Oil-Water Interfaces: Surface Tension, Rigidity And Structure

1990 ◽  
pp. 463-469 ◽  
Author(s):  
J. Meunier ◽  
B. Jerome
Keyword(s):  
2011 ◽  
Vol 383-390 ◽  
pp. 826-829 ◽  
Author(s):  
Dao Zhen Xu ◽  
Guo Zhong Zhang ◽  
Xin Zhang

The stratified water-oil two—phase flow was modeled using VOF method in horizontal pipe and surface tension was taken into consideration using CSF model. It was found that the surface tension had great impact on the small density difference two-phase flow even in large diameter pipe, which would lead the interface curved and pressure gradient increased.


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Florian Wilfling ◽  
Abdou Rachid Thiam ◽  
Maria-Jesus Olarte ◽  
Jing Wang ◽  
Rainer Beck ◽  
...  

Lipid droplets (LDs) are ubiquitous organelles that store neutral lipids, such as triacylglycerol (TG), as reservoirs of metabolic energy and membrane precursors. The Arf1/COPI protein machinery, known for its role in vesicle trafficking, regulates LD morphology, targeting of specific proteins to LDs and lipolysis through unclear mechanisms. Recent evidence shows that Arf1/COPI can bud nano-LDs (∼60 nm diameter) from phospholipid-covered oil/water interfaces in vitro. We show that Arf1/COPI proteins localize to cellular LDs, are sufficient to bud nano-LDs from cellular LDs, and are required for targeting specific TG-synthesis enzymes to LD surfaces. Cells lacking Arf1/COPI function have increased amounts of phospholipids on LDs, resulting in decreased LD surface tension and impairment to form bridges to the ER. Our findings uncover a function for Arf1/COPI proteins at LDs and suggest a model in which Arf1/COPI machinery acts to control ER-LD connections for localization of key enzymes of TG storage and catabolism.


2021 ◽  
Author(s):  
Bahshillo Akramov ◽  
◽  
Sherali Umedov ◽  
Odiljon Khaitov ◽  
Jaloliddin Nuriddinov ◽  
...  

The work is devoted to increasing the degree of depletion of reserves of longterm exploited hydrocarbon deposits on the basis of the obtained results of theoretical and experimental studies of the application of electrodynamic technologies for stimulating the formation and bottomhole formation zone. The electrolysis of formation fluids, water, oil-bearing rocks, is accompanied by a mass transfer, primary and secondary chemical reactions, the formation of all kinds of salts, alkalis and acids, new organic substances and all kinds of surfactants. Not only the liquid is subjected to electrolysis, but also the oil and gas bearing rocks themselves (solid electrolyte). The magnetic and electrical forces arising during the electric treatment of reservoirs make it possible to effectively drain heterogeneous reservoirs and extract residual oil from non-working layers. The work also carried out experiments to study the effect of the electric field on the surface tension coefficient at the oil-water interface. The circumstance of an abrupt change in the surface tension coefficient at the oil-water interface makes it possible in principle to create conditions in the reservoir that make it possible to slow down the cusping processes by applying an electric field of various magnitudes or, in other words, by regulating the amount of mass transfer. In numerical terms, the oil recovery factor without electrophysical treatment was 52.94%. Under electrophysical impact, the oil recovery factor was 94.12%, i.e. equaled to almost complete extraction of oil from the sample. In the field, this figure, of course, will decrease by 2-3 times, but it remains quite high in comparison with other methods of increasing oil recovery. Thus, the studies performed on samples in laboratory conditions indicate the possibility of using constant electric fields to increase oil recovery from depleted watered formations. Electrochemical treatment of the formation can significantly increase the displacement of oil from the formation. The increase in oil displacement reaches 15-20% and more. With the help of water alone, 58% of the oil (of its total volume in the sand) was displaced from the sand, and under electric field with a voltage of 10 V and 20 V, the total amount of displaced oil, respectively, increased to 67 and 83%. Thus, the laboratory studies performed on the samples also indicate the possibility of using constant electric fields to increase oil recovery from depleted watered formations. The carried out theoretical and experimental studies show the possibility of using the technology of electrochemical and electrothermochemical leaching of oilsaturated rocks to intensify oil production. The effectiveness of the recommended technology is especially noticeable in fields that have entered the final stage of development with a high water cut.


