Oil Bubble Research Articles

تحسين علاقة المرهون لضغط نقطة الفقاعة للنفط الخام الليبي

Accurate estimation of crude oil bubble point pressure plays a vital role in many petroleum engineering calculations, such as reserve estimation, material balance, reservoir simulation, production equipment design, and optimization of well performance. The Pb can be measured in the pressure-volume-temperature (PVT) experiments. Nonetheless, the PVT measurements have limitations, such as being costly and time-consuming. In this paper, the Al-Marhoun correlation for bubble point pressure for black oil reservoirs is improved using the linearization of non-linear regression techniques to fit Libyan crudes accurately. A total of 62 PVT data reports taken from various Libyan oil fields were used in the study. The PVT data consist of an oil gravity range of 24.7 ºAPI to 46.8 ºAPI and bubble point pressures of 123 psig to 6100 psig. Statistical error analyses and graphical methods were used to evaluate the original and modified Al-Marhoun correlations. The results showed that the improved Al-Marhoun correlation exhibits significantly lower average absolute error and deviation than the published ones. The correlation coefficient of R2 of the improved Al-Marhoun correlation is 96.70%, and the average percent error (APE) is 0.70% with a standard deviation (SD) of 14.70.

Collision adhesion law of oil Droplets-Bubbles with different particle sizes in free floating

The treatment of oily wastewater has become a serious problem in the late stage of oilfield development. At the same time, it is of great significance to the improvement of ecological environment. As the key process of oil-bearing wastewater treatment, the study on the binding and adhesion law of oil droplets and bubbles in flotation and its related mechanism can provide reference for its application. Using a double high-speed camera acquisition system, the floating process and collision adhesion law of oil droplets and bubbles in a vertical transparent circular tube were experimentally studied, and the collision adhesion process of oil droplets (0.721 ∼ 3.759 mm) and bubbles (0.797 ∼ 2.886 mm) in different diameters were analysed. It is concluded that the oil droplet and the bubble collide with each other, and then the bubble slides along the surface of the oil droplet, and a neck shape appears at the end of the contact site, and then the neck increases with the diffusion of the oil droplet to form an oil-bubble adhesion body. And the process of elastic drags and contraction separation of the mixture is also demonstrated. It is found that the combination of oil droplets and bubbles with different diameters will have two types of collision adhesion modes, which oil droplet type and oil film type, respectively. Therefore, the diameter ratio of oil droplets and bubbles is a key factor, and when the diameter ratio is greater than 0.75, the adhesion mode of the adhesive body changes from unstable oil droplet type to more stable oil film type.

The 50-year-old Oil Crisis and its Impact on the Global Economy: A Bibliometric Analysis

The world faced different crises, several times, in the last five decades. The COVID-19 pandemic, debt crisis and oil bubble were the most important crises among them. During the crisis, the main financial driving factor was the oil price which transmitted an alarming hit to other economic nexus factors. The objective of this paper was to find out the crisis period, caused by crude oil and its eventuality in different markets’ historical plots. Scopus data represent 605 studies, using the bibliometrix R tool, about crude oil and related crises. Within the context of the contemporary scientific literature, the most significant authors, publications, and research institutions were included in this paper. In the context of the most recent scientific literature, the most significant authors, publications, and research institutions were identified and the relevance of their contributions was established. This research employed disaggregated sectoral analysis and mechanistic analysis on grounded theory, which included moderation analysis. Finally, this bibliometric analysis tried to locate roadblocks in the current literature as well as indicate new directions for investigation.

Research of bubble motion and correction of drag coefficient in viscous oil at low Reynolds number

As the core fundamental components in the field of fluid transmission and control, viscous oil fluid components determine the technological level of fluid machinery and high-end equipment. However, bubbles as effective cavitation nuclei widely exist in the interior of viscous oil fluid components, directly affecting their performance and technological development. In order to reveal the bubble motion characteristics in viscous oil and establish a high-precision prediction method, this paper focuses on No. 110 technical white oil and develops a visualized observation system for studying the motion characteristics and morphological features of bubbles in viscous oil. The bubble motion trajectory, rising rate, and force state are analyzed, and a prediction model for the drag coefficient is proposed and corrected. The research results indicate that during the rising process, the bubble morphologies in viscous oil show an elliptical shape. The oil temperature has a significant influence on the bubble motion characteristics, with the occurrence of oscillations during the rise process after reaching 80 °C. Additionally, a new prediction model for the drag coefficient of bubble is fitted, where the relative error of bubble motion rate can be controlled within 5.5% for 0.3 < Re < 50. This research provides significant theoretical significance and engineering application value.

