Production of lubricating oils

Claim 1

A process for the production of a lube blend of improved viscosity index which comprises subjecting a crude petroleum oil to distillation to produce a light lube oil distillate having an initial boiling point between about 600° and 650°F. and an end point between about 800° and 850°F. and a residual fraction having an initial boiling point between about 800° and 850°F., separating said residual fraction into a heavy crude distillate and a vacuum residuum, deasphalting said vacuum residuum, passing a member of the group consisting of said heavy crude distillate and said deasphalted residuum into contact with a hydrorefining catalyst at a temperature between about 600° and 900°F., a pressure between about 800 and 5000 psig and a space velocity between about 0.1 and 5 v/v/hr. in the presence of added hydrogen, separating the hydrorefining zone effluent into a gas rich in hydrogen, a fraction having an end point between about 600° and 650°F. and a hydrorefined lube oil fraction having an initial boiling point between about 600° and 650°F., separating from said hydrorefined lube oil fraction a light hydrorefined fraction having an initial boiling point between 600° and 650°F. and an end point between about 800° and 850°F. and blending with said hydrorefined lube oil fraction having an initial boiling point between about 800° and 850°F. said light lube oil distillate in an amount between 50 and 200 percent by volume of said light hydrorefined fraction to produce a lube oil blend having a viscosity index higher than either said hydrorefined lube oil fraction or said light lube oil distillate.