Lee Kean Chuan

Synthesis and Characterization of Yttrium Iron Garnet (YIG) Nanoparticles Activated by Electromagnetic Wave in Enhanced Oil Recovery

Due to the geographical location and technological limitation, various novel enhanced oil recovery (EOR) methods has been proposed to recover the remaining oil from a depleted oil reservoir. Research on application of nanoparticles either on its own or coupled with other stimulating agents has been growing enormously and some of them have shown a promising future. In high temperature and high pressure reservoirs, thermal degradation will cause failure to the conventional chemicals. In this work, temperature-stable YIG magnetic nanoparticles with an electromagnetic wave has been proposed as a new candidate for reservoir stimulating agent. The purpose of nanoparticle injection is to increase the sweep efficiency in the reservoir by increasing the viscosity of displacing fluid. In this research, Yttrium iron garnet (YIG) nanoparticles have been injected into a waterflooded oil saturated porous medium to recover the remaining oil in the presence of an electromagnetic wave. At the sintering temperature 1200°C, a mixture of hematite and YIG was obtained, suggesting a higher temperature for single phase YIG. From VSM analysis, the average magnetic saturation, coercivity and remanence are 18.17 emu/g, 21.73 Oe and 2.38 emu/g, respectively. 1.0 wt% of YIG nanofluid was prepared and subsequently injected into the pre-saturated porous medium in the presence of square electromagnetic wave of 13.6 MHz. As much as 43.64% of the remaining oil in place (ROIP) was recovered following the injection of 2 pore volume of YIG nanofluid.

Microscopic evolution of dielectric nanoparticles at different calcination temperatures synthesized via sol-gel auto-combustion

Dielectric nano powder synthesis is carried by a simple and fast sol-gel auto-combustion method. The transformation of crystalline phases of as-synthesized nano powders is investigated through the detailed transmission electron microscopy (TEM), revealed the crystallographic alterations and morphological information even at lattice scale. From specific area electron diffraction (SAED) pattern, has specified the d-spacing and corresponding planes supported by the observed lattice fringes. The morphological characterization of nanoparticles is performed through field-emission scanning electron microscopy (FESEM), exhibiting the increment in particle size due to agglomeration with the increase in annealing temperature. Furthermore, EDX pattern has been used to verify the formation of nanoparticles by revealing the presence of required elements.

Effect of EM propagation medium on electrorheological characteristics of dielectric nanofluids

ABSTRACT The effect of dielectric loss on the electrorheological (ER) characteristic of dielectric nanofluids under shear was studied. When nanofluids are activated by an applied electric field, it behaves like a non-Newtonian fluid under ER effect by creating the chains of nanoparticles. ER characteristics of ZnO and Al2O3 nanofluids with various nanoparticles concentration (0.1, 0.05, 0.01 wt%) were measured. For this purpose, a solenoid-based electromagnetic (EM) transmitter was used under different propagation media including air, tap water, and salt water. The result shows that all the nanofluids exhibit pseudo-plastic behavior, while the electric field causes a significant increase in viscosity in the presence of tap water, followed by salt water. Additionally, the viscosity of nanofluid shows a high dependence on particle loading. A possible mechanism was also proposed to describe the effect of dielectric properties on the ER behavior of dielectric nanofluids. GRAPHICAL ABSTRACT

Effect of CMC on the stability of ZnO nanofluid at high temperature and salinity

In this research, the critical micellar concentration (CMC) of different anionic surfactants was determined by employing the UV–Vis spectroscopic technique. The CMC is crucial to evaluate the adsorption of anionic surfactant on a surface of charged metal oxide (i.e. zinc oxide), to prepare a stable nanofluid for different applications including enahced oil recovery (EOR). Three anionic surfactants (sodium dodecyl sulfate, sodium dodecylbenzenesulfonate and oleic acid) were studied in this research. The amount of CMC was determined in the deionized water and brine solution, using the values from the data extracted from the graph between absorbance and concentration of surfactants. A comparative study was also conducted based on CMC results that shows a good agreement between the present research and the literature. In addition, the effect of temperature on CMC value was also examined which provide a better stability of ZnO nanofluid in the high-temperature environment. The overall result reveals that with ...

An evaluation of iron oxide nanofluids in enhanced oil recovery application

This paper evaluates the oil recover efficiency of Iron Oxide (Fe2O3) nanofluids in EOR. Iron Oxide nanoparticles were synthesized at two different temperatures via sol-gel method. TEM results show that the Fe2O3 prepared at 300°C and 600°C were ranged from 10-25nm and 30-90nm, respectively. Results showed that the nanofluid composed of Iron Oxide nanoparticles prepared at 300°C gives 10% increase in the oil recovery in comparison with Fe2O3 nanoparticles calcined at 600°C.