Extreme events, economic uncertainty and speculation on occurrences of price bubbles in crude oil futures

This paper examines the impacts of extreme events, economic uncertainty and speculation on price bubbles in crude oil futures. For better forecast and estimate the positive/negative price bubbles of crude oil futures, the log-periodic power law singularity confidence multi-scale indicators application is used. The panel probit model examines impacts of extreme events, economic uncertainty and speculation on price bubbles in crude oil. The results show that the recent extreme events including Corona Virus Disease 2019 and Russia-Ukraine war significantly affect both positive/negative bubbles in crude oil futures. Measures of economic uncertainty significantly affect both positive/negative bubbles in the crude oil. However, the results find that the speculation significantly affect the positive bubbles and does not significantly affect the negative bubbles. Overall, extreme events, economic uncertainty, and speculation can all contribute to the occurrences of price bubbles in crude oil futures markets. This study provides new insights for the policy makers and market participants to monitor the occurrence of price bubbles.

A Novel Fast Coupled Algorithm for Analyzing the Dynamic Behavior of the Bubble in the Transformer Oil under the Electric Field

A Novel Fast Coupled Algorithm for Analyzing the Dynamic Behavior of the Bubble in the Transformer Oil under the Electric Field

Capillary flow of two immiscible liquids initially separated by a Taylor gas bubble

We investigate the capillary displacement of silicone oil columns by water in tandem with a Taylor gas bubble in horizontally aligned tubes that initially separate the two immiscible liquids. The experiments show that the gas slug's motion forces the drainage of the prefilling liquid through a thin film deposited on the tube's wall. The displaced oil is then recovered at the advancing water meniscus. The dynamics of the capillary displacement and drainage are studied as functions of the silicone oil and gas bubble volumes. We find that the Taylor bubble's length has a small influence on the capillary displacement and drainage of the prefilling liquid. The study presents an adapted model for the capillary drainage and oil recovery using Taylor's law for the deposited film thickness on the tube's wall, which collapses all experimental data onto a single curve.

Enhancement of the attachment performance with oil droplet by coating of condensate film on the surface of air bubble

The weak adhesion between oil droplets and bubbles frequently reduces the flotation effectiveness of oil removal. This study focuses on the hydrophobic and oleophilic modification of bubble surfaces by encapsulating light hydrocarbon homologue-condensate to address this issue. The adhesion properties were characterized by the surface properties and interaction barriers of oil droplets and air/ condensate bubbles. The results indicated that condensate bubbles exhibited shorter induction time and faster spreading rate than air bubbles when adhering to oil droplets. The condensate film effectively extracted the oil droplets and completely enveloped the bubble surface. Furthermore, the non-DLVO model best fitted bubble induction time, revealing negative interaction energy barriers that promoted adhesion between condensate bubbles and oil droplets. In summary, coating a condensate film on bubble surfaces enhances the adhesion effect on oil droplets, which research provides valuable theoretical guidance for applying condensate bubble flotation process.

Retrieving A retained Heavy Silicone Oil Bubble: Two Novel Surgical Techniques.

To describe two surgical techniques for rescuing a retained heavy silicone oil bubble in the posterior pole: 1) light pipe method and 2) perfluorocarbon liquid method. The surgical techniques are described in detail, along with an illustrative video for each. A short 25-gauge metallic cannula and active suction pump are used for standard heavy silicone oil removal. Both surgical approaches are practical and effective options to complete the removal of heavy silicone oil when a bubble sinks to the posterior pole. Both the light pipe and perfluorocarbon methods are suitable to remove retained heavy silicone oil and thus avoid the need for further incisions and the risks associated with the use of larger gauge instrumentation.

