The paper shows that depending on the degree of blockage of the pore space due to paraffin precipitation the ultrasonic treatment has different effects. If a part of permeable channels is irreversibly deteriorated, then the activation of elastic oscillations contributes to postponing the moment of blocking the remaining part and helps to maintain the oil flow through a sample at a constant level. Without additional means an ultrasonic treatment does not have a significant effect in the case of strong blockage of permeable channels. If elastic oscillations are imposed on the rock and liquid at the initial moment of flow, then the porous space of the rock will be preserved from the precipitation of paraffins.