Manufacture of lube base stock oil

A process for preparing a high quality lube base stock oil having a pour point of about -25.degree. to +30.degree. F. from waxy crude oil, which comprises:

• extracting a distillate fraction that boils within the range of 450.degree. to 1100.degree. F. or a deasphalted short residuum fraction of said waxy crude with a solvent selective for aromatic hydrocarbons to yield a raffinate from which undesirable compounds have been removed;
• mixing the raffinate with hydrogen and contacting the mixture at a temperature of 500.degree. to 675.degree. F. with a dewaxing catalyst comprising an aluminosilicate zeolite having a silica/alumina ratio of at least about 12 and a constraint index of about 1 to about 12, thereby converting wax contained in the raffinate to lower boiling hydrocarbons;
• cascading the dewaxed raffinate to a hydrotreating zone wherein the dewaxed raffinate is contacted in the presence of hydrogen at a temperature of 425.degree. to 600.degree. F. with a hydrotreating catalyst comprising a hydrogenation component on a non-acidic support;
• and
• topping the dewaxed, hydrotreated raffinate to remove therefrom components of a low molecular weight.