Hassan YM*, Guan BH, Chuan LK and Adam AA
Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Malaysia
*Corresponding author: Yarima Mudassir Hassan, Department of Fundamental and Applied Sciences, Universiti Teknologi Petronas, Bandar Seri Iskandar, Tronoh, Perak, Malaysia
Submission: September 07, 2021;Published: September 24, 2021
ISSN 2637-8035Volume4 Issue2
Rock wettability change is one of the important parameters that determine Enhanced Oil Recovery (EOR) in which various Nanoparticles (NPs) have influenced in that regard. Hence, proving an alternative approach to improve wettability is essential, it was recently proposed that modifying wetted reservoir rock by applying an Electro Magnetic (EM) field (Electrowetting) can facilitate oil displacement because the injected NPs could be activated profoundly under EM field and lead to bring an optimistic change. Dielectric NPs were recently used for electrowetting analysis due to their essential thermal conductivity and a reasonable outcome was subsequently reported. This is attributed to the free charges of the dielectric NPs that were found to be attracted by the electric field near the contact line, and the polarized dipoles of the NPs that appear to be on the oil/NFs interface because of which the electrowetting will subsequently improve. Hence, electrowetting could serve as a substantial approach that can facilitate oil displacement in the reservoir which in turn improves EOR.
Keywords: Electrowetting; Dielectric NPs; Enhanced oil recovery
Abbreviations: NPs: Nanoparticles; EM: Electro Magnetic; EOR: Enhanced Oil Recovery
Hydrocarbon is one of the important and major contributing factors for gaining energy
globally [1-3]. Unfortunately, oil reservoirs in the world are suffering from the persistent
attachment of the crude oil in the reservoir rock pores in which more than 70% of the existing
oil in reservoirs across the globe cannot be extracted by using an outdated method of oil
extraction which were known to be primary and secondary methods [2]. The primary method
causes by the underground pressure or gas expansion in the reservoir that can cause oil to
flow which resulted in oil being removed without the requirement of using an external force
to detach oil from the reservoir, utilizing this method cannot recover more than 15% of the
residual oil in the reservoir. Subsequently, advanced methods of secondary recovery were
initiated in which the water used to be flushed in the reservoirs and stimulate oil mobility.
Still, additional challenges that restrain oil mobility did exist in the sense that 55 to 70% of the
oil cannot be recovered due to the continued viscous fingering as crude oil is heavily viscous
and therefore water as less viscous fluids cannot displace plentiful oil and therefore will slide
past the oil front, causing adverse fingering and lowering the recovery factor [1]. This has
necessitated the innovation of tertiary/Enhanced Oil Recovery (EOR), which is the method
in which the oil can be recovered by three methods which include heating oil (thermal), gas
miscible flooding, and chemical injection. Significantly, EOR was found to have recovered 30
to 60% of the residual oil.
The small size of NPs against reservoir rock holes allowed them to successfully flow
in reservoir rock with limited distraction [2], significantly, different NPs were explored to
show some positive change for reservoir characteristics such as wettability alteration and
interfacial tension. Therefore, the rock surface wetting stage is an important parameter that determines EOR. Reservoir rock is often found to be oil-wet, which
brings some limitations for the successful conveyance of fluids. As a
result, changing the oil-wet reservoir rock to a water-wet situation
will significantly improve the removal of the trapped oil in the
rock holes. The contact angle is the most common method used
to measure the wettability of the rock surfaces which relies upon
whether the angle is above, below, or equal to 90o (Figure 1a) [2].
Different NPs were studied to influence in changing rock surface
wettability from oil-wet to water-wet which included TiO2 [4,5],
Al2O3 [4-7], ZrO2 [6], and Fe2O3/Fe3O4 [7,8], and SiO2 [5,7]. However,
NPs in reservoir still phases challenges of agglomeration that
render them less effective and being trapped in the rock holes due
to the high temperature of the reservoir, a new idea of employing
energy via the electrician method in the reservoir that liberates the
active mobility of the fluids was proposed by Haroun [9]. Therefore,
reservoir rock wettability could be improved profoundly under the
influence of an EM field known as (electrowetting), because the
energy absorption of the NPs from the EM sources could introduce
some disturbances within the fluids that facilitate oil displacement.
Figure 1: (a) Wettability of rock surface (b) Goniometer with EM connection for electrowetting measurements.
The high response of energy stimulus by dielectric NPs makes them a suitable candidate to be used in the EM field which could stimulate NPs mobility in the reservoir. Recently, Goniometer was connected to the frequency generator in which the energy can be introduced through solenoid coil to the nanofluids which can activate the fluid performance (Figure 1b) [10]. Few experiments have recently shown a considerable outcome concerning electrowetting while employing dielectric NPs of ZnO and Al2O3 ZnO [10-12], moreover, Yttrium Iron Garnet (YIG) was also recently reported to have shown a significant influence concerning interfacial tension and wettability under the influence of EM field [13-15].
Considering the significant influent of the rock surface wettability change for improving oil productivity by employing different NPs, the idea of utilizing the EM field for reservoir rock wettability analysis (electrowetting) was proposed. Dielectric NPs are regarded as a good candidate for the task considering their electrical conductivity in the presence of EM field, and it was reported to have displayed an essential outcome by changing rock wettability from oil-wet to water-wet.
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