A process for producing olefins comprising the steps of separating the liquid oil in the fractionator to produce a light oil product; separating the light oil product in the extractor to produce a paraffin fraction stream; increasing a pressure of the paraffin fraction stream in a paraffin pump to produce a pressurized paraffin stream; mixing the pressurized paraffin stream with a pressurized water feed in the water mixer to produce a paraffin-containing water stream; heating the paraffin-containing water stream in the water heater to produce a hot paraffin-water stream, wherein a temperature of the hot paraffin-water stream is greater than 450 deg C., wherein the short chain paraffins are operable to crack at the temperature of the hot paraffin-water stream; mixing the hot paraffin-water stream and the hot feedstock in the feed mixer to produce a mixed feed stream; and introducing the mixed feed stream to the supercritical unit.