Gel permeation chromatography has been effectively used for the fraction-ation of residuals. The preparative-scale gel permeation chromatograph employed for these studies is described along with selected operating parameters. The instrument has been used to fractionate a shale oil residue, 50% reduced crude, and 25% reduced crude, into fairly narrow molecular weight fractions. The individual cuts from each residual have been analyzed and the elemental distribution established. The trends of heteroatom distribution, i.e., nitrogen, sulfur, nickel, and vanadium, as a function of molecular weight for the various residuals are discussed.