During the using of the traditional PDC bit, the bit surface will be destoryed if the local flow rate of the flow field of the bit is too large, and balling up may occur if the flow rate is too small.

• 针对原有PDC钻头井底流场存在局部流速过大而对钻头表面造成破坏,局部流速过小容易产生泥包的问题,对原有钻头做如下结构改进:增加大胫板的长度;