Physicochemical Properties of Porang Nanocoating with the Addition of Essential Oils

Porang nanocoating is a food coating that has the potential to be developed and is gaining popularity among the public to extend the shelf life of fruits and vegetables. Porang Nanocoating is a nano-sized edible coating made from porang tuber glucomannan. The addition of essential oils can improve the property of the nanocoating of people as a natural antimicrobial coating. Thyme, cinnamaldehyde and eugenol essential oils are known to have excellent antimicrobial properties. Antimicrobial ability is strongly influenced by the concentration of added essential oil. The purpose of this study was to determine the effect of the type and concentration of essential oils on the physicochemical properties of porang nanocoating. This study used a factorial completely randomized design (CRD) with two factors, namely the type of essential oil treatment including essential oils of thyme, eugenol, cinnamaldehyde. While other treatments are essential oil concentrations, namely 1%, 2%, and 3%. The results of this study indicate that the type of essential oil and its concentration affect the physicochemical properties of the porang nanocoating. The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few While other treatments are essential oil concentrations, namely 1%, 2%, and 3%. The results of this study indicate that the type of essential oil and its concentration affect the physicochemical properties of the porang nanocoating. The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few While other treatments are essential oil concentrations, namely 1%, 2%, and 3%. The results of this study indicate that the type of essential oil and its concentration affect the physicochemical properties of the porang nanocoating. The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few. Treatment of essential oil concentrations gives physicochemical properties to Porang Nanocoating which has an average Viscosity value of 16.11 m.Pa.s. – 18.61 m.Pa.s; The degree of acidity (pH) ranges from 6.25 to 6.39; Color 12.80 – 14.91; Transparency 89.39 – 89.52; has stable properties or does not occur emulsion separation in the stability test and in the microscopic test has few oil droplets or bubbles.

Study on the Dynamic Evolution of Bubbles in Oil/Pressboard Insulation

Power transformer may generate bubbles in the transformer oil due to various factors such as internal insulation winding vibration and pressure change. Bubbles distort the spatial electric field, which makes the discharge breakdown along the gas channel, accelerate the discharge breakdown of insulating medium. Therefore, in order to prevent the arc discharge induced by micro bubbles inside the transformer from increasing the risk of transformer combustion damage, it is necessary to conduct in-depth research on the dynamic law of suspended bubbles before insulation breakdown from the source by combining experiments and simulations. In this paper, the bubble dynamic model of needle plate electrode under the multi coupling physical field of transformer is established in terms of the migration and deformation of suspended bubbles in liquid phase. By comparing the migration trajectories of single suspended bubbles obtained from experiments and simulations, the reliability of the model is verified. The variation of velocity component of voltage amplitude and the change of shape stretching of single suspended bubble in power frequency period are simulated, and the fluctuation law of pressure formed by electrostriction force inside and outside the bubble during migration is analyzed. The capacity absorption process of multi bubbles in the strong field region near the needle electrode was simulated. The changes of the surrounding liquid pressure and the spatial electric field distribution during the formation of the gas channel were analyzed, and the internal relationship between the gas channel and the formation of the discharge breakdown was revealed.

Transformer oil quality assessment based on lens-free holographic microscopy

In order to avoid serious problems caused by excessive gas in transformer oil and to realize online monitoring of transformer oil, we propose a method based on lens-free holographic microscopy for transformer oil quality assessment. Using a lens-free device, we can obtain a hologram of the gas bubbles with a large field of view in transformer oil. After the reconstruction, the quantitative phase and shape information of the gas bubbles in the oil can be acquired, thus we can further calculate the parameter of the area, volume, amount, and gas to oil volume ratio of the gas bubbles in transformer oil, which can be used to evaluate the quality of transformer oil effectively. During the experiment, we measured the smallest diameter of the gas bubble in oil was 8 μm. The newly designed method provides a new solution for the assessment of transformer oil quality.

Demonstration of Sensor Monitoring of Lubricants

Due to the spread of carbon neutral, the effective use of lubricant has been drawing attention. Since the main component of lubricant is petroleum-derived hydrocarbon oil, reducing the amount used by 1 kg will reduce CO2 by approximately 3 kg. The value of CO2 reduction is very important. In order to reduce the amount of lubricant used, there is a movement to reduce the frequency of lubricant exchange or continue to use lubricant without exchanging it. However, it is known that lubricant-induced mechanical failures occur. For this reason, equipment condition monitoring using oil sensors has been spread. The color of the lubricant, also called machine blood, indicates the condition of the machine. The oil sensor measures contamination, which has a fatal effect on machine failure, and oxidation degradation, which is related to the performance of lubricant and the machine failure. Contamination includes water and wear debris, and oxidative degradation includes consumption of additives and oxidation of base oil. By digitizing the hue of wind turbine gear oil through color diagnosis using an oil sensor, the oil contamination and degradation is identified. Additives in the gear oil were quantified by liquid chromatography-mass spectrometry, and it was found that the color change of gear oil was highly correlated with the depletion of the extreme pressure additive. It is known that the depletion of the extreme pressure additive is correlated with the useful life of the gear oil. Using the technique, the remaining life diagnosis of the gear oil was shown. Demonstration in the gearbox with the oil sensor was succeeded by avoidance of the effects of air bubbles in the gear oil.

