Hyperspectral remote sensing identification of marine oil emulsions based on the fusion of spatial and spectral features

Marine oil spill emulsions are difficult to recover,and the damage to the environment is not easy to eliminate.The use of remote sensing to accurately identify oil spill emulsions is highly important for the protection of marine environments.However,the spectrum of oil emulsions changes due to different water content.Hyperspectral remote sensing and deep learning can use spectral and spatial information to identify different types of oil emulsions.Nonetheless,hyperspectral data can also cause information redundancy,reducing classification accuracy and efficiency,and even overfitting in machine learning models.To address these problems,an oil emulsion deep-learning identification model with spatial-spectral feature fusion is established,and feature bands that can distinguish between crude oil,seawater,water-in-oil emulsion(WO),and oil-in-water emulsion(OW)are filtered based on a standard deviation threshold–mutual information method.Using oil spill airborne hyperspectral data,we conducted identification experiments on oil emulsions in different background waters and under different spatial and temporal conditions,analyzed the transferability of the model,and explored the effects of feature band selection and spectral resolution on the identification of oil emulsions.The results show the following.(1)The standard deviation–mutual information feature selection method is able to effectively extract feature bands that can distinguish between WO,OW,oil slick,and seawater.The number of bands was reduced from 224 to 134 after feature selection on the Airborne Visible Infrared Imaging Spectrometer(AVIRIS)data and from 126 to 100 on the S185 data.(2)With feature selection,the overall accuracy and Kappa of the identification results for the training area are 91.80%and 0.86,respectively,improved by 2.62%and 0.04,and the overall accuracy and Kappa of the identification results for the migration area are 86.53%and 0.80,respectively,improved by 3.45%and 0.05.(3)The oil emulsion identification model has a certain degree of transferability and can effectively identify oil spill emulsions for AVIRIS data at different times and locations,with an overall accuracy of more than 80%,Kappa coefficient of more than 0.7,and F1 score of 0.75 or more for each category.(4)As the spectral resolution decreasing,the model yields different degrees of misclassification for areas with a mixed distribution of oil slick and seawater or mixed distribution of WO and OW.Based on the above experimental results,we demonstrate that the oil emulsion identification model with spatial–spectral feature fusion achieves a high accuracy rate in identifying oil emulsion using airborne hyperspectral data,and can be applied to images under different spatial and temporal conditions.Furthermore,we also elucidate the impact of factors such as spectral resolution and background water bodies on the identification process.These findings provide new reference for future endeavors in automated marine oil spill detection.

Experimental investigation on using CO_(2)/H_(2)O emulsion with high water cut in enhanced oil recovery

CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility reduction.However,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fraction),while CO_(2) emulsion with high water cut has been rarely researched.In this paper,we carried out a comprehensive experimental study of using high water cut CO_(2)/H_(2)O emulsion for enhancing oil recovery.Firstly,a nonionic surfactant,alkyl glycosides(APG),was selected to stabilize CO_(2)/H_(2)O emulsion,and the corresponding morphology and stability were evaluated with a transparent PVT cell.Subsequently,plugging capacity and apparent viscosity of CO_(2)/H_(2)O emulsion were measured systematically by a sand pack displacement apparatus connected with a 1.95-m long capillary tube.Furthermore,a high water cut(40 vol%) CO_(2)/H_(2)O emulsion was selected for flooding experiments in a long sand pack and a core sample,and the oil recovery,the rate of oil recovery,and the pressure gradients were analyzed.The results indicated that APG had a good performance on emulsifying and stabilizing CO_(2) emulsion.An inversion from H_(2)O/CO_(2) emulsion to CO_(2)/H_(2)O emulsion with the increase in water cut was confirmed.CO_(2)/H_(2)O emulsions with lower water cuts presented higher apparent viscosity,while the optimal plugging capacity of CO_(2)/H_(2)O emulsion occurred at a certain water cut.Eventually,the displacement using CO_(2)/H_(2)O emulsion provided 18.98% and 13.36% additional oil recovery than that using pure CO_(2) in long sand pack and core tests,respectively.This work may provide guidelines for EOR using CO_(2) emulsions with high water cut.

