Blending Compatibility Calculator


General Information

According to research done by Dr. Irv Wiehe of Soluble Solutions, mixing incompatible crudes can result in asphaltene precipitation which can damage equipment used in the processing of crudes. In order to determine the compatibility of blending a crude and a diluent, testing can be done to determine the solubility blending number (SBN) and insolubility number (IN). From testing an oil sample (typically with toluene and n-heptane), SBN and IN can be determined.

To determine blending compatibility, Dr. Wiehe requires the resulting P value (which is equal to the ratio of SBN to IN) of the blend to be equal or greater than 1.3. This calculator requires a more conservative P value of greater than 2.0. As such, the optimal percentage of diluent in the blend is calculated as that which gives a P value of exactly 2.0.


Liability Statement

This calculator has been provided as a tool, and should be used solely for informational purposes. It is not intended to replace your own calculations as each situation requires specialized considerations. Crude Quality Inc. accepts no responsibility for any inconsistencies with the actual chemistry that may arise from the use of this calculator.

Initial Component:

IN = 32
SBN = 96
P = 3.0




P = SBN/IN

Diluent Component:

IN = 0
SBN = 6.4

IN = 0
SBN = -2.5


("0" for a diluent)


 (out of 100%)