scholarly journals Stability of liquid bridges with elastic interface

RSC Advances ◽  
2017 ◽  
Vol 7 (78) ◽  
pp. 49344-49352 ◽  
Author(s):  
Paulo Hoyer ◽  
Vladimir Alvarado
Keyword(s):  
Crude Oil ◽  
Elastic Response ◽  
Liquid Bridges ◽  
Experimental Demonstration ◽  
Low Salinity ◽  
Elastic Interface ◽  
The Stability

Experimental demonstration that the enhanced elastic response of the brine–crude oil interface under low-salinity conditions increase the stability of the oil–brine interface as shown by uniquely designed bridge experiments.

scholarly journals Changes of Heart Rate and Lipid Composition in Mytilus Edulis and Modiolus Modiolus Caused by Crude Oil Pollution and Low Salinity Effects

2021 ◽  
Vol 11 (2) ◽  
pp. 46-60
Author(s):  
Igor Bakhmet ◽  
Natalia Fokina ◽  
Tatiana Ruokolainen
Keyword(s):  
Heart Rate ◽  
Crude Oil ◽  
Mytilus Edulis ◽  
Lipid Composition ◽  
Oil Pollution ◽  
Cardiac Activity ◽  
Blue Mussels ◽  
Low Salinity ◽  
Crude Oil Pollution ◽  
Modiolus Modiolus

Blue mussels, Mytilus edulis, inhabiting tidal zones, are naturally exposed to fluctuating environmental conditions (e.g., fluctuations in temperature and salinities), while horse mussels, Modiolus modiolus, live under relatively invariable shelf water conditions. The present investigation tested the hypothesis: blue mussels, in comparison to horse mussels, have an increased ability to tolerate the stress of pollution combined with low salinity. To assess the response of blue mussels and horse mussels to oil pollution at seawater salinities of 25 psu (normal) and 15 psu (low), we used a combination of heart rate and lipid composition as physiological and biochemical indicators, respectively. A sharp decrease in heart rate as well as important fluctuations in cardiac activity was observed under all oil concentrations. Modifications in the concentrations of the main membrane lipid classes (phosphatidylcholine, phosphatidylethanolamine, and cholesterol) and storage lipids (primarily triacylglycerols) in response to different crude oil concentrations were time- and dose-dependent. Both chosen indicators showed a high sensitivity to crude oil contamination. Furthermore, both bivalve species showed similar responses to oil pollution, suggesting a universal mechanism for biochemical adaptation to crude oil pollution.

scholarly journals Bulk and Surface Aqueous Speciation of Calcite: Implications for Low-Salinity Waterflooding of Carbonate Reservoirs

SPE Journal ◽  
2017 ◽  
Vol 23 (01) ◽  
pp. 84-101 ◽  
Author(s):  
Maxim P. Yutkin ◽  
Himanshu Mishra ◽  
Tadeusz W. Patzek ◽  
John Lee ◽  
Clayton J. Radke
Keyword(s):  
Ionic Strength ◽  
Ion Exchange ◽  
Crude Oil ◽  
Surface Charge ◽  
Double Layer ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Diffuse Double Layer ◽  
Low Salinity ◽  
Low Salinity Waterflooding

Summary Low-salinity waterflooding (LSW) is ineffective when reservoir rock is strongly water-wet or when crude oil is not asphaltenic. Success of LSW relies heavily on the ability of injected brine to alter surface chemistry of reservoir crude-oil brine/rock (COBR) interfaces. Implementation of LSW in carbonate reservoirs is especially challenging because of high reservoir-brine salinity and, more importantly, because of high reactivity of the rock minerals. Both features complicate understanding of the COBR surface chemistries pertinent to successful LSW. Here, we tackle the complex physicochemical processes in chemically active carbonates flooded with diluted brine that is saturated with atmospheric carbon dioxide (CO2) and possibly supplemented with additional ionic species, such as sulfates or phosphates. When waterflooding carbonate reservoirs, rock equilibrates with the injected brine over short distances. Injected-brine ion speciation is shifted substantially in the presence of reactive carbonate rock. Our new calculations demonstrate that rock-equilibrated aqueous pH is slightly alkaline quite independent of injected-brine pH. We establish, for the first time, that CO2 content of a carbonate reservoir, originating from CO2-rich crude oil and gas, plays a dominant role in setting aqueous pH and rock-surface speciation. A simple ion-complexing model predicts the calcite-surface charge as a function of composition of reservoir brine. The surface charge of calcite may be positive or negative, depending on speciation of reservoir brine in contact with the calcite. There is no single point of zero charge; all dissolved aqueous species are charge determining. Rock-equilibrated aqueous composition controls the calcite-surface ion-exchange behavior, not the injected-brine composition. At high ionic strength, the electrical double layer collapses and is no longer diffuse. All surface charges are located directly in the inner and outer Helmholtz planes. Our evaluation of calcite bulk and surface equilibria draws several important inferences about the proposed LSW oil-recovery mechanisms. Diffuse double-layer expansion (DLE) is impossible for brine ionic strength greater than 0.1 molar. Because of rapid rock/brine equilibration, the dissolution mechanism for releasing adhered oil is eliminated. Also, fines mobilization and concomitant oil release cannot occur because there are few loose fines and clays in a majority of carbonates. LSW cannot be a low-interfacial-tension alkaline flood because carbonate dissolution exhausts all injected base near the wellbore and lowers pH to that set by the rock and by formation CO2. In spite of diffuse double-layer collapse in carbonate reservoirs, surface ion-exchange oil release remains feasible, but unproved.