Effects of Different Heavy Crude Oil Fractions on the Stability of Oil-in-water Emulsions—the film properties of heavy crude functional components and water system

A series of π-A isotherms are drawn to study the film properties of the components with Langmuir-Blodgett technique. The effects of the aromaticity of spread solvents and pH value on the air/water film formed by the components are investigated. Acid fraction and asphaltene can form stable two-dimensional insoluble films on an air/water surface. The surface film pressure of acid fraction and asphaltene is higher and more stable than that of the other fractions. The surface film pressure of the fraction increases evidently under the basic condition (pH=12). The results show that the interfacial activity of acid fraction and asphaltene is superior to that of the other fractions and the basic condition is favorable to the stability of the O/W emulsion.

Modeling and Simulation of High Power Ultrasonic Process in Preparation of Stable Oil-in-Water Emulsion

The aims of this research are to study application of high power ultrasound in preparation of stable oil-in-water emulsion. The effect of pH, ionic strength, pectin, Guar gum, lecithin, egg yolk, and xanthan gum as well as the time of sonication, temperature and viscosity of oil-water mixture on the specific surface area and size of droplets, and creaming index of the emulsion samples was investigated. The experimental data were analyzed with Taguchi method and optimum conditions were determined. In addition, an adaptive neuro-fuzzy inference system (ANFIS) was employed to modeling and categorizes the properties of the resulted emulsion. The results showed that increasing sonication time narrowed the range of droplets size distribution. Pectin and xanthan enhanced the stability of emulsion, although they had different impacts on the emulsion stability when used individually or together. Guar gum improved the viscosity of the continuous phase. Emulsions stabilized by egg yolk were found to be stable to droplet flocculation at pH 3 and at relatively low salt concentrations.

Impact of sesame lignan on physical and oxidative stability of flaxseed oil-in-water emulsion

Recent studies have shown that the highly susceptibility to oxidation ofα-linolenic acid(ALA)enriched emulsion delivery system was harmful for human health which limited their incorporation into functional food.Impacts of natural sesamol(SOH)and sesamin(SES)on stability of flaxseed oil-in-water emulsion were investigated.Results showed that SOH indicated higher antioxidant activity and significantly prolonged the time of emulsion oil-off by retarding oil droplet aggregation in a dose dependent manner throughout storage.Moreover,SOH showed substantial extended lag phase of lipid oxidation products,especially for secondary oxidation products(thiobarbituric acid-reactive substances,TBARS),with a maximum reduction of 70%with 800 M dosage.The antioxidative efficiency of SOH might relate to its strong ability of scavenging free radical and chelate transition metal.Furthermore,SOH significantly enhanced interfacial barrier property and reduced permeation rate of peroxyl radical across emulsion interface by hydrogen bonds between sugar groups of saponin molecules and SOH.However,no obvious change in barrier property of emulsion was observed in SES.SOH improved physicochemical property of flaxseed oil-in-water emulsion with higher antioxidant activity and stronger interfacial barrier property,so that it could be serve as plant-based antioxidant in oil-in-water emulsion delivery system.

Rheo-optic in situ synchronous study on the gelation behaviour and mechanism of waxy crude oil emulsions

An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest.

Brucea javanica oil emulsion improves the effect of radiotherapy on esophageal cancer cells by inhibiting cyclin D1-CDK4/6 axis

