The relevance of the work is in need to obtain new data on the impact of dispersion medium composition on structural and mechanical properties of the wax-systems, treated in ultrasonic field. This will determine the optimal conditions for exposure to wax disperse systems, including oil, to reduce the viscosity-temperature characteristics and inhibiting process of sedimentation. The aim of the work is to determine the effect of dispersion medium composition on structural and mechanical properties and sedimentation of wax-model systems after ultrasonic treatment. The methods: rotary viscosimetry, pour point, liquid-adsorption chromatography, method of «cold finger», wax deposit, FT-IR spectroscopy, GC-MS. The results. The authors have studied the structural and mechanical properties and sedimentation of petroleum wax solutions in the decane and aviation kerosene TS-1 treated in the acoustic field. Viscosity, pour point, and energetic parameters of the petroleum wax solutions in decane increase at ultrasonic exposure. High alifacity of dispersion medium, which is characteristic for petroleum wax solution in decane, causes a reduction of aggregate and sedimentation stability and intensification of precipitation in high-paraffin crude oil systems after sonication. In composition of sediments allocated from the petroleum wax solutions, the content of n-alkanes C27-C32 increases. The aromatic compounds in the dispersion medium of the petroleum wax solution in TC-1 retard crystallization of paraffin hydrocarbons and decrease the amount of sediments, allocated from treated samples. In composition of these sediments the aromatic and naphthenic hydrocarbons, captured by paraffins during formation of disperse phase are concentrated. The experimental data show that the use of the petroleum wax solutions can adequately describe the behavior of high-paraffin crude oils in the acoustic field. Results. We defined the main complicating factors which influence the efficiency of rod pump operation. The analysis of the rod screw pumps repair causes shown that low quality of polished rods produced by the manufacturer, rod deviation from geometric parameters of different structures, hardness, chemical composition of rods (factory defect) are often the causes of breaks. Open threaded rod or polished rod was primarily due to insufficient torque screwing the threaded connection or a bend in the rod head. The breackage of polished rods mainly occur in the oil seal and due to fatigue voltage. The fatigue fracture occurs as a result of permanent deformation forces and temperature action. One of the main causes of the elastomer swelling is the maintenance with pressure at the reception of rod screw pumps below the saturation pressure. It leads to saturation of elastomer material with gases and rotor jamming in the stator which can turn into breakages of the rod string and polished rod.