Mesoscopic Damage Simulation of PDC Cutter Pressed into Conglomerate under Static Load

As conglomerate generally has the characteristics of complex pore structure and serious non-uniformity, the rock breaking efficiency of Polycrystalline Diamond Compact (PDC) bit drilling conglomerate stratum is generally low, and it is difficult to effectively study the PDC tooth rock breaking process in laboratory test. A numerical model of PDC teeth pressing into conglomerate is established by DEM, and the accuracy of the numerical model is verified by laboratory test. The fracture pattern and process of conglomerate under different impingement displacement, rake Angle and heterogeneity of conglomerate are studied. The results show that: The number of cracks in conglomerate increases with the increase of inputting displacement and heterogeneity within a certain range. Tensile crack is the main crack when gravel is pressed, shear crack is the main crack when matrix is pressed. With the increase of conglomerate heterogeneity, the maximum pressure will be increased and the distribution of conglomerate field will be wider, and the supporting effect of gravel in conglomerate will be enhanced.