Formation Kinetics and Viscoelastic Properties of Water/Crude Oil Interfacial Films

Quintero, Carlos Gerardo; Noı̈k, Christine; Dalmazzone, Christine; Grossiord, J. L.

doi:10.2516/ogst/2009031

Cited by 52 publications

(61 citation statements)

References 35 publications

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“…The evolution of elastic modulus with the frequency satisfied equation (1) with the slope of 0.25. It is noteworthy that our value for the slope is very close to the literature values for other oils containing asphaltenes (Quintero et al, 2009). The measured phase angle is essentially constant with the frequency and about 23.7 o .…”

Section: A 2d (Bidimensional) Gel Near Its Gelation Pointsupporting

confidence: 89%

Effect of Diluents on Interfacial Properties and SAGD Emulsion Stability: I. Interfacial Rheology

2013

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In SAGD (Steam Assisted Gravity Drainage) operations the produced fluids are a complex water-in-oil-in-water (W/O/W) emulsion. A diluent, which is a major operational cost item, is often added to the produced fluid to reduce the density and viscosity of the heavy crude, thereby facilitating oil and water separation. The variable quality of the diluent and various types of diluent can increase the emulsion stability and cause the dehydration of the oil to be more difficult as there are more surface-active agents added to the oil from the diluent stream. In this work, the effect of various diluents on interfacial films was studied by measuring interfacial elasticity and "dynamic" surface pressure isotherms and then correlated with emulsion stability and oil dehydration. Compressibility, crumpling film ratio (ratio of the compressed surface area to the original area at which the interface starts to collapse), and surface pressure were determined from the surface pressure isotherms.When interfacial rheological measurements were conducted on fluids treated with the diluent, the system behaved as if a bidimensional gel near its gelation point had organized at the interface. In other words, adsorbed amphiphilic materials such as asphaltenes and resins had self-aggregated at the interface and formed a network, which presents all the rheological characteristics of a gel, acting as a stabilizing mechanism for produced emulsions. When the interface was aged for 20 hrs, its gel strength was nearly 70% higher than the fresh interface, suggesting an explanation why aged emulsions are more difficult to treat. As the surface area of an oil droplet submersed in water is reduced, asphaltene molecules adsorbed onto the interface are drawn closer together and resist compression. This gives information about how rigid the drop surface becomes. The software of interfacial rheological measurements can be set up to capture drop images during compression measurements, allowing us to observe the formation of rigid interfacial skins at the oil-water interface. The amount of skin formed at a droplet surface increased with increasing asphaltene concentration and varied in different diluents. Unlike elasticity and interfacial tension measurements, this method can predict emulsion stability in different diluents and at various asphaltene concentrations. A correlation exists between the interfacial compressibility, crumpling film ratio, and emulsion stability: the higher the crumpling film ratio and the lower the compressibility, the more stable the emulsion. This new test method gives more insights into mechanisms of emulsion stabilization caused by the diluent and asphaltene and potentially can be employed to study the structure and demulsifying performance relationships of EBs (emulsion breakers) and REBs (reverse emulsion breakers).

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Section: A 2d (Bidimensional) Gel Near Its Gelation Pointsupporting

confidence: 89%

Effect of Diluents on Interfacial Properties and SAGD Emulsion Stability: I. Interfacial Rheology

2013

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“…This is essentially due to the reorganization of asphaltenes molecules already present at the interface. The dilational modulus of asphaltenes diluted in toluene or toluene-heptane mixtures continuously increases in times greater than 20 h. This occurs due to the continuous reorganization of asphaltenes molecules, which conform the interfacial film [14,77,84,85,87].…”

Section: Dynamic Dilational Modulusmentioning

confidence: 99%

The Oscillatory Spinning Drop Technique. An Innovative Method to Measure Dilational Interfacial Rheological Properties of Brine-Crude Oil Systems in the Presence of Asphaltenes

