Fundamental Investigation of Auto-Emulsification of Water in Crude Oil: An Interfacial Phenomenon and its Pertinence for Low Salinity EOR

2020 ◽  
Author(s):  
Duboué Jennifer ◽  
Bourrel Maurice ◽  
Dusautoir Théo ◽  
Santanach Carreras Enric ◽  
Klimenko Alexandra ◽  
...  
Keyword(s):  
Crude Oil ◽  
Interfacial Phenomenon ◽  
Low Salinity ◽  
Fundamental Investigation

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.

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.

Oil Configuration Under High-Salinity and Low-Salinity Conditions at Pore Scale: A Parametric Investigation by Use of a Single-Channel Micromodel

SPE Journal ◽  
2017 ◽  
Vol 22 (05) ◽  
pp. 1362-1373 ◽  
Author(s):  
W.-B.. -B. Bartels ◽  
H.. Mahani ◽  
S.. Berg ◽  
R.. Menezes ◽  
J. A. van der Hoeven ◽  
...  
Keyword(s):  
Contact Angle ◽  
Crude Oil ◽  
Single Channel ◽  
Scale Effects ◽  
Model System ◽  
Pore Scale ◽  
Clay Particles ◽  
Low Salinity ◽  
Natural Rock ◽  
Brine Salinity

Summary Low-salinity waterflooding (LSF) is receiving increased interest as a promising method to improve oil-recovery efficiency. Most of the literature agrees that, on the Darcy scale, LSF can be regarded as a wettability-modification process, leading to a more-water-wet state, although no consensus on the microscopic mechanisms has been reached. To establish a link between the pore-scale and the Darcy-scale description, the flow dynamic at an intermediate scale—i.e., networks of multiple pores—should be investigated. One of the main challenges in addressing phenomena on this scale is to design a model system representative of natural rock. The model system should allow for a systematic investigation of influencing parameters with pore-scale resolution while simultaneously being large enough to capture larger-length-scale effects such as saturation changes and the mobilization and connection of oil ganglia. In this paper, we use micromodels functionalized with active clay minerals as a model system to study the low-salinity effect (LSE) on the pore scale. A new method was devised to deposit clays in the micromodel. Clay suspensions were made by mixing natural clays (montmorillonite) with isopropyl alcohol (IPA) and were injected into optically transparent 2D glass micromodels. After drying the models, the clay particles were deposited and stick naturally to the glass surfaces. The micromodel was then used to investigate the dependence of the LSE on the type of oil (crude oil vs. n-decane), the presence of clay particles, and aging. Our results show that the system is responsive to low-salinity brine as the effective contact angle of crude oil shifts toward a more-water-wetting state when brine salinity is reduced. When using n-decane as a reference case of inert oil, no change in contact angle occurred after a reduction in brine salinity. This responsiveness in terms of contact angle does not necessarily mean that more oil is recovered. Only in the cases where the contact-angle change (because of low-salinity exposure) led to release of oil and reconnection with oil of adjacent pore bodies did the oil become mobile and the oil saturation effectively reduce. This makes contact-angle changes a necessary but not sufficient requirement for incremental recovery by LSF. Interestingly, the wettability modification was observed in the absence of clay. Osmosis and interfacial tension (IFT) change were found not to be the primary driving mechanisms of the low-salinity response.

Low Salinity Water Flooding: Effect Of Crude Oil Composition

2014 ◽  
Author(s):  
Ingebret Fjelde ◽  
Aruoture Voke Omekeh ◽  
Yen Adams Sokama-Neuyam
Keyword(s):  
Crude Oil ◽  
Water Flooding ◽  
Oil Composition ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water

scholarly journals Cooperative effect of crude oil and low salinity on the digestive glands lipid composition of the White Sea blue mussels Mytilus edulis

2016 ◽  
Vol 320 (3) ◽  
pp. 357-366 ◽  
Author(s):  
N.N. Fokina ◽  
I.N. Bakhmet ◽  
N.N. Nemova
Keyword(s):  
Crude Oil ◽  
Mytilus Edulis ◽  
Lipid Composition ◽  
White Sea ◽  
High Energy ◽  
Cooperative Effect ◽  
The White Sea ◽  
Blue Mussels ◽  
Low Salinity ◽  
Digestive Glands

The response of the organism to the pollutant impact is influenced by a variety of abiotic and biotic environmental factors that may have a synergistic or antagonistic effect on the biodegradation, accumulation, distribution and elimination of the xenobiotics. It is known that lipophilic organic contaminants including oil hydrocarbons can be accumulated in lipid-rich tissues of marine animals, thus causing changes in biosynthesis and transport of phospholipids and triacylglycerols, as well as in the physical state of biological membranes. The cooperative effect of crude oil and low salinity on digestive gland lipid composition of the White Sea blue mussels Mytilus edulis L. was studied in aquarium experiment. Low salinity (15‰) impact reflects on the lipid composition indicating high energy costs directed to acclimation of the mussels to new environmental conditions. However, the response of the lipid composition on the crude oil effect is almost not dependent on the ambient salinity, and is mainly determined by exposure duration to crude oil and its dose in aquarium water. On the third experimental day a significant increase in the cholesterol/phospholipids ratio and the subsequent its recovery to initial level possibly indicate the development of the protective compensatory mechanisms to provide low permeability of cell membranes in digestive glands under crude oil pollution. It was observed that the leading factor contributing the lipid composition modifications in blue mussel digestive glands is crude oil effect, mainly in its higher concentrations.

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