The article presents a review of PDC (polycrystalline diamond composite) drill bit manufacturing technologies and used metals in order to provide surface quality and accuracy as well as to attract a wider range of scientists to find new technologies and improve current ones in the field of oil and gas production. The review deals with studies of mechanical and physical characteristics, properties, structure effects as well as modern PDC drill bit manufacturing technologies, tools and technical means. Authors discuss the main tendencies and analyse differences in the technologies determined by the used metals. A drill bit quality assurance diagram is developed, which depicts drill bit quality as a complex indicator determined by both used metals and drill bit element-manufacturing technologies. The follow technological stages are defined as the drill bit quality assurance stages: workpieces production, rough and semi-rough machining, chemical and thermal treatment, body covering, finishing machining, cutter soldering and drill bit assembling. As stressed, the used metals determine not only drill bit manufacturing technology, but also drill bit design.

Compositions with minimal Gibbs free energy for single-and multi-phase high-entropy alloys (HEAs) containing Ni, Co, Fe, Cr, Cu, Al, Mn, Ti, Zr, V elements are developed using a developed thermodynamic approach. The phase compositions for some equiatomic HEAs are predicted and the influence of various factors on its formation are described. A correlation between theoretical and experimental data is obtained. Criteria for search of HEAs compositions favourable for formation of single-phase and multi-phase solid solutions are formulated.

The mechanism of generation of forces, holding the drill pipes in case sludge sedimentation, caving in and collapse, as well as buckling and flow of plastic rocks, formation of oil seals was described. The modern ideas about friction forces were reviewed. A mathematical model of frictional self-oscillations for release a stuck drill string was developed. The necessity of application a vibration smoothing method of generating self-oscillations during emergency was substantiated. Using the computer program, parametric calculations of velocity change of the stuck drill pipe release were made. The author conducted numerical studies of the drilling line speed impact and oscillator frequency on the efficiency the sticking elimination process.