Adsorption of asphaltenes and resins on organic and inorganic substrates and their correlation with precipitation problems in production well tubing

Acevedo, Sócrates; Ranaudo, María Antonieta; Escobar, Gastón; Gutiérrez, Luis Felipe Higuita; Ortega, P. A. Ramírez

doi:10.1016/0016-2361(95)98363-j

Cited by 142 publications

(107 citation statements)

References 14 publications

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“…The effect of hydrophobic copolymer C was weaker, confirming that the amphiphilic character is necessary condition for diminishing asphaltene adsorption. Asphaltene adsorption usually depends on various parameters such as the origin [31], the nature of mineral surface [32], the nature of solvent [32] and eventual presence of co-adsorbents (resins) [29,30]. Although some reports proposed a multilayer-type adsorption [31,33,34], the adsorption isotherms of asphaltenes seem to be Langmuir-type [29,32,35].…”

Section: Polysiloxane Mediated Desorption Of Asphaltene From Silica Pmentioning

confidence: 99%

Destabilisation of Water-in-Crude Oil Emulsions by Silicone Copolymer Demulsifiers

Daniel‐David

Follotec

Pezron

et al. 2008

Oil & Gas Science and Technology - Rev. IFP

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Résumé -Déstabilisation des émulsions eau dans pétrole brut par des polymères siliconés désémulsionnants -Des émulsions stables de type eau dans huile se forment lors de la production de pétrole brut. Les asphaltènes, molécules tensioactives naturellement présentes dans le pétrole, créent un film viscoélastique qui empêche les gouttelettes d'eau de coalescer. La séparation de l'eau par l'ajout de tensioactifs désémulsionnants est indispensable avant l'étape du raffinage. Récemment, des formulations à base de copolymères polyéther siliconés ont prouvé leur efficacité et leur caractérisation aux interfaces eau/air et eau/pétrole a été effectuée. Différents mécanismes de désémulsification peuvent être envisagés : (i) dissolution des agrégats d'asphaltènes ou (ii) déplacement de ceux-ci dû à l'adsorption des polysiloxanes à l'interface eau/pétrole. Afin d'élucider le type de mécanisme, diverses techniques ont été utilisées pour étudier les interactions entre asphaltènes et copolymère : rayons X aux petits angles permettant d'étudier une éventuelle influence du copolymère sur la taille des agrégats d'asphaltènes, capacité du copolymère à chasser les agrégats d'asphaltènes préalablement adsorbés sur des billes de silice (modélisant les gouttelettes d'eau), microscopie à force atomique utilisée pour observer l'action du copolymère sur la structure des films asphalténiques. Abstract -Destabilisation of Water-in-Crude Oil Emulsions by Silicone Copolymer Demulsifiers -Asphaltene aggregates are known to form viscoelastic film preventing the coalescence of droplets in water-in-oil emulsions formed during crude oil exploitation. Since phase separation is necessary for oil refining process, demulsifying additives are used. It was found that formulations based on polysiloxane copolymers promote separation of water from crude oil even at very low concentration (few tens of ppm). Two alternative scenarios of emulsion destabilisation can be envisaged: (i) dissolution of asphaltene aggregates or (ii) displacement of the asphaltene network by adsorption of the more surface active copolymer into void sites at the oil/water interface. In order to reveal the mechanism of destabilisation, interactions between asphaltene aggregates and copolymer were explored. For that purpose various techniques have been employed: small angle X-ray scattering allowing the determination of the influence of copolymer on the size of asphaltene aggregate; capacity of copolymer to displace asphaltene aggregates initially adsorbed on silica particles (which simulate water droplets); Atomic Force Microscopy (AFM) was used to observe the influence of copolymer on the interfacial structure of asphaltene films spread on water surface.

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Section: Polysiloxane Mediated Desorption Of Asphaltene From Silica Pmentioning

confidence: 99%

Destabilisation of Water-in-Crude Oil Emulsions by Silicone Copolymer Demulsifiers

Daniel‐David

Follotec

Pezron

et al. 2008

Oil & Gas Science and Technology - Rev. IFP

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“…Mica, because it can be cleaved to provide uniform and molecularly smooth surfaces has been used to study asphaltene adsorption. 14,30 Recently, Adams published a comprehensive review on the chemical and physical nature of asphaltenes and corresponding characteristics of asphaltene adsorption. 37 The above research provided valuable information on stabilization mechanisms and adsorption kinetics of asphaltenes.…”

Section: Introductionmentioning

confidence: 99%

Understanding Mechanisms of Asphaltene Adsorption from Organic Solvent on Mica

et al. 2014

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The adsorption process of asphaltene onto molecularly smooth mica surfaces from toluene solutions of various concentrations (0.01 -1 wt%) was studied using a Surface Forces Apparatus (SFA). Adsorption of asphaltenes onto mica was found to be highly dependent on adsorption time and concentration of the solution. The adsorption of asphaltenes led to an attractive bridging force between the mica surfaces. The adsorption process was identified to be controlled by diffusion of asphaltenes from the bulk solution to the mica surface with a diffusion coefficient on the order of 10 -10 m 2 /s at room temperature, depending on asphaltene bulk concentration. This diffusion coefficient corresponds to a hydrodynamic molecular radius of approximately 0.5 nm, indicating that asphaltene diffuses to mica surfaces as individual molecules at very low concentration (e.g. 0.01 wt%). Atomic force microscopy (AFM) images of the adsorbed asphaltenes on mica support the results of the SFA force measurements. The results from the SFA force measurements provide an insight on the molecular interactions (e.g. steric interaction, bridging attraction as a function of distance) of asphaltenes in organic media and hence their roles in crude oil and bitumen production.

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“…Asphaltenes as an organic colloid can adsorb electrolyte ions from aqueous solutions [1][2][3]36]. However, they may themselves be adsorbed from the organic phase on rock reservoirs [5,[37][38][39][40][41]. These adsorption processes are further complicated by the behaviour of asphaltenes in organic solutions.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of asphaltenes from toluene on mineral surface

Marczewski

Szymula

2002

Colloids and Surfaces A: Physicochemical and Engineering Aspect

173

124

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Undesirable adsorption of asphaltenes on rock minerals was studied. Asphaltenes are an important component of crude oil, being also natural surfactant stabilising water/crude oil emulsions. Owing to their chemical nature, asphaltenes are able to associate, form micelles and create a surface charge at the interface. Asphaltenes may be adsorbed on rock reservoir from the organic solvents in crude oil and as an organic colloid, they can adsorb electrolyte ions from aqueous solution. In order to simulate natural conditions we used asphaltenes from local drills, toluene as solvent and several typical oxides and carbonate rock components or minerals as adsorbents. Our study included natural Brazilian quartz, dolomite, calcite and kaolin, as well as pure oxides: Fe 2 O 3 and TiO 2 . The typical shape of asphaltene adsorption isotherms was obtained for all systems studied with the characteristic 'steps' which indicate changes in the state of asphaltene molecules in the solution and at the mineral surface. Those changes are related to the asphaltene association and further formation of hemimicelles and micelles.

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Adsorption of asphaltenes and resins on organic and inorganic substrates and their correlation with precipitation problems in production well tubing

Cited by 142 publications

References 14 publications

Destabilisation of Water-in-Crude Oil Emulsions by Silicone Copolymer Demulsifiers

Destabilisation of Water-in-Crude Oil Emulsions by Silicone Copolymer Demulsifiers

Understanding Mechanisms of Asphaltene Adsorption from Organic Solvent on Mica

Adsorption of asphaltenes from toluene on mineral surface

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