A method and apparatus for upgrading heavy oil is described, having a symbiotic relationship between a cracking reactor vessel and a steam reformer vessel. A first portion of an uncracked residue oil stream from the cracking reactor vessel is passed through a heat exchanger positioned within the steam reformer vessel and back to the cracking reactor vessel, such that a heat exchange takes place which heats the uncracked residue oil stream to promote cracking. A second portion of the uncracked residue oil stream from the cracking reactor vessel is injected directly into the steam reformer vessel. That portion of the uncracked residue oil stream not vaporized in the steam reformer vessel is converted into coke which becomes deposited in a fluidized bed of the steam reformer vessel. The fluidized bed activates steam which reacts with the coke to generate hydrogen. Hydrogen from the steam reformer vessel is directed into the cracking reactor vessel to assist with cracking.