Theoretical foundations of interaction between rock-destroying elements and rock during well drilling

Purpose. The purpose of this study is to develop the scientific foundations of the interaction between rock-destroying elements (RDE) and rock to enhance the efficiency of well drilling. The research focuses on analyzing RDE designs, rock destruction mechanisms, the influence of rock properties, and methods for calculating drilling parameters to optimize the technological process. Methodology. The study employs a comprehensive approach, integrating theoretical analysis (Evans, Detournay, and Teale models), empirical analysis (processing data from IADC and SPE), numerical modeling (Finite Element Method, FEM), and comparative analysis of the efficiency of various RDE types (roller-cone, PDC, blade, hybrid, and core bits). The use of credible literature sources ensures the reliability of the findings. Results. It was determined that RDE design dictates their specialization: roller-cone bits are optimal for hard rocks (ROP 10–20 m/h), PDC bits for ultra-hard formations (ROP up to 30 m/h), and blade bits for soft rocks (ROP 10–15 m/h). Geometry (attack angle, shape) influences destruction mechanisms (crushing, cutting, shearing), while rock properties (hardness, abrasiveness, plasticity) affect wear and performance. Theoretical methods provide precision in predictions, empirical methods offer practicality, and numerical methods deliver detailed insights. Scientific Novelty. For the first time, the reverse impact of rock on RDE (abrasiveness, sticking, friction) under dynamic drilling conditions has been systematically analyzed. A comprehensive approach to optimizing RDE geometry and operating modes, considering the bidirectional "tool-rock" interaction, is proposed. Practical Significance. The findings enable improved drilling efficiency by selecting optimal RDE and operating modes based on rock type. Recommendations for advancing hybrid bits and numerical models contribute to reducing energy consumption and costs in the oil and gas and geological exploration industries. Keywords: rock-destroying elements, well drilling, rock, rate of penetration, wear resistance, RDE geometry.