Abstract: A process to prepare a base oil having a saturates content of more than 90 wt %, a sulphur content of less than 0.03 wt %, and, a viscosity index of between 80 and 120 from a solvent refined base oil feedstock, which process comprises: (a) contacting the solvent refined base oil feedstock in the presence of a hydrogen containing gas in a first reaction zone containing one or more fixed beds of a catalyst, which catalyst comprises at least one Group VIB metal component and at least one non-noble Group VIII metal component supported on a refractory oxide carrier; and (b) contacting the effluent of step (a) in the presence of a hydrogen containing gas in a second reaction zone containing one or more fixed beds of a catalyst, which catalyst comprises a catalyst comprising a noble metal component supported on an amorphous refractory oxide carrier, wherein the oil feedstock in step (a) flows counter-current to the up flowing hydrogen containing gas.

Abstract: A process to prepare a base oil having a saturates content of more than 90 wt %, a sulphur content of less than 0.