2021 ◽  
Author(s):  
MD Ferdous Wahid ◽  
Reza Tafreshi ◽  
Zurwa Khan ◽  
Albertus Retnanto

Abstract Fluid pressure gradient in a wellbore plays a significant role to efficiently transport between source and separator facilities. The mixture of two immiscible fluids manifests in various flow patterns such as stratified, dispersed, intermittent, and annular flow, which can significantly influence the fluid’s pressure gradient. However, previous studies have only used limited flow patterns when developing their data-driven model. The aim of this study is to develop a uniform data-driven model using machine-learning (ML) algorithms that can accurately predict the pressure gradient for the oil-water flow with two stratified and seven dispersed flow patterns in a horizontal wellbore. Two different machine-learning algorithms, Artificial Neural Network (ANN) and Random Forest (RF), were employed to predict the pressure gradients. A total of 662 experimental points from nine different flow patterns were extracted from five sources that include twelve variables for different physical properties of oil-water, wellbore’s surface roughness, and input diameter. The variables are entrance length to diameter ratio, oil and water viscosity, density, velocity, and surface tension, between oil and water surface tension, surface roughness, input diameter, and flow pattern. The algorithms’ performance was evaluated using median absolute percentage error (MdAPE) and root mean squared error (RMSE). A repeated train-test split strategy was used where the final MdAPE and RMSE were computed from the average of all repetitions. The MdAPE and RMSE for the prediction of pressure gradients are 13.89% and 0.138 kPa/m using RF and 12.17% and 0.088 kPa/m using ANN, respectively. The ML algorithms’ ability to model the pressure gradient is demonstrated using measured vs. predicted analysis where the experimental data points are mostly located in close proximity of the diagonal line, indicating a suitable generalization of the models. Comparing the performance between RF and ANN shows that the latter algorithm’s prediction accuracy is significantly better (p<0.01).


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhongbin Ye ◽  
Guangfan Guo ◽  
Hong Chen ◽  
Zheng Shu

The interaction between hydrophobically associating polyacrylamide (HAPAM) and dodecyl dimethyl betaine (BS-12) is studied through surface tension, interfacial tension (IFT), apparent viscosity, aggregation behavior, and microscopic morphologies. Results show that surface and interface properties of BS-12 are largely affected by HAPAM. BS-12 critical micelle concentrations are increased with the increment of polymer concentrations. Abilities of reduced air-water surface tension and oil-water interfacial tension are dropped. The oil-water interfacial tension to reach minimum time is increased. HAPAM can form network structures in the aqueous solution. Mixed micelles are formed by the interaction between BS-12 micelles and hydrophobic groups of HAPAM in aqueous solution and self-assembly behavior of HAPAM is affected. With the increment of surfactant concentrations, the apparent viscosity, apparent weight average molecular weights (Mw, a), root mean square radius of gyration (〈Rg〉), and hydrodynamic radius of HAPAM increase first and then decline. Moreover, microscopic morphologies of the mixed system are formed from relatively loose network structures to dense network structures and then become looser network structures and the part of network structures fracture.


2015 ◽  
Vol 35 (3) ◽  
pp. 588-600 ◽  
Author(s):  
Sergio T. Decaro Junior ◽  
Marcelo da C. Ferreira ◽  
Olinto Lasmar

The physical characteristics of a spray liquid are important in getting a good droplet formation and control efficiency over a particular target. As a function of these characteristics, it is possible to decipher which is the best adjuvant based on the respective concentration used during the spray. Therefore, ten spraying liquids were prepared, which varied in concentrations of pesticide lufenuron + profenofos, mineral oil, water and manganese sulfate. Pendant droplets formed from these mixtures were measured to examine their impact on surface tension. Droplets were applied to the surface of coffee leaves and the surface tension, contact angle formed and the leaf area wetted by the droplet, were measured. A smooth glass surface was taken as a comparative to the coffee leaves. The highest concentrations of oil resulted in lower surface tension, smaller contact angles of droplets on leaf surfaces and larger areas wetted by the droplets. Both surfaces showed hydrophilic behavior.


2021 ◽  
pp. 22-28
Author(s):  
R.G. Ismailov ◽  
◽  
E.F. Veliev ◽  
◽  
◽  
...  

Nowadays, one of the more perspective technologies for oil recovery increase in the fields with heavy oils is formation of intrastratal emulsion. The paper presents the research on the increase of oil recovery in the fields with heavy oil via injection of combined composition based on the viscosity minimizer and surface active agent. Obtained composition allows significantly increase the stability of intrastratal emulsion, dramatically reducing the values of surface tension in the border of oil/water. The analysis of synergetic efficiency for suggested composition on the emulsion stability, surface tension and rheological properties has been carried out. More efficient concentrations of composition components have been specified. Obtained results have been justified with experiments on the replacement of high viscous oil from Galmaz field on the sand packed tubes of reservoir.


2014 ◽  
Vol 915-916 ◽  
pp. 927-932
Author(s):  
Wei Guang Shi ◽  
Peng Xiang Wang ◽  
Xiao Gang Ma ◽  
Cui Qin Li ◽  
Jun Wang

A novel cashew-based gemini surfactant was synthesized from cashew phenol, 1, 3-dibromopropane and chlorosulfonic acid through etherification, sulfonation and neutralization. The critical micelle concentration (cmc) for cashew-based gemini surfactant was 6.2×10-2 mmol·L-1, the surface tension (γcmc) was 36.92 mN.m-1. Foam properties and emulsification properties were investigated including the affection of inorganic salts and sodium hydroxide. The oil / water interfacial tension can be decreased efficiently to 10-3mN / m.


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