Numerical simulation study on the characteristics and dynamic response of PDC cutter breaking rock under the influence of rock physical properties

Abstract:

With the continuous intensification of the exploration and development of unconventional energy resources in our country， drilling operations in deep and complex lithologic strata are becoming increasingly frequent. Against this backdrop， achieving efficient， economical and safe drilling operations has become a key issue in the industry， and the intelligent and precise improvement of drilling technology and equipment is the core driving force. The PDC cutter， as the core unit of the drill bit that directly participates in rock breaking， and its interaction mechanism with the rock is a key factor affecting the structural design of the drill bit， the decision-making of drilling parameters， and the overall drilling efficiency. Therefore， this paper focuses on the rock-breaking process of PDC cutters， and uses ABAQUS finite element software to establish a two-dimensional numerical model of the rock-breaking process of the PDC cutter， systematically exploring the influence of rock physical properties on the rock-breaking mechanism and the dynamic response of the cutter. By introducing the Drucker-Prager failure criterion and the Cohesive element model， the rock crack initiation， propagation and fracture behavior during the rock-breaking process of the cutter were simulated. The study analyzed the response characteristics of cutting force and vibration acceleration under different rock physical properties and lithology conditions. The results show that the compressive strength of the rock has the most significant influence on the cutting force and vibration response， followed by the internal friction angle， and the elastic modulus has a relatively small influence. The average cutting force of different lithologies is ranked as granite > conglomerate > limestone > sandstone， and the vibration acceleration is positively correlated with the average cutting force. This research provides a theoretical basis for the identification of rock physical parameters based on the dynamic response of drill bits， with important implications for the parameter optimization of deep drilling for unconventional energy resources， the identification of formation lithology and the development of intelligent drilling technology.