BACKGROUND Esophageal cancer is one of the most common cancers around the world, and it has high incidence and mortality rates. The conventional therapy for esophageal cancer is radiotherapy, although its effect is highly limited by the resistance of esophageal cancer cells. Thus, strong radiosensitizers can be very crucial during radiotherapy against esophageal cancer. Brucea javanica oil emulsion (BJOE) is a widely used drug against various cancers, such as liver, colon, and ovarian cancer. However, its anti-cancer effect and mechanism and the use of BJOE as a radiosensitizer have not been explored in esophageal cancer. AIM To evaluate the anti-cancer effect and mechanism of BJOE and explore the potential use of BJOE as a radiosensitizer during radiotherapy. METHODS The inhibitory effect of BJOE and its enhancement function with radiation on cell viability were examined with the calculated half-maximal effective concentration and half-maximal lethal concentration. The influence of BJOE on cell migration and invasion were measured with EC109 and JAR cells by wound-healing and transwell assay. Clonogenesis and apoptotic rate, which was measured by Hoechst staining, were investigated to confirm its enhancement function with radiation. To investigate the molecular pathway underlying the effect of BJOE, the expressions of several apoptosis- and cycle-related proteins was detected by western blotting.cell lines more than normal cell lines, and it markedly reduced migration and invasion in esophageal cancer cells (EC109 and JAR). Moreover, it promoted cell apoptosis and enhanced the effect of radiotherapy against esophageal cancerous cells. In the viability test, the values of half-maximal effective concentration and half-maximal lethal concentration were reduced. Compared to the control, only around 1/5 colonies formed when using BJOE and radiation together in the clonogenic assay. The apoptotic rate in EC109 was obviously promoted when BJOE was added during radiotherapy. Our study suggests that the expression of the apoptosis-proteins Bax and p21 were increased, while the expression of Bcl-2 was stable. Further detection of downstream proteins revealed that the expression of cyclin D1 and cyclin-dependent kinase 4/6 were significantly decreased. CONCLUSION BJOE has a strong anti-cancer effect on esophageal cancer and can be used as a radiosensitizer to promote apoptosis in cancerous esophageal cells via the cyclin D1-cyclin-dependent kinase 4/6 axis.

Influence of surfactants used in surfactant-polymer flooding on the stability of Gudong crude oil emulsion

The influences of an anionic-nonionic composite surfactant and petroleum sulfonate, used in surfactant-polymer flooding in Shengli Gudong oilfield, East China, on the interfacial properties of Gudong crude model oil and synthetic formation water was studied by measuring interfacial tension, interfacial viscoelasticity and Zeta potential. The in？ uence of the surfactants on the stability of Gudong water-in-oil （W/O） and oil-in-water （O/W） emulsions was evaluated by separating water from the W/O emulsion and residual oil in the aqueous phase of the O/W emulsion respectively. The results showed that the two kinds of surfactants, namely anionic-nonionic composite surfactant and petroleum sulfonate, are both able to decrease the interfacial tension between the oil phase and the aqueous phase and increase the surface potential of the oil droplets dispersed in the O/W emulsion, which can enhance the stability of the W/O and O/W crude oil emulsions. Compared with petroleum sulfonate, the anionic-nonionic composite surfactant is more interfacially active and able to enhance the strength of the interfacial film between oil and water, hence enhance the stability of the W/O and O/W emulsions more effectively.

A novel oil-in-water drilling mud formulated with extracts from Indian mango seed oil

Drilling muds with less environmental impact are highly desired over conventional diesel-based mud systems,especially in light of the emerging strict environmental laws.In this article,a novel oil-in-water(O/W)emulsion drilling fluid formulated with a methyl ester extracted from Indian mango seed oil was evaluated.The effect of the weight percent of different constituents of the emulsion/suspension including the oil phase,bentonite,and polyanionic cellulose polymer on the rheology and the fluid loss was examined.The methyl ester oil phase/mud system displayed superior physical,chemical,rheological and filtration properties relative to the diesel and the mango seed oil.Eco-toxicity of the methyl ester and diesel(O/W)emulsion mud systems was assessed using the acute lethal concentration test.The Indian mango methyl ester(O/W)emulsion mud displayed much less impact on fish population.Flow characteristics collected from the flow model at 85°C suggested excellent shear thinning behavior of the Indian mango methyl ester(IMME)(O/W)emulsion mud.Moreover,the IMME(O/W)emulsion displayed strong pseudoplastic behavior,an attractive feature in a drilling mud,with increasing clay content and polymer concentration.The methyl ester mud was thermally stable over a wide range of the constituent concentrations.Furthermore,a particle size analysis revealed that engineered drilling muds targeting suspension of particles with certain size range can be formulated by changing the volume fraction of the methyl ester in the mud system.

