The results of studies of the effect of group and hydrocarbon composition of oils on their physicochemical properties and capacity to form cross-linked oil disperse systems (ODS) are reported. Pulsed nuclear magnetic resonance (NMR) method was used to determine the molecular mobility of the components of the dispersion medium and the disperse phase and to establish a correlation between the structural-dynamic, physicochemical, and rheological properties of the ODS. The degree of effect of surfactants on the change in mobility of the phases of the ODS and their rheological behavior is determined. It is shown that the processes of breakdown of associates of complex structural units of ODS in the presence of a surfactant occur in all oils and water-oil emulsions and their effect on the mobility of ODS increases with increase of initial degree of cross-linking of the ODS. The mechanism of the action of polyalkylbenzene resin (PABR) in the oil medium stems from the peculiarities of its structure, and addition of PABR enhances molecular mobility of the ODS components and alters their solvation, structural-mechanical, and adsorptive properties. Keywords: heavy oil, oil disperse systems, rheological properties of oil, NMR.