. The micromodels were initially saturated with crude oil. Precise analyses of the high quality pictures, which were taken during experiments, were used to explore the surfactant's displacement efficiency. It has been found that two mechanisms govern such a process at the pore scale. One is responsible for decreasing the residual oil saturation and the other mechanism is increasing the matrix-fracture interactions through the porous media. The experimental results show that the magnitude of interfacial tension between the existing fluids was the most important parameter that altered the flow behavior at pore level. The observations revealed that high penetration of surfactant solutions from fractures into the matrixes perfectly postponed the breakthrough time and increased the oil recovery. As a result of better dispersion of surfactant through the matrix, it has been found that the higher fracture density yields a higher oil recovery. The media containing continuous fractures showed that higher oil recovery compared to discontinuous fractures. The results also showed that the average oil recovery during water injection is a strong function of the fracture properties, whereas use of Sodium Dodecyl Sulfate solution extremely reduces the effect of fracture geometrical properties. The results of this work can be helpful to better understanding the surfactant-crude oil displacements in fractured reservoirs.