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...

Abstract Carbonate acidization is the process of creating wormholes by injecting acid to increase reservoir permeability and oil production. Nevertheless, some oils are problematic with low asphaltene stability, which affects wormholing process. The interactions between acid, rock, lead acid-asphaltene sludge formation, reduces productivity injectivity. Neglecting this formation leads over pred...

in this work, the precipitation and re-dissolution of asphaltenes were studied for an iranian relatively heavy crude oil. a series of experiments were designed and carried out to quantitatively examine the reversibility of asphaltenes precipitation upon the change in the solvent concentration along with the temperature. n-heptane was used as the precipitant, and a temperature range of 30 to 70°...

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 organic deposition particularly asphaltenes has many detrimental effects on the oil industries, such as plugging in pipelines, wellbore and facilities and subsequently, considerable reduction in well productivity.Asphaltenes are the most polar fractions, which they have been dispersed as colloidal clusters in crude oil. The accumulation of these clusters lead to the flocculation of colloids...

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...