Experimental investigation of the effects of various parameters on viscosity reduction of heavy crude by oil-water emulsion

The effects of water content, shear rate, temperature, and solid particle concentration on viscosity reduction （VR） caused by forming stable emulsions were investigated using Omani heavy crude oil. The viscosity of the crude oil was initially measured with respect to shear rates at different temperatures from 20 to 70℃. The crude oil exhibited a shear thinning behavior at all the temperatures. The strongest shear thinning was observed at 20℃. A non-ionic water soluble surfactant （Triton X-100） was used to form and stabilize crude oil emulsions. The emulsification process has significantly reduced the crude oil viscosity. The degree of VR was found to increase with an increase in water content and reach its maximum value at 50 % water content. The phase inversion from oil- oil emulsion occurred at 30 in-water emulsion to water-in- % water content. The results indicated that the VR was inversely proportional to temperature and concentration of silica nanoparticles. For water-in-oil emulsions, VR increased with shear rate and eventually reached a plateau at a shear rate of around 350 s^-1. This was attributed to the thinning behavior of the continuous phase. The VR of oil-in-water emulsions remained almost constant as the shear rate increased due to the Newtonian behavior of water, the continuous phase.

Study on the thixotropy and structural recovery characteristics of waxy crude oil emulsion

Waxy crude oil emulsion has thixotropic properties at the temperature near gel point,which is a macromechanical characterization of the structure failure and recovery of waxy crude oil emulsion.In this paper,the thixotropic behaviors of waxy crude oil emulsion near gel point were studied using hysteresis loop formed by stress linear increase and decrease,as well as the structural recovery characteristics.The influence of the loading conditions and water content on the thixotropy of waxy crude oil emulsion were analyzed with hysteresis loop area.The concept of"structural recovery"was introduced to study the degree of structural recovery after different stewing,and influencing factors were taken into account.Results have shown that for waxy crude oil emulsion,the failure to fully restore of the structure after lysis is the cause of the formation of hysteresis loop,and the loading conditions will not affect the strength of thixotropy and the degree of structural recovery.Additionally,the dispersed phase droplets weaken the thixotropy and structure recovery characteristics of waxy crude oil emulsion,and the greater the water content,the weaker the thixotropy.The findings can help to better understand the safe and economic operation of waxy crude oil-water pipeline transportation.

Activity of Brucea javanica oil emulsion against gastric ulcers in rodents

The present study aims to investigate the gastroprotective effect of Brucea javanica oil emulsion(BJOE) in animals. Gastroprotective potential of BJOE was studied on absolute ethanol,aspirin, reserpine and restraint plus water immersion-induced gastric ulcers in mice as well as glacial acetic acid(GAA) and pyloric ligation(PL)-induced gastric ulcers in rats. Except for ulcer scores, total acidity as well as pepsin activity as for the PL-induced gastric ulcer model and ulcer incidence as for the GAA-induced gastric ulcer model were also determined. Histopathological evaluation as for aspirin, reserpine, PL-induced models was conducted. Results showed that BJOE significantly(P < 0.05) reduced ulcer index in the mouse and rat models in a dose-dependent manner. It had significant(P < 0.05) suppressive effect on total activity of gastric juice as well in PL-induced model. Histopathological examination for the stomach samples confirmed the findings in the aspirin, reserpine or PLinduced gastric lesion models, which showed relatively complete mucosa structure and less inflammation. It is concluded that BJOE could be effective on gastric ulcer in rodents and its gastroprotective activity might be related to antioxidant, anti-inflammatory ability and promote gastric mucus secreted. The results may provide beneficial basis for increasing BJOE's clinical indication in future.

