The molecular-mass distribution of the asphaltene fraction of petroleum is rapidly becoming more constrained, but themolecular architecture remains poorly understood. Two types of molecular structures have been proposed to be representative of asphaltenes: the “island” model and the “archipelago” model. Here, nine compounds were synthesized on the basis of pyrene, representing both types of mod...

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...

The process of CO2-SAG flooding involves conventional miscible CO2 until breakthrough (BT), followed by a period soaking or shut-in, and then continuation the flooding. SAG provides different improvements in oil recovery for positions each layer multilayer reservoirs, has effects on distribution pore throat blocking adsorption asphaltene to mineral surfaces. In this paper, both experiments have...

Energy & Fuels is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Article Sensitivity of Asphaltene Properties to Separation Techniques H. Alboudwarej, J. Beck, W. Y. Svrcek, H. W. Yarranton, and K. Akbarzadeh Energy Fuels, 2002, 16 (2), 462-469• DOI: 10.1021/ef010213p • Publication Date (Web): 06 February 2002 Downloaded from http://pubs.acs.org on ...

Here, we investigate the surface shear rheology of class II HFBII hydrophobin layers at the oil/water interface. Experiments in two different dynamic regimes, at a fixed rate of strain and oscillations, have been carried out with a rotational rheometer. The rheological data obtained in both regimes comply with the same viscoelastic thixotropic model, which is used to determine the surface shear...

Experiments are described which demonstrate that asphaltenes precipitated from a refinery tar using an excess of n-heptane spontaneously partition into a contacting water phase in the presence of an ethoxylated nonionic surfactant by effecting a temperature change. The process appears to be related to the temperature-dependent phase behaviour of the particular surfactant. Hot (ca. 80-90°C) aque...