Heavy ends, bitumen

The heavy-end portions (usually called heavy fractions) of bitumen (e.g. asphaltenes, preasphaltenes) can exist both in a random oriented particle aggregate form or in an ordered micelle form, peptized with resin molecules (16.17). In their natural state, asphaltenes exists in an oil-external (Winsor s terminology) or reversed micelle. The polar groups are oriented toward the center, which can be water, silica (or clay), or metals (V, Ni, Fe, etc.). The driving force of the polar groups... 

Chemical Modification of Bitumen Heavy Ends and Their Non-Fuel Uses... 

A New Tool for Studying Heavy Ends of Petroleum and Bitumens... 

This chapter describes the status of the technique and the results obtained so far. Some assumptions will be made to try to explain the postulated existence of two main types of nitrogen- or sulfur-containing species in heavy ends of petroleum and bitumens. 

Table 3.2 shows the remaining potential (the sum of reserves and resources) of conventional oil at the end of 2005, which amounts to around 1800 Gb, made up of 1200 Gb reserves and 600 Gb resources. In line with the definition in Section 3.3.1, these figures do not include unconventional oil, such as crude bitumen from oil sands production in Canada or extra heavy oil from Venezuela.11 Almost three-quarters of... 

The end point for the Hempel distillation is equivalent to 425°C. Data for bitumen and heavy oils were obtained by simulated distillation, and data for light oils were obtained by Hempel distillation. 

Some emulsions are made to reduce viscosity so that an oil can be made to flow. Emulsions of asphalt, a semisolid variety of bitumen dispersed in water, are formulated to be both less viscous than the original asphalt and stable so that they can be transported and handled. In application, the emulsion should shear thin and break to form a suitable water-repelling roadway coating material. Another example of emulsions that are formulated for lower viscosity with good stability are those made from heavy oils and intended for economic pipeline transportation over large distances. Here again the emulsions should be stable for transport but will need to be broken at the end of the pipeline. 

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