Determination of hydrophilic–lipophilic balance value and emulsion properties of sacha inchi oil

Objective: To determine hydrophilic–lipophilic balance(HLB) value, stability of formulate emulsion and properties of sacha inchi oil.Methods: The physiochemical characteristics of sacha inchi oil were first investigated.Free radical scavenging property was studied by DPPH assay. HLB value of sacha inchi oil was experimentally determined by preparing the emulsion using emulsifiers at different HLB value. Sacha inchi oil emulsion was prepared using the obtained HLB and its stability was conducted by centrifugation, temperature cycling, and accelerated stability test. The efficiency of the prepared emulsion was clinically investigated by 15 volunteers. The primary skin irritation was performed using closed patch test. Subjective sensory assessment was evaluated by using 5-point hedonic scale method.Results: Peroxide value of sacha inchi oil was 18.40 meq O2/kg oil and acid value was1.86 KOH/g oil. The major fatty acids are omega-3(44%), omega-6(35%) and omega-9(9%). The vitamin E content was 226 mg/100 g oil. Moreover, sacha inchi oil(167 ppm)and its emulsion showed 85% and 89% DPPH inhibition, respectively. The experimental HLB value of sacha inchi oil was 8.5. The sacha inchi oil emulsion exhibited good stability after stability test. The emulsion was classified as non-irritant after tested by primary skin irritation method. The skin hydration value significantly increased from38.59 to 45.21(P < 0.05) after applying sacha inchi oil emulsion for 1 month and the overall product satisfaction of volunteers after use was with score of 4.2.Conclusions: This work provides information on HLB value and emulsion properties of sacha inchi oil which is useful for cosmetic and pharmaceutical application.

Regulation of ω-3 Fish Oil Emulsion on the SIRS during the Initial Stage of Severe Acute Pancreatitis

The aim of this study was to explore the effects of parenteral supplementation with ω-3 fish oil emulsion （Omegaven） on systemic inflammatory response syndrome （SIRS） during the initial stage of severe acute pancreatitis （SAP）. In a prospective, randomized and controlled trial, 60 patients with SAP were randomized either to treat with conventional therapy （Con group, n=30） or conventional therapy plus intravenous supplementation with ω-3 fish oil emulsion 0.2 g/kg every day （FO group, n=30）. The effects were analyzed by the SIRS-related indexes. The results showed that APACHE-Ⅱ scores in FO group were significantly lower, and the gap increased much farther after the 4th day than those in Con group （P〈0.05）. Fluid equilibrium time became shorter markedly in FO group than in Con group （5.1±2.2 days vs 8.4±2.3 days）. In FO group, SIRS scores were markedly decreased and the SIRS state vanished after the 4th day; Plasma level of TNF-α was significantly reduced, while IL-10 decreased markedly, most prominently between the 4th and 7th day, and the ratio of IL-10/TNF-α raised as compared with Con group （P〈0.05）. During the initial stage of SAP, parenteral supplementation with ω-3 fish oil emulsion could efficiently lower the magnitude and persistence time of the SIRS, markedly retrieve the unbalance of the pro-/anti-inflammatory cytokines, improve severe condition of illness and may provide a new way to regulate the SIRS.

Investigation into the effect of silica nanoparticles on the rheological characteristics of water-in-heavy oil emulsions

The effect of silica nanoparticles on the rheological characteristics of water-in-heavy oil emulsions has been investigated.Enhanced oil recovery methods for heavy oil production(most especially,thermal fluid injection)usually result in the formation of water-in-oil(W/O)emulsion.In reality,the emulsion produced also contains some fine solid mineral particles such as silica,which,depending on its quantity,may alter the viscosity and/or rheological properties of the fluid.A series of binary-component emulsions were separately prepared by dispersing silica nanoparticles[phase fraction,βs,=0.5%–5.75%(wt/v)]in heavy oil(S/O suspension)and by dispersing water[water cut,θw=10%–53%(v/v)]in heavy oil(W/O emulsion).Ternary-component emulsions comprising heavy oil,water droplets and suspended silica nanoparticles(S/W/O)were also prepared with similar ranges ofθw andβs.The viscosity was measured at different shear rates(5.1–1021.4 s-1)and temperatures(30–70°C).Both binary-component and ternary-component emulsion systems were observed to exhibit nonNewtonian shear thinning behaviour.The viscosity of the heavy oil and W/O emulsions increased in the presence of silica nanoparticles.The effect was,however,less signifi cant belowβs=2%(wt/v).Moreover,a generalized correlation has been proposed to predict the viscosity of both binary-component and ternary-component emulsions.

