We apply a cubic-plus-association equation of state to study the asphaltene precipitation from n-alkane diluted model solutions (asphalteneþtoluene), and heavy oils and bitumens. Heavy oils and bitumens are characterized in terms of saturates, aromatics/resins, and asphaltenes; n-alkanes are treated independently. The asphaltene precipitation is modeled as liquid-liquid phase equilibrium. The s...

The scaling and modeling of the viscosity of suspensions of asphaltene nanoaggregates is carried out successfully taking into consideration the solvation and clustering of nanoaggragates, and the jamming of the suspension at the glass transition volume fraction of asphaltene nanoaggregates. The nanoaggregates of asphaltenes are modeled as solvated disk-shaped “core–shell” particles taking into ...

The asphaltene precipitation of two reservoir oil samples collected from Jinlin oil field has been studied under pressure and with/without CO2-injection conditions. No asphaltene precipitation was detected during the pressure depletion processes without CO2 injection. For the CO2-injected oil systems, the effects of operating pressure, injected CO2 concentration, and multiple-contact on the ons...

A method to characterize crude oil including asphaltenes using the perturbed chain form of the statistical associating fluid theory (PC-SAFT) is presented. The theory accurately predicts the bubble point, density, and asphaltene precipitation onset for the oil. Examples show that the theory predicts asphaltene instability due to changes in pressure, temperature, and fluid composition. Further w...

Asphaltene precipitation occurs in petroleum fluids under certain unfavorable conditions, but can be controlled by tuning composition. Aromatic solvents in large quantities can prevent precipitation entirely and can dissolve already precipitated asphaltenes. Some polymeric surfactants can dissolve asphaltenes when added at much lower concentrations than required by aromatic solvents. Other disp...

We study the structure and phase behavior of asphaltenes comprised of large polyaromatic molecules in blends of naturally occurring crude oils using small angle neutron scattering (SANS). When two compatible oils are blended together, the asphaltenes remain dispersed as colloidal nanoparticles; however, when two incompatible oils are blended together, these asphaltene nanoparticles can aggregat...

Asphaltene precipitation is a perennial problem in producing and rejming crude oils. To avoid precipitation, it is usefid to know the solubility of asphaltenes in petroleum liquids as a function of temperature, pressure and liquid-phase composition In the novel molecular-thermodynamic flamework presented here, both asphaltenes and resins are represented by pseudo-pure components while all other...

• The asphaltene fractions are isolated from HFOs with differing bulk behaviours. Ultra-high resolution mass spectrometry yields detailed characterization. Infra-red multi photon dissociation is used to provide structural insight. Novel visualization allows rapid comparison of fragment alkylation and condensation. Components that may underly handling issues identified. Marine heavy fuel oils (H...

BACKGROUND AND HYPOTHESIS In the oil industry, asphaltenes are known for their tendency to aggregate in solution and to deposit on surfaces, with both properties being connected with operational problems associated with recovery, production and refining. Interactions involving asphaltenes and other crude oil components have been a major aspect of investigation in attempting to understand the fu...

We apply a cubic-plus-association equation of state (CPA-EOS) to study the asphaltene precipitation in live oils from temperature, pressure, and composition effects. The live oils are characterized by considering the pure components, the pseudo-hydrocarbon components, and the hydrocarbon residue. The hydrocarbon residue is further divided into the “heavy” component and asphaltenes. The asphalte...