Low compressive strength of soft tomedium formations. Such as soft shale, soft limestone, soft sandstone, hard and soft abrasive interbedded medium formation.
低抗压强度的软到中等地层，如中软页岩。中软石灰岩。中软砂岩。和软硬研磨性夹层的中等地层。
2
PDC bits have been used to drill the homogeneous formation from soft tomedium-hard, but they are not suitable for drilling in gravel and multi-interbedded formation.
PD C钻头用于软到中硬的均质地层钻进具有钻速高、寿命长等特点，但不适合含砾石地层和软硬交错地层。
3
Suitable for soft tomediumhard Non-abrasive formation.