Oil/Water Emulsions Stabilized by Nanoparticles of Different Wettabilities

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ilias Gavrielatos ◽  
Ramin Dabirian ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Particle Concentration ◽  
Emulsion Stability ◽  
State Of The Art ◽  
Water Emulsion ◽  
Dispersion Phase ◽  
Spherical Silica ◽  
Oil Water ◽  
Water Cut ◽  
Phase Water ◽  
Kinetics Of

A state-of-the-art, portable dispersion characterization rig (P-DCR) is used to investigate the effect of nanoparticles (NP) on oil-water emulsion formation and stabilization. Spherical silica NP of different wettabilities were used to investigate their effect on separation kinetics of solid stabilized emulsions in terms of solid particle concentration, wettability, initial dispersion phase, water-cut, and shearing time. The main findings of the study include the following: NP, even at concentrations as low as 0.005% or 0.01% (by weight), can significantly increase separation time of oil/water emulsions from a few minutes to several hours or even days. The P-DCR is recommended as an effective inline tool to measure emulsion stability in the field.

Separation Kinetics of Oil/Water Emulsions Stabilized by Nanoparticles

2017 ◽  
Author(s):  
Ilias Gavrielatos ◽  
Ramin Dabirian ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Silica Nanoparticles ◽  
Solid Concentration ◽  
Water Emulsion ◽  
Dispersion Phase ◽  
Wide Range ◽  
Series Of Experiments ◽  
Oil Water ◽  
Water Cut ◽  
Kinetics Of ◽  
Separation Kinetics

A state-of-the-art, Portable Dispersion Characterization Rig (P-DCR) is used to investigate the effect of nanoparticles on oil-water emulsion formation and stabilization. Mineral oil and distilled water are used as the test fluids and separation profiles are obtained from the experiments using a sophisticated software. Spherical silica nanoparticles of average primary particle size of 20 nm were selected as the emulsifying agent, since silica is commonly found in the produced fluids. Nanoparticles of different wettabilities were used to investigate their effect on separation kinetics of solid stabilized emulsions in terms of solid particle concentration, wettability, initial dispersion phase, water-cut, and shearing time. In one series of experiments the emulsions were prepared with intermediate-wet nanoparticles. Both simple water-in-oil (W/O), as well as multiple oil-in-water-in-oil (O/W/O) emulsions were observed. Faster separation occurred when the particles were initially dispersed in oil. Increased nanoparticle concentration, as well as shearing time typically resulted in slower emulsion separation rates. Another series of experiments was performed with hydrophobic and hydrophilic nanoparticles. Very fast separation rates were observed when using hydrophilic silica nanoparticles and 25% water-cut regardless of solid concentration. However, when the water-cut was increased to 50% and 75% very stable emulsions were produced. Emulsions prepared using hydrophobic particles were the most stable across all water-cuts. For the case of 25% water-cut, no water coalescence was observed for a wide range of oil-wet nanoparticle concentrations. Oil creaming was promoted as the concentration of solids decreased, and the emulsions remained oil continuous and highly resistant to water coalescence even for very low solid concentration (100 ppm), resulting in a dispersed phase volume fraction as high as 93%. The effect of nanoparticles on the properties of pure fluids, namely, density, viscosity and surface/interfacial tension is also reported. The main findings of the study include the following: Nanoparticles, even at low concentrations, can significantly decrease separation rates of oil and water emulsions. The Portable Dispersion Characterization Rig (P-DCR) is recommended as an effective way to measure emulsion stability in the field.

