The analysis for the common causes of damage to PDC Drill Bits is as follows: 

1. There is gravel in the stratum;        2. There are more hard interlayers in the formation.

During the drilling process, the PDC polycrystalline diamond composite drill bit is drilled from soft formation to hard interlayer. The shape of the crown structure forms the cutting teeth of the same part of the drill bit. The hardness of the formation is different, which makes the cutting of different parts of the drill bit. When the tooth cuts the ground, the force is uneven, forming the suppression of the drilling and bouncing of drill. Most of the load acting on the drill bit will be collected on the cutting teeth of the cutting hard interlayer, and the instantaneous interception caused by the suppressing and drilling will cause the cutting teeth to be broken due to the large force, especially in the cutting hard formation. At a hard point, the instantaneous load is sufficient to form a chipping of the cutting teeth.

The hydraulic parameters of PDC polycrystalline diamond composite bit are not suitable: when using PDC bit, if the water power is too large, the bit body will be severely eroded. If the nozzle is not properly placed, the injected fluid will reflect directly after the bottom of the well. Erosion of the cutting teeth. If the water power is too small, it will be unfavorable for the cleaning and cooling of the composite plate, especially in the soft formation. Thermal accelerated wear of the composite plate is easily formed in the hard formation.