Effect of oxidation on the viscosity of athabasca bitumen

Abstract

The effect of low temperature oxidation on the viscosity of Athabasca bitumen was investigated over the temperature range 320 to 370K, and to extents of oxidation as high as 41.7 × 10−3 kg‐O2/kg‐bitumen. Even at this relatively low extent of oxidation, the viscosity was observed to be more than two orders of magnitude higher than that of unoxidized bitumen. It was found that the Andrade viscosity model could adequately characterize the temperature dependence of the viscosity at all extents of oxidation. However, the pre‐exponential constant in the model was observed to be a strong function of extent of oxidation.

Phase behaviour modelling of Athabasca bitumen for in situ combustion applications

“…The results related to the model predictability of this attribute (at 80°C) are available in Figure . It is worth noting that in this graph the viscosity increase trend is different between the work of Ursenbach and the other authors . The main reason for this may be that Ursenbach used the original bitumen asphaltenes and measured the maltenes‐asphaltenes solution viscosity by adding certain amounts of original asphaltenes to the solution .…”

“…Finally, the increase in bitumen viscosity with asphaltenes production during LTO reactions is considered, an important step that should be considered for in situ combustion applications. This variation in bitumen viscosity is a well‐known fact in the in situ combustion literature and is reported by a number of researchers . An adequate fluid model for in situ combustion modelling, therefore, should be able to accurately capture these changes in bitumen viscosity.…”

“…This variation in bitumen viscosity is a well-known fact in the in situ combustion literature [26,49,50] and is reported by a number of researchers. [26,51,52] An adequate fluid model for in situ combustion modelling, therefore, should be able to accurately capture these changes in bitumen viscosity. The results related to the model predictability of this attribute (at 80 C) are available in Figure 6.…”

Low-temperature oxidative asphaltenes liquefaction for petrochemicals: fact or fiction?

“…The alkoxy radical (1) can abstract hydrogen from another hydrocarbon to produce an alcohol (2). At low temperature this is the dominant pathway.…”

“…Unfortunately the literature also contains reports that state that oxidation, even at temperatures as low as 60°C and oxidation times as long as 229 h at 130°C, leads to substantial hardening with little lighter liquid products being produced [2,8,11,18]. These studies all dealt with heavy oils, rather than just the asphaltenes fraction.…”