Designing and Experimental Validation of an Electromagnetic Setup at MHz Frequency Under Different Propagation Media

For successful underwater electromagnetic (EM) wave operation, knowledge is required of the wave propagation properties of seawater overall distances both short and long. This paper presents a novel application of EM wave propagation through seawater, in the field of nano-EOR by manipulating the nanoparticle characteristics under EM waves. For this purpose, a solenoid-based 167 MHz transmitter is designed, simulated, and fabricated in the laboratory and has been studied in two steps under air, tap water, and salt water as a transmission medium. Firstly, a laboratory-scale model was simulated by using computer simulation technology (CST) to test the designed solenoid under different background media, whereas in second step, these simulation results were validated experimentally using a scale tank with a scale factor of 4360. It is noted that the solenoid has been best to propagate at an optimum applied voltage of 1.5 V in salt water. The comparative results at 1.5 V show that the magnitude of the EM waves was found to deviate up to 8.23 % in salt water, while it deviates by 21.3 and 44.3 % for tap water and air, respectively. This proved its suitability to employ in underwater EOR application.

Structural and magnetic properties of hexagonal barium ferrite synthesized through the sol-gel combustion route

Single-phased barium ferrite with the chemical formula of BaFe12O19 was synthesized through the sol-gel combustion method by using stoichiometric amounts of the precursor materials Structural characterizations were done through X-ray diffraction (XRD) analysis. The magnetic properties were determined through vibrating sample magnetometer (VSM) measurement. Pure single-phased BaFe12O19 was successfully obtained at 850°C without any accompanying secondary phases. This was reflected in the magnetic measurements where a prominent hysteresis was displayed by the synthesized powder. Values as high as 50.37 emu/g, 2984.9 G and 26.15 emu/g was observed for the magnetic saturation, coercivity and remanence respectively.

Structural and magnetic properties of Ni1-xZnxFe2O4 synthesized through the sol-gel method

Modification of crystal structure by means of substitution would result in the modification of the overall physical properties of crystallite materials especially in ferrites. This study aims to investigate the effect of non-magnetic Zn substitution in spinel NiFe2O4 and its direct effect towards its microstructural and magnetic properties. Magnetic nanoparticles of Nickel-Zinc ferrite with the chemical formula, Ni1-xZnxFe2O4 (x=0.00, 0.25, 0.50, 0.75) were synthesized through the sol-gel route. Phase formation and structural properties of the synthesized ferrite were identified through X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). Magnetic properties such as the magnetic saturation, coercivity and remanence were measured by a vibrating sample magnetometer (VSM). XRD measurements reveals successful synthesis of single-phased Nickel ferrite and Nickel—Zinc ferrite. Both crystallite and grain size shows fluctuation with increasing Zn content. The ferrites were found to be ferr...

Structural and Magnetic Properties of Ni0.5Zn0.5Fe2O4 Synthesized through the Sol-Gel Method

This study investigates the influence of calcination temperatures on the magnetic properties of Ni0.5Zn0.5Fe2O4(Ni-Zn) ferrites.Ni-Zn ferrite with the chemical formula Ni0.5Zn0.5Fe2O4 was prepared from their respective nitrate salts through the sol-gel method. The resulting ferrites were characterized using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). Single phased Ni0.5Zn0.5Fe2O4 was obtained at all calcination temperatures.FESEM Micrographs reveals an increase in the grain size with the increase of the calcination temperature. Consequently, the magnetic saturation of the samples were found to increase with each increase in the calcination temperature where the highest value obtained is 70.58 emu/g for the samples calcined at 1000°C.

Co-precipitation synthesis of Cox2+Fe1−x2+Fe2O4 nanoparticles: Structural characterization and magnetic properties

Cobalt ferrite is known as a promising magnetic material for various applications. This metal-ceramic composite (Cox2+Fe1−x2+Fe2O4) was synthesized via co-precipitation route, by varying the Co/Fe ratios (Co/Fe = 0.3, 0.2, and 0). The structures and magnetic properties of nano-composites were analyzed by XRD and VSM. As deduced from the XRD line broadening, the average crystallite size of the samples was found to be in the range of 13.0-15.0 nm and contain fcc structure with smaller lattice constant as the Co/Fe ratios increases. FESEM and TEM images revealed the morphology of the samples, which consist of irregular shapes of diameter in the range of 9.0-15.0 nm. Magnetic properties measurement shows that sample S11 with the highest Co/Fe ratio has the highest value of saturation magnetization (Ms) of 65.23 emu/g. On the other hand, increase in the concentration of cobalt ions improves the remanence magnetization (Mr) and coercivity (Hc) of the same sample to 12.18 emu/g and 238.92 Oe, respectively. It is...