Abstract: A process for upgrading bitumen recovered from an oil reservoir without hydrogen production is particularly useful in field upgrading applications. In this process, recovered bitumen enters a fractionator and is contacted with heated gases from a fluidized bed reactor. The bitumen and heated gases are fractionated into segregated products including at least a liquid pitch, unstable fractions, and an upgraded liquid product. The liquid pitch is introduced into the reactor to produce a vapor phase liquid product; the reactor comprises solid particles moving through the reactor and a fluidizing gas fluidizing the solid particles at a conversion temperature which is suitable for facilitating the conversion of at least some of the liquid pitch into the vapor phase liquid product. The heated gases comprising the vapor phase liquid product and fluidizing gas are directed from the reactor to the fractionator to contact the bitumen stream.