Investigation of the Ultrasonic Stimulation Performance on Permeability Enhancement in Coal Seam: Field Tests and In Situ Permeability Evaluation

Table 5

Result of gas permeability inversion.

Zone	Borehole	Distance from the antireflection borehole	Permeability	Increment
Zone 0	Average	/	m^2	/
Zone 1	#1	8 m	m^2	2.36 times
	#2	4 m	m^2	4.05 times
	#3	2 m	m^2	7.53 times
Zone 2	#1	8 m	m^2	4.12 times
	#2	4 m	m^2	5.36 times
	#3	2 m	m^2	6.73 times