Effect of Shear and Water Cut on Phase Inversion and Droplet Size Distribution in Oil–Water Flow

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Mo Zhang ◽  
Ramin Dabirian ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Size Distribution ◽  
Droplet Size ◽  
Phase Inversion ◽  
Droplet Size Distribution ◽  
Continuous Phase ◽  
Dispersed Phase ◽  
Water Emulsion ◽  
Inversion Region ◽  
Oil Water ◽  
Water Cut

Oil–water dispersed flow occurs commonly in the petroleum industry during the production and transportation of crudes. Phase inversion occurs when the dispersed phase grows into the continuous phase and the continuous phase becomes the dispersed phase caused by changes in the composition, interfacial properties, and other factors. Production equipment, such as pumps and chokes, generates shear in oil–water mixture flow, which has a strong effect on phase inversion phenomena. The objective of this paper is to investigate the effects of shear intensity and water cut (WC) on the phase inversion region and also the droplet size distribution. A state-of-the-art closed-loop two phase (oil–water) flow facility including a multipass gear pump and a differential dielectric sensor (DDS) is used to identify the phase inversion region. Also, the facility utilizes an in-line droplet size analyzer (a high speed camera), to record real-time videos of oil–water emulsion to determine the droplet size distribution. The experimental data for phase inversion confirm that as shear intensity increases, the phase inversion occurs at relatively higher dispersed phase fractions. Also the data show that oil-in-water emulsion requires larger dispersed phase volumetric fraction for phase inversion as compared with that of water-in-oil emulsion under the same shear intensity conditions. Experiments for droplet size distribution confirm that larger droplets are obtained for the water continuous phase, and increasing the dispersed phase volume fraction leads to the creation of larger droplets.

Effects of the Dispersed Phase on Oil/Water Wax Deposition

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Pengyu Wang ◽  
Wei Wang ◽  
Jing Gong ◽  
Yuanxin Zhou ◽  
Wei Yang
Keyword(s):  
Particle Size ◽  
Crude Oil ◽  
Dispersed Phase ◽  
Wax Deposition ◽  
Waxy Crude Oil ◽  
Water Emulsion ◽  
Oil Emulsion ◽  
Wax Content ◽  
Oil Water ◽  
Water Cut

In the study of the foundation of the oil / water wax deposition experiment, the emulsification characteristics of crude oil emulsion with high wax content have gradually become the hot research area. In the current research of emulsification characteristics of oil/water emulsion, the attention has been focused on the study of the effects of water cut, stirring speed, particle size distribution on the viscosity of waxy crude oil emulsion in the experiment, in which heavy oil and simulated oil are adopted as the working fluids. In this study, the emulsion with different water cut and stirred by different speed was prepared under three different temperature conditions, the temperature above the wax appearance temperature (WAT), near the WAT, and below the WAT. The polarization microscope and rotary viscometer were applied to measure the effects of the particle size of the dispersed phase and waxy crystal distribution on the oil/water emulsion viscosity. The results suggest that preparing the temperature for crude oil emulsion with high wax content has an important influence on the emulsion microstructure. This study lays the foundation for further study of oil/water two phase dynamic wax deposition experiments.

scholarly journals Laboratory studies of physico-chemical methods to break emulsions stabilized with surfactant-polymer cocktails

2021 ◽  
Vol 6 (4) ◽  
pp. 154-159
Author(s):  
Nataliya N. Tomchuk ◽  
Ekaterina A. Filatova ◽  
Daria S. Burakova ◽  
Mariam R. Karimova ◽  
Nikolay Yu. Tretyakov ◽  
...  
Keyword(s):  
Physicochemical Parameters ◽  
Laboratory Tests ◽  
Economic Feasibility ◽  
Oil Field ◽  
Model Systems ◽  
Technical Equipment ◽  
Water Emulsion ◽  
Well Production ◽  
Oil Water ◽  
Water Cut

