Аңдатпа
The aim of this study is to provide a geological and technical justification for the parameters of a diamond core drill bit with an outer diameter of 95.6 mm and a core diameter of 62–65 mm, designed to improve the efficiency of core drilling in hard rock formations containing dispersed valuable minerals. The study included an analysis of the geological conditions governing the application of the drill bit, determination of the requirements for its design parameters, and investigation of the interaction between the rock-cutting elements and the rock mass. A technical justification was developed for the relative arrangement of a patented cylindrical diamond-containing element with high hardness and wear resistance and a polycrystalline diamond compact (PDC) cutter. The mechanism of rock fragmentation was investigated, whereby a highly fractured zone with reduced strength is first generated beneath the PDC cutter, after which the weakened rock is efficiently removed by the cutting elements of the drill bit. In addition, the process of gauge control of both the borehole wall and the recovered core was analyzed, taking into account the correspondence between their formation rate and the rate of rock destruction at the borehole bottom. The obtained results demonstrate that the proposed arrangement of the diamond-containing element and the PDC cutter intensifies the rock-breaking process by reducing the energy required for rock separation, improving the cutting efficiency of the drilling tool, and enhancing core formation conditions. The geological and technical justification of the proposed drill bit parameters supports its application in core drilling of hard rocks with dispersed mineralization, ensuring higher drilling productivity, increased tool service life, and improved quality of the recovered core. The proposed design is of both theoretical and practical significance for the development of high-performance drilling tools intended for geological exploration in hard rock formations.