A generalized regular solution model for asphaltene precipitation from n-alkane diluted heavy oils and bitumens

Akbarzadeh, Kamran; Alboudwarej, Hussein; Svrcek, William Y.; Yarranton, Harvey W.

doi:10.1016/j.fluid.2005.03.029

Cited by 188 publications

(214 citation statements)

References 14 publications

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“…The average translational diffusion coefficient is close to the one found for experiments with different concentrations. The average molar mass is bigger than found before and is close to that given in the literature (Agrawala and Yarranton, 2001;Akbarzadeh et al, 2005) but it is far from those given by SAXS and SANS ( Table 2). The average segment number is bigger (60 compared to 40) and shows that the asphaltene molar volume is certainly different in the case of fractioned asphaltenes and so the polydisperse asphaltenes solution is probably non ideal.…”

Section: Estimation Results For Various Asphaltene Fractions Having Dsupporting

confidence: 83%

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Diffusion of asphaltene molecules through the pore structure of hydroconversion catalysts

Tayakout

Ferreira

Espinat

et al. 2010

Chemical Engineering Science

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Section: Estimation Results For Various Asphaltene Fractions Having Dsupporting

confidence: 83%

“…The estimated molar mass in this work (5000 g/mol) is lower than values in literature of 7000 g/mol (Agrawala and Yarranton, 2001;Akbarzadeh et al, 2005), or even more than 10 000 g/mol (Fenistein and Barre, 2001;Roux et al, 2001). It is also lower than the values measured by SANS and SAXS methods given in Table 2 (Fig.…”

Section: Parameter Estimationcontrasting

confidence: 74%

Diffusion of asphaltene molecules through the pore structure of hydroconversion catalysts

Tayakout

Ferreira

Espinat

et al. 2010

Chemical Engineering Science

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“…However, it has proven very difficult to provide standard evaluations due to their heteroatom content, complex molecular structure, and polarity [5][6][7]. Heat is either evolved or absorbed during the creation or destruction of these molecular bonds and thus provides the framework for this study.…”

Section: Introductionmentioning

confidence: 99%

Study of the thermo-physical properties of bitumen in hydrocarbon condensates

Miadonye¹,

Cyr²,

Secka³

et al. 2009

WIT Transactions on Modelling and Simulation

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The reduction of viscosity with inappropriate diluents could lead to asphaltene precipitation. To use condensates effectively however, their effects on asphaltene precipitation and deposition must be well examined. In this study, the influence of inter-particle interactions of asphaltene on the viscosity and heat of mixing in solutions of bitumen-condensate mixtures are compared to those of bitumen in aromatic solvents and in condensate-toluene mixtures. Three bitumen, two heavy oils, and five condensates from different reservoirs were examined. The results indicate that the presence of aromatic solvent in bitumen delays the on-set of asphaltene precipitation due to the presence of dipole-dipole interactions as well as hetero-molecular interactions. In pure condensates, strong hydrogen bonding and moderate homo-molecular interactions are predominant and, therefore, result in reduced asphaltene precipitation and low enthalpy of mixing. The on-set of asphaltene precipitation in bitumen and heavy oils is delayed in the presence of aromatic solvents, decreasing with reduction in the composition of aromatic solvent in the condensates.

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“…However, there was lack of evidence to support the phenomena of resin self-association and hence the authors did not incorporate it into the model. 58 Similarly, the model accurately predicted asphaltene precipitation at moderate pressures (around 2.1 MPa) but under-predicted amount of precipitation at high pressures (around 6.9 MPa).…”

Section: Yarranton and Co-workersmentioning

confidence: 77%

Asphaltene Precipitation Models: A Review

Subramanian

Simon

Sjöblom

2015

Journal of Dispersion Science and Technology

105

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Asphaltenes are the heaviest and the most polar fraction of crude oil and are defined as a solubility class (typically soluble in toluene but insoluble in n-alkanes like n-heptane).Precipitation and deposition of asphaltenes during production, processing and transportation of oil is a major challenge faced by oil industry. Over the last thirty years, a number of different models have been proposed for predicting the onset of asphaltene precipitation and also the amount of precipitated asphaltenes. This article reviews the different models that have been proposed for predicting asphaltene precipitation either at atmospheric pressure or under depressurization. A brief summary of the different modeling approaches is presented followed by description of work done by different research groups. Our focus will be on the description of the basic assumptions underlying different models and also the ability/performance of the model to match the experimental data. Finally, a comparison of models is presented and discussed along with suggestions for improvement. Keywords:Asphaltene precipitation, Thermodynamic models, Solubility models, Equation of state models, Colloidal models INTRODUCTIONAsphaltenes are considered to represent the most polar and the heaviest components in crude oil. 1 They are a solubility class and defined as the fraction that is insoluble in n-alkane (like n-heptane) but soluble in aromatic solvents (like toluene). [2][3] The precipitation and deposition of asphaltenes during production and transport of crude oil is recognized as a serious problem in the oil industry since it can lead to formation damage, plugging of wellbores and production facilities. [4][5] Asphaltene precipitation can be encountered during primary recovery of oil as well as during enhanced oil recovery operations like miscible flooding with CO 2 or natural gas. 6The precipitation of asphaltenes occurs due to a number of reasons. These include changes in pressure, temperature, chemical composition of crude oils, acid stimulation, mixing of oil with diluents, other oil and gas components like CO 2 . 4 Heavy crudes usually have a lower tendency to give asphaltene deposition problems inspite of their higher asphaltene content.This observation is normally attributed to their higher resin content and lower saturate content. 7Asphaltenes are generally assumed to be composed of fused ring aromaticity, small aliphatic side chains and heteroatom functional groups. 8 The molecular weight of asphaltenes has been a source of controversy for a very long time. 9 It is now recognized to be close to 750 g/mol with a factor of 2 in the width of the molecular weight distribution. Solubility ApproachThe solubility models are most commonly used for predicting asphaltene precipitation. These models make use of the concept of solubility parameter and assume that petroleum crude Models based on Solution theory and Flory-Huggins theory assume that asphaltenes have homogenous structure and properties while models based on Scott-Magat theory assum...

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A generalized regular solution model for asphaltene precipitation from n-alkane diluted heavy oils and bitumens

Cited by 188 publications

References 14 publications

Diffusion of asphaltene molecules through the pore structure of hydroconversion catalysts

Diffusion of asphaltene molecules through the pore structure of hydroconversion catalysts

Study of the thermo-physical properties of bitumen in hydrocarbon condensates

Asphaltene Precipitation Models: A Review

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