Viscoelastic Properties of Crude Oil Components at Oil‐Water Interfaces. 2: Comparison of 30 Oils

Hannisdal, Andreas; Orr, Robert; Sjöblom, Johan

doi:10.1080/01932690601107708

Cited by 34 publications

(28 citation statements)

References 41 publications

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“…At higher concentrations, the elastic and total modulus decreased as the increasing diffusion of molecules from the bulk phase to the interface affected the moduli. Similar observations were made by Hannisdal et al, (2007) who studied the viscoelastic properties of the crude oil diluted in heptol, suggesting that the decrease in viscoelastic modules at high bitumen concentrations was a combined effect of both the increased diffusion flux to the interface and the change in composition of the interfacial material. A maximum in film elasticity with the increased asphaltene concentration in solutions with high aromatic solvents has been reported by several authors (Verruto and Kilpatrick 2008;Sjoblom et al,2003;Hannisdal et al, 2007)…”

Section: Interfacial Rheological Propertiessupporting

confidence: 80%

Role of Aqueous Phase Chemistry, Interfacial Film Properties, and Surface Coverage in Stabilizing Water-in-Bitumen Emulsions

et al. 2016

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Section: Interfacial Rheological Propertiessupporting

confidence: 80%

Role of Aqueous Phase Chemistry, Interfacial Film Properties, and Surface Coverage in Stabilizing Water-in-Bitumen Emulsions

et al. 2016

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“…The most important one (because it should be observed whatever the experimental conditions are) is that phase shift should be lower than 45° (i.e., the viscous modulus should always be lower than the elastic modulus). Provided that enough information is given, this can be verified in all publications that can be found in the literature about asphaltenes, crude oil, and bitumen solutions, − ,,− ,− which represents more than 1400 data points corresponding to a wide range of experimental conditions: frequency from 10 –6 to 0.5 Hz, aging time from minutes to days, asphaltenes concentrations from 10 1 to 10 5 ppm (i.e., 10% in weight), different solvents, different water phases, and samples of different origins. It should be emphasized here that cross-linking polymers or physical gels very often exhibit phase shifts higher than 45° (either before or after the gel point). − , …”

Section: Comparison With the Published Data On Asphaltenesmentioning

confidence: 71%

Mixture Effect on the Dilatation Rheology of Asphaltenes-Laden Interfaces

et al. 2017

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Asphaltenes are a solubility class of crude oils comprising polyaromatic and heterocyclic molecules with different interfacial activities. The previously neglected effects of compositional mixture on dilatational rheology are discussed in the light of diffusional relaxation models. It is demonstrated that the reported deviations from the Lucassen-van den Tempel model for a single-component solution could largely originate from a distribution in adsorption coefficients within the asphaltenes class. This particularly applies to the peculiar gel point rheology previously ascribed to asphaltenes cross-linking at the interface. Furthermore, an extensive bibliographical review shows that asphaltenes dilatational rheology data always verify the main features of diffusional relaxation, including a decrease in modulus at high bulk concentrations and phase shift values always lower than 45°. Using diffusional relaxation concepts, the reanalysis of the most extensive dataset so far confirmed recently published studies, showing that asphaltenes exhibit a unique equation of state (EOS) irrespective of adsorption conditions. This EOS proves to be very similar for bitumen and petroleum asphaltenes. Finally, a numerical application of a binary diffusional model proved efficient to capture both dynamic interfacial tension and dilatational rheology, with the same parameters. It appears that a minority of asphaltenes (less than 10%) have a much stronger interfacial activity than the bulk of them, as previously demonstrated by fractionation. These results open up the need for a reinterpretation of the physical mechanisms of asphaltenes adsorption in terms of classical amphiphilic behavior, with a potential impact on emulsion breaking and enhanced oil recovery strategies.

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“…The authors also noticed that G' increases when the solubility of asphaltenes in the bulk decreases. Dilatational rheology experiments using an oscillating pendant/sessile drop tensiometer by Bouriat et al 107 Sjöblom et al 108,109 and Yarranton et al 110,111 also showed that asphaltenes form an elastic structure at the liquid/oil interface. to form dimers in toluene solution, which does not match the aggregation behavior of asphaltenes.…”

Section: Adsorption At Liquid/liquid Interfacesmentioning

confidence: 99%