Revisiting the flocculation kinetics of destabilized asphaltenes

Fávero, Cláudio Vilas Bôas; Maqbool, Tabish; Hoepfner, Michael P.; Haji-Akbari, Nasim; Fogler, H. Scott

doi:10.1016/j.cis.2016.06.013

Cited by 54 publications

(55 citation statements)

References 34 publications

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“…It is important to note that previous research has shown that this phase separation is a dynamic process, which indicates that the instantaneous precipitation point is time-dependant. 39,40 Therefore, the instantaneous precipitation point measured occurred at approximately 10 minutes, which is the timescale for which oil would contact the porous media. Asphaltenes were forced to precipitate out of the model oil by mixing with n-heptane at the volumetric ratio of 20:80, which was well above the instantaneous precipitation point.…”

Section: Asphaltenes In Model Oils and Crude Oil With Dispersantsmentioning

confidence: 99%

Characterizing Asphaltene Deposition in the Presence of Chemical Dispersants in Porous Media Micromodels

Lin

Tavakkoli

et al. 2017

Energy Fuels

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Asphaltenes are components in crude oil known to deposit and interrupt flows in critical regions during oil production, such as the wellbore and transportation pipelines. Chemical dispersants are commonly used to disperse asphaltenes into smaller agglomerates or increase asphaltene stability in solution with the goal of preventing deposition. However, in many cases, these chemical dispersants fail in the field or even worsen the deposition problems in the wellbores. Further understanding of the mechanisms by which dispersants alter asphaltene deposition under dynamic flowing conditions are needed to better understand flow assurance problems. Here, we describe the use of porous media microfluidic devices to evaluate how chemical dispersants change asphaltene deposition. Four commercially used alkyl-phenol model chemical dispersants are tested with model oils flowing through porous media, and the resulting deposition kinetics are visualized at both the matrix-scale and the pore-scale. Interestingly, initial asphaltene deposition worsens in the presence of the tested dispersants, but the mechanism by which plugging and permeability reduction in the porous media varies. The velocity profiles near the deposit are analyzed to further investigate how shear forces affect asphaltene deposition. The deposition tendency is also related to the intermolecular interactions governing the asphaltene-dispersant systems. Furthermore, the model system is extended to a real case. The use of porous media microfluidic devices offers a unique

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Section: Asphaltenes In Model Oils and Crude Oil With Dispersantsmentioning

confidence: 99%

Characterizing Asphaltene Deposition in the Presence of Chemical Dispersants in Porous Media Micromodels

Lin

Tavakkoli

et al. 2017

Energy Fuels

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“…Recently, the same group organized a critical review about this kinetics question related to the flocculation of asphaltenes. 54 The authors also proposed a model for the growth of the aggregates based on the initial nucleus being already of colloidal nature. It was observed that the model fits adequately to the experimental data, as well as that the collision efficiency becomes greater at higher n-heptane concentrations.…”

Section: R E L Eva N T ( E M P H a S I S O N R E C E N T ) Experimementioning

confidence: 99%

“…Thus, shorter times are required for precipitation to start or be detected. 54 Another relevant contribution to this issue was made by Abudu and Goual 55 who carried out measurements in systems diluted with n-alkanes and toluene in order to characterize the interaction between the oil and solid surfaces under flow conditions. These authors observed that the adsorbed asphaltenes film becomes more viscoelastic as the n-alkane concentration approaches the onset concentration.…”

Section: R E L Eva N T ( E M P H a S I S O N R E C E N T ) Experimementioning

confidence: 99%

“…These particles appear to grow under certain circumstances (such as the addition of flocculants) that may represent instability conditions in the field and process plants. One key aspect related to their colloidal behavior is the kinetics of their aggregation, 21,53,54,57 that has been not fully considered with respect to experimental studies, regardless of sound evidences supporting its importance. Finally, there are evidences that the performance of inhibitors for asphaltenes aggregation and deposition involves colloidal interactions and not exclusively specific interactions.…”

Section: R E L Eva N T ( E M P H a S I S O N R E C E N T ) Experimementioning

confidence: 99%

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Recent Developments on the Elucidation of Colloidal Aspects of Asphaltenes and Their Relevance to Oilfield Problems

Balestrin¹,

Loh²

2020

J. Braz. Chem. Soc.

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Asphaltenes constitute the heavy petroleum fraction responsible for deposition events that may lead to reduced oil production, therefore of great interest for flow assurance. These molecules selfassemble in solutions leading to formation of aggregates that eventually grow towards precipitation and blockages in reservoirs and pipelines. Based on the Yen-Mullins aggregation model, two complementary scenarios are involved in asphaltenes phase behavior: one called thermodynamic, in which interacting molecules and other species can be assumed to be in equilibrium, and a second one, involving interacting colloidal particles, both being described by different theoretical frameworks. For the first, molecular interactions can explain the experimental observations or theoretical models. For the second stage, colloidal forces such as those described by Derjaguin, Landau, Verwey and Overbeek (DLVO) theory, steric particle stabilization and diffusion or reaction limited aggregation processes might control the process. Our evaluation is that this second approach is underrepresented in the current literature. For this reason, this review focuses on describing evidences for the presence of colloidal particles in crude oils obtained with different experimental techniques, drawing attention to this important attribute and we raise a few questions that we believe must be addressed in order to better understand the contributions from colloidal aspects.

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“…Dodatkowo istotne jest wagowe oznaczanie ilości asfaltenów wytrącanych przez daną objętość n-heptanu. Inną miarodajną techniką jest również badanie spadku ciśnie-nia, jaki wywołują osady asfaltenowe powstałe przy tłoczeniu przez specjalną kapilarę ropy bądź produktu naftowego wraz z określoną objętością n-heptanu [28].…”

Section: Agregacja Asfaltenów I Jej Następstwaunclassified

Asfalteny naftowe – przegląd wybranych zagadnień

Jarosiński

Warszawska

Lorek

2018

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Asfalteny naftowe-przegląd wybranych zagadnień Asfalteny naftowe są to polarne, aromatyczne składniki ropy naftowej o dużych masach cząsteczkowych. W trakcie przerobu ropy gromadzą się w znacznych ilościach w ciężkich frakcjach pozostałościowych. Ich obecność powoduje takie problemy jak zatykanie rurociągów oraz dezaktywację katalizatorów procesów pogłębionej konwersji. Jest to efektem skłonności asfaltenów do agregacji, skutkującej wytrącaniem osadów. W artykule opisano budowę cząsteczek asfaltenów, mechanizmy agregacji (flokulacji) i czynniki na nią wpływające, a także następstwa tego zjawiska. Przedstawiono również metody oceny stabilności fazowej ropy i produktów naftowych oraz omówiono działanie dodatków dyspergujących, służących jej poprawie.

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Revisiting the flocculation kinetics of destabilized asphaltenes

Cited by 54 publications

References 34 publications

Characterizing Asphaltene Deposition in the Presence of Chemical Dispersants in Porous Media Micromodels

Characterizing Asphaltene Deposition in the Presence of Chemical Dispersants in Porous Media Micromodels

Recent Developments on the Elucidation of Colloidal Aspects of Asphaltenes and Their Relevance to Oilfield Problems

Asfalteny naftowe – przegląd wybranych zagadnień

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