Ind. Eng. Chem. Res. 1994,33, 1412
1412
Response to Comments on “Modeling the Viscosity of Middle-East Crude Oil Mixtures” Birbal Singh Department of Mechanical Engineering, Lakehead University, Thunder Bay, Ontario, Canada P7B 5E1
Sir: We note with regret a typographical error in our recent paper (Singh et al. Ind.Eng. Chem. Res. 1993,32, 2183-2186). In the second line after eq 7, viscosity in m2/s should have been viscosity in mm2/s. With regards to the form of our correlation, it should be noted that we developed it so that (1)our model requires only one viscosity measurement of a sample a t one atmospheric pressure and a convenient temperature such as 30 “C (which is the least expensive input parameter compared to any other correlation published to date); (2) with this one measurement the correlation is capable of accurately predicting the viscosity of pure hydrocarbons as well as mixtures; and (3) our correlation is in a form which makes it computationally efficient which makes it very suitable for reservoir simulation models where viscosity calculations may be made billions of times in one large simulation run. We found that by considering a mixture of crude oils effectively as a “new” crude oil, our
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model proved to be accurate, It is due to these attributes that a large number of scientists and engineers in oil industry have adopted our model in their reservoir simulators. Our model is not based on relating viscosity to other parameters such as density because it is easily found that it can not be used to accurately predict the viscosity. For example, it is well-known that for Lloydminster heavy oils in Canada, one sample may have a viscosity almost 10 times as much compared to another sample of almost identical density. In developing our model, we decided to use the viscosity at a convenient temperature, such as 30 “C, as the characterization parameter because we found it to be most useful in accurately estimating viscosity. Our main objective was to present a model which can be easily used by other researchers and we believe it has met that objective.
0 1994 American Chemical Society