Analysis of Bubble Motion Characteristics in Oil Based on Level Set Method

At present, transformer oil is the primary insulation method for large power transformers, and the dynamic behavior of bubbles in transformer oil can impact the insulation performance of transformer oil. Therefore, based on the level set method in this paper, the motion characteristics of bubbles in two structures, a horizontal oil channel and a vertical oil channel, under various conditions of different bubble numbers, different flow velocities, and different bubble sizes are studied using finite element simulation. The simulation results show that the kinetic behavior of bubbles becomes more complicated as the radius increases, the number of bubbles increases, and the flow velocity increases. At the same time, the bubble expansion and deformation is a cyclic process due to the electric field force, laminar flow and surface tension in the bubble suspension process.

Identification of oil–water-gas flow patterns by super-sparse near-infrared wavelengths sensor

This paper puts forward a method of using two wavelengths of near-infrared light to identify the oil–gas-water mixed flow patterns. Propose a new method of multiple correlation algorithm (MCA) to solve the sensor super-sparse representation problem. Use MCA results as input layer parameters, use BP neural network to train the voltage signal and identify different flow patterns. The experimental results show that the recognition degrees of water, oil bubble, and oil flow patterns have reached 96.77%, 98.39%, and 100%, respectively, and the recognition rate of the water–gas phase has 78.38%. Using a correction model can further improve the accuracy. Test the samples with water cut from 90% to 70%, and the average RMSE = 1.59e-2. This method can be applied to the detection of the water cut of crude oil in oil fields and has a certain reference value for the wavelength selection of near-infrared light sensors.

Simulation Study on Dynamic Characteristics of Bubbles in Transformer Oil under Extremely Nonuniform Field

Bubbles in transformer oil seriously threaten the deterioration of internal insulation performance during its movement, leading to severe transformer failure. A gas-liquid two-phase flow simulation model is established based on the phase field method to study the effect of bubbles on the insulation performance of transformer oil. The dynamic characteristics of bubbles in transformer oil under extremely non-uniform electric fields are studied. The results show that the electric field force has a pushing effect on the bubble. As the voltage increases, the pushing effect is more significant, and the displacement distance of the bubble in the horizontal direction is larger. The velocity curve of a single bubble in the vertical direction shows an oscillating attenuation trend. The pushing effect of electric field force on the bubble causes the bubble velocity near the needle electrode to decrease, but the stretching effect increases the average bubble velocity. When the electric field strength is further improved due to the enhanced push-off impact of the electric field force on the bubbles, the bubbles will gather under the needle electrode to form cluster bubbles, further reducing the insulation performance of the transformer oil. This needs to be paid attention to in the design of the insulation structure to avoid the accumulation of bubbles caused by too high an electric field intensity at a particular place.

STRAWBERRY RETINA: SILICONE OIL-RETINA INTERFACE ON MULTIMODAL IMAGING.

To report a new photographic macular feature identified on multimodal imaging in eyes with silicone oil in situ. Retrospective, observational case series of three eyes of three patients. Two eyes had undergone initial vitrectomy for vitreous hemorrhage with fibrovascular membranes causing tractional retinal detachments secondary to retinovascular occlusion. One eye had further vitrectomy for rhegmatogenous retinal detachment complicated with proliferative vitreoretinopathy. All three eyes had multiple, discrete, coarse, hyperreflective deposits at the silicone oil-retina interface on optical coherence tomography macular scans, with increased reflectivity from the inner retinal layers. On multicolor and infrared images, these preretinal deposits produced hyporeflective darker spots giving a quasi-pitting appearance of the retinal surface against glossy bright reflection from silicone oil, thus simulating an appearance of ‟a strawberry." These deposits are causing inverse pitting of the oil bubble. On blue autoflourescence imaging, the preretinal deposits caused hypoautoflourescence. Partial silicone oil emulsification was seen superiorly in two of these patients with a different clinical and optical coherence tomography appearance from these hyperreflective macular deposits. We describe a new distinctive ‟Strawberry Retina" appearance identified on multicolor and infrared macular images associated with hyperreflective, coarse deposits at the silicone oil-retina interface.

