A process to produce a light hydrocarbon fraction from a heavy residue feed, the process comprising the steps of operating the first supercritical reactor such that the heavy residue feed and the supercritical water stream undergo conversion reactions to produce a reactor effluent, introducing the reactor effluent to a top inlet in a top portion of a second supercritical reactor, introducing a supercritical water stream to a bottom inlet in a bottom portion of the second supercritical reactor, operating the second supercritical reactor such that the bottom of the barrel fraction is configured to settle in the bottom portion of the second supercritical reactor, withdrawing an upgraded product stream from a top outlet in the top portion of the second supercritical reactor, and withdrawing a heavy product stream from a bottom outlet in the bottom portion of the second supercritical reactor.