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To ensure the trouble-free operation of the rock-destroying tool, the peculiarities of its interaction with the rock at different stages of work must be additionally studied. Still unexplored in full is the relationship between the state of the equipment of the rock-destroying tool and the oscillatory processes during the operation of the drilling tool. The basic dependences for determining the wear indicators of the equipment of the rock-destroying tool have been proposed. The scheme for implementing the method of assessing the condition and predicting the wear of equipment, taking into account the peculiarities of its interaction with the rock, has been improved. Underlying its implementation is the presence of a law of change of at least one generalized coordinate of an arbitrary cross-section of a drilling tool. Bench experimental studies were carried out, according to the results of which the dependence of the depth of the face deepening on the mode parameters of drilling and the geometry of the equipment was established. It was found that the wear of the cutter by 1 mm causes a decrease in the amplitude of longitudinal oscillations by an average of 1.4 times. The obtained functions of deepening the face were used to determine the energy indicators of the process of rock destruction. Given the peculiarities of the implementation of the experiment, the work and power of the axial load for the destruction of the rocks of the pit were used for such indicators. It should also be noted that the construction of numerical models is necessary for a complete assessment and prediction of the wear of rock-destructive tools. They should reflect the mechanical system and provide the ability to obtain the values of parameters that are not determined by the results of a laboratory experiment.

At present, the most common tools for drilling operations are those rock-destroying ones that are equipped with cutting elements made from polycrystalline diamonds (PDC) and diamond carbide inserts (DCI). Given this, it is a relevant task to study the influence of the degree of wear of cutting elements on the strength and energy parameters of the process of rock destruction. In order to determine this influence, we have experimentally investigated the cutting process involving a single cutter under laboratory conditions. The mean values of the cutting force components (circular ((Рz) and normal (Рy)) have been established at the cutting depth 0.5; 1.0; 1.5; and 2.0mm, at a varying degree of the cutting element wear (a flat of 0; 5.0; and 8.0mm). We have determined the magnitude of cutting work and the specific energy of rock destruction. At a cutting depth of 0.5mm, with an increase in the cutting element wear rate from 0 to 8mm, the magnitude of work grows from 0.06376 to 0.121 N∙m. At a cutting depth of 2.0mm, the magnitude of work increases from 0.624 to 3.603 N∙m. The energy intensity of the rock destruction process increases, with an increase in the cutting depth from 0.5 to 2.0mm, from 3.88kJ/m2to 11.66kJ/m2for a sharp cutter. Based on the study results, we have built dependence charts of the average values of the cutting force components and its normal component (Рy) on cutting depth and the cutting element wear degree. The results obtained have shown a significant influence of the size of the wear flat on the increase in the process strength parameters, which is the basis for regulating a wear degree of cutting elements during drilling. We have established the tendency towards a growth in the resultant force and specific work of rock cutting by a cutting element with an increase in wear degree. This makes it possible to determine, based on the indicators of fluctuations in the instantaneous strength values during drilling of wells, or based on a change in power, the wear degree of the cutting elements, and to predict the probability of their destruction