New Synthetic Partial Discharge Calibrator for Qualification of Partial Discharge Analyzers for Insulation Diagnosis of HVDC and HVAC Grids.

A synthetic partial discharge (PD) calibrator has been developed to qualify PD analyzers used for insulation diagnosis of HVAC and HVDC grids including cable systems, AIS, GIS, GIL, power transformers, and HVDC converters. PD analyzers that use high-frequency current transformers (HFCT) can be qualified by means of the metrological and diagnosis tests arranged in this calibrator. This synthetic PD calibrator can reproduce PD pulse trains of the same sequence as actual representative defects (cavity, surface, floating potential, corona, SF6 protrusion, SF6 jumping particles, bubbles in oil, etc.) acquired in HV equipment in service or by means of measurements made in HV laboratory test cells. The diagnostic capabilities and PD measurement errors of the PD analyzers using HFCT sensors can be determined. A new time parameter, "PD Time", associated with any arbitrary PD current pulse i(t) is introduced for calibration purposes. It is defined as the equivalent width of a rectangular PD pulse with the same charge value and amplitude as the actual PD current pulse. The synthetic PD calibrator consists of a pulse generator that operates on a current loop matched to 50 Ω impedance to avoid unwanted reflections. The injected current is measured by a reference measurement system built into the PD calibrator that uses two HFCT sensors to ensure that the current signal is the same at the input and output of the calibration cage where the HFCT of the PD analyzer is being calibrated. Signal reconstruction of the HFCT output signal to achieve the input signal is achieved by applying state variable theory using the transfer impedance of the HFCT sensor in the frequency domain.

Pore-scale Ostwald ripening of gas bubbles in the presence of oil and water in porous media

HypothesisOstwald ripening of gas bubbles is a spontaneous mass transfer process that can impact the storage volume of trapped gas in the subsurface. In homogeneous porous media with identical pores, bubbles evolve toward an equilibrium state of equal pressure and volume. How the presence of two liquids impacts ripening of a bubble population is less known. We hypothesize that the equilibrium bubble sizes depend on the surrounding liquid configuration and oil/water capillary pressure. Method and numerical experimentsWe investigate ripening of nitrogen bubbles in homogeneous porous media containing decane and water using a level set method that alternately simulates capillary-controlled displacement and mass transfer between bubbles to eradicate chemical-potential differences. We explore impacts of initial fluid distribution and oil/water capillary pressure on the bubble evolution. FindingsRipening in three-phase scenarios in porous media stabilizes gas bubbles to sizes that depend on their surrounding liquids. Bubbles in oil decrease in size while bubbles in water increase in size with increasing oil/water capillary pressure. Bubbles in oil reach local equilibrium before the three-phase system stabilizes globally. A potential implication for field-scale gas storage is that the trapped gas fractions in oil and water vary with depth in the oil/water transition zone.

Magnetic Resonance Imaging of Multi‐Phase Lava Flow Analogs: Velocity and Rheology

AbstractThe rheology of lavas and magmas exerts a strong control on the dynamics and hazards posed by volcanic eruptions. Magmas and lavas are complex mixtures of silicate melt, suspended crystals, and gas bubbles. To improve the understanding of the dynamics and effective rheology of magmas and lavas, we performed dam‐break flow experiments using suspensions of silicone oil, sesame seeds, and N2O bubbles. Experiments were run inside a magnetic resonance imaging (MRI) scanner to provide imaging of the flow interior. We varied the volume fraction of sesame seeds between 0 and 0.48, and of bubbles between 0 and 0.21. MRI phase‐contrast velocimetry was used to measure liquid velocity. We fit an effective viscosity to the velocity data by approximating the stress using lubrication theory and the imaged shape of the free surface. In experiments with both particles and bubbles (three‐phase suspensions), we observed shear banding in which particle‐poor regions deform with a lower effective viscosity and dominate flow propagation speed. Our observations demonstrate the importance of considering variations in phase distributions within magmatic fluids and their implications on the dynamics of volcanic eruptions.