Research on Formation Identification Based on Drilling Shock and Vibration Parameters and Energy Principle

Table 15

Statistics of rock structure types based on drilling specific energy.

Rock classification	VI-V/IV	IV-III	III/II	II-II/I
Rock structure	Soil and soft rock	Fragmented hard rock	Medium hard rock	Hard rock
Average drilling specific energy (kN·m·cm^−3)	0.0626	0.2952	0.6592	1.2915
Range of drilling specific energy (kN·m·cm^−3)	0.0116–0.5785	0.0685–0.7496	0.2598–1.1268	0.7635–2.6951