Márquez

Bullón

Forgiarini

et al. 2021

Colloids and Interfaces

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The oscillatory spinning drop method has been proven recently to be an accurate technique to measure dilational interfacial rheological properties. It is the only available equipment for measuring dilational moduli in low interfacial tension systems, as it is the case in applications dealing with surfactant-oil-water three-phase behavior like enhanced oil recovery, crude oil dehydration, or extreme microemulsion solubilization. Different systems can be studied, bubble-in-liquid, oil-in-water, microemulsion-in-water, oil-in-microemulsion, and systems with the presence of complex natural surfactants like asphaltene aggregates or particles. The technique allows studying the characteristics and properties of water/oil interfaces, particularly when the oil contains asphaltenes and when surfactants are present. In this work, we present a review of the measurements of crude oil-brine interfaces with the oscillating spinning drop technique. The review is divided into four sections. First, an introduction on the oscillating spinning drop technique, fundamental and applied concepts are presented. The three sections that follow are divided according to the complexity of the systems measured with the oscillating spinning drop, starting with simple surfactant-oil-water systems. Then the complexity increases, presenting interfacial rheology properties of crude oil-brine systems, and finally, more complex surfactant-crude oil-brine systems are reviewed. We have found that using the oscillating spinning drop method to measure interfacial rheology properties can help make precise measurements in a reasonable amount of time. This is of significance when systems with long equilibration times, e.g., asphaltene or high molecular weight surfactant-containing systems are measured, or with systems formulated with a demulsifier which is generally associated with low interfacial tension.

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“…The presence (formation) of solid-like (elastic dominant) asphaltene films at the oil-water interface has been shown to significantly hinder the coalescence of two contacting water droplets, as such that when two droplets interact and undergo significant compression, they continue to remain stable without coalescence. 48,51 The correlation between interfacial dilatational elasticity and overall emulsion stability has been qualitatively proven by several researchers, 49,50,[52][53][54][55][56] although there is clear disagreement at high asphaltene concentrations where emulsion stability increases and E' decreases. The discrepancy between the interfacial rheology and emulsion stability is believed to be associated with a change in the interfacial layer structure, transitioning from a compact and rigid monolayer, to a collapsed interfacial layer dominated by threedimensional structures.…”

Section: Asphaltene Adsorptionmentioning

confidence: 99%

Fractionation of Asphaltenes in Understanding Their Role in Petroleum Emulsion Stability and Fouling

et al. 2017

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SARA fractionation separates the oil into fractions of saturates (S), aromatics (A), resins (R), and asphaltenes (A) based on the differences in their polarizability and polarity.Defined as a solubility class, asphaltenes are normally considered as a menace in the petroleum industry mainly due to their problematic precipitation and adsorption at oil water and oil-solid interfaces. As a broad range of molecules fall within the group of asphaltenes with distinct sizes and structures, considering the asphaltenes as a whole was noted to limit the deep understanding of governing mechanisms in asphaltene-induced problems.Extended-SARA (E-SARA) is being proposed as a concept of asphaltene fractionation according to their interfacial activities and adsorption characteristics, providing critical information to correlate specific functional groups with certain characteristics of asphaltene aggregation, precipitation and adsorption. Such knowledge obtained is essential to addressing asphaltene-related problems by targeting specific subfractions of asphaltenes for selective removal.2

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Formation Kinetics and Viscoelastic Properties of Water/Crude Oil Interfacial Films

Cited by 52 publications

References 35 publications

Effect of Diluents on Interfacial Properties and SAGD Emulsion Stability: I. Interfacial Rheology

Effect of Diluents on Interfacial Properties and SAGD Emulsion Stability: I. Interfacial Rheology

The Oscillatory Spinning Drop Technique. An Innovative Method to Measure Dilational Interfacial Rheological Properties of Brine-Crude Oil Systems in the Presence of Asphaltenes

Fractionation of Asphaltenes in Understanding Their Role in Petroleum Emulsion Stability and Fouling

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