Steam-aqua catalytic upgrading of bitumen at near in situ production conditions

Abstract

Oil upgrading at reservoir conditions via chemical reactions that break long hydrocarbon chains and improve viscosity is highly desirable for transportability of crude oils. Previous studies showed C-S and C-O bonds as main participants in reactions between water and organic compounds present in heavy oils, causing upgrading of crude oil at temperatures used in in-situ recovery processes. The rupture of C-C bonds in the heaviest molecular components seems also needed to reach the viscosity required for transportation. Thermodynamic calculations presented here for representative molecules of Athabasca Bitumen group families in presence of water illustrate the feasibility of primary reactions involving C-C bonds at relatively low (T>250°C) in-situ temperatures. Transition metal oxide particle catalysts involving Ni, Mo and Fe were tested, with a Ni-Fe oxides combination yielding the highest upgrading level of Athabasca bitumen. Results under different hydrogen partial pressure atmospheres suggest it may prevent water dissociation. The Ni-Fe catalyst was used in reactions with a model molecule (propylbenzene), to initiate the analysis of the chemistry behind the heavy oil tests performed.