MODERN METHODS OF EVALUATING THE EFFECTIVENESS OF ROCK DESTRUCTION BY CUTTING WITH PDC BITS

Abstract

The relevance of the work is justified by the need to study interaction of cutting elements of modern PDC (Polycrystalline Diamond Compact) bits with rock, and, as a result, the presence of various approaches in the world scientific centers to assess the mechanism of dynamic penetration of PDC cutters into rocks during well drilling. The purpose: detailed analysis of the current state and prospects for the development of scientific research for a comprehensive assessment of the dynamic processes of rock cutting with PDC bits. Methods: theoretical analysis of the problems of the efficiency of rock destruction by cutters and modern PDC bits; application of mathematical and physical modeling of rock cutting processes, fluctuation theory of solid strength to describe the patterns of rock behavior during the operation of PDC cutters; comparative assessments of the study of processes and mechanisms of static and dynamic embedding when cutting rock with single elements and PDC bits, based on research conducted by the world's leading scientific schools in this field. Results. The paper introduces the results of research conducted by the world's leading schools on various fundamental aspects of the interaction of the executive bodies of PDC bits with destructible rocks. It is revealed that many research results give a complete qualitative picture of the work of PDC drill bits. However, there are not many most important and accurate quantitative characteristics of rock cutting processes with modern PDC chisels in the scientific literature. The ways of development of new methods of increasing the efficiency of rock cutting based on more accurate methods of assessing their behavior during cutting by PDC bits are considered. One of the considered promising techniques allows us to experimentally obtain a characteristic of the «dynamic hardness of rocks», which can be successfully used for the design of drilling modes and the design of PDC bits.

Keywords

• rock cutting
• oil well drilling
• pdc bits
• rock hardness
• cutting forces
• modeling rock destruction processes
• bit rotation frequency
• bake rake angle of the cutter
• side rake angle of the cutter