The composition of acid/oil interface in acid oil emulsions

In well stimulation treatments using hydrochloric acid,undesirable water-in-oil emulsion and acid sludge may produce and then cause operational problems in oil field development.The processes intensify in the presence of Fe(Ⅲ),which are from the corroded surfaces of field equipment and/or iron-bearing minerals of the oil reservoir.In order to understand the reasons of the stability of acid emulsions,acid emulsions were prepared by mixing crude oil emulsion with 15% hydrochloric acid solutions with and without Fe(Ⅲ) and then separated into free and upper(water free) and intermediate(with water) layers.It is assumed that the oil phase of the free and upper layers contains the compounds which do not participate in the formation of acid emulsions,and the oil phase of the intermediate layers contains components involved in the formation of oil/acid interface.The composition of the oil phase of each layer of the emulsions was studied.It is found that the asphaltenes with a high content of sulfur,oxygen and metals as well the flocculated material of protonated non-polar oil components are concentrated at the oil/acid interface.In addition to the above,in the presence of Fe(Ⅲ) the Fe(Ⅲ)-based complexes with polar groups of asphaltenes are formed at the acid/oil interface,contributing to the formation of armor films which enhance the emulsion stability.

Factors Influencing Droplet Size of Silicone Oil Emulsion with High Solid Content

A silicone oil emulsion with 60% of solid content was prepared with methyl silicone oil used as the main material by means of the emulsifier-in-oil method.The influence of emulsification conditions on the droplet diameter of silicone oil emulsion was discussed.The experimental results showed that the emulsification method,including the quantity of the emulsifier,the time and temperature of emulsification,the emulsifying water dosage,and the stirring speed,had significant impact on the droplet size.The optimal conditions were identified to achieve a smallest droplet diameter of the emulsion at an emulsifier dosage of 6%,an emulsification temperature of 70 ℃,an emulsification time of 30 min,and a stirring speed of 1100 r/min,with water added in two portions at a ratio of 1:1.The high-solid content silicone oil emulsion with a mean droplet diameter of 2.731 μm was prepared under these conditions that could ensure absence of stratification and floating oil under centrifuging at a speed of 3000 r/min for 30 min.

Development and applications of solids-free oil-in-water drilling fluids

The increasing application of near balanced drilling technology to low-pressure and depleted fractured reservoirs requires the use of low-density drilling fluids to avoid formation damage. Solidsfree oil-in-water （O/W） emulsion drilling fluid is one type of low-density drilling fluid suitable for depleted fractured reservoirs. In this paper, the solids-free O/W drilling fluid was developed and has been successfully used in the Bozhong 28-1 oil and gas field, by which lost circulation, a severe problem occurred previously when drilling into fractured reservoir beds, was controlled, thereby minimizing formation damage. The O/W emulsion drilling fluid was prepared by adding 20% （by volume） No. 5 mineral oil （with high flash point, as dispersed phase） into seawater （as continuous phase）. Surfactant HTO-1 （as a primary emulsifier） and non-ionic surfactant HTO-2 （as a secondary emulsifier） were added into the drilling fluid system to stabilize the emulsion; and YJD polymer was also added to seawater to improve the viscosity of the continuous phase （seawater）. The drilling fluid was characterized by high flash point, good thermal stability and high stability to crude oil contamination.

Characterization of water-in-crude oil emulsions in oil spill response

The formation of water in crude oil emulsions occurs when crude oils are spilled into sea. The water in crude oil emulsions significantly change the properties of the spilled crude oils and in turn influence the choices made relating to oil spill countermeasures. The water in crude oil emulsions were characterized using various techniques in this study. The environmental scanning electron microscopy observation of water droplets in the emulsions is also presented. It is a powerful tool in emulsion observations.