Patent ID: 7537686

Claim:
A method for upgrading a heavy oil comprising the steps of: a) contacting the heavy oil with an effective amount of an inhibitor additive to provide an inhibitor additized heavy oil, which inhibitor additive is represented by the chemical structure: R-PNA-(X) n wherein R is an alkyl group containing from 0 to 40 carbon atoms; PNA is a polynuclear aromatic hydrocarbon containing 2 to 15 aromatic rings; X is an acid functionality selected from the group consisting of SO 3 H, COOH, and PO 3 H; and n is an integer from 1 to 15; and b) thermally treating said inhibitor additized heavy oil at a temperature in the range of about 250° C. to 500° C. in the presence of hydrogen at hydrogen partial pressure of between 500 to 2500 psig for a time between 0.1 to 10 hours.