The Role of Asphaltene Solubility and Chemical Composition on Asphaltene Aggregation

Asphaltenes from four different crude oils (Arab Heavy, B6, Canadon Seco, and Hondo) were fractionated in mixtures of heptane and toluene and analyzed by small angle neutron scattering (SANS). Fractionation appeared to concentrate the most polar species into the least soluble sub-fraction as indicat...

Full description

Saved in:
Bibliographic Details
Published inPetroleum science and technology Vol. 21; no. 3-4; pp. 461 - 489
Main Authors Gawrys, Keith L., Matthew Spiecker, P., Kilpatrick, Peter K.
Format Journal Article Conference Proceeding
LanguageEnglish
Published Colchester Taylor & Francis Group 01.02.2003
Taylor & Francis
Subjects
Agglomeration
Aggregates
Applied sciences
Asphaltenes
Asphalts
Constitution and properties of crude oils, shale oils, natural gas and bitumens. Analysis and characteristics
Crude oil
Crude oil, natural gas and petroleum products
Energy
Exact sciences and technology
Fractal analysis
Fuels
Molecular weight
Styrene acrylonitrile resins
Aggregation
Asphaltene
Small angle neutron scattering
Colloid properties
Crude oil
Solubility
Deposit formation
Chemical composition
Online AccessGet full text

Cover

More Information
Summary:Asphaltenes from four different crude oils (Arab Heavy, B6, Canadon Seco, and Hondo) were fractionated in mixtures of heptane and toluene and analyzed by small angle neutron scattering (SANS). Fractionation appeared to concentrate the most polar species into the least soluble sub-fraction as indicated by elemental analysis. SANS results indicated a wide spectrum of asphaltene aggregate sizes and molecular weights; however, the less soluble (more polar) fraction contributed the majority of the species responsible for asphaltene aggregation in solution. This more polar, less soluble fraction is likely the major cause for many petroleum production problems such as deposition and water-in-oil emulsion stabilization. A comparison of molecular weight and aggregate size indicated that asphaltenes formed fractal aggregates in solution with dimensions between 1.7 and 2.1. This was consistent with the "archipelago" model of asphaltene structure. Resins were shown to effectively solvate asphaltene aggregates as observed by an increase in asphaltene solubility, reduction in aggregate size and molecular weight, and an increase in the fractal dimension to ˜ 3.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1091-6466
1532-2459
DOI:10.1081/LFT-120018533