The formation of organic deposits in model petroleum-containing systems of various compositions has been studied. Introduction of asphaltene-resin substances into a model paraffin system reduces the amount of precipitated wax deposit to 40 wt %; significantly changes the ratio of liquid and solid hydrocarbons in then-alkane composition of the deposits, shifting the distribution maximum towards a lower molecular weight; and substantially reduces the mechanical strength. In the model paraffin system in the presence of resins and asphaltenes, which contain a greater amount of condensed aromatic structures and a smaller amount of paraffin structures, a precipitate is formed with an increased proportion of the liquid phase. The deposits are characterized by lower strength of the crystal lattice and, hence, a decreased value of ultimate shear stress.