Introduction. Oil field treatment often makes it necessary to combine different methods of well production treatment, taking into account the development regimes and parameters, produced and injected fluids, technical equipment and economic feasibility. The carried-out complex of laboratory tests is aimed at the creation and subsequent destruction of model systems with specified parameters. The list of the considered methods and the temperature regime of the tests are due to the physicochemical parameters and the field specifics. The purpose of this article is to search for an effective method for the primary treatment of well production after SP-flooding — a highly stable oil-water emulsion, additionally stabilized during pumping by means of an ESP. Materials and methods. The laboratory tests helped to develop an optimal mode of creating an artificial emulsion based on oil from BS10-1 reservoir of the Kholmogorsk field in the Yamalo-Nenets Autonomous Okrug, and a surfactant-polymer cocktail, which simulates well production after SP-flooding. The research tested physicochemical methods of destroying oil-water emulsions, such as their dilution with formation fluids, thermal settling, gravitational separation by centrifugation at RPM = 4000–12000 rpm, introduction of demulsifiers, as well as a combined effect, including all of the above approaches. The tested methods were supplied with the calculated values of the oil phase final water-cut, which allowed us to evaluate the effectiveness of the applied approaches to the destruction of model systems. Results. It has been found that not all of the applied approaches provide the extraction of the estimated amount of oil from emulsion systems with varying degrees of dilution by formation fluids. Satisfactory destruction of the emulsion was achieved after 10–20 min of centrifugation at T = 40 °C and RPM within 4000–8000 rpm. The traditional introduction of industrial demulsifiers into the studied systems without additional influences is ineffective. Conclusion. The optimal level of water cut in the oil phase of ≤5% was achieved after diluting the emulsion with formation fluids, with a combined approach to the destruction of the original and diluted emulsion with formation fluids. In addition, the research showed that it is possible to re-use the extracted SP-composition when controlling its physicochemical parameters, taking into account the effect of the introduced additives.

OIL SPILL DISPERSION STABILITY AND OIL RE-SURFACING

2008 ◽  
Vol 2008 (1) ◽  
pp. 661-665 ◽  
Author(s):  
Merv Fingas
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Emulsion Stability ◽  
Dispersed Phase ◽  
Water Interface ◽  
Water Emulsion ◽  
Stabilization Process ◽  
Oil In Water ◽  
Oil Water ◽  
Oil In Water Emulsion

ABSTRACT This paper summarizes the data and the theory of oil-in-water emulsion stability resulting in oil spill dispersion re-surfacing. There is an extensive body of literature on surfactants and interfacial chemistry, including experimental data on emulsion stability. The phenomenon of resurfacing oil is the result of two separate processes: de stabilization of an oil-in-water emulsion and desorption of surfactant from the oil-water interface which leads to further de stabilization. The de stabilization of oil-in-water emulsions such as chemical oil dispersions is a consequence of the fact that no emulsions are thermodynamically stable. Ultimately, natural forces move the emulsions to a stable state, which consists of separated oil and water. What is important is the rate at which this occurs. An emulsion is said to be kinetically stable when significant separation (usually considered to be half or 50% of the dispersed phase) occurs outside of the usable time. There are several forces and processes that result in the destabilization and resurfacing of oil-in-water emulsions such as chemically dispersed oils. These include gravitational forces, surfactant interchange with water and subsequent loss of surfactant to the water column, creaming, coalescence, flocculation, Ostwald ripening, and sedimentation. Gravitational separation is the most important force in the resurfacing of oil droplets from crude oil-in-water emulsions such as dispersions. Droplets in an emulsion tend to move upwards when their density is lower than that of water. Creaming is the de stabilization process that is simply described by the appearance of the starting dispersed phase at the surface. Coalescence is another important de stabilization process. Two droplets that interact as a result of close proximity or collision can form a new larger droplet. The result is to increase the droplet size and the rise rate, resulting in accelerated de stabilization of the emulsion. Studies show that coalescence increases with increasing turbidity as collisions between particles become more frequent. Another important phenomenon when considering the stability of dispersed oil, is the absorption/desorption of surfactant from the oil/water interface. In dilute solutions, much of the surfactant in the dispersed droplets ultimately partitions to the water column and thus is lost to the dispersion process. This paper provides a summary of the processes and data from some experiments relevant to oil spill dispersions.

