The influence of acoustic, high-frequency electromagnetic, and combined acoustic and high-frequency electromagnetic radiation on the group and fractional composition of oil and oil residue subjected to heat treatment is studied. It is shown that when oil is exposed to acoustic and combined acoustic and electromagnetic radiation, the "consequence" effect, which is accompanied by lowering of viscosity, initial boiling point, and the pour point, is observed for up to a few days after exposure. Data on the influence of the nature of wave radiation on the group composition of the oil are furnished. Based on the obtained data, the mechanism of spin-catalysis of thermal cracking of oil and oil residues is proposed.