TREATMENT OF HEAVY OILS TO REDUCE OLEFIN CONTENT

摘要

A process for treating heavy oil to provide a treated heavy oil having a reduced density and viscosity, as well as an olefin content that does not exceed 1.0 wt. %. The process comprises separating the initial heavy oil into a first fraction, which in general contains lower-boiling components, and a second fraction. The second fraction comprises a heavy oil having a p-value of at least 5% greater than the p-value of the initial heavy oil prior to separating the initial heavy oil into the first fraction and the second fraction, and the second fraction has an aromaticity that is no more than 5% less than the aromaticity of the initial heavy oil prior to separating the initial heavy oil into the first fraction and the second fraction. The second fraction then is upgraded to reduce the density and viscosity of the heavy oil. After the second fraction is upgraded, it is recombined with at least a portion of the first fraction to provide a treated heavy oil having an olefin content that does not exceed 1.0 wt. %. The separation of the initial heavy oil into first and second fractions enables one to achieve improved reduction of the density and viscosity of the treated heavy oil while maintaining the olefin content at an acceptable level.