Research and Application of Coal Seam Permeability Improvement Technology by Sectional Directional Hydraulic Fracturing

Table 2

Borehole parameter.

Test site		Drilling number	Drilling diameter (mm)	Drilling depth (m)	Borehole azimuth
23# coal mining roadway	Reference group	1	94	61	Vertical roadway side
		2	94	55	Vertical roadway side
	Fracturing group	3	94	62	Vertical roadway side
		4 (fracturing hole)	94	61	Vertical roadway side
		5	94	61	Vertical roadway side