Abstract: The regression analysis of seven groups of viscosity-temperature data from Liaohe oilfield published in Ref. [1] of this paper is made, and the results are compared with those from Ref. [1]. It is found that the regression coefficient calculation from Ref. [1] is in error. The error analysis indicates great effect of the regression coefficient on the precise of viscosity calculation. In addition, the denomination of universal equation given in Ref. [1] is oppugned, and it is better regarded as the empirical equation.

Key words: heavy oil, viscosity-temperature curve, regression analysis