Dynamic rock-breaking temperature distribution of PDC bit cutter based on orthogonal cutting theory

In the process of oil and gas drilling, the dynamic rock-breaking behavior of PDC bit exhibits highly nonlinear characteristics, which is characterized by a complex coupling between displacement field and temperature field. During the cutting process, the heat generated by friction accumulates on the cutter, leading to a significant increase in the temperature of the cutting system. Excessive temperatures can accelerate wear of the cutter, and may even cause it to fail, which negatively impacts drilling efficiency and increases drilling costs. In order to predict and analyze the temperature distribution of PDC bit cutters during rock-breaking and reveal its dynamic rock-breaking characteristics, a three-dimensional coupled displacement field-temperature field model is proposed based on orthogonal cutting theory and rock elastoplastic mechanics. This model is used to simulate the nonlinear dynamic behavior of PDC bit cutters during rock-breaking. Furthermore, the cutting force and temperature distribution under different cutting parameters and structural parameters are analyzed. The results indicate that the high-temperature zone of the cutter is located in an elliptical area near the cutting edge, with an angle ranging from 90° to 230° centered on the cutting edge. For optimal cutting depth of 0.001 m and a preferred pitch angle of 7.5°, cutting force and maximum temperature are minimized, which helps to reduce cutter wear while avoiding high-temperature failure. It reduces drilling costs while maintaining efficient drilling operations. This method provides a theoretical basis and analysis method for the study of PDC bit structure design and cutter thermal damage, which is helpful to design PDC bit structure more suitable for complex formation characteristics.