The molecular properties of asphaltenes have been the subject of uncertainty in the literature; in particular the molecular architecture is still a matter of debate. Some literature reports provide evidence that the contrast of petroleum asphaltenes versus coal-derived asphaltenes is useful for understanding the governing principles of asphaltene identity. Here, we employ fluorescence correlati...

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...

A petroleum fluid can be di®ided into three types of species: asphaltenes, resins, and oils. Asphaltenes and resins are polar, while the rest of the so-called oils are either nonpolar or mildly polar. The interaction among these species strongly affect asphaltene precipitation from petroleum fluids. Different measuring methods for asphaltenes in a petroleum fluid gi®e similar results, but diffe...

Molecular-level characterization of petroleum asphaltenes is important for addressing reservoir concerns such as connectivity and flow assurance. Laser desorption single-photon ionization mass spectrometry (LDSPI-MS) has emerged as a favored technique for asphaltene analysis, because of its ability to detect these samples with minimal artifacts from fragmentation, aggregation, and multiple char...

/ Petroleum asphaltenes are defined as the n-pentane or n-heptane insoluble but toluene soluble fraction of crude oils or petroleum residua. This operational definition is a consequence of the extremely complex structure of asphaltenes which consist of thousands of compounds containing highly aromatic cores, long chain aliphatic groups, heteroatoms (sulfur, nitrogen, and oxygen) as well as trac...

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 asphaltene concentration of the solution. The adsorption of asphaltenes led to an attractive bridging force between...

A fungal strain isolated from a microbial consortium growing in a natural asphalt lake is able to grow in purified asphaltenes as the only source of carbon and energy. The asphaltenes were rigorously purified in order to avoid contamination from other petroleum fractions. In addition, most of petroporphyrins were removed. The 18S rRNA and β-tubulin genomic sequences, as well as some morphologic...

Asphaltenes from four different crude oils (Arab Heavy, B6, Canadon Seco, and Hondo) were fractionated in mixtures of heptane and toluene and analyzed chemically, by vapor pressure osmometry (VPO), and by small angle neutron scattering (SANS). Solubility profiles of the asphaltenes and their subfractions indicated strong cooperative asphaltene interactions of a particular subfraction that is po...

This study investigates the effect of surface acidity and basicity of aluminas on asphaltene adsorption followed by air oxidation. Equilibrium batch adsorption experiments were conducted at 25°C with solutions of asphaltenes in toluene at concentrations ranging from 100 to 3000 g/L using three conventional alumina adsorbents with different surface acidity. Data were found to better fit to the F...

Integration of Asphaltenes Flocculation Modeling into Athos Reservoir Simulator — To respond to the ever-growing needs of reservoir simulation studies in a large range of applications, it has been considered necessary to integrate an asphaltenes flocculation model into the Athos software. Athos is a multipurpose simulator which provides a lot of different physical options. Operating companies w...