Herbicide-Oil-Water Emulsions

1989 ◽  
Vol 3 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Frank A. Manthey ◽  
John D. Nalewaja ◽  
Edward F. Szelezniak
Keyword(s):  
Soybean Oil ◽  
Seed Oil ◽  
Emulsion Stability ◽  
Seed Oils ◽  
Water Emulsion ◽  
Esterified Fatty Acids ◽  
Oil In Water ◽  
Crop Origin ◽  
Oil Water ◽  
Oil In Water Emulsion

Oil-water emulsion stability was determined for crop origin and refinement of seed oils and their methyl esterified fatty acids (methylated seed oil) as influenced by emulsifiers and herbicides. Oil-in-water emulsion stability of one-refined, degummed, and crude seed oils was affected by the emulsifier. However, emulsion stability of methylated seed oil was not affected by the refinement of the seed oil used to produce the methylated seed oil or by the emulsifier. Oils without emulsifiers or emulsifiers alone added to formulated herbicide-water emulsions reduced emulsion stability depending upon the herbicide and emulsifier. Further, emulsion stability of formulated herbicides plus oil adjuvants was influenced by the oil type, the emulsifier in the oil adjuvant, and the herbicide. Oil-in-water emulsions improved or were not affected by increasing concentration of the emulsifier in the oil. However, T-Mulz-VO at a concentration greater than 10% with soybean oil or 5% with methylated soybean oil reduced emulsion stability with sethoxydim. Emulsion stability of herbicides with adjuvants depends upon the herbicide, the emulsifier, emulsifier concentration, and the crop origin, type, and refinement of oil.

Comparison of Nanoparticle and Surfactant Oil/Water-Emulsion Separation Kinetics

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 2182-2194 ◽  
Author(s):  
I.. Gavrielatos ◽  
R.. Dabirian ◽  
R.. Mohan ◽  
O.. Shoham
Keyword(s):  
Water Separation ◽  
Equal Concentration ◽  
Water Emulsion ◽  
Efficient Operation ◽  
Surveillance Camera ◽  
Hydrophilic Lipophilic Balance ◽  
Emulsion Separation ◽  
Oil Water ◽  
Water Cut ◽  
Separation Kinetics

Summary Experimental observations, during oil–production operations, regarding the formation of oil/water emulsions stabilized by nanoparticles and surfactants, are presented. Similarities and differences between the two types of emulsions are discussed on the basis of acquired separation profiles, as well as respective fluid interfacial properties. A state–of–the–art portable dispersion–characterization rig (PDCR) was used to run the experiments, and a surveillance camera was deployed to monitor the emulsion separation kinetics. Commercial–grade mineral oil and distilled water were used as the test fluids. Silica nanoparticles of different wettabilities, as well as surfactants with different hydrophilic-lipophilic balance (HLB) values, were deployed to investigate commonalities/differences between the surfactant– and nanoparticle–stabilized emulsions under ambient–temperature and –pressure conditions. Separation profiles were analyzed, and similar behaviors between the corresponding surfactant and nanoparticle emulsions were observed for the 25%–water–cut case. For higher water cuts, however, the surfactant–stabilized emulsions were tighter than their nanoparticle counterparts, displaying much lower separation rates. In the most severe cases, the surfactants totally inhibited the oil–creaming process and oil remained trapped in the emulsion for several hours. Multiple emulsions (O/W/O) were observed in certain cases [for hydrophilic nanoparticles and lipophilic surfactants (Span® 80)]. On the basis of the aforementioned experimental observations, the presence of surfactants caused more–severe problems for the oil/water–separation process than did the presence of an equal concentration of nanoparticles. Pendant–drop measurements indicated that the surfactants significantly lowered the interfacial tension (IFT) between the oil and water, whereas the nanoparticles did not. Finally, a literature model was used to predict separation profiles for the oil/water dispersions and evaluated by comparing the predictions with the acquired experimental data. Current research sets the benchmark for more–thorough investigations aimed at providing guidelines for a more efficient operation of separators that handle surfactant– or nanoparticle–stabilized emulsions and a better understanding of the related phenomena.

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