A process for the production of very high quality base oils optionally with simultaneous
production of high quality middle distillates comprises the stages for hydrotreatment,
preferably hydrocracking, on Y or beta zeolite, and atmospheric distillation. The
effluent is subjected to a catalytic dewaxing on the ZSM-48 catalyst. The process
then comprises a hydrofinishing stage for hydrogenating the aromatic compounds,
preferably on a catalyst that comprises at least one noble metal of group VIII,
chlorine and fluorine, and the stages of atmospheric and vacuum distillation. The
hydrofinishing stage is conducted at a temperature lower by 20-200 C. than
the catalytic dewaxing stage.
