Chemical enhanced oil recovery (EOR) and particularly surfactant injection has recently received a great deal of attention. The suggested recovery mechanisms after injecting surfactants include ...wettability alteration and IFT reduction. If a surfactant is properly selected according to the environmental variables-such as pressure, temperature, salinity, it can lead to more efficient enhanced recovery from an oil reservoir. On the other hand, poor selection of the surfactant can result in a low recovery and can even become detrimental to the reservoir due to undesirable wettability alteration and possible rock dissolution resulting in a chemical reaction with displacing fluid and blockage of the pore space. Also, choosing the wrong surfactant without considering the rock mineralogy may result in high adsorption on the pore surface of the rock and unnecessary waste of resources. It is also worthy to note that surfactants are some of the most expensive chemicals used during EOR. Extensive literature review suggests that anionic surfactant are the preferred surfactant category for EOR especially when it comes to sandstone reservoirs. Occasionally, in specific situations a better performance have been reported after injecting cationic, non-ionic or mixtures of both surfactants, particularly when dealing with carbonate reservoirs. This paper presents in detail a review of the most commonly applied surfactants in EOR studies and the optimum application criteria for of each type. To the best of the authors' knowledge, such detailed and comprehensive review is not available in the literature, presently.
The assembling of MXenes at various interfaces to form various building blocks, including films, electrodes, aerogels, and other building blocks is summarized in detail. Mechanisms are explained. ...Applications of these architectures are also demonstrated.
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Two-dimensional (2D) transition metal carbides, carbonitrides and nitrides, known as MXenes, are emerging quickly at the frontiers of 2D materials world. Their exotic properties such as the highest electrical conductivity among all solution-processed 2D materials, the best electromagnetic interference shielding performance outperforming that of copper or aluminum at a nanoscale thickness, as well as the highest volumetric capacitance for pseudocapacitors, have been attracting extensive fundamental research and applications. Their unique surface chemistries, that is, hydrophilic groups terminated on the surface of MXenes after etching and delamination, enable plenty of opportunities for assembling into MXene building blocks. Particularly, assembling at liquid–liquid, liquid–solid, liquid–air, and solid–solid interfaces allows the efficient fabrication of various structures, including MXene surfactants, MXene heterostructures, MXene transparent films. Interfacial assembly of MXenes is of significance in unveiling more versatilities of MXenes as well as impacts on novel MXene-based architectures, based on which enhanced performance of devices is achieved. As such, this review focuses on the interfacial assembly of MXenes, explaining mechanisms behind various assembling and providing classical examples for corresponding interfacial assembling techniques. Applications of these as-assembled architectures are also discussed in brief. We believe this review may shed light on the interfacial chemistry of MXenes, thus guiding more efficient fabrication of MXene-based functional films/coatings/electrodes/devices.
Interfacial and surface tensions were measured at 25 degree C for the toluene/water and air/water systems with dissolved nonionic surfactants Tween 20 or Tween 80. Dynamic surface/interfacial ...tensions were measured with the use of the drop volume method and were successfully fitted with the Hua and Rosen equation with characteristic times t*. Static surface/interfacial tensions were determined from extrapolation of the dynamic data to t arrow right infinity on sigma or gamma versus t super(-1/2) graphs. Obtained results were verified by measurements performed with the use of the Wilhelmy plate method. Critical micelle concentrations for considered surfactants were determined as well as maximum surface excess, minimum surface area per adsorbed molecule and diffusion coefficients were calculated for both fluid/fluid systems. The Frumkin adsorption isotherm was assumed and the Frumkin equation of state fits the experimental static surface/interfacial tensions well. Although the difference between HLB numbers of studied Tweens is small, it is sufficient to observe a different surface activity of surfactants at the air/water surface and toluene/water interface. Performed measurements and analysis give a deeper insight into the surface effects exerted by the nonionic surfactants such as Tween 20 and Tween 80, which in an agitated liquid/liquid dispersions are a source of the additional disruptive stresses generation.
Chemical methods of enhanced oil recovery (CEOR) are applied for improving oil recovery from different kinds of oil reservoirs due to their ability for modifying some crucial parameters in porous ...media, such as mobility ratio (M), wettability, spreading behavior of chemical solutions on rock surface and the interfacial tension (IFT) between water and oil. Few decades ago, the surfactant and polymer flooding were the most common CEOR methods have been applied for producing the remained hydrocarbon after primary and secondary recovery techniques. Recently, more attention has been focused on the potential applications of the nanotechnology in enhanced oil recovery (EOR). For this purpose, many studies reported that nanoparticles (NPs) have promising roles in CEOR processes due to their ability in changing oil recovery mechanisms and unlocking the trapped oil in the reservoir pore system. This paper presents a comprehensive and up-to-date review of the latest studies about various applications of nanoparticles (NPs) within the surfactant (S), polymer (P), surfactant-polymer (SP), alkaline-surfactant-polymer (ASP) and low salinity waterflooding processes, which exhibits the way for researchers who are interested in investigating this technology. The review covers the effects of nanoparticles on wettability alteration, interfacial tension reduction and oil recovery improvement, and discusses the factors affecting the rock/fluid interaction behavior in porous media through the nanofluid flooding.
The dispersion of small particles provides an inexpensive and convenient way to significantly improve various functional properties of the base fluid. Nanodispersions can be used to solve various ...industrial and technical problems, such as increasing the efficiency of heat generating systems, cooling electrical equipment, water desalination, control of thermal regimes of chemical processes and electronic devices, enhancing oil recovery, and so on. This review targets to highlight the recently published results that are of general importance for understanding the processes occurring during wetting and spreading of nanofluids over various surfaces, as well as the mechanisms that determine these processes.
