Methods are provided for producing lubricant base stocks from deasphalted oils formed by sequential deasphalting. The deasphalted oil can be exposed a first deasphalting process using a first solvent that can provide a lower severity of deasphalting and a second deasphalting process using a second solvent that can provide a higher severity of deasphalting. This can result in formation of at least a deasphalted oil and a resin fraction. The resin fraction can represent a fraction that traditionally would have been included as part of a deasphalter rock fraction.

An oxidative treatment system, e.g., oxidative desulfurization or denitrification, is provided in which the oxidant is produced in-situ using an aromatic-rich portion of the original liquid hydrocarbon feedstock. The process reduces or replaces the need for the separate introduction of liquid oxidants such as hydrogen peroxide, organic peroxide and organic hydroperoxide in an oxidative treatment process.

Deep desulfurization of hydrocarbon feeds containing undesired organosulfur compounds to produce a hydrocarbon product having low levels of sulfur, i.e., 15 ppmw or less of sulfur, is achieved by hydrotreating the feed under mild conditions, and separating the hydrotreated effluent into an aromatic-rich fraction which contains a substantial amount of the aromatic refractory and sterically hindered sulfur-containing compounds, and an aromatic-lean fraction. The aromatic-rich fraction is contacted with isomerization catalyst, and the isomerized aromatic-rich fraction is recycled to the mild hydrotreating process.

Aromatic extraction and hydrocracking processes are integrated to optimize the hydrocracking units design and/or performance. By processing aromatics-rich and aromatic-lean fractions separately, the hydrocracking operating severity and or catalyst reactor volume requirement decreases.

A process for heavy base oil production, comprising: a. performing an aromatic extraction of a first hydrocarbon feed to produce an aromatic extract, and a waxy raffinate; b. mixing the aromatic extract with a second hydrocarbon feed to make a mixed feed having greater than 2,000 wt ppm sulfur; c. feeding the mixed feed to a hydroprocessing unit to produce a heavy API Group II base oil having a kinematic viscosity at 70 C. from 22.6 to 100 mm.sup.2/s. An integrated refinery process unit for making heavy base oils, comprising: a. an aromatic extraction unit fluidly connected to a solvent dewaxing unit and a hydroprocessing unit; b. a first line from the aromatic extraction unit, that feeds an aromatic extract to a second hydrocarbon feed to make a mixed feed having greater than 2,000 wt ppm sulfur; and c. a connection that feeds the mixed feed to the hydroprocessing unit.

Deep desulfurization of hydrocarbon feeds containing undesired organosulfur compounds to produce a hydrocarbon product having low levels of sulfur, i.e., 15 ppmw or less of sulfur, is achieved by hydrotreating the feed under mild conditions, and separating the hydrotreated effluent into an aromatic-rich fraction which contains a substantial amount of the aromatic refractory and sterically hindered sulfur-containing compounds, and an aromatic-lean fraction. The aromatic-rich fraction is contacted with isomerization catalyst, and the isomerized aromatic-rich fraction is recycled to the mild hydrotreating process.

Aromatic extraction and hydrocracking processes are integrated to optimize the hydrocracking units design and/or performance. By processing aromatics-rich and aromatic-lean fractions separately, the hydrocracking operating severity and or catalyst reactor volume requirement decreases.

An oxidative treatment system, e.g., oxidative desulfurization or denitrification, is provided in which the oxidant is produced in-situ using an aromatic-rich portion of the original liquid hydrocarbon feedstock. The process reduces or replaces the need for the separate introduction of liquid oxidants such as hydrogen peroxide, organic peroxide and organic hydroperoxide in an oxidative treatment process.

Described are processes to produce base oils with one more improved properties, e.g., lower aromatics, economically and/or efficiently. In some embodiments the processes comprise a step that reduces the amount of residual refractory sulfur compounds prior to or simultaneous with a hydrofinishing step which advantageously provides base oils with lower aromatics than comparable processes.

Described are processes to produce base oils with one more improved properties, e.g., lower aromatics, economically and/or efficiently. In some embodiments, the processes relate to two stage (or more) hydrofinishing which advantageously provides base oils with lower aromatics than comparable one stage processes.