Effects of the Interaction between Neighboring Droplets on the Stability of Nanoscale Liquid Bridges

2021 ◽  
Author(s):  
Kai-wen Tong ◽  
jian-hua Guo ◽  
Wei Zhang ◽  
Shi-chang Li ◽  
Kang Huang ◽  
...  
Keyword(s):  
Liquid Bridges ◽  
The Stability

scholarly journals Method for Judging the Stability of Asphaltenes in Crude Oil

ACS Omega ◽  
2020 ◽  
Vol 5 (34) ◽  
pp. 21420-21427
Author(s):  
Ruiying Xiong ◽  
Jixiang Guo ◽  
Wyclif Kiyingi ◽  
Hengshui Feng ◽  
Tongcheng Sun ◽  
...  
Keyword(s):  
Crude Oil ◽  
The Stability

Interfacial Viscoelasticity of Crude Oil/Brine: An Alternative Enhanced-Oil-Recovery Mechanism in Smart Waterflooding

SPE Journal ◽  
2018 ◽  
Vol 23 (03) ◽  
pp. 803-818 ◽  
Author(s):  
Mehrnoosh Moradi Bidhendi ◽  
Griselda Garcia-Olvera ◽  
Brendon Morin ◽  
John S. Oakey ◽  
Vladimir Alvarado
Keyword(s):  
Crude Oil ◽  
Water Chemistry ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Interaction Mechanism ◽  
Field Trials ◽  
Wettability Alteration ◽  
Low Salinity ◽  
Injection Water

Summary Injection of water with a designed chemistry has been proposed as a novel enhanced-oil-recovery (EOR) method, commonly referred to as low-salinity (LS) or smart waterflooding, among other labels. The multiple names encompass a family of EOR methods that rely on modifying injection-water chemistry to increase oil recovery. Despite successful laboratory experiments and field trials, underlying EOR mechanisms remain controversial and poorly understood. At present, the vast majority of the proposed mechanisms rely on rock/fluid interactions. In this work, we propose an alternative fluid/fluid interaction mechanism (i.e., an increase in crude-oil/water interfacial viscoelasticity upon injection of designed brine as a suppressor of oil trapping by snap-off). A crude oil from Wyoming was selected for its known interfacial responsiveness to water chemistry. Brines were prepared with analytic-grade salts to test the effect of specific anions and cations. The brines’ ionic strengths were modified by dilution with deionized water to the desired salinity. A battery of experiments was performed to show a link between dynamic interfacial viscoelasticity and recovery. Experiments include double-wall ring interfacial rheometry, direct visualization on microfluidic devices, and coreflooding experiments in Berea sandstone cores. Interfacial rheological results show that interfacial viscoelasticity generally increases as brine salinity is decreased, regardless of which cations and anions are present in brine. However, the rate of elasticity buildup and the plateau value depend on specific ions available in solution. Snap-off analysis in a microfluidic device, consisting of a flow-focusing geometry, demonstrates that increased viscoelasticity suppresses interfacial pinch-off, and sustains a more continuous oil phase. This effect was examined in coreflooding experiments with sodium sulfate brines. Corefloods were designed to limit wettability alteration by maintaining a low temperature (25°C) and short aging times. Geochemical analysis provided information on in-situ water chemistry. Oil-recovery and pressure responses were shown to directly correlate with interfacial elasticity [i.e., recovery factor (RF) is consistently greater the larger the induced interfacial viscoelasticity for the system examined in this paper]. Our results demonstrate that a largely overlooked interfacial effect of engineered waterflooding can serve as an alternative and more complete explanation of LS or engineered waterflooding recovery. This new mechanism offers a direction to design water chemistry for optimized waterflooding recovery in engineered water-chemistry processes, and opens a new route to design EOR methods.

Magnetomechanical Instabilities in Elastic-Plastic Cylinders, Part I: Elastic Response

1996 ◽  
Vol 63 (3) ◽  
pp. 734-741 ◽  
Author(s):  
D. L. Littlefield
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Fields ◽  
Threshold Value ◽  
Substantial Effect ◽  
Elastic Response ◽  
Linear Perturbation ◽  
Azimuthal Magnetic Field ◽  
Physical Mechanisms ◽  
Linear Perturbation Theory ◽  
The Stability

The effects of electromagnetic fields on instabilities in metal cylinders are considered in this analysis. The cylinder is assumed to be infinitely long and perfectly conducting. An axial electric current is introduced in the cylinder, giving rise to an azimuthal magnetic field in the surrounding vacuum, causing mechanical distortion in the cylinder. The current is assumed to be small so that the deformation remains elastic; in an accompanying paper (Littlefield, 1996) larger currents are considered where plastic flow becomes important. After solutions to the idealized motion of the cylinder under uniaxial strain conditions are developed, small perturbations to the motion are considered. The equations governing the motion of these disturbances are derived using linear perturbation theory. Solutions to the equations indicate that electromagnetic fields can have a substantial effect on the stability spectrum in the cylinder. In general, the frequency of oscillating perturbations is suppressed by the azimuthal magnetic field, and distending instabilities are possible if the magnetic field is above a threshold value. The underlying physical mechanisms contributing to these deviations are proposed.

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