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In H2, CO2 and natural gas geo-storage, rock-fluid interfacial tension (γrock−fluid) is a key parameter which influences pore-scale fluid distribution and reservoir-scale gas storage capacity and ...containment security. However, γrock−fluid data is seriously lacking because of the inability to measure this parameter experimentally. Therefore herein, a semi-empirical method is used to calculate γrock−fluid at geo-storage conditions. Additionally, effects of organic acid and silica nanofluid on γrock−fluid are studied. The following results are obtained. γrock−gas decreases with pressure, temperature, organic acid concentration and carbon number increase, while γrock−H2O increases with organic acid concentration and carbon number increase; γrock−gas first increases and subsequently decreases with silica nanofluid concentration increase, while γrock−H2O first decreases and then increases with silica nanofluid concentration increase; for same thermo-physical and rock surface chemistry conditions, γrock−gas follows the order H2 > CH4 > CO2. These insights provide pivotal guidance on gas geo-storage and thus aids in the implementation of a more sustainable energy supply chain.
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•γrock−gas decreases with increasing pressure and organic acid concentration.•γrock−gas first increases and then decreases with nanofluid concentration increase.•γrock−gas follows the order H2 > CH4 > CO2.
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Asphaltenes subfractions with distinct interfacial behaviors may play different roles in stabilizing oil–water emulsions.
In this work, whole asphaltenes were separated into ...interfacially active asphaltenes (IAA) and interfacially non-active asphaltenes (INAA). Employing advanced nanomechanical techniques, we have explored the compositions, morphologies, sizes, adsorption, and interfacial behaviors of IAA and INAA.
IAA exhibits a high and unevenly distributed oxygen content, distinguishing it from INAA. In toluene, the diameters of IAA and INAA are about 60 nm and 6 nm, respectively. When adsorbed irreversibly on mica surfaces, the thickness of the IAA and INAA film was measured at ∼5.5 nm or 1 nm, respectively; while in a toluene solution, the film thickness reached ∼46 nm and 3.1 nm for IAA and INAA, respectively. IAA demonstrates superior interfacial activity, and elastic/viscous moduli compared to INAA at the water-toluene interface. Quantified surface force measurements reveal that IAA stabilizes water droplets in toluene at a concentration of only 10 mg/L, while INAA requires a higher concentration of 100 mg/L. This work provides the first comprehensive investigation into the adsorption and interfacial behaviors of asphaltene subfractions and provides useful insights into the asphaltenes-stabilization mechanism of emulsions.
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•M−MEA was prepared by a simple two-step reaction.•Demulsification efficiency of 100% could be achieved in various emulsions.•M−MEA exhibits a clover-shaped structure with a ...hydrophilic core and twelve hydrophobic chains.
A clover-shaped demulsifier (M−MEA) was synthesized via a simple two-step reaction, and its chemical structure was corroborated using 1H NMR and FT-IR. The demulsification efficacy of M−MEA was investigated on two distinct water-in-oil emulsions. The bottle test results indicated that in a W/O emulsion with 30 % oil content, M−MEA achieved a demulsification efficiency (DE) of 100 % at a concentration of 300 mg/L, temperature of 60 °C, and settling time of 120 min. Similarly, in a W/O emulsion with 70 % oil content, the DE also reached 100 % at a concentration of 500 mg/L and a settling time of 90 min. Moreover, M−MEA exhibited remarkable demulsification performance at high salinity and across a wide pH range. Comparative analysis with other commercially available demulsifiers revealed that M−MEA offered high demulsification efficiency and yielded a clearly separated water phase. The study delved into the demulsification mechanism through assessments of dynamic interfacial tension (IFT), surface tension (ST), three-phase contact angle (TCA), and zeta potential. The findings demonstrated that M−MEA, acting as an effective demulsifier, swiftly migrated to the oil–water interface, displaced the natural surfactant, and destabilized the emulsion, thereby facilitating the oil–water separation of emulsions.
Stable emulsions can have numerous negative impacts on both the oil industry and the environment. This study focuses on the synthesis of two ionic liquids (via. PPBD and PPBH) with four hydrophobic ...branches and four ionic centers that can effectively treat oil-water emulsions at a low temperature of 40 °C. Their chemical structure was explored using Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance hydrogen spectra (1H NMR). The effect of temperature, PPBD and PPBH concentration, oil-water ratio, salinity and pH value on the demulsification efficiency (DE) of W/O emulsion was studied detailly and several commercial demulsifiers were also used for comparison. Results revealed that by adding 250 mg/L of PPBH in an E30 emulsion and leaving it for 120 min at 40 °C, the DE could reach 96.34%. Meanwhile, in an E30 emulsion (oil-water mass ratio of 3:7) with 250 mg/L of PPBD, the DE of 95.23% could be obtained at 40 °C for 360 min. Especially, the DE of PPBH could reach 100% in an E70 emulsion (oil-water mass ratio of 7:3) at the same conditions. Additionally, the demulsifier (PPBH) exhibited excellent salt resistance and outperformed some commonly used commercial demulsifiers. Several methods were utilized to investigate the potential demulsification mechanism, including measuring interfacial tension (IFT), three-phase contact angle (CA), droplet contact time, zeta potential, and observing samples under optical microscopy.
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•Two ionic liquid demulsifiers with four hydrophobic branches and four ionic centers were synthesized via a two-step route.•The demulsifiers have low demulsification temperature and high demulsification efficiency.•The demulsifier PPBH demonstrates exceptional resistance to both acid and salt.•The performance of the demulsifiers outperform some commonly used commercial demulsifiers.
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